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CANCER
Cancer may be regarded as a group of
disease! . Cancer can occur at any site or
tissue of the body and may involve any
type of cells .
The three main reasons are being a longer
life expectancy, more accurate diagnosis
and the rise in cigarette smoking,
especially among males
Characteristics
A cancer is characterised by an
(i) abnormal growth of cells
(ii) ability to invade adjacent tissues and
even distant organs,
(iii) the eventual death of the affected
patient if- the tumour has progressed
beyond that stage when it can be
successfully removed
Incidence
The most common cancers worldwide are
lung cancer 11. 23 per cent of all cancers),
breast cancer (10.4 per cent) and
colorectal cancer (9.4 per cent)) The
burden of cancer is distributed unequally
between developed and developing
countries, with particular cancer types
exhibiting different patterns of distribution
Categories of cancer
The major categories of cancer are :
Carcinomas, which arise from epitheial
cells lining the internal surfaces of the
various organs (e.g. mouth, oesophagus,
intestines, uterus and from the skin
epithelium;
Sarcomas
Sarcomas, which arise from mesodermal
cells constituting the various connective
tissue;
(e.g. fibrous tissue, fat and bone);
SELECTED CANCERS
1. Oral Cancer
2. Cancer of the Cervix
3. Breast Cancer
4. Lung Cancer
5. Stomach Cancer
Lymphomas
Lymphomas myeloma and leukaemias
arising from the cells of bone marrow and
immune systems.
PREDOMINANT CANCERS
In males predominant cancer is lung
cancer. Stomach, esophageal and bladder
cancer are also much more common in
males.
Among
women
of
underdeveloped
countries , the cancers of cervix and
breast account for nearly 60 percent of all
cancers.
Oral cancer
Oral cancer is one of the ten most
common cancers in the world.
In Central and South East Asian countries
its frequency is very high.
EPIDEMIOLOGICAL FEATURES
Approximately 90 per cent of oral
cancers in South East Asia are linked to
tobacco chewing and tobacco smoking.
Oral cancer and precancerous lesions
occurred almost always among those
who smoked or chewed tobacco.
Oral cancer is almost always preceded
by some type of precancerous lesion.
Pre -cancerous stage
There is often a precancerous stage
that precedes the development of
cancer.
The
precancerous
lesions
(leukoplakia, erythroplakia) can be
detected for up to 15 years prior to
their
change
to
an
invasive
carcinoma.
RISK FACTORS
(a) Tobacco: Tobacco is smoked in the
form of Cigarettes, Huqqa, and Powder
form
(b) Alcohol: High concentrations of alcohol,
also causes oral cancer. Alcohol appears
to have a synergistic effect in tobacco
users.
High -risk groups
These include tobacco chewers and
smokers, bidi smokers.
People using tobacco in other forms such
as betel quid.
People who sleep with the tobacco quid in
the mouth.
PREVENTION
PRIMARY PREVENTION:
If the tobacco habits are eliminated from
the community, a great deal of reduction in
the incidence of oral cancer can be
achieved. This requires
Intensive public education
Motivation for changing life styles
Supported by legislative measures like
banning or restricting the sale of tobacco.
SECONDARY PREVENTION
Oral cancers are easily accessible for
inspection allowing early detection. If
detected early, possibly at the
precancerous stage, they can be
treated or cured.
The main treatment modalities that
offer
hope
are
surgery
and
radiotherapy.
Cancer of the
Cervix
Cancer of the Cervix
This is the second most common cancer
among women worldwide,
In developing countries, where it is often
the most common cancer among women,
account for 80% of cases.
Screening for Cancer of Cervix
The prolonged early phase of cancer can
be detected by the Pap smear.
Current policy suggests that all women
should have a Pap test (cervical smear) at
the beginning of sexual activity, and then
every 3 years thereafter .
A periodic pelvic examination is also
recommended.
NATURAL HISTORY
The duration of the preinvasive stage is
also not known.
Once the invasive stage is reached, the
disease spreads by direct extension into
the lymph nodes and pelvic organs.
