This document defines cancer and its major categories. It provides worldwide statistics on cancer incidence and mortality. The most common cancers by gender and region are described. Environmental and genetic factors that can cause cancer are discussed. Methods of cancer prevention, screening, and treatment are outlined. Two specific cancers - oral and stomach cancer - are summarized in terms of epidemiology, causes, diagnosis, and prevention.

1. CANCER
EPIDEMIOLOGY

2. DEFINITION
• A group of diseases characterized by :
• abnormal growth of cells
ability to invade adjacent tissues & even distant organs
• the eventual death of the affected patient if the tumour has
progressed beyond that stage when it can be successfully
removed

3. MAJOR CATEGORIES OF CANCER
• Carcinoma - arise from epithelial cells lining internal surfaces of various
organs & from skin epithelium
• Sarcoma- arise from mesodermal cells constituting various connective
tissues
• Lymphoma, myeloma & leukaemia- arise from cells of bone marrow &
immune systems

4. • “Primary tumour” – cancer in the organ of origin
• “Secondary tumour”-
• cancer that has spread to regional lymph nodes and distant organs

5. WORLDWIDE
• 22.4 million living with cancer
• 10 million diagnosed every year
• 6 million deaths every year

6. INCIDENCE MORTALITY
Lung (12.3%) Lung (17.4%)
Breast (10.4%) Stomach(10.4%)
Colorectal (9.3%) Liver(8.8%)

7. GENDER WISE (PERSON) DISTRIBUTION OF
CANCER
Males (LSC)
• Lung
• Stomach
• Colorectal
Females (BCC)
• Breast
• Cervix
• Colorectal

8. TIME TRENDS
6th cause of death in the 1900s
2nd cause of death in 2000 because of:
 Increase in life expectancy
 Better & accurate diagnosis
 Increase in cigarette smoking

9. DISTRIBUTION
Developed countries:
• lifestyle and dietary habits e.g. Ca lung, Ca breast, Ca colorectal
Developing countries: infective origin e.g. Ca Cervix, Ca Liver, Ca
stomach
• Ca stomach common in Japan, not in US
• Ca Cervix more common in EAR, not in Japan

10. CAUSES OF CANCER
I.Environmental factors
Tobacco
Alcohol: oesophageal ,liver cancer,rectal cancer
Dietary factors:
Smoked fish-stomach cancer, beef-bowel cancer,high fat diet-
breast cancer
Also food additives & contaminants-suspicion as causative agents
Low fruit and vegetable intake

20. CARCINOGENS IN DIFFERENT
OCCUPATIONS

22. IMMUNOSUPPRESSIVE AGENTS AND
CANCER

23. RADIATIONS AND CANCER

25. INFECTIONS AND CANCER

26. SCHISTOSOMIASIS AND
OPISTORCHIASIS

27. AUTOMOBILE EMISSIONS

30. PAH EXPOSURE

31. INDUSTRIAL EMISSIONS

32. AFLATOXINS

33. ASBESTOS AND LUNG CANCER

35. CHERNOBYL NUCLEAR TRAGEDY

36. GENETIC FACTORS
1.Mutations in genes result in altered proteins
•During cell division •External agents
2. Most cancers result from mutations in somatic cells
3. Some cancers are caused by mutations in germline cells

38. CANCER PREVENTION AND CONTROL
• More than 30% of cancer deaths can be prevented
Primary prevention
• Control of tobacco and alcohol consumption
• Personal hygiene
• Radiation protection
• Occupational protection
• Immunization: HPV,Hep.B

39. • Cautious use of foods, drugs and cosmetics
• Control of Air pollution
• Treatment of precancerous lesions
• Legislation
• Cancer education

40. CANCER PREVENTION

42. SECONDARY PREVENTION
1. Cancer registration
– Hospital-based registry
– Population-based registry
3. Treatment: Surgery, Radiotherapy and chemotherapy
4. Palliative care: Relief from pain and other problems

43. CANCER SCREENING
Why screening is possible?
• Precancerous or premalignant lesions
• Localized lesions initially
• 75% Of cancer are at accessible body sites

44. METHODS OF CANCER SCREENING
Mass screening of more than one site
(of cancer)
• Mass screening at single site
• Selective screening: high risk group

46. EPIDEMIOLOGY OF ORAL CANCER
• Commonest cancer in India (70%)
• 90% of oral cancers due to tobacco
• Alcohol
• High risk groups:
tobacco smokers & chewers, smokers, betel quid, tobacco quid
• Cultural patterns: Cigarttes,bidi,cigar,chilum, hookah(hubble-
bubble),khaini,nasswar,snuff
• Ca palate :
with habit of reverse smoking of cigar

47. PREVENTION AND CONTROL OF ORAL
CANCER
1.Primary
• Education, motivation, legislative
2.Secondary
Early case detection and treatment
Leukoplakia treatment:
• Cessation of tobacco use
• Surgery
• Radiotherapy

48. STOMACH CANCER
• World’s 2nd most common cancer
• 1 million new cases/year
• 2/3 cases in developing countries
• Most are adenocarcinoma
• Causes: H.pylori inf.,improper preservation of foods ,smoked fish
• Symptoms non specific
• Diagnosis: barium x-ray,biopsy
• Treatment: Surgery, chemotherapy