Interval to Recurrence Affects Survival in Recurrent Head and Neck Squamous Cell Carcinoma

Background/Aim: Approximately half of head and neck squamous cell carcinoma (HNSCC) cases recur, with most recurrences occurring within the first two years after treatment. Although it has been suggested that the interval to recurrence after radical treatment is associated with prognosis in patients with HNSCC, further investigation is needed. Patients and Methods: Patients diagnosed with HNSCC at Kyushu University Hospital were retrospectively analyzed (n=500). Early recurrence (ER) was defined as disease recurrence within six months of radical treatment, whereas late recurrence (LR) was defined as recurrence after more than six months. Continuous variables were assessed using the Mann–Whitney U-test and categorical variables were assessed using Fisher’s exact test. Results: A total of 234 patients experienced recurrence, with 110 and 124 patients experiencing ER (recurrence within two to six months) and LR (recurrence after six months), respectively. Multivariate analyses identified two independent risk factors for poor prognosis: ER [hazard ratio (HR)=3.200, 95% confidence interval (CI)=1.570-6.521, p=0.001] and absence of radiotherapy (HR=0.374, 95%CI=0.191-0.733, p=0.004). In patients with recurrent HNSCC, a short interval to recurrence is a risk factor for poor prognosis and survival. This study demonstrated the prognostic value of ER in these patients. Conclusion: The selection of treatment for patients with recurrent head and neck squamous cell carcinoma should consider the timing of recurrence, the initial treatment regimen, and the strategy for changing salvage therapy depending on the recurrence status.