What is Mouth Cancer?
Cancer of the mouth, or "oral cavity", includes that extending back as far as behind
the last molar ("wisdom tooth"). This would include the area behind the lips, gums,
inside of the cheeks, palate, and front 2/3 of the tongue. The tonsils and back of
the
tongue are further back, and are located in the "oropharynx". Thus, cancers of areas
behind the last molar are not considered "mouth cancer". Also, cancers of our 3 major
salivary glands (parotid, submaxillary, sublingual) are considered separately, as
well
as those of the jaw bones and muscles. Therefore, it is important to identify the
area
the cancer arose from, even if it subsequently spread to other areas. It is this area it
originally arose from which determines what type of cancer it is.
Cells in the mouth are subjected to lots of injury from heat and abrasion, and
thus must divide frequently to replace those lost due to injury and old age. Normally,
cells
divide quickly as we develop in the womb and through infancy, and then the rate slows
down considerably, just to replace cells that die. The division of cells in the mouth
and
elsewhere is under very tight control, regulated by the genes within the cells. When
this control is lost, the cells may start to divide in ahaphazard, uncontrolled manner,
and grow to form a swelling of abnormal cells, called a "tumor". A"benign" tumor only grows within it'slocal area, it doesnot spread to distant organs, and it isnot
cancer. In contrast, a"malignant" tumorcan spread to any area of the body,it is
cancer. It is this ability to spread, or "metastasize", to vital organs which makes a
cancer so dangerous. Cancers of the mouth tend to grow to large sizes locally before
they spread, but any cancer can spread at any time.
How Common is Mouth Cancer?
Each year in the United States there are about 20,000 new cases of mouth cancer leading to 4,000 deaths annually from this disease. Men are affected twice as often as women. Overall,
mouth cancer represents about 3% of all new cancers each year, and it is more common
in blacks than whites, and in those of "lower socioeconomic status" (poor people).
The average patient is 60 years old.
What Causes, or Increases Risk for Mouth Cancer?
Like any cancer, the exact reason why one person gets mouth cancer and another
does not remains unknown. However, several"risk factors" have been shown to
be much more likely to be present in mouth cancer patients. These include:
1) Tobacco Usage-- This is the single strongest risk factor for developing cancers
of the head and neck, and especially mouth cancer. Any form of tobacco
taken
through the mouth, whether smoked or chewed, increases the risk over time.
Even children who use chewing tobacco (often to emulate famous baseball
players) have gotten mouth cancer. The more tobacco that is used, for a
longer
period of time, the higher the chance to get mouth cancer. Likewise, when
use
is stopped, the risk declines almost to normal over a 5 to 10 year period.
2) Alcohol Usage-- Is the next strongest risk factor after tobacco. Occasional wine
or beer may raise risk very slightly, if at all, but frequent use of strong
drinks like
whiskey will increase cancer risk to the mouth, throat, esophagus (food pipe),
stomach and pancreas. Furthermore,combining alcohol with tobacco will have a
"super additive" effect to greatly increase cancer risk for all of these areas.
This
means that the risk is much more than twice as high as for using either tobacco
or alcohol alone. Like tobacco, people who stop frequent drinking will gradually
lower their cancer risk to nearly that of non-drinkers.
3) Poor Mouth Hygiene-- The more unclean the mouth is, the more is is subject
to constant irritation from grime. Each teaspoon of saliva contains about 1
billion
bacteria, which are making waste products which cling to teeth ("plaque").
This
allows gum disease (pyorrhea) to develop, with subsequent tooth loss. Although
plaque itself is not showto cause cancer, it helps other chemicals (like in smoke)
to stick in the mouth, irritate it, and stimulate the cells to divide. The
more cells
divide, the more chance one of them will become cancerous. That is why the
common thread of many risk factors is irritation, leading to lots of cell division.
4) Ill-Fitting Dentures irritate the gum lining ("gingiva") and trap debris. This can
lead to mouth cancers over time.
5) Betel-Nut Chewing in Indian populations is strongly associated with tooth loss
and mouth cancer, again the common factor is prolonged irritation.
6) Infections such as syphilis and some viruses can lead to cancer over time,
these cause mouth sores which heal poorly. The constant attempt to heal
leads
to chronic cell division and thus more chance for cancer. Viruses can also
get
into the mouth cells themselves and change the genes in them to form a cancer
cell. This elaborate process is called "oncogene activation".
