Geographic differences in cancer incidence by sex at various sites in city wards in Greater Bombay.

ABSTRACT

In this paper an attempt has been made to study the geographic variations in cancer incidence at various sites, by sex, in Greater Bombay. Crude incidence rates at each site for individual wards have been calculated using the data collected by the Bombay Cancer Registry, for the years 1979 to 1984. To study the variations highest and lowest crude incidence rates in the different wards and the ratio of the highest to the lowest rates for each primary site were calculated. Detailed analyses show that there is a positive relationship between male and female rates for certain sites such as the Buccal Mucosa, Oesophagus, Stomach, Colon, Rectum and Liver. The Tongue, Oropharynx, Hypopharynx, Lung and Larynx present rates that vary widely in males but only slightly in females. Sites such as the Pancreas, Hodgkin's Disease, Lymphoma and Leukaemias do not seem to present any particular pattern. It was interesting to find that those sites where environmental factors are of likely value, such as excessive tobacco chewing and smoking tend to fall in the second category. Particularly striking is the the fact, that habits of etiological value are those to which men are more frequently addicted to than women, probably explaining the low rates in females of the wide variation in male rates.