Background: The magnitude of risk conferred by the interaction between tobacco and alcohol use on the risk of head and neck cancers is not clear because studies have used various methods to quantify the excess head and neck cancer burden. Methods: We analyzed individual-level pooled data from 17 European and American case-control studies (11,221 cases and 16,168 controls) participating in the International Head and Neck Cancer Epidemiology consortium. We estimated the multiplicative interaction parameter (y) and population attributable risks (PAR). Results: A greater than multiplicative joint effect between ever tobacco and alcohol use was observed for head and neck cancer risk (y = 2.15; 95% confidence interval, 1.53-3.04). The PAR for tobacco or alcohol was 72% (95% confidence interval, 61-79%) for head and

Background Patients with HPV-positive oropharyngeal squamous cell carcinoma (OPC) have high survival rates when treated with radiotherapy plus cisplatin. Whether replacement of cisplatin with cetuximab, an antibody against the epidermal growth factor receptor, can preserve high survival rates and reduce treatment toxicity is unknown. Methods In a randomized, non-inferiority, multicenter trial, patients with locoregionally-advanced p16-positive OPC were stratified by American Joint Committee on Cancer T (T1-T2 vs. T3-T4) and N (N0-N2a vs. N2b-N3), Zubrod Performance Status (0 vs. 1), and tobacco smoking history (≤ vs. >10 pack-years) and randomized 1:1 to radiotherapy plus cetuximab 400 milligrams per square meter of body surface area (mg/m2), followed by 250 mgs/m2 for seven weekly doses or cisplatin 100 mgs/m2 for two doses, 21 days apart. The sample size was 800 eligible patients. The primary endpoint was overall survival (OS) with non-inferiority margin 1.45 (hazard ratio). Findings From June 2011 through July 2014, 849 patients (805 eligible; 399 cetuximab; 406 cisplatin) were randomized at 182 centers in the United States and Canada. With median follow-up 4·5 years, radiotherapy plus cetuximab did not meet the non-inferiority criterion for OS. Estimated 5-year OS was 77·9% (95% confidence interval [CI] 73·4-82·5) in cetuximab group versus 84·6% (95%CI=80·6-88·6) in cisplatin group (hazard ratio [HR], 1·45, 1-sided 95% upper CI, 1·94; non-inferiority p=0·5056; 1-sided log-rank p=0.0163). PFS was significantly lower in cetuximab group than in cisplatin group (HR 1·72, 95%CI=1·29-2·29; 5-year rates, 67·3% vs. 78·4%), and LRF was significantly higher (HR 2·05, 95%CI=1·35-3·10; 5-year rates, 17·3% vs. 9·9%). The rate of moderate-to-severe toxicity that was acute (77·4% vs. 81·7%, p=0·1586) and late (16·5 vs. 20·4%, p=0·1904) was similar in the cetuximab and cisplatin groups, respectively. Interpretation For patients with HPV-positive OPC, radiotherapy plus cetuximab demonstrated inferior OS and PFS compared to radiotherapy plus cisplatin; toxicity rates were similar (NCT01302834). Funding National Cancer Institute USA, Eli Lilly and The Oral Cancer Foundation

Our results represent the most precise estimates available of the independent association of each of the two main risk factors of head and neck cancer, and they exemplify the strengths of large-scale consortia in cancer epidemiology.