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PREVENTING
CANCER
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PREVENTING CANCER |
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Can cancer be prevented? |
| Yes.
Cancer can definitely be prevented in a large number
of cases. It has been found that many preventable
types of cancer are there. Among the most important
preventable cancers are tobacco related cancers.
Abuse of tobacco (smoking and smokeless) causes
cancer of the mouth, throat (pharynx), voicebox
(larynx), food pipe (esophagus), lung, pancreas,
kidney, urinary bladder, and , uterine cervix. Tobacco
is the single most important cause of cancer and
the most important preventable cause of cancer.
The risk of cancer due to tobacco occurs after many
years of use. On cessation of tobacco use, the risk
decreases slowly over 5 to 10 years. After nearly
10 years of cessation, the risk may approach normal
population. |
| Alcohol
is another cause of cancer. It increased the risk
of cancers of mouth, pharynx, larynx, esophagus
where it also increases the risk of tobacco related
cancer significantly. It is also an important cause
of cancer |
| Cancer
of the head & neck, the most common type of cancer
in India, is related to tobacco, alcohol, Betel,
Areca (Supari), poor oral hygiene, etc. All these
factors are potentially avoidable and avoidance
reduces the risk of cancer significantly. |
| Another
group of preventable cancers is those caused by
infections. Cancer of the liver is caused by hepatitis
B virus infection. Vaccination against hepatitis
B can thus play a big role in its prevention. Cancer
of the uterine cervix is related to papilloma virus
infection which is transmitted sexually. Use of
condoms can reduce papilloma virus infections and
thus, cancer of the utrerine cervix. |
| Cancers
of the skin (basal cell and squamous cell types)
are related to exposure to sunlight. They can be
prevented by reducing the exposure to sun and using
sunscreens, etc. |
| A
number of cancers are related to increasing use
of potentially carcinogenic chemicals in various
aspects of life. These chemical find way to our
body through air, water, food, etc. Identification
of such chemicals and their avoidance is another
way of cancer prevention. Air pollution caused by
various sources can increase the risk of cancer.
Carcinogenic chemicals in air can come from automobiles
and industries and affect the lung. Control of automobile
and industrial exhaust for air pollution will be
beneficial to the whole society. |
| Nutrition
& diet also have an important role in cancer prevention.
Obesity or being overweight increases the risk of
cancer of breast, gallbladder, ovary, uterus, large
intestine (colon) and prostate. Diet which is high
in fresh fruits and vegetables protects against
many cancers. High fiber diet (whole grain cereals,
fruits and vegetables) may reduce the risk of colon
cancer. A diet low in total fat also reduces the
risk of development of some cancers. Certain methods
of food preservation (salt cured, smoked, and nitrite
cured) increase the risk of cancer of the esophagus
and stomach. Modern methods of food preservation
or using unpreserved, fresh food are also important
in prevention of these cancers. |
| Occupation
may also expose the individual to risk of certain
cancers. Awareness of these factors can be helpful
in taking preventing care and avoiding unnecessary
exposure to harmful agents. Cancer of the lungs
is increased in people working in asbestos industries.
Cancer of the urinary bladder is more common in
people working with chemicals, especially organic
chemicals. |
| Ionizing
radiation also increases the risk of cancers. Exposure
to radiation can occur among doctors (Radiology,
Radiotherapy, Nuclear Medicine), technicians and
other staff in these set ups and any set up having
the possibility of radiation exposure (laboratories,
nuclear power stations). |
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What is screening for cancer and how does it
help? |
| Screening
refers to examination and investigation of persons
without any symptoms or signs suggestive of cancer
with a view to detect cases of cancer before they
cause symptoms. It is expected that by this approach
cancers can be detected at a very early stage and
thus lead to a much higher chance of cure. Screening
has been tried in some of the common cancers such
as cancer of the breast and uterine cervix, the
two commonest cancers in women and found to be effective
in early detection and reducing the death rate due
to these cancers in the screened populations. Screening
has also been found to be effective in prostate
cancer, a common cancer of elderly males. Cancer
of the large intestine (colon or rectal cancer)
which is very common in western countries is also
amenable to early detection by screening. |
| Screening
for breast cancer is by breast self examination,
annual clinical examination by a specialist and
mammography (x-ray of the breasts done using special
x-ray machines) starting at an appropriate age.