7) Lowered Immunity such as from AIDS or transplant anti-rejection drugs will
increase the risk for many cancers, including those of the "aero-digestive
tract"
(i.e. the area from the nose and mouth to the lungs and stomach). This
will be
especially important in combination with the other risk factors noted
above.
8) History of Cancer of the aero-digestive tract can mean as much as 5% chance
of a separate simultaneous cancer, and a 25% chance of developing another
cancer in this area over time (especially if risks like smoking are continued).
What are the Symptoms of Mouth Cancer?
A cancer must grow to 1 billion cells to be just 1 cm. (about 1/2) across, so a very
early cancer will have no symptoms and likely go undetected. As it grows, it produces
symptoms in it's local area, and eventually in distant areas as it spreads. A mouth
cancer may be first noticed by the patient or their dentist, with these possible findings:
1) A Sore that Doesn't Heal is one of the American Cancer Societies "7 signs of
cancer" and the most frequent symptom of mouth cancer. It can be flat, raised
or a pit (ulcer), and is usually hard and not very tender. It tends to grow
slowly.
2) Local Pain is possible as the tumor enlarges, especially if it invades nerves.
The mouth shares nerves with the ear and throat, so some deep mouth cancers cause pain in these areas ('referred pain"). Interestingly, the
further back
in the mouth the cancer, the deeper in the ear the pain appears.
3) Difficulty Chewing, Swallowing or Speaking is caused by mechanical factors
the tumor enlarges. Dentures may not fit anymore; one side of the face
may
become swollen. If a duct from a salivary gland is blocked, it may also
swell.
4) Swelling in the Neck is possible as the lymph nodes in the neck are invaded.
The chance for this increases with enlarging cancer and those near the
midline of the mouth; at diagnosis as many as 40% of patients may have
spread
to neck ("cervical") lymph nodes. This swelling is usually firm and
painless.
Neck lymph nodes can also swell up from non-cancerous conditions such
as
infection, so swelling alone does not prove cancer. However, larger,
harder
and more persistent swellings are more likely to be cancerous.
5) Nerve Syndromes result from lymph nodes getting invaded by cancer, then
enlarging and pressing upon crucial nerves for the face. The nerves
then fail.
Two particular syndromes include the Jacod's (leading to trouble with
facial
expression, eye and jaw movement) and Villaret's (trouble swallowing
and
tongue and neck movement problems). These will worsen if untreated.
6) Distant Spread Symptoms are uncommon with mouth cancer until the tumor
has grown very large locally and spread to lymph nodes in the neck.
Cancer
can spread to any area in the body, but most likely goes to lung, liver,
bone
brain. New symptoms in these areas are very suspicious for spread in
the
patient with a large mouth cancer. The chance of distant spread from
a small
cancer (< 3 cm.) is less than 2%.
How Does Mouth Cancer Spread?
The behavior of a disease in the average patient is called it's "natural history".
Recall that cancer starts in a single cell, which divides in an uncontrolled manner
to
make millions and billions of copies of itself. It generally starts on the surface
of the
mouth (the "mucosa") and gradually penetrates deeper. As it goes deeper, it can
invade lymphatic channels and spread to local lymph nodes in the neck. It may invade
nerves and cause pain, and into the underlying bone to destroy it. Commonly, an untreated
mouth cancer will grow larger and larger in it's local area ultimately become
a huge, infected and bleeding mass. It may then protrude through the skin to form
a gaping and seeping wound, and spread via the bloodstream to distant organs.
How is Mouth Cancer Diagnosed and Evaluated?
The only way to absolutely diagnose any cancer is to get a piece of it ("biopsy")
and analyze it under the microscope. A pathologist examines the biopsy specimen, this is a physician who specializes in making diagnoses
from tissue samples. The usual steps in the evaluation of a suspected mouth cancer include:
1) Physical Examination is done carefully and includes a meticulous description
of the tumor, including it's location, size, color, texture, and whether
it is "fixed" to underlying tissue or can be moved about. The doctor looks for
white patches
("leukoplakia") and reddish patches ("erythroplasia") which may be pre-cancerous areas. The condition of the teeth are noted. A thorough exam of
the neck
is always done, noting any enlarged enlarged glands which may represent
the
cancer spreading to lymph nodes. The back of the throat is examined,
and a
mirror is used to visualize the vocal cords ("indirect laryngoscopy").
