Transcript Oral cancer
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.