A cause-specific Cox model for second primary tumors in patients with head and neck cancer: A RONCDOC study.

Background: The aim of this study was to identify risk factors for the development of second primary tumors (SPTs) in the head and neck region, lungs, and esophagus in patients with head and neck cancer.

Methods: We collected data from 1581 patients. A cause-specific Cox model for the development of an SPT was fitted, accounting for the competing risks residual/recurrent tumor and mortality.

Survival of patients with head and neck cancer with metachronous multiple primary tumors is surprisingly favorable.

Background: The objectives of this study are to determine the incidence and survival rate of patients with head and neck squamous cell carcinoma (HNSCC) with multiple primary tumors (MPT) in the HN-region, lung, or esophagus.

Methods: Patient and tumor specific data of 1372 patients with HNSCC were collected from both the national cancer registry and patient records to ensure high-quality double-checked data.

Results: The total incidence of MPTs in the HN-region, lung, and esophagus in patients with HNSCC was 11% (149/1372).