Author: Gina Mauro

Depth of invasion, lymphovascular space invasion, and positive glossectomy specimen margins were all found to be linked with inferior locoregional control (LRC) in patients with pT1-2N0 oral tongue squamous cell carcinoma who were treated with partial glossectomy and elective neck dissection alone. The retrospective findings, which were presented during the 2024 ASTRO Multidisciplinary Head and Neck Cancers Symposium, were seen even with final negative tumor bed margins.

Results showed that, at a median follow-up of 45.6 months, the 3-year LRC and overall survival (OS) rates were 88.0% and 92.5%, respectively, in the all-comer patient population. In patients with pT1 disease, these rates were 92.0% and 95.2%, respectively; they were 85.0% and 90.5% in those with pT2 disease.

However, upon the multivariate analysis, those with positive glossectomy margins had worse LRC (HR, 6.66; 95% CI, 1.60-27.78; P = .009). Lymphovascular space invasion (HR, 6.90; 95% CI, 1.42-33.65; P = .02) and depth of invasion (HR, 1.31; 95% CI, 1.06-1.63; P = .01) were also associated with inferior LRC.

“Patients with these risk factors may be considered for adjuvant radiotherapy to optimize disease control,” lead study author Michael Modzelewski, MD, of Kaiser Permanente Bernard J. Tyson School of Medicine, in Pasadena, California, and coinvestigators wrote in a poster presented at the meeting.

Patients who have early-stage tongue squamous cell carcinoma do not typically receive adjuvant radiation because they are often at low risk for recurrence. Following surgery, the status of main glossectomy specimen margin has been shown to correlate with local recurrence rather than the status of additional tumor bed margins, the authors noted.

Investigators sought to determine the pathologic factors linked with locoregional recurrence in patients with early-stage tongue squamous cell carcinoma who had surgery alone, and whether a positive glossectomy specimen margin impacted disease control as it relates to final negative tumor bed margins.

The review included 110 patients with American Joint Committee on Cancer (AJCC) 8th edition pT1-2N0 oral tongue squamous cancer who underwent partial glossectomy and elective dissection between 2015 and 2021 without receiving adjuvant radiation. Investigators assessed pathology reports for factors including tumor size, depth of invasion, glossectomy specimen margin and final tumor bed margin status, and perineural or lymphovascular space invasion. Those who had positive final margins or received prior head and neck radiation were excluded from the analysis.

Investigators utilized the Kaplan-Meier method to estimate LRC and OS, while a Cox proportional hazards model was used for the multivariate analysis to determine the prognostic factors for LRC.

Regarding baseline characteristics, the median age was 52 years, and more than half of patients were male (54.5%) and had pT2 stage disease (58.2%). The median number of lymph nodes dissected was 33, and the median tumor size was 16 mm, with a median depth of invasion of 5 mm. Most patients did not have perineural invasion (84.7%), and 3.6% had lymphovascular space vision. A total 8.2% of patients had positive glossectomy specimen margins.

Additional findings showed that in patients with and without positive glossectomy specimen margins, the 3-year LRC rate was 66.7% and 89.5%, respectively. Similarly, the rates were 0.0% and 89.4% in those with and without lymphovascular space invasion, respectively. Of 8 patients who experienced regional failure, 5 had recurrence in the ipsilateral neck alone (62.5%) compared with 2 in the bilateral neck (25.0%) and 1 with isolated contralateral neck recurrence (12.5%).

Modzelewski M, Abrahams J, Beighley A, et al. Prognostic factors for locoregional control in early-stage oral tongue squamous cell carcinoma treated with partial glossectomy and elective neck dissection. Presented at: 2024 ASTRO Multidisciplinary Head and Neck Cancers Symposium; February 29-March 2, 2024; Phoenix, AZ. Abstract 123.