The nerves
which arise from the brain (12 of them called "cranial nerves) supplying
the
face, eyes ears nose and throat are tested to look for signs of nerve
invasion
or compression by cancerous lymph nodes. Naturally, it is also appropriate
to
do a complete exam of the rest of the body to assess general health
and look
for signs of distant cancer spread.
2) Endoscopic Examination means placing a visualization tube under light local
anesthesia into the nose and down the throat. The preferred procedure
is a
"triple endoscopy", which looks at the nose, esophagus and larynx (voicebox).
Clear endoscopic visualization of the larynx is called "direct laryngoscopy".
A biopsy is taken of any suspicious areas, and sometimes "blind biopsies"
are taken of areas most likely to develop cancer (such as the tonsil).
This is
done since, as mentioned, 5% of patients will have a "second primary"
when
they come to medical attention-- that means another simultaneous cancer.
Endoscopy is a very safe procedure, and is the clearest way to actually
look
at tissues of the aero-digestive tract.
3) Blood and Urine Tests are standard pre-operative ones to assess general
health; there are no special blood tests ("tumor markers") yet to detect
spread
of squamous cell cancer as there are for some other cancers. Routine
tests
include Complete Blood Count("CBC") to look for anemia and infection. A
Blood Chemistry Panel ("SMA") measures sodium, potassium, blood sugar,
cholesterol and liver and kidney function. If a major surgery is contemplated,
blood tests for clotting ability (PT, PTT and bleeding time ) are standard. A
Urinalysis(UA) to check for protein, blood or infection completes the lab tests.
4) Imaging Tests are done in the radiology department and standardly include
a Chest X-ray to look for signs of infection or lung tumors. Special imaging
of the head and neck is often obtained; a"panorex" is a series of jaw X-rays
which is excellent for detecting spread of cancer to local bone.
A CT scan
in "thin slices" of the tumor area helps define the extent of the tumor,
as does
the more expensive Magnetic Resonance Imaging(MRI) scan. MRI, which
uses magnetism instead of radiation, allows the area to be viewed
in three
dimensions. It is great for looking at the tumor as well as checking local
muscle, cartilage and nervesfor signs of invasion by cancer.
Other more exotic tests are only obtained in the presence of suspicious symptoms. For instance, a bone scan is gotten if there is new bone pain, a
CT of the
Chest and Abdomen is obtained if the plain Chest X-ray appears to show
tumor
in the lung, and a CT of the Brain is gotten if new neurological symptoms
occur.
There are special tests which can be ordered to look at just about any
area of
the body-- but only if necessary.
5) Biopsy of the tumor is crucial, since only by examining an actual piece of the
tumor under the microscope can a diagnosis of cancer be made, and the
particular type known with certainty. For a small tumor, the whole of
it may be
removed, along with a "safety margin" of surrounding normal tissue, and
sent
for evaluation ("Excisional Biopsy"). For a larger tumor, a cut is made
into it so
some tissue can be removed for examination ("Incisional Biopsy"). It
usually
takes several days (of anxious waiting) for the pathology report to come
back.
What are the Types of Mouth Cancer?
Over 95% of cancers in the mouth arise from the surface lining ("mucosa") which
is made up of a type of cell called "epithelial". Epithelial cells look like a fried egg under the microscope. When these epithelial
cells become cancerous, they specific type is called "squamous cell carcinoma". Thus, almost all cancer in the mouth
are this squamous cell carcinoma type. Much less common (<2%) the small saliva
gland in the palate or inside of the cheek become cancerous, this type is then called
"adenocarcinoma". More rare still are cancers arising from the immune system cells
in the mouth("lymphoma") or the muscle, bone or cartilage("sarcoma"), the therapy
for these cancers follows that of when they occur elsewhere in the body (where they
are more common). Since the squamous carcinoma type is by far the most common, the treatments to be discussed here are for it.
How is the Extent of Mouth Cancer Gauged?
Like all cancers, the extent of mouth cancer is given by the"stage". These stages
were developed by the American Joint Committee on Cancer (AJCC) to help make
appropriate treatment decisions, and tally the results of therapy for various levels
of
disease. The stage grouping for mouth cancer is:
Stage
Description
Average 5- year Survival
0 Microscopic tumor only 98%
I Tumor no larger than 2 cm.
80%
II Tumor between 2 and 4 cm.
70%
III Tumor larger than 4 cm, or one neck lymph node (<3 cm.)
