Questions Remain About the Role of Transoral Surgery for Oropharyngeal Cancer

August 19, 2019

Researchers compared the swallowing-related quality-of-life scores of patients with oropharyngeal squamous cell carcinoma who received radiotherapy and patients who received transoral robotic surgery with neck dissection.

Patients with oropharyngeal squamous cell carcinoma (OPSCC) who received radiotherapy instead of transoral robotic surgery (TORS) with neck dissection had superior swallowing-related quality-of-life scores 1 year after treatment, according to the phase II ORATOR study published in Lancet Oncology.

“These findings suggest that the TORS should not be favored over radiotherapy, and that the widespread adoption of TORS in some jurisdictions was premature,” wrote researchers led by Anthony C. Nichols, MD, of Western University, London, Ontario.

However, the researchers noted that this improvement did not represent a clinically meaningful change.

ORATOR was a multicenter, international, phase II randomized clinical trial that include 68 patients aged 18 years or older with T1-T2, N0-N2 OPSCC. Patients were randomly assigned to radiotherapy (with chemotherapy if N1 or N2), or TORS plus neck dissection (with or without adjuvant chemoradiotherapy). The primary endpoint was swallowing detected quality of life at 1 year as measured by the MD Anderson Dysphagia Inventory (MDADI).

With a median follow-up of longer than 2 years, the mean MDADI total scores at 1 year were 86.9 in the radiotherapy group compared with 80.1 in the TORS plus neck dissection group (P=.042). This difference did not meet the prespecified 10-point threshold for clinical meaningful difference.

All of the patients in the radiotherapy group received total oral diet with no restrictions compared with 84% of patients in the TORS with neck dissection group (P=.055).

The researchers noted difference in MDADI scores by treatment intensity of radiotherapy. Among patients assigned radiotherapy alone, the MDADI total scores at 1 year were 89.5; for chemo-radiotherapy, 88.0; and for chemoradiotherapy with subsequent salvage surgery, 68.0. Difference by treatment intensity were not noted for the TORS group.

Patients in the radiotherapy group experienced more cases of neutropenia (18% vs none), hearing loss (38% vs 15%), and tinnitus (35% vs 6%) compared with the TORS with neck dissection group. Patients assigned TORS with neck dissection experienced more cases of trismus (26% vs 3%).

The most common adverse events in the radiotherapy group were dysphagia, hearing loss, mucositis. Among patients in the TORS with neck dissection group, the most common adverse event was dysphagia, and there was one death caused by bleeding after TORS.

In an accompanying editorial, Vincent Grégoire, of Centre Leon Berard, and Piero Nicolai, of University of Brescia, congratulated the researchers on conducting this trial, which they wrote “shed light on a controversial issue”.

However, the results raise several issues, they noted. Among the ones noted, the trial included patients with disease stage up to N2, which meant some patients received single-modality therapy and other bimodality or trimodality treatments. Additionally, a 1-cm surgical margin was required around the primary tumor in this trial when in OPSCC, smaller margins are often considered negative. This leaves open the question of “whether a more minimally invasive but still adequate surgery would have resulted in less impaired swallowing function”.

The MDADI evaluation used in the trial was reported up to 3.5 years, “which might be a little short to fully establish the late toxicity of radiotherapy.” Due to the study’s modest sample size, confirmatory trials will be needed, they wrote.