Comparative mortality for 621 second cancers in 29356 testicular cancer survivors and 12420 matched first cancers
Background: Testicular cancer survivors, many of whom have undergone radiotherapy, are at substantial risk of second cancers. Treatment for testicular cancer may limit treatment options for second cancers, thereby adversely affecting survival after the second cancer. However, no data on outcomes of testicular cancer survivors with second cancers compared to patients with comparable first cancers exist.
Methods: Among 29356 white testicular cancer patients reported to the Surveillance, Epidemiology, and End Results (SEER) program (1973–2002), 621 developed a second cancer with known stage and were matched to a random sample of 12420 white male first cancer patients in the SEER program by cancer site, stage, diagnosis year, and age at diagnosis. Mortality was ascertained through 2002. Cancer-specific and all-cause mortality following second cancers were compared with those of matched first cancers, and rate ratios (RRs) were estimated using proportional hazards analysis. Survival functions were calculated using product-limit estimates.
Results: During the study period, 284 testicular cancer survivors with second cancers died, 191 from their second cancer; 5443 matched first cancer patients died, 3929 from their first cancer. Rate ratios for cancer-specific and all-cause mortality for second cancers compared with matched first cancers were 1.05 (95% confidence interval [CI] = 0.90 to 1.23) and 1.09 (95% CI = 0.96 to 1.23), respectively. However, among testicular cancer patients who were diagnosed during 1973–1979, an era in which radiation therapy was given at high doses and to the chest area, all-cause mortality following second cancers at sites below the diaphragm (79 deaths) and second lung cancers (29 deaths) was statistically significantly higher than that from matched first cancers (RR = 1.44, 95% CI = 1.13 to 1.83, and RR = 1.65, 95% CI = 1.12 to 2.42, respectively).
Conclusions: Mortality from second cancers following testicular cancer was similar to matched first cancers, except for selected tumors in the radiotherapy field among testicular cancer patients who were diagnosed during 1973–1979, a time when radiotherapy doses for treatment of testicular cancer were high and chest irradiation was an option in standard practice.