50%
IV Tumor invades bone or cartilage, more than one lymph
35%
node in neck (or one lymph node bigger than 3 cm.)
IV Distant spread of tumor to other organs
10%
In general, cancers of the floor of mouth and lip do better than the tongue or
cheek
lining, while cancers of the gum line are very near the averages quoted above. Cancer
near the front of the mouth tends to do better than that at the rear of the mouth.
There
has been an overall improvement in survival over the past 20 years.
What is the Conventional Treatment for Mouth Cancer?
Conventional treatment for mouth cancer involves surgery and radiation therapy,
and often both together for more advanced cancers. Chemotherapy is in itself not
curative for squamous cell carcinoma, but may be used as an "adjunct" (extra therapy)
along with radiation and surgery to improve cure rates. The specifics of each therapy
is now described:
Surgery is an excellent way to deal with small (i.e. stage I and II) cancers which
have not spread. It also has it's place in more advanced cancers, when combined
with other treatment. If all the cancer removed at surgery, the patient will be cured.
The
surgery is performed by an "otolaryngologist", that is a head and neck surgeon (an
ENT who specializes in cancer surgery). The chance of being able to remove all of
the cancer decreases as the tumor gets larger and lymph nodes are involved. Two other
important considerations in surgery are not comprising function (i.e. drastic surgery
which leaves the patient unable to speak or swallow) and cosmesis (how the patient
looks after surgery). Heroic operations to remove large cancers are rarely successful,
since the cancer has usually spread by this time to structures that the surgeon cannot
safely remove. Patients themselves usually do not want an operation that cuts out
the
tongue, or leaves their appearance socially unacceptable. Fortunately, advances in
surgical techniques, such as plastics and using tissue from other body areas to fill
in gaps, have been developed. The following are some considerations for surgery:
1) For small cancers, either surgery or radiation are generally equally effective,
but only one of the "modalities" should be used. The other treatment is
then
saved for "salvage" if the initial treatment fails. There is no sense in
giving the
side-effects of both therapies if not necessary. If the patient is in decent
medical
condition, then surgery will be recommended first. The cancer is removed with
with a wide "safety margin" of surrounding normal tissue, and sent to pathology
for confirmation of "clear margins" (meaning no cancer specimen's edge).
If
there is suspicion of neck lymph node involvement, a"neck dissection" can be
done to look for disease there; this leaves skin scarring. Overall, surgery
for
small cancers is quick, with healing time of several weeks and high cure
rate.
If the cancer has not been totally removed at surgery, either at its original
site
or in the neck, then subsequent radiation therapy will be necessary for
cure.
2) Forlarger cancers (stage II, III and locally advanced stage IV) both surgery and
radiation are needed for the best chance of cure. The goal of surgery
is help
restore function immediately (such as when chewing has been blocked by
a
large tumor, and to try to remove all "gross disease" (that which can
be seen). Radiation treatment is then used after the operation to mop up residual disease.
The extremes to which surgery are taken depend upon the likelihood for cure,
and the effectiveness of radiation for destroying remaining microscopic
disease.
Surgery is indicated for large primary tumors and lymph nodes larger than
3 cm.
in the neck, since a high enough radiation dose to eradicate these will
cause
unacceptable side effects (see section on radiation therapy). In general,
when
both surgery and radiation are to be combined, studies have favored doing
the
surgery first, waiting about 4 weeks for the surgical wounds to close, and
then
starting the radiation treatments. This requires close cooperation between
the
surgeon, pathologist, radiation oncologist , dentist, nutritionist, social
worker,
speech pathologist and the patient's family members. Treating advanced mouth
cancer is truly an "interdisciplinary" approach! It is critical for the
patient to have
clear communication with the surgeon to know exactly what to expect with
the
surgery, especially in terms of speech, chewing, swallowing and appearance.
3) Tumors withDistant Spread are not curable with local surgery. In this case, the
role of surgery is palliative, that is to increase patient comfort and
improve the
quality of life. Obviously, major surgical adventures that are justifiable
for curing
local disease only are inappropriate if we know the disease has spread.
Often,
the problem is determining if the disease has actually spread, or just
may have.
For instance, if the standard chest X-ray shows a small abnormality in
the lung,
we really don't know if that is cancer or not. While a CT scan of the chest
will
help define the shape of the abnormality, only an actual biopsy of it (commonly
done in the radiology department under CT guidance) will prove if it's
cancer or
not. These "staging procedures" are crucial to determine the proper therapy.
