Patients with testicular germ cell tumor (TGCT) are at increased risk of developing a contralateral TGCT (CTGCT). Although some studies suggest that prior treatment with platinum-based chemotherapy affects CTGCT risk, a relationship between CTGCT risk and platinum dose has not previously been assessed. We analyzed the association between the number of platinum-based chemotherapy cycles and CTGCT risk.
The risk of developing a metachronous CTGCT was evaluated in a nationwide cohort of 4,755 patients diagnosed with primary TGCT in the Netherlands between 1989 and 2007. Standardized incidence ratios were computed to compare CTGCT incidence with expected TGCT on the basis of TGCT incidence in the general population. The cumulative incidence of CTGCT was estimated in the presence of death as competing risk. The effect of treatment with platinum-based chemotherapy on CTGCT risk was assessed using multivariable Cox proportional hazards regression models.
CTGCT was diagnosed in 136 patients (standardized incidence ratio, 14.6; 95% CI, 12.2 to 17.2). The cumulative incidence increased up to 20 years after primary diagnosis, reaching 3.4% (95% CI, 2.8% to 4.0%) after 20 years of follow up. The risk of developing a CTGCT decreased with age (hazard ratio [HR], 0.93; 95% CI, 0.90 to 0.96), was lower after nonseminomatous germ cell tumor (HR, 0.58; 95% CI, 0.35 to 0.96) and decreased with every additional cycle of chemotherapy (HRper cycle, 0.74; 95% CI, 0.64 to 0.85).
Approximately one in every 30 survivors of TGCT will develop a CTGCT, with CTGCT incidence increasing up to 20 years after a primary TGCT. Treatment with platinum-based chemotherapy shows a dose-dependent inverse association with CTGCT risk.
Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2020 Oct 29 [Epub]
Joost M Blok, Harmke J Groot, Eline H Huele, Ronald de Wit, Simon Horenblas, Janine Nuver, Gerard Groenewegen, J L H Ruud Bosch, J Alfred Witjes, Jacqueline M Tromp, Peter J M de Brouwer, Hetty A van den Berg, Ben G L Vanneste, Tineke J Smilde, Maureen J B Aarts, Jourik A Gietema, Richard P Meijer, Michael Schaapveld
Department of Oncological Urology, University Medical Center Utrecht, Utrecht, the Netherlands., Department of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Amsterdam, the Netherlands., Department of Medical Oncology, Erasmus University Hospital, Rotterdam, the Netherlands., Department of Urology, The Netherlands Cancer Institute, Amsterdam, the Netherlands., Department of Medical Oncology, University Medical Center Groningen, Groningen, the Netherlands., Department of Medical Oncology, University Medical Center Utrecht, Utrecht, the Netherlands., Department of Urology, Radboud University Medical Center, Nijmegen, the Netherlands., Department of Medical Oncology, Amsterdam University Medical Center, Amsterdam, the Netherlands., Department of Radiation Oncology, Dr Bernard Verbeeten Institute, Tilburg, the Netherlands., Catharina Hospital, Eindhoven, the Netherlands., Department of Radiation Oncology, MAASTRO-clinic, Maastricht, the Netherlands., Department of Medical Oncology, Jeroen Bosch Hospital, 's-Hertogenbosch, the Netherlands., Department of Medical Oncology, Maastricht University Medical Center+, Maastricht, the Netherlands.