CANCERCANCER

Cancer may be regarded as a group of Cancer may be regarded as a group of disease! . Cancer can occur at any site or disease! . Cancer can occur at any site or tissue of the body and may involve any tissue of the body and may involve any type of cells . type of cells .

The three main reasons are being a longer The three main reasons are being a longer life expectancy, more accurate diagnosis life expectancy, more accurate diagnosis and the rise in cigarette smoking, and the rise in cigarette smoking, especially among malesespecially among males

CharacteristicsCharacteristics

A cancer is characterised by anA cancer is characterised by an

(i) abnormal growth of cells (i) abnormal growth of cells

(ii) ability to invade adjacent tissues and (ii) ability to invade adjacent tissues and even distant organs,even distant organs,

(iii) the eventual death of the affected (iii) the eventual death of the affected patient if- the tumour has progressed patient if- the tumour has progressed beyond that stage when it can be beyond that stage when it can be successfully removedsuccessfully removed

IncidenceIncidence

The most common cancers worldwide are The most common cancers worldwide are lung cancer 11. 23 per cent of all cancers), lung cancer 11. 23 per cent of all cancers), breast cancer (10.4 per cent) and breast cancer (10.4 per cent) and colorectal cancer (9.4 per cent)) The colorectal cancer (9.4 per cent)) The burden of cancer is distributed unequally burden of cancer is distributed unequally between developed and developing between developed and developing countries, with particular cancer types countries, with particular cancer types exhibiting different patterns of distributionexhibiting different patterns of distribution

Categories of cancerCategories of cancer

The major categories of cancer are :The major categories of cancer are :

Carcinomas, Carcinomas, which arise from epitheial which arise from epitheial cells lining the internal surfaces of the cells lining the internal surfaces of the various organs (e.g. mouth, oesophagus, various organs (e.g. mouth, oesophagus, intestines, uterus and from the skin intestines, uterus and from the skin epithelium; epithelium;

SarcomasSarcomas

Sarcomas, which arise from mesodermal Sarcomas, which arise from mesodermal cells constituting the various connective cells constituting the various connective tissue;tissue;(e.g. fibrous tissue, fat and bone); (e.g. fibrous tissue, fat and bone);

SELECTED CANCERSSELECTED CANCERS

1. Oral Cancer1. Oral Cancer

2. Cancer of the Cervix2. Cancer of the Cervix

3. Breast Cancer3. Breast Cancer

4. Lung Cancer4. Lung Cancer

5. Stomach Cancer5. Stomach Cancer

LymphomasLymphomas

Lymphomas Lymphomas myeloma myeloma and and leukaemias leukaemias arising from the cells of bone marrow and arising from the cells of bone marrow and immune systems.immune systems.

PREDOMINANT CANCERSPREDOMINANT CANCERS

In males predominant cancer is lung In males predominant cancer is lung cancer. Stomach, esophageal and bladder cancer. Stomach, esophageal and bladder cancer are also much more common in cancer are also much more common in males.males.

Among women of underdeveloped Among women of underdeveloped countries , the cancers of cervix and countries , the cancers of cervix and breast account for nearly 60 percent of all breast account for nearly 60 percent of all cancers.cancers.

Oral cancerOral cancer

Oral cancer is one of the ten most Oral cancer is one of the ten most common cancers in the world. common cancers in the world.

In Central and South East Asian countries In Central and South East Asian countries its frequency is very high.its frequency is very high.

EPIDEMIOLOGICAL FEATURESEPIDEMIOLOGICAL FEATURES

Approximately 90 per cent of oral Approximately 90 per cent of oral cancers in South East Asia are linked to cancers in South East Asia are linked to tobacco chewing and tobacco smoking.tobacco chewing and tobacco smoking.

Oral cancer and precancerous lesions Oral cancer and precancerous lesions occurred almost always among those occurred almost always among those who smoked or chewed tobacco.who smoked or chewed tobacco.

Oral cancer is almost always preceded Oral cancer is almost always preceded by some type of precancerous lesion.by some type of precancerous lesion.

Pre -cancerous stagePre -cancerous stage

There is often a precancerous stage There is often a precancerous stage that precedes the development of that precedes the development of cancer. cancer.

The precancerous lesions The precancerous lesions (leukoplakia, erythroplakia) can be (leukoplakia, erythroplakia) can be detected for up to 15 years prior to detected for up to 15 years prior to their change to an invasive their change to an invasive carcinoma. carcinoma.

RISK FACTORSRISK FACTORS

(a) Tobacco: Tobacco is smoked in the (a) Tobacco: Tobacco is smoked in the form of Cigarettes, Huqqa, and Powder form of Cigarettes, Huqqa, and Powder formform

(b) Alcohol: (b) Alcohol: High concentrations of High concentrations of alcohol, also causes oral cancer. Alcohol alcohol, also causes oral cancer. Alcohol appears to have a synergistic effect in appears to have a synergistic effect in tobacco users.tobacco users.

High -risk groupsHigh -risk groups

These include tobacco chewers and These include tobacco chewers and smokers, bidi smokers.smokers, bidi smokers.