If
spread cannot be proven (but is possible), or is very small and removed,
the
patient in good general condition may want to be aggressive, and get
major
surgery. It is possible that control of the local disease in the mouth will
lengthen
lifespan, and it will certainly improve daily life. Some surgeons are willing
to be
much more aggressive than others, and the key is to pick a highly experienced
cancer surgeon and be comfortable with them. Commonly, however, a patient
with evidence of distant spread will be referred for radiation treatment,
with the
addition of chemotherapy if cure is the goal.
Radiation Therapy has been used for eight decades for many cancers, including
those of the mouth. In fact, radiation isquite successful in treatment mouth cancer,
and for small tumors is equally effective to surgery. Radiation may be given alone,
or
be added to surgery ("adjuvant therapy") . It may be combined with chemotherapy,
or all three methods of surgery, radiation and chemotherapy can be offered together
("multimodality therapy") . Radiation is prescribed by a "radiation oncologist", who
is a cancer doctor specializing in it's administration. It can be given in several
forms,
most commonly a series of "external beam" treatments with photons or electrons.
After being seen in consultation by the radiation oncologist, the patient getting
external beam treatment is scheduled for"simulation". During simulation, the patient is placed on a replica treatment machine, and the
area to be treated is marked out. Instead of placing marks on the patient's skin,
a "mask" is made for head and neck cancers, and the marks designating the treatment
area are placed on the mask .
X-rays are taken to confirm positioning. Information from the simulation, along with
other scans, is fed into a "treatment planning computer" and a "plan" is generated. This plan tells how much radiation is going to the cancer, and how much
to local normal tissues. Special lead "blocks", which fit into the head of the treatment
machine, determine the shape of the radiation field administered. The patient then returns to the department for their "treatment start", which takes about 45 minutes.
They lay upon a hard table in a shielded room, and are aligned with laser lights
shone
upon the marks on the mask. The actual machine which delivers photons or electrons
is called a "linear accelerator" or Linac for short; occasionally Cobalt-60 machines
are
still used. The head of the machine pivots around the patient, so they stay perfectly
still during the treatment, even as the radiation is delivered from various angles.
The
actual treatment only takes several minutes per day, and is usually given from Monday
through Friday for 6 or 7 weeks. The usual dose is 60 to 75 Gray (units of radiation)
to
the actual tumor, with less to surrounding tissues. This is given in "fractions" of
about
2 Gray per treatment, accounting for the 7 or so weeks of total therapy. For head
and
neck cancers, a combination of photons and electrons is often utilized. Photons will
penetrate very deep, and tend to spare the skin, while electrons give shallower dose
to "boost" up the dose the the more superficial tissues. The "plan" from the simulation
helps determine the optimal mixture of photon and electron dose. If a treatment day
is missed, it is simply tacked onto the end so that the same total prescribed dose
is
given. The actual treatment is given by "radiation therapy technologists", or R.T.T.'s,
who are supervised by the physician. A radiation physicist checks over the treatment
plan as a safety measure.
Radiation is usually very well tolerated, treatments themselves are painless.
The
side-effects of localized radiation are generally only within the area treated. That
is,
patients will lose scalp hair only if the actual scalp is treated, or become sterile
only
if the testicles or ovaries are treated. The side effects of radiation are thus specific
for
the area treated, and are divided into"acute" and "late" reactions. "Acute" reactions
occur during the treatment period, while "late" reactions may occur months to years
later. Common acute reactions, which start after about a week of treatment, include
skin reddening and irritation; this may progress to frank peeling. Special salves
or
steroid creams may be prescribed to alleviate this. A foreign, "metallic" taste may
be
noted in the mouth, and the saliva thickens. The salivary glands may initially swell,
and mouth dryness occurs as the dose to these glands builds up. Soreness and the
mouth and throat may be quite painful, and require special numbing agents (viscous
lidocaine) to make eating less uncomfortable. Mild narcotic may be needed for relief.
Weight loss is common with treatment for head and neck cancers, so nutrition must
be carefully monitored. Some patients even require a temporary feeding tube ("PEG")
placed through the abdominal wall and into the stomach during treatment. This tube
is removed when the acute radiation reaction subsides. Mouth and throat pain may be
increased by fungal infections, like thrush, which are more likely during radiation.
