When should patients with T1N0 oral squamous cell carcinoma be considered for elective neck dissection?

AIMS: To identify adverse pathological features (APF) predicting nodal failure in clinically node negative T1 oral squamous cell carcinoma (OSCC). METHODOLOGY: This study evaluated patients with T1N0 (≤5 mm depth of invasion (DOI) and ≤2 cm diameter) oral cancers from a prospectively maintained database between 1988 and 2020. All patients underwent surgical excision of the primary lesion without neck dissection. Patients underwent three monthly clinical surveillance and salvage neck dissection was performed if nodal relapse was diagnosed. RESULTS: Overall, 141 patients were included. Nodal relapse was reported in 16/141 (11.3%) patients. Factors impacting regional recurrence-free survival were DOI ≥3 mm (HR: 2.4, P < 0.001), maximum tumour diameter ≥12 mm (HR: 1.1, P = 0.009), perineural invasion (PNI) (HR 7.5, P = 0.002) and poor differentiation (HR 5.3, P = 0.01). Rates of nodal relapse increased from 2% amongst patients with no APFs to 100% for those with four APFs. Patients with two or more APFs had significantly poorer 5-year regional recurrence-free survival (94.8% vs. 56.3%, P < 0.001). CONCLUSION: Patients with T1N0 OSCC with two or more APFs (DOI ≥3 mm, diameter ≥12 mm, PNI or poor differentiations) should be considered for elective neck dissection.

Depth of invasion, size and number of metastatic nodes predicts extracapsular spread in early oral cancers with occult metastases.

OBJECTIVE: Presence of extracapsular spread (ECS) significantly decreases survival in oral cancer patients. Considering its prognostic impact, we have studied the incidence and factors predicting ECS in clinically node negative early oral cancers. MATERIALS AND METHODS: We performed a retrospective chart review of 354 treatment naïve clinically node negative early oral cancer patients operated between 2012 and 2014. Chi-square test and logistic regression were used for identifying predictors of ECS, while cox-regression test was used for survival analysis. RESULTS: The incidence of occult nodal metastasis was 28.5% (101/354). Among them, ECS was seen in 15.3%(54/354) patients. The incidence of ECS in T1 and T2 lesion was 13.4% (21/157) and 16.8% (33/197), respectively. The overall incidence of ECS was 48% and 29% in lymph nodes smaller than 10 mm and 5 mm respectively. We found that tumor depth of invasion (>5 mm; p-0.027) and node (metastatic) size >15 mm (p-0.018) were significant predictors of ECS. p N2b disease was seen in 41/354 (11.6%) of which 31/354 (8.7%) had ECS, i.e. 75.6% of pN2b patients been ECS positive (p-0.000). The 3-year OS of patients without nodal metastasis, nodal metastasis without ECS and nodal metastasis with ECS was 88.4%, 66.9% and 59.2% (p-0.000) respectively. CONCLUSION: A significant number of patients with metastatic nodal size less than 1 cm have ECS which suggests aggressive behavior of the primary tumor. Thus, elective neck dissection is the only way of detecting ECS in these patients which may warrant treatment intensification.

Impact of radical treatments on survival in locally advanced T4a and T4b buccal mucosa cancers: Selected surgically treated T4b cancers have similar control rates as T4a.

INTRODUCTION: In the absence of any robust data supporting the TNM classification of T4 buccal mucosa cancers, we did this prospective study to compare the oncologic outcomes of T4a and T4b buccal mucosa cancer patients. PATIENTS AND METHODS: This is a prospective study of 210 treatment naïve T4 buccal mucosa cancer patients. All patients underwent upfront radical surgery followed by adjuvant radiotherapy (RT)/chemoradiotherapy (CCRT). This is the largest prospective series in the literature on T4 buccal cancers. RESULTS: T4a disease was seen in 135(64.3%) patients and T4b in 75(35.7%) patients. On comparison between all T4a and T4b cases, a significant difference was observed with regard to 3-year local control (49.6% vs. 41.1%: p-0.025) and disease-free survival (DFS) (65.3% vs. 42%: p-0.035) with a slightly higher incidence of distant metastasis in T4b patients (17.3% vs. 9.6%). Inadequate cut margin (<5 mm) was seen only in 7.4% patients with T4a disease and 12% patients with T4b disease. When patients with adequate cut margins were considered for analysis, local recurrence rate was similar for T4a (26/135; 19.3%) and T4b (15/66; 22.7%) disease suggesting the importance of radical surgery in infra-notch T4b buccal cancers. While the 3-year survival for T4a patients who received adjuvant RT alone was 72.2%, it was only 42.1% for similar T4b patients suggesting a need to intensify adjuvant treatment for these patients. CONCLUSION: Surgery should be considered as the primary modality of treatment for T4b patients, where clear margins are achievable. The benefit of treatment intensification with adjuvant CCRT should be explored in T4b buccal cancers.