ABSTRACT
The relationship of cancer incidence to terrestrial radiation and population density was investigated. Cancer incidence was obtained using 40 years of age-standardized data from the Connecticut Tumor Registry, and environmental radiation was estimated using data from an airborne gamma radiation survey of the entire state. These variables were examined ecologically, using the 169 towns of the state as the analytic units in a weighted regression analysis. The study design involves a large population base in a state having relatively high terrestrial radiation exposure levels overall and reasonable variation in exposure between towns. For all cancer combined, only one of the eight sex-specific analyses by decade yielded a significant radiation regression coefficient, and this was negative. In the sex- and site-specific analyses, almost all the coefficients for radiation were not significantly different from zero. In contrast, significant positive relationships of cancer incidence with population density were found for all cancer, for cancer of the lung for both sexes, for stomach, colonic, and prostatic cancer for males, and for lymphomas, thyroid, breast, and ovarian cancer for females. Both the radiation and population density relationships were adjusted for socioeconomic status. Socioeconomic status was significantly negatively associated with stomach and lung cancer in males and with cervical cancer in females; it was also positively associated with lymphomas and breast cancer in females. A power calculation revealed that, despite the relatively large size of this study, there was only a small probability of detecting a radiation effect of the strength anticipated from previous estimates.
Subject(s)
Air Pollution, Radioactive/adverse effects , Neoplasms/epidemiology , Air Pollution, Radioactive/analysis , Connecticut , Demography , Environmental Exposure , Epidemiologic Methods , Female , Humans , Male , Neoplasms/etiology , Population Density , Registries , Sex Factors , Socioeconomic FactorsABSTRACT
Population-based tumor registries collect data on all cancer patients within a defined geographic area. The information they provide on demographic factors and tumor characteristics contribute greatly to the conduct of etiologic studies. Illustrations based on data reported to the Connecticut Tumor Registry include examples from case-control and retrospective cohort studies, from investigations of multiple primary cancers and precursor lesions, and from a plan to develop a surveillance system for cancers related to occupation and smoking. This statewide project calls for hospitals to collect, on admission of all in-patients, basic data on occupation/business and smoking status and to enter this information on the patient's admission form. These data are to be included subsequently in the tumor record of each cancer patient in the State, thus enhancing the value and usefulness of the Connecticut Tumor Registry.
Subject(s)
Neoplasms/prevention & control , Registries , Adult , Female , Humans , Male , Middle Aged , Neoplasms, Multiple Primary/epidemiology , Occupational Diseases/prevention & control , Precancerous Conditions/epidemiology , Retrospective Studies , Tobacco Use Disorder/complicationsABSTRACT
The proportion of colorectal cancer occurring above the rectosigmoid junction has been increasing over time. The 40,771 cases of colorectal carcinoma reported to the Connecticut Tumor Registry from 1940 through 1973 were analyzed to determine the incidence in the ascending colon, the transverse, descending, and sigmoid colon, and the rectum. The numbers of cases, the proportion, and incidence rates of cancer in the ascending colon and sigmoid have increased over the 34 years. The increases were greatest among people over 65 years old. Only about half of colorectal cancer can now be identified with the rigid sigmoidoscope. Other tests must be used for early diagnosis of the increased numbers of cancers in the upper parts of the colon.
Subject(s)
Colonic Neoplasms/epidemiology , Rectal Neoplasms/epidemiology , Adolescent , Adult , Age Factors , Aged , Child , Child, Preschool , Colonic Neoplasms/diagnosis , Connecticut , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Rectal Neoplasms/diagnosis , Sigmoid Neoplasms/diagnosis , Sigmoid Neoplasms/epidemiologyABSTRACT
Data on over 3,700 patients with renal cell carcinoma, reported to the Connecticut Tumor Registry from 1935 through 1973, were used to assess incidence, survival, and associations of risk with demographic characteristics. Incidence increased over time among men, but not among women; a birth cohort effect suggesting increasing incidence rate over time was demonstrated for men. A comparison of male and female age-specific incidence rates indicated that, in the 15- to 39-year-old age group, men were three times more likely than women to develop the disease; after age 40, renal cell carcinoma was diagnosed in men twice as often as in women. Survival probability has increased from 1940 to the present time. A high density of persons per square mile was associated with a higher-than-expected incidence. No trends in incidence according to socioeconomic status were observed.
