Department of Otolaryngology Head and Neck Surgery, Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
Department of Otolaryngology-Head and Neck Surgery, Sunnybrook Health Sciences Center, Toronto, Ontario, Canada.
Cancer. 2023 Oct 15;129(20):3263-3274. doi: 10.1002/cncr.34932. Epub 2023 Jul 4.
The objective of this study was to examine the utility of postoperative radiation for low and intermediate grade cancers of the parotid and submandibular glands.
The authors conducted a retrospective, Canadian-led, international, multi-institutional analysis of a patient cohort with low or intermediate grade salivary gland cancer of the parotid or submandibular gland who were treated from 2010 until 2020 with or without postoperative radiation therapy. A multivariable, marginal Cox proportional hazards regression analysis was performed to quantify the association between locoregional recurrence (LRR) and receipt of postoperative radiation therapy while accounting for patient-level factors and the clustering of patients by institution.
In total, 621 patients across 14 tertiary care centers were included in the study; of these, 309 patients (49.8%) received postoperative radiation therapy. Tumor histologies included 182 (29.3%) acinic cell carcinomas, 312 (50.2%) mucoepidermoid carcinomas, and 137 (20.5%) other low or intermediate grade primary salivary gland carcinomas. Kaplan-Meier LRR-free survival at 10 years was 89.0% (95% confidence interval [CI], 84.9%-93.3%). In multivariable Cox regression analysis, postoperative radiation therapy was independently associated with a lower hazard of LRR (adjusted hazard ratio, 0.53; 95% CI, 0.29-0.97). The multivariable model estimated that the marginal probability of LRR within 10 years was 15.4% without radiation and 8.8% with radiation. The number needed to treat was 16 patients (95% CI, 14-18 patients). Radiation therapy had no benefit in patients who had early stage, low-grade salivary gland cancer without evidence of nodal disease and negative margins.
Postoperative radiation therapy may reduce LLR in some low and intermediate grade salivary gland cancers with adverse features, but it had no benefit in patients who had early stage, low-grade salivary gland cancer with negative margins.
本研究旨在探讨腮腺和颌下腺低度和中度恶性肿瘤术后放疗的作用。
作者对 2010 年至 2020 年间接受或未接受术后放疗的腮腺或颌下腺低度或中度涎腺癌患者的队列进行了回顾性、加拿大牵头的国际多机构分析。采用多变量边际 Cox 比例风险回归分析，在考虑患者水平因素和机构间患者聚类的情况下，量化局部区域复发（LRR）与术后放疗之间的关系。
共纳入 14 个三级医疗中心的 621 例患者，其中 309 例（49.8%）接受了术后放疗。肿瘤组织学包括 182 例（29.3%）涎腺闰管细胞癌、312 例（50.2%）黏液表皮样癌和 137 例（20.5%）其他低度或中度原发性涎腺癌。10 年 LRR 无复发生存率为 89.0%（95%置信区间[CI]，84.9%-93.3%）。多变量 Cox 回归分析显示，术后放疗与 LRR 风险降低独立相关（调整后的危险比，0.53；95%CI，0.29-0.97）。多变量模型估计，无放疗的 10 年内 LRR 概率为 15.4%，放疗的概率为 8.8%。需要治疗的患者人数为 16 例（95%CI，14-18 例）。对于无淋巴结疾病和阴性切缘的早期低度涎腺癌患者，放疗无获益。
对于具有不良特征的某些低度和中度涎腺癌，术后放疗可能会降低 LRR，但对于具有阴性切缘的早期低度涎腺癌患者，放疗无获益。