Hair on the face is lost during treatment, but a man's beard will usually grow back,
albeit thinner. There is often a sense of fatigue during the therapy period. Overall,
treatment is not pleasant, but is made more tolerable by prescribing relieving medications
as appropriate. People differ in their tolerance to radiation, and to really effectively kill the tumor cells, it is necessary to get the acute reaction showing that
both cancer and normal cells in the mouth are dying. The normal ones can be repaired
and replaced, but not the cancerous ones. This is why radiation works.
The matter of more ultimate concern is "late" reactions, for these will stay with the
patient indefinitely. The frequency and severity of late reactions are less when therapy
is given as many small fractions, and this is why we take many weeks to give it all.
The most common late reaction from treatment of mouth cancer is dry mouth, called
"xerostomia" in medical parlance. This is due to damage to salivary glands, which then produce
a thickened, whitish saliva. Artificial saliva ("salivart"), pills which will
stimulate saliva ("pilocarpine"), humidifiers and plain spray bottles may be tried
to
moisten the mouth. Taste is usually decreased also, leading to a craving for sweet
foods. The combination of dry mouth and sweet diet leads to more chance fso or dental
problems, so the teeth must be carefully checked prior to starting radiation
therapy, and regularly in the years afterward. If major dental procedures are needed
after radiation therapy, the jaw bone may die in places ("osteoradionecrosis") and
need to be surgically removed. The skin in the area of treatment is often slightly discolored, and may be of tougher
texture. A more grave concern is of damage to the
spinal cord, which in this area tolerated about 50 Gray of radiation. Beyond this,
the
chance for damage increases dramatically. Mild damage is shown by an shock-like
sensation going through the body with neck flexion ("Lhermitte's sign"), but this
is
actually temporary and scary but not dangerous. Serious damage results in paralysis,
but fortunately this is extremely rare with modern radiation techniques (less than
1 in
500 patients). Another rare but possible complication is the development of a second
cancer in the area due to radiation, these are usually of the bone, cartilage or muscle
("sarcomas"). The worst complication is failure of treatment to control the existing
cancer, so it is crucial that radiation be given meticulously yet aggressively by
a highly
experienced radiation oncologist. It is truly remarkable and gratifying to see the
locally
advanced cancers cured by proper radiation treatment!
Several other methods of radiation administration are worthy of note. A smaller
machine ("orthovoltage") can be equipped with a "cone" to aim a beam of photons
directly on a tumor in the mouth("intra-oral cone therapy"). Different sizes of cones,
inserted into the mouth, can be used for various tumors, with consistent positioning. The orthovoltage radiation delivered through the cone gives a strong dose on the
surface of the tumor; this dose quickly decreases with distance (not very penetrating).
Thus, only relatively thin tumors near the surface of the mouth or tongue are effectively
treated with the cone, but it is very useful to give localized"boost" therapy to a large
tumor after external beam treatment. It is also excellent for cancers of the lips
and skin
as the primary therapy. Not all radiation therapy departments have an orthovoltage
machine, but many university hospital departments do. Like other external beam
therapy, intra-oral cone is done as a series of treatments, 3 or 5 days per week for
several weeks, and takes about 15 minutes per day total.
Another different strategy for administering radiation is "brachytherapy", which
means "slow therapy". For mouth cancers, this is accomplished by actually sewing
("implanting") a radiation source, such as Iridium-192 wire, into the tumor. Another
name for this procedure is"interstitial brachytherapy", interstitial meaning that the
radioactive sources actually penetrate the flesh. The advantage of this "implant",
like
the cone treatment, is that high doses of radiation are given to the local tumor area
but very little to the surrounding normal tissues. Therefore, the side-effects to
these
normal tissues are much less. The actual dose to the tumor and other local tissue
are seen by a "plan" generated by the radiation physics department, much like the
that previously described. This plan says how long the radiation source will be in
place. Of course, implantation is a surgical procedure which requires anesthesia.
It may be used in combination with external beam therapy, as a "boost", or for relapsed
cancer for which no further external beam treatment can be given. The radioactive wire
stays in for several days (during which time the patient is hospitalized) and then
is
clipped and removed. Although uncommon, this procedure may be repeated. Only
specialized radiation oncology facilities do implantation, so not all radiation doctors
are familiar with the techniques. Nonetheless, it is a valuable tool to fight cancer.
