Long-term platinum retention after platinum-based chemotherapy in testicular cancer survivors: a 20-year follow-up study

Evaluation of long-term platinum (Pt) retention in testicular cancer survivors (TCSs) treated with platinum-based chemotherapy to elucidate possible mechanisms of developing late effects. 458 TCSs treated 1980-1994 participated in a national follow-up study (2007-2008). Four treatment groups were evaluated for long-term serum Pt levels: surgery (n=135), cumulative cisplatin≤850 mg (n=252), cisplatin>850 mg (n=57) and carboplatin (n=14). The median observation time was 20 (range=13-28) years. The median Pt level according to treatment group was: surgery, 50 ng/l; cisplatin≤850 mg, 85 ng/l; cisplatin>850 mg, 106 ng/l; carboplatin, 40 ng/l. The risk for having a Pt level in the highest quartile was positively associated with cisplatin dose (Ordinal regression (OR)=1.29, per 100 mg increase in cisplatin dose, 95% Confidence interval (CI)=1.20-1.38), and negatively associated with follow-up time (OR=0.50 per 5-year increase in follow-up time, 95% CI=0.37-0.68). Pt levels are significantly elevated in serum at a median of 20 years after cisplatin-based chemotherapy for testicular cancer.