Identification of risk factors and prediction models for secondary malignant neoplasms (SMNs)-free survival and SMNs-specific survival in testicular cancer survivors

Objective This research endeavored to determine the key demographic and pathological factors tied to secondary malignant neoplasms (SMNs) in survivors of testicular cancer and to develop a predictive model. Method A total of 53,309 testicular cancer patients from the SEER national database (1975–2016) were included in our analysis. The primary outcome measured was SMNs-free survival, defined as the duration from testicular cancer diagnosis to the detection of a non-testicular malignancy. The secondary outcome was SMN-specific survival, defined as the period from testicular cancer diagnosis until the patient's death due to SMNs. Findings Of the patients in the SEER cohort, 2978 (5.6%) developed non-testicular cancer SMNs. Higher age, receipt of chemotherapy, and radiation treatment were all significantly associated with the development of SMNs in survivors of testicular cancer (all p < 0.001). Kaplan–Meier analysis revealed a worse SMNs-free survival and poor SMN-specific survival in patients who underwent radiation therapy (both p < 0.001). Multivariable Cox regression analysis found non-Hispanic Black ethnicity, higher age, chemotherapy, and radiation therapy to be significantly associated with worse SMNs-free survival ( p = 0.002, p < 0.001, p < 0.001, and p < 0.001, respectively), while lymphoma histology was associated with better SMNs-free survival ( p < 0.001). The most common SMN types in patients receiving radiation therapy were prostate, lung, and bladder cancers. Predictive nomograms for SMNs-free survival and SMNs-specific survival were developed, with a C-index of 0.776 and 0.824, respectively. Conclusion The age of diagnosis, non-Hispanic Black ethnicity, lymphoma histology, and treatment history with chemotherapy and radiation therapy were identified as prognostic factors for SMNs-free survival.