Evidence‑Based Management of Buccal Squamous Cell Carcinoma

Early‑Stage (T1‑T2, N0) Surgical Management

Single‑modality wide local excision with ≥5 mm margins combined with elective ipsilateral selective neck dissection (levels I‑III) is recommended for early‑stage buccal SCC, because occult cervical metastasis occurs in ≈23 % of clinically node‑negative patients. 1

Post‑operative radiation therapy (RT) should be administered within 6–7 weeks after surgery for any of the following high‑risk pathological features: pT3‑T4 disease, positive surgical margins (R1/R2), more than one involved lymph node, or extracapsular extension. 2
Post‑operative concurrent chemoradiotherapy (CRT) is mandatory when microscopically positive margins (R1) or extracapsular extension/rupture are present. 1
When high‑risk features are limited to pT3‑T4 disease without extracapsular extension, RT alone is sufficient. 1
The standard CRT regimen consists of cisplatin 100 mg/m² on days 1, 22, and 43 concurrent with 70 Gy of IMRT/VMAT. 2
For patients unsuitable for cisplatin, acceptable alternatives include carboplatin + 5‑FU, cetuximab, or hyper‑fractionated/accelerated RT without chemotherapy. 2

Primary en bloc surgical resection (including bone or skin when involved) followed by appropriate neck dissection is the preferred initial treatment for T3/T4 buccal SCC. 1
Comprehensive ipsilateral neck dissection is mandatory; bilateral dissection should be considered for midline‑crossing tumors. 1

For tumors expressing PD‑L1 (CPS ≥ 1), pembrolizumab combined with platinum‑based chemotherapy and 5‑FU is recommended when rapid tumor shrinkage is needed. [1][2]
Pembrolizumab monotherapy is an alternative for PD‑L1‑high disease (TPS ≥ 50 %). 2
For PD‑L1‑negative disease, the EXTREME regimen (platinum + 5‑FU + cetuximab) remains the standard first‑line therapy. [1][2]

Nivolumab is the preferred second‑line agent, providing a median overall survival of 7.5 months versus 5.1 months with single‑agent chemotherapy. [1][4]
Other options after platinum failure include cetuximab (FDA‑approved; median OS ≈ 5–6 months) or taxane‑based regimens (with or without cetuximab or methotrexate), although the latter lack randomized trial support. [1][3]

All treatment decisions must be reviewed by a multidisciplinary tumor board comprising head‑and‑neck surgeons, radiation oncologists, medical oncologists, pathologists, radiologists, and supportive‑care specialists (speech/swallowing, nutrition, psychology). [1][2]
Management should be performed at high‑volume centers with dedicated head‑and‑neck oncology expertise to optimize outcomes. 1

Close surveillance is essential because approximately 50 % of patients experience recurrence, most within the first two years post‑treatment. Follow‑up should include head‑and‑neck examination with flexible endoscopy. 2
Monitoring for second primary tumors (incidence 2‑4 % per year) and long‑term treatment‑related toxicities is recommended during follow‑up visits. 2