Chemotherapy is not curative alone for mouth cancer, but may be used effectively
in combination with other therapies. It is only recommended for large cancers, those
that have recurred, or those that have spread to distant organs. Chemotherapy may
be given before, after, or at the same time as radiation treatments, and may precede
or follow surgery. Many agents have been tried for squamous cell cancer of the head
and neck, either alone or in combination. Much progress has been made in using the
chemotherapy along with radiation and surgery, given in "clinical trials" where results
and side-effects for treatments can be monitored and compared.
The most effective single chemotherapy agents are Cisplatinum and 5-Fluorouracil (5-FU), Methotrexate and Bleomycin. . They show tumor shrinkage in 20 - 30% of
patients. Side effects of these agents include lowered blood cell counts leading
to
anemia and infection, diarrhea and mouth sores, hair thinning, kidney and nerve damage
(cisplatinum), and heart and lung damage (bleomycin). Combinations of chemotherapy
agents have not been consistently superior in results to single drugs.
Furthermore, combination treatment will have additive side-effects of each agent.
The
most studied combination chemotherapy for head and neck cancer is Cisplatin with
5-Fluorouracil. Each of these is given intravenously, in "cycles" 3 - 4 weeks apart.
The
cisplatin is commonly given only on the first day of each cycle, and the 5-FU is given
as a slow intravenous "infusion" over 5 days. The "response" to this combination
is
70%, with 30% of patients having "complete response". If the response is complete
(no evidence of disease left) it lasts an average of one year. Unfortunately, cancers
become resistant to chemotherapy much as bacteria develop resistance to antibiotic.
Thus, even an excellent response to chemotherapy doesnot mean definite cure, or
even improved survival. Overall in the literature, their is asmall trend to increased
survival when chemotherapy is added to standard surgery and radiation, and this is
an area of intense research. The main gain of chemotherapy appears to be a slightly
decreased level of distant spread, rather than any affect on the original tumor location.
This is reasonable, since we would expect any effective chemotherapy to more easily
"mop-up" microscopic cells which have sloughed off of the main tumor, rather than
eradicate a large mass of tumor cells. In combination with radiation, chemotherapy
often helps shrink large tumors by "radiosensitizing" the cancer cells-- that is
making
them more susceptible to be killed by radiation therapy.
What is the Latest Effective Therapy for Mouth Cancer?
The latest effective therapy is refinements in conventional therapy for mouth
cancer. Improvedsurgical techniques include use of operative lasers and plastic
reconstruction of areas destroyed by tumor, to maintain proper speech, chewing and
swallowing. Bone grafts and muscle "flaps" can be taken from other body areas to
reconstruct the jaw, if necessary, and preserve acceptable cosmetic appearance.
The surgeon can rely upon radiation therapy afterward to eliminate microscopic cancer remaining, and therefore less mutilating surgeries can be done initially. Improved
dental techniques can implant prosthetic teeth to replace those that must be pulled
prior to radiation therapy. Hyperbaric (high pressure) oxygen treatments have been
found to help healing in the mouth when surgeries are done after radiation.
reconstruct the jaw, if necessary, and preserve acceptable cosmetic appearance.
Radiation improvements include the use of sophisticated three - dimensional treatment plans which tell the
dose to each area in the head and neck, and allow a
prediction of the most suitable energies of radiation to be used. If an implant is
possible, superior results are obtained when combining external beam therapy (50
Gray) and an implant (30 Gray) compared to external beam alone. A newer way of giving
brachytherapy is"High-Dose Rate" ("HDR") . This means that "catheters" (tubes) are inserted through the tumor area, and a series
of treatments is given by loading them with a high-dose radiation source. It takes
about 10 minutes per treatment, and this may be repeated 5 to 7 times about 1 week
apart. This repetition helps reduce the "late-effects". In this way, an extremely high dose can be safely
given to the local tumor area. A more readily available way of increasing effectiveness
of radiation treatments in head and neck cancers is "hyperfractionation" . This will mean getting more treatments (usually 2 per day) at a lower dose per
treatment. Although inconvenient, it has improved response to radiation by about
20% in major studies! It is recommended for large tumors which will need a higher
dose of radiation (over 70 Gray) to control them. Fortunately, since smaller "fractions" are
given with each treatment, it leads to less "late" side-effects than conventional
radiation treatments, even while giving a higher total dose! A new and exciting way
of increasing the effectiveness of radiation is "hyperthermia". This means heating the area of the tumor, usually just prior to radiation treatment.
