A 52-year-old male presents with a 3 cm ulceroinfiltrative lesion on the lateral border of the tongue with clinically positive ipsilateral cervical lymph nodes (N1). Biopsy confirms squamous cell carcinoma. He has no distant metastases. What is the drug of choice for neoadjuvant chemotherapy in this locally advanced oral cavity carcinoma?

Explanation

## Neoadjuvant Chemotherapy in Locally Advanced Oral Cavity Carcinoma ### Standard Regimen **Key Point:** Cisplatin and 5-fluorouracil (5-FU) is the gold-standard neoadjuvant chemotherapy regimen for locally advanced squamous cell carcinoma of the oral cavity [cite:Robbins 10e Ch 8]. ### Mechanism of Action - **Cisplatin**: Platinum-based alkylating agent; induces DNA cross-linking and apoptosis - **5-FU**: Antimetabolite; inhibits thymidylate synthase and RNA synthesis - Combined synergistic effect improves response rates and overall survival ### Clinical Evidence **High-Yield:** Cisplatin + 5-FU neoadjuvant therapy followed by surgery ± postoperative radiotherapy is the standard of care for: - T3–T4 tumors - N1–N3 nodal disease - Resectable locally advanced disease ### Dosing Schedule - Cisplatin: 75–100 mg/m² IV on day 1 - 5-FU: 750–1000 mg/m² IV daily × 4–5 days - Repeat every 3–4 weeks for 2–3 cycles ### Rationale for This Case The patient has a T3 lesion (>3 cm) with N1 disease—meets criteria for neoadjuvant therapy to downstage the tumor and improve surgical margins before definitive resection. **Clinical Pearl:** Neoadjuvant chemotherapy improves locoregional control and may reduce distant metastasis risk, though survival benefit is modest (5–10% absolute improvement at 5 years).