Are all high-volume surgeons equally good outcome? A survival analysis of patients with oral cavity squamous cell carcinoma in relation to surgical margin status based on propensity score matching analysis

Abstract

Abstract Background In this retrospective study, we assessed whether Taiwanese high-volume surgeons performing oral cavity squamous cell carcinoma (OCSCC) removal may differ in terms of margin status, and examined how this variable – as a quality standard – could have an impact on clinical outcomes after adjustment for clinicopathological risk factors and treatment modalities. Methods On analyzing a nationwide dataset, margins < 5 mm (including positive margins) were identified in 49.5% (6927/13984) of patients with OCSCC. We subsequently identified the surgeon with the highest absolute volume (number of operated patients = 560), who was located below the mean value (49.5%). Among surgeons above the mean, we identified the two surgeons with the highest volumes (termed as Surgeon 2 and Surgeon 3). The number of patients and survival operated by Surgeon 2 and Surgeon 3 were similar (number 229 and 221, respectively, totaling 450 patients; 5-year overall survivals [OSs] 64% and 65%, respectively) and thus they were grouped together for the purpose of analysis (Surgeons 2–3). Results The patient proportion of margins ≥ 5 mm was markedly higher in Surgeon 1 than Surgeons 2 − 3 (75.4% and 22.5%, respectively). Compared to Surgeons 2 − 3, the tumor severity was higher in Surgeon 1 (mainly a higher frequency of pT4a status, p-Stage IV, and poorly differentiated tumor). The clinical outcomes of patients treated by Surgeon 1 were more favorable than those treated by Surgeons 2 − 3 and these survival differences were even more pronounced after adjusting for baseline differences using propensity score matching (before propensity score: disease-specific survival [DSS], 83%/70%, p < 0.0001; OS, 77%/64%, p < 0.0001; after propensity score: DSS, 87%/68%, p < 0.0001; OS, 81%/63%, p < 0.0001). When patients were stratified according to the operating surgeon and margin status, we found that Surgeon 1 consistently outperformed Surgeons 2 − 3 in terms of clinical outcomes, regardless of surgical margin status (i.e., ≥ 5 mm, < 5 mm, and positive margins). Conclusions We conclude that the achievement of clear margins (≥ 5 mm) is a surgeon-dependent variable which is not necessarily related to hospital and/or surgeon volumes, therefore surgeons should strive to achieve adequate margins to optimize survival in OCSCC.