Prostate cancer incidence and mortality in rural men--a systematic review of the literature.

INTRODUCTION Prostate cancer is a common health problem in men worldwide. This systematic review has been undertaken to determine if there are differences in incidence of and mortality from prostate cancer between rural and urban men. The understanding of geographical patterns of prostate cancer incidence and mortality is necessary in order to identify and assess any disparities between rural and urban residents in gaining access to healthcare services, such as screening, diagnosis and treatment. METHODS Medline, CINAHL and Embase were searched using relevant mesh phrases, such as 'prostate cancer incidence rural' or 'prostatic neoplasms mortality rural'. Secondary literature and reports not published in peer-reviewed journals were included if inclusion criteria had been met. The following inclusion criteria were applied: cohort (population-based study) of adult men, diagnosis of prostate cancer, comparing rural and urban groups, and incidence or mortality with available statistical parameters as outcome. RESULTS In total, 25 studies were found to fit the inclusion criteria. Sixteen cohort studies were identified that examined incidence of prostate cancer in rural and urban populations, while 18 studies focused on mortality. Nine of these publications discussed both aspects. Twenty of these studies were published in scientific journals, while five were reports identified through secondary literature search. Prostate cancer incidence was found to be higher in urban men, while mortality patterns seemed to vary to some degree depending on different definitions of rural/urban groups, as well as on variations in demographic factors and study periods. There is evidence, however, that after prostate-specific antigen testing was introduced death rates tended to be higher in rural men with prostate cancer. CONCLUSIONS The review of the literature showed that in spite of inconsistent definitions of rural/urban categories among studies the majority reported higher incidence rates in urban men. This finding suggests that rural men are less likely to be screened and less likely to be subsequently diagnosed with prostate cancer. Although mortality patterns tended to be heterogeneous, there was some evidence that rural residents with prostate cancer experience higher death rates. It would be beneficial if future studies take into consideration factors such as stage at initial diagnosis, ethnicity, and socioeconomic and health status when assessing differences in cancer outcomes. Few studies in this review accounted for one or more of these variables, although there are indications that they contribute to differences in prostate cancer incidence and mortality between rural and urban populations.