Purpose: Previous therapy, genetic susceptibility, and the type of first malignant neoplasm (FMN) are known to be associated with the risk of second malignant neoplasm (SMN) among patients treated for a childhood cancer. The aim of this study was to investigate the independent role of the FMN in the onset of any SMN.
Patients and methods: A case-control study nested in a European cohort of 4,581 patients treated for a solid cancer during childhood was conducted. One hundred forty-six patients with an SMN and 417 controls were matched for sex, age at FMN, chemotherapy, radiotherapy, the local radiation dose received at the site of SMN for patient cases and at the same site for the matched controls, and follow-up.
Results: A significantly increased risk of developing any SMN was observed after Hodgkin's lymphoma, retinoblastoma, malignant bone tumor, soft tissue sarcoma (STS), and germ cell tumor as FMN, after adjustment for chemotherapy and family cancer syndrome. No significant risk of developing a carcinoma was observed among patients who had developed Hodgkin's lymphoma as FMN. A significantly increased risk of developing a sarcoma was observed among patients who had developed a retinoblastoma (adjusted odds ratio [ORa] = 7.5; 95% CI, 1.2 to 46), a malignant bone tumor (ORa = 13.3; 95% CI, 1.5 to 117), an STS (ORa = 4.8; 95% CI, 1.3 to 18), or a carcinoma (ORa = 9.4; 95% CI, 1.1 to 82) as FMN.
Conclusion: Survivors of Hodgkin's lymphoma, retinoblastoma, malignant bone tumor, STS, and germ cell tumor should receive close surveillance because they are at increased risk of developing any SMN.