Radiotherapy for salivary gland cancer: REFCOR recommendations by the formal consensus method

Therapeutic strategy for advanced stages salivary carcinomas of the tongue: A multicenter REFCOR study

INTRODUCTION

Salivary carcinomas of the tongue represent a therapeutic challenge as their radical excision is particularly mutilating. We aimed to study the oncologic and functional outcomes of advanced stages salivary carcinomas of the tongue.

MATERIALS AND METHODS

This retrospective multicentric study, based on the French national network on rare head and neck cancers (REFCOR), included all patients with a T3-T4 salivary carcinoma of the tongue, diagnosed between January 2009 and December 2018.

RESULTS

In total, 47 patients were included, of which 44.7 % underwent surgery. Histologies were mostly adenoid cystic carcinomas (61.7 %), followed by other adenocarcinomas (27.7 %) and mucoepidermoid carcinomas (10.6 %). Median follow-up duration was 63.9 months. In multivariable analysis, surgery was significantly associated with better Recurrence-Free Survival (HR = 0.23, 95 %CI [0.09;0.55]) and Local/Regional Recurrence-Free Survival (HR = 0.31, 95 %CI [0.10;0.95]). The rate of distant metastasis at the end of follow-up was 61.9 % in the surgical group and 57.7 % in the non-surgical group. The Distant Metastasis Free Survival was 54.9 % [38.3;68.7], without statistical difference between both groups. There were similar rates of definitive gastrostomies but the rate of normal oral diet at the last follow-up seemed higher in the surgery group (38.1 % vs 15.4 %).

CONCLUSION

Radical surgery in that population mainly aims to improve local/regional control, which may result in better long-term swallowing functions. About half of these tumors may be associated with occult distant metastasis at initial presentation. More studies are warranted to establish the role of postoperative RT and non-surgical treatment with concurrent CRT.

The Current Position of Postoperative Radiotherapy for Salivary Gland Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Because of the rarity, heterogeneous histology, and diverse anatomical sites of salivary gland cancer (SGC), there are a limited number of clinical studies on its management. This study reports the cumulative evidence of postoperative radiotherapy (PORT) for SGC of the head and neck.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, Embase, Cochrane Library, and Web of Science databases between 7th and 10th November 2023.

RESULTS

A total of 2962 patients from 26 studies between 2007 and 2023 were included in this meta-analysis. The median RT dose was 64 Gy (range: 56-66 Gy). The median proportions of high-grade, pathological tumor stage 3 or 4 and pathological lymph node involvement were 42% (0-100%), 40% (0-77%), and 31% (0-75%). The pooled locoregional control rates at 3, 5, and 10 years were 92% (95% confidence interval [CI], 89-94%), 89% (95% CI, 86-93%), and 84% (95% CI, 73-92%), respectively. The pooled disease-free survival (DFS) rates at 3, 5, and 10 years were 77% (95% CI, 70-83%), 67% (95% CI, 60-74%), and 61% (95% CI, 55-67%), respectively. The pooled overall survival rates at 3, 5, and 10 years were 84% (95% CI, 79-88%), 75% (95% CI, 72-79%), and 68% (95% CI, 62-74%), respectively. Severe late toxicity ≥ grade 3 occurred in 7% (95% CI, 3-14%).

CONCLUSION

PORT showed favorable long-term efficacy and safety in SGC, especially for patients with high-grade histology. Considering that DFS continued to decrease, further clinical trials exploring treatment intensification are warranted.