People using tobacco in other forms such People using tobacco in other forms such as betel quid.as betel quid.

People who sleep with the tobacco quid in People who sleep with the tobacco quid in the mouththe mouth..

PREVENTIONPREVENTION

PRIMARY PREVENTION:PRIMARY PREVENTION:

If the tobacco habits are eliminated from If the tobacco habits are eliminated from the community, a great deal of reduction in the community, a great deal of reduction in the incidence of oral cancer can be the incidence of oral cancer can be achieved. This requires achieved. This requires

Intensive public education Intensive public education

Motivation for changing life styles Motivation for changing life styles

Supported by legislative measures like Supported by legislative measures like banning or restricting the sale of tobacco.banning or restricting the sale of tobacco.

SECONDARY PREVENTIONSECONDARY PREVENTION

Oral cancers are easily accessible for Oral cancers are easily accessible for inspection allowing early detection. If inspection allowing early detection. If detected early, possibly at the detected early, possibly at the precancerous stage, they can be precancerous stage, they can be treated or cured.treated or cured.

The main treatment modalities that The main treatment modalities that offer hope are surgery and offer hope are surgery and radiotherapy.radiotherapy.

Cancer of the Cancer of the CervixCervix

Cancer of the CervixCancer of the Cervix

This is the second most common cancer This is the second most common cancer among women worldwide, among women worldwide,

In developing countries, where it is often In developing countries, where it is often the most common cancer among women, the most common cancer among women, account for 80% of cases.account for 80% of cases.

Screening for Cancer of CervixScreening for Cancer of Cervix

The prolonged early phase of cancer can The prolonged early phase of cancer can be detected by the Pap smear.be detected by the Pap smear.

Current policy suggests that all women Current policy suggests that all women should have a Pap test (cervical smear) at should have a Pap test (cervical smear) at the beginning of sexual activity, and then the beginning of sexual activity, and then every 3 years thereafter every 3 years thereafter . .

A periodic pelvic examination is also A periodic pelvic examination is also recommended.recommended.

NATURAL HISTORYNATURAL HISTORY

The duration of the preinvasive stage is The duration of the preinvasive stage is also not known.also not known.

Once the invasive stage is reached, the Once the invasive stage is reached, the disease spreads by direct extension into disease spreads by direct extension into the lymph nodes and pelvic organs.the lymph nodes and pelvic organs.

Normal <—> Dysphasia <—> Normal <—> Dysphasia <—> cancer —> Invasive Cancercancer —> Invasive Cancer

Causative agentCausative agent

There is evidence pointing to Human There is evidence pointing to Human papilloma virus (HPV) - sexually papilloma virus (HPV) - sexually transmitted - as the cause of cervical transmitted - as the cause of cervical cancercancer

RISK FACTORSRISK FACTORS

AGE AGE

GENITAL WARTSGENITAL WARTS

MARITAL STATUSMARITAL STATUS

EARLY MARRIAGEEARLY MARRIAGE

ORAL CONTRACEPTIVE PILLSORAL CONTRACEPTIVE PILLS

SOCIO-ECONOMIC CLASSSOCIO-ECONOMIC CLASS

PREVENTION AND CONTROLPREVENTION AND CONTROL

PRIMARY PREVENTION: PRIMARY PREVENTION: Until the Until the causative factors are more clearly causative factors are more clearly understood, there is no prospect of understood, there is no prospect of primary prevention of the disease.primary prevention of the disease.SECONDARY PREVENTION : SECONDARY PREVENTION : This rests This rests on early detection of cases through on early detection of cases through screening and treatment by radical surgery screening and treatment by radical surgery and radiotherapy.and radiotherapy.

BREAST BREAST CANCERCANCER

Breast cancerBreast cancer

Breast cancer is one of the commonest Breast cancer is one of the commonest causes of death in many developed causes of death in many developed countries in middle-aged women, and is countries in middle-aged women, and is becoming frequent in developing countries becoming frequent in developing countries as well.as well.

Screening for breast cancerScreening for breast cancer

There is evidence that screening for breast There is evidence that screening for breast cancer has a favourable effect on mortality cancer has a favourable effect on mortality from breast cancerfrom breast cancer. .

TECHNIQUES OF SCREENINGTECHNIQUES OF SCREENING

The basic techniques for early detection of The basic techniques for early detection of breast cancer are : breast cancer are :

(a) breast self examination (BSE) by the (a) breast self examination (BSE) by the patientpatient

(b) palpation by a physician(b) palpation by a physician

(c) thermography and (c) thermography and

(d) mammography.(d) mammography.

RISK FACTORSRISK FACTORS

The established risk factors of breast The established risk factors of breast cancer include the following:cancer include the following:

AGEAGE

FAMILY HISTORYFAMILY HISTORY

PARITYPARITY

AGE AT MENARCHE AND MENOPAUSEAGE AT MENARCHE AND MENOPAUSE

Risk FactorsRisk Factors

HORMONAL FACTORSHORMONAL FACTORS

PRIOR BREAST BIOPSYPRIOR BREAST BIOPSY

DIETDIET

SOCIO-ECONOMIC STATUSSOCIO-ECONOMIC STATUS

OTHERSOTHERS

PREVENTIONPREVENTION

a. a. PRIMARY PREVENTION:PRIMARY PREVENTION:

The aims of primary prevention are The aims of primary prevention are towards elimination of risk factors.towards elimination of risk factors.

