Analysis of clinical efficacy of postoperative low-dose radiotherapy in patients with advanced hypopharyngeal cancer without high-risk factors / 中华放射肿瘤学杂志

ABSTRACT

Objective:To evaluate the efficacy of low-dose radiotherapy in patients with advanced hypopharyngeal cancer without high-risk factors.Methods:Clinical data of 235 patients diagnosed with advanced hypopharyngeal cancer treated in Department of Head and Neck Surgery of Shandong Provincial ENT Hospital from December 2013 to August 2018 were retrospectively analyzed. All patients were divided into two groups low-dose radiotherapy group (50 Gy, n=158) and high-dose radiotherapy group (>60 Gy, n=77). Clinical baseline characteristics, treatment, follow-up and survival of patients were collected. Survival curve was delineated using the Kaplan-Meier method, and the differences in survival between two groups were calculated using the log-rank test. Clinical baseline characteristics between two groups were compared by χ2 test. Univariate and multivariate analyses of prognostic factors were conducted by logistic regression model. Results:The median follow-up time was 45 months (5-94 months). The 3-year overall survival (OS) rate of the whole group was 68.5%, and 70.3% and 64.9% in the low-dose and high-dose groups, respectively ( P=0.356). The 3-year progression-free survival (PFS) rate of the whole group was 64.3%, and 65.8% and 61.0% in the low-dose and high-dose groups, respectively ( P=0.361). Univariate analysis showed that T stage, N stage, lesion location and degree of pathological differentiation significantly affected clinical prognosis (all P<0.05), whereas there was no significant relationship between age, sex, radiotherapy dose, interval between surgery and radiotherapy and survival. Multivariate analysis showed that T stage, N stage and the degree of pathological differentiation were the independent prognostic factors (all P<0.05) of the 3-year OS and PFS. Sex, radiotherapy dose and interval between surgery and radiotherapy were not correlated with OS and PFS. Conclusion:This study showed that for hypopharyngeal cancer patients without positive surgical margins and extracapsular extension, postoperative radiotherapy at a dose of 50 Gy given to tumor bed and selective lymph node drainage area does not compromise local disease control and OS.