Screening for cancer of the uterine cervix involves
examination by a specialist and a test called the
pap test which is a very simple test without any
discomfort. Screening for prostate cancer involves
examination by the specialist, a blood test for
prostate specific antigen, and TRUS (transrectal
ultrasound of the prostate). Screening for cancer
of the large intestine involves examination of stool
samples for present of blood (occult blood testing)
and examination by a specialist. |
| When
screening is done for any cancer, abnormalities
detected on screening need to be evaluated by additional
investigations to confirm or exclude the presence
of cancer. If a cancer is diagnosed, it has to be
treated appropriately. |
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What are the signs and symptoms of cancer? |
| The
signs and symptoms of cancer depend upon the body
part affected by the disease. Symptoms may be caused
by the primary tumor or the spread of tumor to lymph
nodes or distant parts of the body. In general,
cancer has a tendency to start as a nodule or mass
of tissue which keeps on growing. The growth rate
of cancers is variable with some cancers growing
very rapidly and others growing slowly. With further
growth, cancers which affect external or internal
body surfaces can form wounds or ulcers leading
to dirty discharge, bleeding etc. Common symptoms
of cancer can be described as follows. |
| Lump
or swelling: A swelling or lump is a symptom
of cancers of superficial body parts such as skin,
breast, muscles, bones, etc. Cancer in the abdomen
can cause development of lumps but such lumps are
felt by patients only when they become large. For
breast cancer, which is the commonest cancer of
women all over the world, a lump in the breast is
the symptom in more than 90% of cases. |
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A sore that doesn't heal: A wound, ulcer
or sore caused by cancer does not heal on its own
or with dressings. There may be foul smelling discharge
from the sore or bleeding may occur. Sores occur
due to cancers of superficial tissues such as skin,
muscles, etc. Sores or ulcers are common in cancers
of mouth where pain may be a common accompanying
symptom. Similarly sores in the region of anus can
also be caused by cancer. |
| Recent
change in a wart/mole: Warts and moles are common
findings in all people and we do not think of cancer
usually. Sometimes, longstanding warts or moles
can develop cancer too. The features of this are
a change in size, itching, bleeding, ulceration,
etc. |
| Unusual
bleeding or discharge: Cancer of deeper parts
of the body can lead to bleeding or discharge. Cancers
of the uterine cervix in women is a very common
cancer in India. It causes dirty vaginal discharge
and bleeding. Bleeding may be spontaneous or after
intercourse. Similarly bleeding with urine and stools
can be a sign of cancers of the urinary tract (kidneys,
ureter or bladder) and intestines (large intestines,
small intestines). Cancers of the lung often manifests
with coughing of blood. |
| Changes
in bladder or bowel habits: Generally, people
have very stable habits of bladder and bowel. Cancers
in the respective organs can affect these. Difficulty
in passing urine, poor stream, etc can be because
of cancers of the prostate also. Similary, constipation
with or without episodes of diarrhea, passage of
mucus with stools, etc can be a symptom of intestinal
cancer. |
| Nagging
cough or hoarseness: Nagging, persistent cough
is common feature of cancers of the lung and larynx.
In India, tuberculosis is a common disease and a
large number of cancers of the lung are misdiagnosed
as tuberculosis. If treatment of tuberculosis does
not lead to definite improvement, cancer should
be considered and excluded. Change in voice is a
common feature of cancer of the larynx and it can
also occur due to lung cancer. |
| Difficulty
in swallowing or dyspepsia: Difficulty in swallowing
is a common feature of cancer of the esophagus (foodpipe)
which is a common cancer in India. It starts with
difficulty in eating solid food and progresses until
it is difficult to swallow liquids or even saliva.
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| Loss
of appetite, heaviness after meals, nausea and vomiting
are common features of cancer of the stomach, a
common cancer in many parts of India. However, these
symptoms are often caused by a variety of cancers
in the human body due to the disabling effect of
cancer on the whole body. |
| It
is important to realize that no symptoms or signs
of cancer are exclusive. Similar symptoms can be
and are often caused by noncancerous diseases. However,
whenever a possibility of cancer exists, the specialists
should be consulted to exclude the diagnosis of
cancer. This is because the biggest hope for cure
of cancer lies with early diagnosis and prompt treatment.
Delay and procrastination are the most important
reasons for poor outcome of cancer. |
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How is cancer treated? |
| Treatment
of cancer is a rapidly evolving field as a result
of the intensive research work being done in cancer
centers all around the world. Basically, three main
approaches to treatment of cancer are used: surgery,
radiation, and, drugs. Correspondingly, three
main types of cancer specialists are there for treating
cancer: surgical oncologists, radiation oncologists,
and medical oncologists. |
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The treatment of cancer is described as a multimodality
approach as a large number of patients need to be
treated with a combination of the approaches available.
Thus, some patients may need only one modality of
treatment, some need a combination of two modalities
and some need to be treated with all three modalities
to achieve the best results. |
| To
decide the best treatment for a given patients,
initial testing is done to make the diagnosis (diagnostic
investigations) and decide the stage of disease
(staging investigations). After this, the specialists
from all three specialties discuss the case in
"tumor board". Together, after going through
the details of the patient, they arrive at a decision
about the best possible treatment of the patient.
If more than one modalities have to be used, the
treatment plan consists of details about the proper
sequence in which the different treatments should
be used. After the initial treatment plan, the treatment
is started. The progress of treatment and response
of disease is assessed from time to time. A review
of the progress is made in subsequent tumor board
meetings to decide whether any change in the treatment
plan is required or not. Once the planned treatment
is completed, cancer patients need regular follow-up.
The purpose of follow-up is to examine the patient
and carry our necessary investigations to detect
re-occurrence of the disease or development of new
cancers so that appropriate and timely treatment
can be done. |
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