Promotion of cancer education.Promotion of cancer education.

SECONDARY PREVENTIONSECONDARY PREVENTION

Breast screening leads toBreast screening leads to

Early diagnosis of breast cancer, Early diagnosis of breast cancer,

It will influence the treatment and, It will influence the treatment and, hopefully, mortality.hopefully, mortality.

LUNG LUNG CANCERCANCER

Lung cancerLung cancer

Lung Cancer is directly associated with Lung Cancer is directly associated with smokingsmoking

In countries where cigarette smoking has In countries where cigarette smoking has only recently begun, lung cancer deaths only recently begun, lung cancer deaths still remain low, it will rise with the passage still remain low, it will rise with the passage of time if the smoking has not been of time if the smoking has not been stoped.stoped.

Screening for Lung CancerScreening for Lung Cancer

At present there are only two techniques At present there are only two techniques for screening for lung cancer, for screening for lung cancer,

Chest radiographChest radiograph

Sputum cytology.Sputum cytology.

Mass radiography has been suggested for Mass radiography has been suggested for early diagnosis at six monthly intervals, early diagnosis at six monthly intervals,

EPIDEMIOLOGICAL FEATURESEPIDEMIOLOGICAL FEATURES

a. AGE AND SEX:a. AGE AND SEX:

About a third of all lung cancer deaths About a third of all lung cancer deaths occur below the age of 65. In many occur below the age of 65. In many industrialized countries, the incidence of industrialized countries, the incidence of lung cancer is at present increasing more lung cancer is at present increasing more in females than in males in females than in males (55).(55).

RISK FACTORSRISK FACTORS

Smoking:Smoking:

Air pollution, radioactivity,Air pollution, radioactivity,

Occupational exposure to asbestos, Occupational exposure to asbestos, arsenic and its compounds,arsenic and its compounds,

Chromates, particles containing polycyclic Chromates, particles containing polycyclic aromatic hydrocarbons and certain nickel-aromatic hydrocarbons and certain nickel-bearing dusts. bearing dusts.

PREVENTIONPREVENTIONPrimary prevention:Primary prevention:

Broadly these methods include:Broadly these methods include:

a.a. Public information and educationPublic information and education

b.b. Legislative and restrictive measuresLegislative and restrictive measures

c.c. Smoking cessation activitiesSmoking cessation activities

d.d. National and international National and international coordination.coordination.

SECONDARY PREVENTIONSECONDARY PREVENTION

This rests on This rests on

Early detection of cases Early detection of cases

And their treatment.And their treatment.

STOMACH STOMACH CANCERSCANCERS

Stomach cancersStomach cancersStomach cancer is the world's second Stomach cancer is the world's second most common cancer, with over 1 million most common cancer, with over 1 million new cases per year.new cases per year.

Most gastric cancers are Aden Most gastric cancers are Aden carcinomas. In contrast to the overall carcinomas. In contrast to the overall decreasing trend, there has recently been decreasing trend, there has recently been a rapid increase of cancers localized to the a rapid increase of cancers localized to the cardia (the upper part of the stomach). cardia (the upper part of the stomach).

Causative AgentsCausative Agents

Infection with the bacterium Infection with the bacterium Helicobacter Helicobacter pylori pylori contributes to the risk, probably by contributes to the risk, probably by interacting with the other factors.interacting with the other factors.

Preventive FactorsPreventive Factors

The constant decline of stomach cancer is The constant decline of stomach cancer is linked to linked to

Improved food preservation practices; Improved food preservation practices;

Better nutrition more rich in vitamins from Better nutrition more rich in vitamins from fresh vegetables and fruits; and fresh vegetables and fruits; and

Less consumption of preserved, and Less consumption of preserved, and salted foods. salted foods.

SymptomsSymptoms

These are nonspecific, which explains why These are nonspecific, which explains why most of the cases are diagnosed when the most of the cases are diagnosed when the disease is at an advanced stage. disease is at an advanced stage.

Patients may complain of weight loss, Patients may complain of weight loss, fatigue or gastric discomfort. fatigue or gastric discomfort.

Diagnosis is performed by barium X-rays Diagnosis is performed by barium X-rays and with biopsy.and with biopsy.

TreatmentTreatmentThis cancer is treated by surgical removal This cancer is treated by surgical removal of the tumour, with or without adjuvant of the tumour, with or without adjuvant chemotherapychemotherapy

PrognosisPrognosis

Stomach cancer cases have a generally Stomach cancer cases have a generally poor survival prognosis, averaging no poor survival prognosis, averaging no more than 20% survival after five years. more than 20% survival after five years.

If the tumour is localized to the stomach, If the tumour is localized to the stomach, 60% of patients survive five years or more. 60% of patients survive five years or more. However, only 18% of all cases are However, only 18% of all cases are diagnosed at this early stage. diagnosed at this early stage.