Testicular cancer (TC) is the most common form of cancer in men aged 15-35 years. Familial risk for TC is among highest of all cancers.
A prospective observational cohort of 9111 relatives in 2,188 families of early-onset TC patients, called probands, diagnosed at age ≤40 years in Finland between 1970 and 2012. Standardized incidence ratios (SIR) were used as measures of familial aggregation for early-onset (≤40 years) TC. Follow-up ended at diagnosis of TC, death or 31 December 2014 whichever earliest.
Among first-degree relatives of early-onset TCs, in all 12 early-onset TC cases (0.24%) were diagnosed over the follow-up; the SIR for any first-degree relative was 4.59 (95% confidence interval (CI): 2.37-8.01) and for brothers the SIR was 6.51 (95% CI 3.12-11.96).
Familial aggregation of TC shows substantial risk for early-onset TC among first-degree relatives of early-onset TC patients in Finland. This is important to acknowledge to avoid diagnostic delay especially of TC.
Cancer epidemiology. 2020 Oct 10 [Epub ahead of print]
Heikki Seikkula, Elli Hirvonen, Antti Kaipia, Peter J Boström, Nea Malila, Janne Pitkäniemi
Department of Surgery, Central Hospital of Central Finland, Keskussairaalantie 19, 40620 Jyväskylä, Finland. Electronic address: ., Finnish Cancer Registry, Unioninkatu 22, 00130 Helsinki, Finland. Electronic address: ., Department of Urology, Tampere University Hospital, PL 2000, 33521 Tampere, Finland. Electronic address: ., Department of Urology, Turku University Hospital, Turku, Finland; Department of Urology, University of Turku, Kiinamyllynkatu 4-8, 20100 Turku, Finland. Electronic address: ., Finnish Cancer Registry, Unioninkatu 22, 00130 Helsinki, Finland. Electronic address: ., Finnish Cancer Registry, Unioninkatu 22, 00130 Helsinki, Finland; School of Health Sciences, University of Tampere, Finland; Department of Public Health, University of Helsinki, Helsinki, Finland. Electronic address: .