Cancer cell kill is much greater when the area is heated. The main difficulty in
giving hyperthermia treatment is the uniform heating of the tumor area, but new microwave
heating helps do this. Hyperthermia is only available at major medical University
Radiation Oncology departments, but has now been shown convincingly to improve radiation
results. The side-effects are only a small increase in normal radiation reaction.
Chemotherapy improvements have been slow, and are based on clinical trials. If
it is given at the same time as radiation therapy, it's called"chemoradiation" . This is
very effective at shrinking the tumor, but has severe local reaction of skin sloughing
and mouth ulceration, and so must be carefully monitored. Chemo-radiation may be given
before, after, or instead of surgery. Patients with large tumors now have them shrunk
with chemo-radiation prior to getting surgery, as a less mutilating procedure
may then be effective (as compared to if radical surgery was performed first). Patients
getting chemo-radiation may be unable to eat due to the soreness, and so often get
a temporary feeding tube. About 6 weeks is given after chemo-radiation to allow the
tumor to shrink and then surgery may be performed. The latest agents for chemoradiation
areTaxol andCisplatinum . This are given intravenously, up to 24 hours prior to the radiation. Blood counts
and nutrition are tracked, and a temporary break in treatment may be required if
the local reaction gets too intense. The radiation may be hyperfractionated to improve
effectiveness and decrease late side-effects. This aggressive treatment will then maximize
all established therapies.
Another aspect to chemotherapy is "chemoprevention" of new cancers. Vitamin
A derivative (Cis-Retinoin) has been shown to help treat small cancers, and prevent
new ones from forming. The dose for this is now being established (high dose has
unacceptable side effects). Nonetheless, taking vitamins A and E are thought to help
prevent a whole spectrum of aero-digestive cancers.
Overall, slow but steady progress is being made for mouth cancers, andsurvival
has improved perhaps 20% over the past 3 decades . Even patients with advanced
cancer have more hope than ever before, at least for comfort. Since radiation is a
mainstay of therapy, it is crucial to get an appointment with an up-to-date radiation
oncologist who communicates well with you. Younger radiation oncologists often have had better training than the older generation, since only in the last 2 decades
did this specialty gain much prestige (and difficulty getting into). New research
is always
continuing in cooperative clinical trials, by the RTOG and EORTC. Patients who have
large cancers and wish to be aggressive should find an oncologist they are comfortable talking too, preferably at a University Academic Center, and seriously consider
joining a recent clinical trial. Current major trials (there are new ones opening
and closing every month) can be found on the National Cancer Institutes website (call
them at 1-800-4-Cancer). Patients should embark upon a program to maintain nutrition,
exercise, increase spirituality, and select a reasonable alternative medicine
regimen in addition to doing conventional medical treatment. This combined approach
is superior to just counting on a pill or ray to cure cancer. If the patient still
smokes, they should quit, since results are better in even recent non-smokers. Above
all, realize that while more patients are being cured than ever before, many people
are also living longer and productive lives with their cancer, and keep a positive attitude to have the best chance for success.
This is the full transcript, offered freely in the spirit of internet sharing, of CancerAnswers' report on Mouth Cancer. Much more, including latest
additional treatments for Mouth Cancer can be found on our order page. Thank you for using CancerAnswers as
your information resource.
|
ADDITIONAL TOPICS
Acute Leukemia
Anal Cancer
Bladder Cancer
Bone Cancer
Brain Cancer
Breast Cancer: Early
Breast Cancer: Advanced
Cartilage Cancer
Cervical Cancer
Chronic Leukemia
Colo-rectal Cancer
Esophagus Cancer
Fat Cancer
Gall-Bladder Cancer
Hodgkin's disease
Kidney Cancer
Larynx Cancer
Liver Cancer
Lung Cancer
Lung "small cell" Cancer
Lymphoma
Melanoma
Mesothelioma
Mouth Cancer
Multiple Myeloma
Muscle Cancer
Muscle and Fat Tumors
Nasal Cavity Cancer
Nasopharynx Cancer
Ovarian Cancer
Pancreas Cancer
Penile Cancer
Plasmacytomia
Prostate Cancer
Skin Cancer
Stomach Cancer
Testicle Cancer
Thyroid Cancer
Tongue Base and Tonsil
Cancer of Unknown Origin
Uterine Cancer
Vaginal Cancer
Vulvar Cancer
|
