Risk factors of secondary cancer in laryngeal, oropharyngeal, or hypopharyngeal cancer after definitive therapy.

BACKGROUND: Our previous research showed that a high rate of secondary carcinogenesis is observed during follow-up after transoral surgery in patients with early-stage laryngeal, oropharyngeal, and hypopharyngeal cancers. We speculate that the contributing factors are alcohol drinking, smoking, and aging; however, we could not provide clear evidence. In this study, we aimed to identify the risk factors for secondary carcinogenesis in patients with these cancers, particularly factors associated with drinking and/or smoking. METHODS: The medical records of all-stage laryngeal, oropharyngeal, and hypopharyngeal cancer patients who had undergone definitive treatment were retrospectively analyzed. Assessments included visual and endoscopic observations of the primary site, enhanced cervical CT or US of the primary site and regional lymph nodes, PET-CT, and enhanced whole-body CT. Clinical characteristics were compared in patients with and without secondary carcinogenesis and in patients with hypopharyngeal cancer and patients with other cancers. RESULTS: Hypopharyngeal cancer was an independent risk factor for secondary cancer. The 5-year incidence rate of secondary cancer was 25.5%, 28.6%, and 41.2% in laryngeal, oropharyngeal, and hypopharyngeal cancers, respectively. Radiotherapy was defined as an independent risk factor in hypopharyngeal cancer patients with secondary cancers. No direct correlation was found between secondary carcinogenesis and alcohol consumption, smoking, or aging. CONCLUSIONS: Patients with hypopharyngeal cancer require close follow-up as they are at high risk of developing secondary cancer, possibly because out-of-field radiation exposure may induce systemic secondary carcinogenesis in hypopharyngeal cancer patients with genetic abnormality induced by alcohol consumption.

A risk factor for newly diagnosed secondary cancer in patients with early-stage laryngeal, oropharyngeal, or hypopharyngeal cancer: sub-analysis of a prospective observation study.

BACKGROUND: We previously identified hypopharyngeal cancer as an independent risk factor for the incidence of newly diagnosed secondary cancers after the treatment of early-stage laryngeal, oropharyngeal, and hypopharyngeal cancers. We subsequently used a different patient cohort to validate the usefulness of this factor during the follow-up period in these patients. METHODS: Patients who underwent transoral surgery (TOS) as a definitive treatment between April 1, 2016, and September 30, 2020, were included. The incidence of secondary cancer was evaluated in hypopharyngeal and other cancers. Overall survival (OS), recurrence-free survival (RFS), and disease-free survival (DFS) outcomes were evaluated. Statistical analyses based on the risk factors were also performed. RESULTS: Incidence of new secondary cancer was 30% in hypopharyngeal cancer patients as compared to 11% in other cancer patients, and the risk was 3.60-fold (95% confidence interval 1.07-12.10) higher after definitive treatment for initial head and neck cancers. The 3-year OS, RFS, and DFS rates were 98%, 86%, and 67%, respectively. CONCLUSIONS: Among patients with early-stage laryngeal, oropharyngeal, and hypopharyngeal squamous cell carcinoma, who were initially treated with TOS, hypopharyngeal cancer patients had a higher risk of newly diagnosed secondary cancers as observed during the follow-up period.

The incidence of newly diagnosed secondary cancer; sub-analysis the prospective study of the second-look procedure for transoral surgery in patients with T1 and T2 head and neck cancer.

BACKGROUND: Our prospective study of patients with early T-stage head and neck cancer indicated a high incidence of newly diagnosed secondary malignancies during the follow-up period. We aimed to determine the incidence rate and risk factors of secondary malignancies in early-stage head and neck cancer patients. METHODS: We sub-analyzed the patient data of a previous study focusing on secondary cancer incidence. The endpoints were statistical analyses of risk factors and survival and incidence rates. RESULTS: The incidence rate of secondary cancer was 37%, the crude incidence of second primary cancers was 10.6 per 100 person-years, and the 5 year secondary cancer-free survival rate was 63%. The hypopharynx as the primary site was an independent significant predictive factor (odds ratio 3.96, 95% confidence interval 1.07-14.6, p = 0.039). CONCLUSIONS: Early stages of laryngeal, oropharyngeal, and hypopharyngeal cancer had a risk of secondary cancer, especially hypopharyngeal cancer. Attention to the secondary cancer has to be paid during the follow-up period after controlling the early-stage disease. These findings highlight the need for awareness of the incidence of secondary cancer in cases of early-stage primary head and neck cancer.