Importance: A major goal of primary transoral robotic surgery (TORS) for oropharyngeal cancer (OPC) is to improve swallowing by personalized treatment based on pathologic rather than clinical staging. Yet, the impact of TORS alone on swallowing outcomes are poorly characterized, particularly in relation to nonsurgical options.
Objective: The aims of this paper were: 1) estimate rates of acute post-TORS dysphagia and recovery by 3-6 months; and 2) compare severity of acute and post-treatment swallowing outcomes after TORS to non-surgical treatment.
Design: Secondary analysis of prospective registry data.
Setting: Single academic institution experience.
Participants: 298 patients with HPV/P16+ T1-2 NX-2b and T3 N0 OPC (AJCC VII) were sampled from a prospective OPC registry.
Main Outcome Measures: Modified barium swallow (MBS) studies graded per DIGEST and multi-symptom MD Anderson Symptom Inventory-Head and Neck Module (MDASI-HN) questionnaires were collected pre, during, and post treatment at standard intervals. Among 82 patients who had primary TORS, repeated measures of DIGEST pre and post-TORS, and 3-6 months post-treatment were compared by omnibus then pairwise using nonparameteric tests. 3-6 month dysphagia grade (DIGEST) was compared between primary treatment modalities with multivariate adjustment. MDASI-HN questionnaires were collected weekly during RT regardless of surgery. To assess difference by treatment status at the time of RT, MDASI-HN swallow items (scale: 0-10) were compared at onset (week 1) and end of RT using multiple linear regression between groups: treatment naïve, post-induction, and post-TORS.
Results: Among 82 patients in the surgical group, MBS DIGEST grade significantly worsened post-TORS (p<0.001): 12% had moderate (grade 2), and 7% severe (grade 3) acute post-TORS dysphagia (median 3.4 weeks postoperatively) prior to adjuvant treatment. At 3-6 months post TORS, dysphagia grades (DIGEST) improved (p = 0.16 relative to post-TORS MBS) but remained worse than baseline (p=0.006) with 7% of patients in the surgical group having moderate-severe dysphagia (DIGEST grade ≥2) compared with 16% in the non-surgical group (p=0.086). DIGEST grades did not significantly differ 3-6 months after therapy between surgical and non-surgical groups in multivariate models. At RT start, MDASI-HN swallow symptoms were significantly worse among the post-TORS group (1.4±1.3) relative to post-induction (0.1±0.4, p=0.01) and treatment naïve (0.5±0.8, p<0.001). This trend inverted at the end of RT and at 3-6 months when swallowing symptoms were better in the post-TORS group relative to non-surgical groups, although this was not statistically significant after controlling for concurrent chemotherapy.
Conclusion: While most have a functional swallow after primary TORS, almost 20% develop moderate-severe pharyngeal dysphagia in the acute postsurgical period that improves but does not recover to baseline by 3-6 months. Post-treatment dysphagia grades per MBS DIGEST were better in patients treated with primary TORS compared to primary radiotherapy, but this was not statistically significant. Symptom trajectories suggest that the trade-off for favorable late swallowing outcomes after primary TORS may be higher swallowing symptom burden during the early weeks of postoperative RT. These data have important implications on supportive care and preoperative counseling.