Subgroup Analysis of Overall Survival among Smoking and Non-Smoking Elderly Patients with HNSCC

The aim of this study was to deliver more insight into factors influencing survival of elderly patients with HNSCC. Although elderly patients have become increasingly important from a demographic point of view, studies dedicated to them are rare. We were able to confirm in a large study cohort that non-smokers with HNSCC have a significantly higher chance of surviving HNSCC than smokers. We showed that elderly non-smokers are also affected by HNSCC; however, both their overall survival and their disease-free survival are increased compared to smokers. Important predictors of survival, both in smokers and in non-smokers, were, among others, alcohol abuse, health status (Karnofsky performance status), biological age (Charlson comorbidity index), site of primary tumour, UICC stage and treatment received. Smoking is a leading cause of head and neck squamous cell carcinoma (HNSCC). However, non-smokers are also affected by HNSCC, and the prognostic factors applicable to older non-smokers with HNSCC are largely unknown. The aim of this study was to determine predictors of overall survival (OS) in patients both with and without a smoking history aged 70 and over at initial diagnosis. Retrospective data of patients aged >= 70 (initial diagnoses 2004-2018) were examined. Evaluated predictors included tumour stage, biological age, health and therapy. A total of 688 patients (520 smokers, 168 non-smokers) were included with a median age of 74. The 5-year OS was 39.6%. Non-smokers had significantly improved OS compared to smokers (52.0% versus 36.0%, p < 0.001). Disease-free survival (DFS) differed significantly between both groups (hazard ratio = 1.3; 95%CI 1.04-1.626). TNM stage and the recommended therapies (curative versus palliative) were comparable. The proportion of p16-positive oropharyngeal carcinomas was significantly higher in non-smokers (76.7% versus 43.8%, p < 0.001). Smokers were significantly more likely to be men (p < 0.001), drinkers (p < 0.001), and have poorer health status (Karnofsky performance status, KPS, p = 0.023). They were also more likely to have additional tumours (p = 0.012) and lower treatment adherence (p = 0.038). Important predictors of OS identified in both groups, were, among others, alcohol abuse, KPS, Charlson comorbidity index, site of primary tumour, UICC stage and treatment received. Elderly non-smokers are also affected by HNSCC, however, both OS and DFS are increased compared to smokers.

Automated summary

The aim of this study was to investigate the factors influencing the survival of elderly patients with HNSCC. It was found that non-smokers had a significantly higher chance of surviving HNSCC than smokers. Elderly non-smokers are also affected by HNSCC, but their overall survival and disease-free survival rates are increased compared to smokers.