Evidence for a spatiotemporal cluster of ovarian cancer cases

Personal and lifestyle factors, rather than environmental factors, have been associated with the occurrence of ovarian cancer. An apparent spatiotemporal cluster of ovarian cancer cases was evaluated by comparing the observed and expected number of cases (1978-1988), examining morphologic data, reviewing medical records, and conducting an environmental survey of the study area. A statistically significant excess of ovarian cancer cases was noted (8 cases observed, 3.4 cases expected; P less than 0.025). Seven of the eight cases resided within 0.75 miles of each other at time of diagnosis; six cases were diagnosed within a 5-year interval. A morphologic review, medical record review, and environmental survey did not provide any possible reasons for this excess. It is hoped that this initial report will stimulate reports of similar observations by clinicians and health researchers in an effort to further elucidate etiologic factors in the development of ovarian cancer.