Risk of second primary cancer among patients with head and neck cancers
Reviewed by Shabbir Akhtar

Patients with head and neck squamous cell carcinoma (HNSCC) have an elevated risk of developing a second primary malignant neoplasm (SPMN). These are of increasing concern because the number of survivors of HNSCC has been growing owing to early detection and advances in cancer treatments. The incidence of SPMN in HNSCC patients is about 3% to 7% per year. Tobacco and excessive alcohol use, as well as human papillomavirus (HPV) infection, are the main causal factors associated with HNSCC. In this study, authors quantified the risk of SPMN among patients with a first HPV-associated HNSCC versus non-HPV-associated HNSCC, and described the anatomical sites of these SPMNs. Data from the Surveillance, Epidemiology, and End Results (SEER) registry revealed 109,512 patients with a first HNSCC were identified; 13,517 (12.3%) developed SPMN. Patients diagnosed with HNSCC experience excess risk of SPMN, which was higher among those with non-HPV-associated HNSCC than with potentially HPV-associated HNSCC. Lung cancer accounted for the largest proportion of excess second cancer burden followed by tongue, gum, and oesophagus. Tobacco and alcohol consumption are estimated to be responsible for 72% of head and neck cancers in the general population. The association of the first HNSCC with SPMNs, particularly with head and neck cancers, has been described in the context of a field cancerisation effect, in which carcinogenic effects from tobacco and alcohol on the aerodigestive tract may simultaneously act on other parts. This is believed to elevate epithelial cancer risk through the head and neck, lung, and oesophagus.

Incidence and risk of second primary malignant neoplasm after a first head and neck squamous cell carcinoma.
Adjei Boakye E, Buchanan P, Hinyard L, et al.
JAMA OTOLARYNGOL HEAD NECK SURGERY
2018;144(8):727-37.