An initial melanoma diagnosis may increase the subsequent risk of prostate cancer: Results from the New South Wales Cancer Registry.

Emerging evidence suggests that a diagnosis of cutaneous melanoma (CM) may be associated with prostate cancer (PC) incidence. We examined if the incidence of CM was associated with an increased subsequent risk of PC. We used data from the New South Wales Cancer Registry for all CM and PC cases diagnosed between January 1972 and December 2008. We calculated the age standardized incidence ratio (SIR) and 95% confidence intervals (95% CI) for PC incidence following a CM diagnosis, applying age- and calendar- specific rates to the appropriate person years at risk. We determined rate ratio (RR) and 95% CI of PC incidence according to specified socio-demographic categories and disease related characteristics, using a negative binomial model. There were 143,594 men diagnosed with PC or CM in the study period and of these 101,198 and 42,396 were diagnosed with PC and CM, respectively, as first primary cancers. Risk of PC incidence increased following CM diagnosis (n = 2,114; SIR = 1.25; 95% CI:1.20.8-1.31: p < 0.0001), with the increased risk apparent in men diagnosed with localised CM (n = 1,862;SIR = 1.26; 95% CI:1.20-1.32). CM diagnosis increased the subsequent risk of PC incidence. This raises the potential for future PC risk to be discussed with newly diagnosed males with CM.

The Cancer, Lifestyle and Evaluation of Risk Study (CLEAR): Rationale and design of an unmatched "case-spouse control" study of over 10,000 participants in New South Wales, Australia.

INTRODUCTION: The New South Wales (NSW) Cancer, Lifestyle and Evaluation of Risk Study (CLEAR) is an open epidemiological bioresource, using an all cancer unmatched case-spouse control design. Participant characteristics and selected confirmed associations are compared to published estimates: current smoking and lung cancer; country of birth and melanoma; body mass index (BMI) and bowel cancer; and paternal history of prostate cancer and prostate cancer, to illustrate the validity of this design. MATERIAL AND METHODS: Cases are NSW residents, ≥18 years, with an incident cancer of any type. Controls are cancer-free spouses of cases. Participants complete a consent form, a questionnaire, and provide an optional blood sample. For analyses, odds ratios for males and females are calculated for cancers and exposures of interest, by sex-matching controls to cases. RESULTS: 10,816 participants (8569 cases, 2247 controls, 54% female) recruited to-date, median age: 61.6 y cases, 61.3 y controls. The top five cancer types are female breast (n=1691), prostate (n=1102), bowel (n=888), melanoma (n=608), and lung (n=265). Adjusted odds ratios (OR) were: 20.65 (95% CI: 13.25-32.19) for lung cancer in current versus never smokers; 1.16 (1.05-1.28) for bowel cancer per 5 kg/m(2) increment in BMI; 1.41 (1.01-1.96) for melanoma in Australian-born compared to those born in UK/Ireland; and 2.47 (1.82-3.37) for prostate cancer in men with versus without a paternal history of prostate cancer. DISCUSSION: This study design, where controls are the spouses of cases diagnosed with a variety of cancers and which are analysed unmatched, avoids potential biases due to overmatching, considered problematic in standard case-spouse control studies, and illustrates that risk estimates analysed are consistent with the published literature. CLEAR methodology provides a practical design to advance local knowledge on the causes of various leading and emerging cancers.