Normal
<—>
Dysphasia
<—>
cancer —> Invasive Cancer
Causative agent
There is evidence pointing to Human
papilloma virus (HPV) - sexually
transmitted - as the cause of cervical
cancer
RISK FACTORS
AGE
GENITAL WARTS
MARITAL STATUS
EARLY MARRIAGE
ORAL CONTRACEPTIVE PILLS
SOCIO-ECONOMIC CLASS
PREVENTION AND CONTROL
PRIMARY PREVENTION: Until the
causative factors are more clearly
understood, there is no prospect of
primary prevention of the disease.
SECONDARY PREVENTION : This rests
on early detection of cases through
screening and treatment by radical surgery
and radiotherapy.
BREAST
CANCER
Breast cancer
Breast cancer is one of the commonest
causes of death in many developed
countries in middle-aged women, and is
becoming frequent in developing countries
as well.
Screening for breast cancer
There is evidence that screening for breast
cancer has a favourable effect on mortality
from breast cancer.
TECHNIQUES OF SCREENING
The basic techniques for early detection of
breast cancer are :
(a) breast self examination (BSE) by the
patient
(b) palpation by a physician
(c) thermography and
(d) mammography.
RISK FACTORS
The established risk factors of breast
cancer include the following:
AGE
FAMILY HISTORY
PARITY
AGE AT MENARCHE AND MENOPAUSE
Risk Factors
HORMONAL FACTORS
PRIOR BREAST BIOPSY
DIET
SOCIO-ECONOMIC STATUS
OTHERS
PREVENTION
a. PRIMARY PREVENTION:
The aims of primary prevention are
towards elimination of risk factors.
Promotion of cancer education.
SECONDARY PREVENTION
Breast screening leads to
Early diagnosis of breast cancer,
It will influence the treatment and,
hopefully, mortality.
LUNG
CANCER
Lung cancer
Lung Cancer is directly associated with
smoking
In countries where cigarette smoking has
only recently begun, lung cancer deaths
still remain low, it will rise with the passage
of time if the smoking has not been
stoped.
Screening for Lung Cancer
At present there are only two techniques
for screening for lung cancer,
Chest radiograph
Sputum cytology.
Mass radiography has been suggested for
early diagnosis at six monthly intervals,
EPIDEMIOLOGICAL FEATURES
a. AGE AND SEX:
About a third of all lung cancer deaths
occur below the age of 65. In many
industrialized countries, the incidence of
lung cancer is at present increasing more
in females than in males (55).
RISK FACTORS
Smoking:
Air pollution, radioactivity,
Occupational exposure to asbestos,
arsenic and its compounds,
Chromates, particles containing polycyclic
aromatic hydrocarbons and certain nickelbearing dusts.
PREVENTION
Primary prevention:
Broadly these methods include:
a. Public information and education
b. Legislative and restrictive measures
c. Smoking cessation activities
d. National and international coordination.
SECONDARY PREVENTION
This rests on
Early detection of cases
And their treatment.
STOMACH
CANCERS
Stomach cancers
Stomach cancer is the world's second
most common cancer, with over 1 million
new cases per year.
Most
gastric
cancers
are
Aden
carcinomas. In contrast to the overall
decreasing trend, there has recently been
a rapid increase of cancers localized to the
cardia (the upper part of the stomach).
Causative Agents
Infection with the bacterium Helicobacter
pylori contributes to the risk, probably by
interacting with the other factors.
Preventive Factors
The constant decline of stomach cancer is
linked to
Improved food preservation practices;
Better nutrition more rich in vitamins from
fresh vegetables and fruits; and
Less consumption of preserved, and
salted foods.
Symptoms
These are nonspecific, which explains why
most of the cases are diagnosed when the
disease is at an advanced stage.
Patients may complain of weight loss,
fatigue or gastric discomfort.
Diagnosis is performed by barium X-rays
and with biopsy.
Treatment
This cancer is treated by surgical removal
of the tumour, with or without adjuvant
chemotherapy
Prognosis
Stomach cancer cases have a generally
poor survival prognosis, averaging no
more than 20% survival after five years.
If the tumour is localized to the stomach,
60% of patients survive five years or more.
However, only 18% of all cases are
diagnosed at this early stage.