Predictive factors and repetition numbers for intraoperative additional resection of initially involved soft tissue resection margins in oral squamous cell carcinoma: a retrospective study.

BACKGROUND: Intraoperative additional resection (IAR) of initially microscopically involved soft tissue resection margins negatively impacts tumor recurrence in oral squamous cell carcinoma (OSCC). Increasing the selected initial macroscopic resection margin distance beyond the tumor tissue may help prevent IAR; however, the existence of predictive factors for IAR and IAR repetition numbers remains unclear. This study aimed to identify predictive factors for IAR and to evaluate the IAR repetition numbers in soft tissue for surgically treated OSCC. METHODS: A cohort of 197 patients surgically treated for OSCC between 2008 and 2019 was retrospectively reviewed (44 patients with IAR and 153 patients without IAR). Clinical parameters (tumor location, midline involvement, clinical T-status, time between staging imaging and surgery, bone resection, monopolar use, and reconstruction flap size) and histopathological parameters (pathologic T-status [pT-status], grading, vascular invasion, and lymphatic invasion) of the two groups were compared. RESULTS: Patients with and without IAR differed in their histopathological parameters, such as pT-status above 2 (47.7% vs. 28.1%, p = 0.014) and lymphatic invasion (13.6% vs. 4.6%, p = 0.033); however, their clinical parameters were similar (all p > 0.05). Only pT-status above 2 was predictive for IAR in a multivariable regression analysis (odds ratio 2.062 [confidence interval 1.008-4.221], p = 0.048). The IAR repetition numbers varied from zero to two (zero = 84.4%, one = 11.4%, and two = 2.3%). CONCLUSIONS: Only postoperative available pT-status was identified as a predictive factor for IAR, underscoring the importance of improving preoperative or intraoperative tumor visualization in OSCC before selecting the initial macroscopic resection margin distance to avoid IAR.

Impact of secondary tumor-free resection margins in soft tissue on local, regional, and distant recurrence in R0-resected oral squamous cell carcinoma.

BACKGROUND: The impact of additional soft tissue resection on recurrence of oral squamous cell carcinoma (OSCC) remains controversial. The study aim was to compare recurrence between patients with secondary tumor-free resection margins after intraoperative additional resection (STF-RM) and patients with primary tumor-free resection margins without additional resection (PTF-RM). METHODS: Forty-five patients with STF-RM were matched with patients with PTF-RM according to Union for International Cancer Control stage, tumor location, and treatment modality and compared for local, regional, and distant recurrence. RESULTS: Patients with STF-RM showed lower local and distant control rates compared to patients with PTF-RM (66.2% vs. 82.8%; p = 0.045 and 86.3% vs. 100.0%; p = 0.021). STF-RM was the only predictor of local recurrence accounting for tumor (T) status, nodal (N) status, tumor grade, margin distance, and extracapsular extension (hazard ratio 4.21 [95% confidence interval 1.26-14.04]; p = 0.019). CONCLUSIONS: STF-RM have an adverse impact on local and distant recurrence of OSCC.