Using complete information on total treatment burden, this population-based study aimed to investigate second cancer (SC) risk in testicular cancer survivors (TCS) treated in the cisplatin era. The Cancer Registry of Norway identified 5 625 1-year TCS diagnosed 1980-2009. Standardized incidence ratios (SIRs) were calculated to evaluate the total and site-specific incidence of SC compared with the general population. Cox regression analyses evaluated the effect of treatment on the risk of SC. After a median observation time of 16.6 years, 572 TCS developed 651 non-germ cell SCs. The SC risk was increased after surgery only (SIR 1.28), with site-specific increased risks of thyroid cancer (SIR 4.95) and melanoma (SIR 1.94). After chemotherapy (CT), we observed 2.0-3.7-fold increased risks for cancers of the small intestine, bladder, kidney and lung. There was a 1.6-2.1-fold increased risk of SC after ≥2 cycles of cisplatin-based CT. Radiotherapy (RT) was associated with 1.5-4.4-fold increased risks for cancers of the stomach, small intestine, liver, pancreas, lung, kidney and bladder. After combined CT and RT, increased risks emerged for haematological malignancies (SIR 3.23). TCS treated in the cisplatin era have an increased risk of developing SC, in particular after treatment with cisplatin-based CT and/or RT. This article is protected by copyright. All rights reserved.

International journal of cancer. 2019 Oct 09 [Epub ahead of print]

Ragnhild Hellesnes, Øivind Kvammen, Tor Åge Myklebust, Roy Martin Bremnes, Ása Karlsdottir, Helene F S Negaard, Torgrim Tandstad, Tom Wilsgaard, Sophie Dorothea Fosså, Hege Sagstuen Haugnes

Department of Oncology, University Hospital of North Norway, Tromsø, Norway., Department of Oncology, Ålesund Hospital, Ålesund, Norway., Department of Research and Innovation, Møre and Romsdal Hospital Trust, Ålesund, Norway., Department of Oncology, Haukeland University Hospital, Bergen, Norway., Department of Oncology, Oslo University Hospital, Oslo, Norway., The Cancer Clinic, St. Olav’s University Hospital, Trondheim, Norway., Department of Community Medicine, UiT The Arctic University, Tromsø, Norway., Department of Registration, Cancer Registry of Norway, Oslo, Norway.