Long-term follow-up and salvage surgery in patients with T2N0M0 squamous cell carcinoma of the glottic larynx who received concurrent chemoradiation therapy with carboplatin (CBDCA) – AUC 1.5 vs AUC 2.0

Abstract

Conclusion: Patients who received concurrent chemoradiation therapy with carboplatin were followed up on a long-term basis. In 25 patients treated with carboplatin at an AUC of 2.0 mg/ml, the complete response (CR), 10-year survival, and 10-year larynx preservation rates were 96.0%, 91.1%, and 75.2%, respectively, and the safety margin for partial laryngectomy was 4 mm from the gross tumor. Objectives: To perform long-term follow-up of the therapeutic outcomes of concurrent chemoradiation therapy and salvage surgery to determine the additive and synergistic effects of anticancer drugs combined with chemoradiotherapy. Methods: Fifty male patients (aged 33–76 years) with untreated T2N0M0 squamous cell carcinoma of the glottic larynx were included. Carboplatin was intravenously administered once a week for 4 weeks. Radiotherapy was delivered by an external beam of 4 MV linac X-ray (total = 66 Gy). Results: The AUC 1.5 combination group showed overall response, CR, 5-year survival, 10-year survival, 5-year larynx preservation, and 10-year larynx preservation rates of 100.0%, 68.0%, 83.4%, 77.0%, 75.2%, and 75.2%, respectively. The AUC 2.0 combination group showed corresponding rates of 100%, 96.0%, 95.7%, 91.1%, 82.9%, and 72.7%, respectively. The most common side effects of grade 3 or more were leukopenia, neutropenia, and mucositis (stomatitis), and all were reversible. Thirteen patients (52.0%) in the AUC 1.5 combination group and nine patients (36.0%) in the AUC 2.0 combination group required salvage surgery. Histologically, concurrent chemoradiation therapy with carboplatin caused more severe cancer tissue degeneration. Pathological examinations indicated that the safety margin for partial laryngectomy was 4 mm from the gross tumor.