Impact of prior cancer history on the prognosis of extranodal NK/T-cell lymphoma.

Our goal was to assess the impact of prior cancer history on the prognosis of extranodal NK/T-cell lymphoma (ENKTCL). We searched the SEER database to retrospectively enroll patients with ENKTCL. The effects of cancer history on overall survival (OS) and disease-specific survival (DSS) were analyzed using the Cox model. A total of 691 patients were included, of whom 54 (7.8%) had prior histories of cancer. The most common solid malignancy was bone/soft tissue sarcoma. Most secondary ENKTCL cases occurred within 5-9 years following the first cancer diagnosis. Radiotherapy and chemotherapy had been administered to 45 and 40 patients, respectively, to treat their previous malignancies. Prior cancer history had little impact on DSS; however, the presence of prior solid cancer history, latency period of 10+ years, and prior administration of radiotherapy or chemotherapy significantly decreased OS. Prior cancer history had no effect on DSS, but survival compromised OS under specific circumstances.