Neoadjuvant Chemotherapy May Contribute Towards Mandibular Preservation in Oral Cavity Cancer

The use of neoadjuvant chemotherapy may to help preserve the mandible with acceptable toxicity and impact on survival for patients with oral cavity cancer, according to a study published in the Journal of Clinical Oncology.

Mandibular preservation was achieved in 16 of 34 patients (95% CI, 31.49-63.24) in the intervention arm. Between standard arm and intervention arm, the disease-free survival (HR, 0.911; 95% CI, 0.516-1.607; P = .715) and overall survival (HR, 0.899; 95% CI, 0.510-1.587; P = .747) were similar.

A total of 68 patients were randomly assigned to either the standard arm, in which patients underwent up-front surgery and adjuvant treatment or the intervention arm, which treated patients with 2 cycles of docetaxel, cisplatin, and flouracil at 3-week intervals; both groups had 34 patients each. Overall, the median duration to follow-up was 3.4 years, with 3.4 years in the standard arm and 4.1 years in the intervention arm.

Of the patients in the intervention arm, 1 defaulted after random assignment, 2 had 2 cycles of chemotherapy and defaulted after treatment, and 1 progressed after neoadjuvant chemotherapy and the disease was declared inoperable. A total of 30 patients completed 2 cycles of therapy and had subsequent treatment. Dose modifications were necessary in 10 patients because of toxicity. One patient had a complete response, 12 had a partial response, 16 had stable disease, and 2 had progression after therapy. Grade 3 toxicities were observed in 14 patients, and grade 4 AEs occurred in 11.

All patients in the standard arm underwent surgery compared with 29 in the intervention arm, with 1 patient receiving concurrent chemoradiation after neoadjuvant chemotherapy. Those in the neoadjuvant chemotherapy arm underwent surgery at a median of 33 days. Fifteen patients received a marginal mandibulectomy, resulting in a preservation rate of 47%. Surgeons most commonly used the pectoralis major myocutaneous flap for reconstruction, and fasciocutaneous was often used in the intervention arm. Two patients in the intervention arm had surgical complications.

Twenty-six patients in the intervention arm received adjuvant concurrent chemoradiation, and 3 patients had adjuvant radiotherapy alone. Sixteen patients in the standard arm had adjuvant radiotherapy and adjuvant chemoradiation, respectively. Additionally, 2 patients did not receive adjuvant treatment because of early stage and no adverse effects. Adjuvant treatment began 5 weeks after surgery.

The median time to completion of adjuvant treatment was 44 days. Adjuvant chemoradiation was administered in 6 cycles of cisplatin once weekly given at 30 mg/m² in both arms. Toxicity was similar between both arms (P = .855). Osteoradionecrosis developed during follow-up in 3 patients in the standard arm and 1 patient in the intervention arm.

The final histopathology report showed no residual tumor in the intervention arm. One patient reported superficial bony invasion for those who underwent marginal mandibulectomy. Between the 2 arms, node positivity and extracapsular spread was similar.

The rate of recurrence between both arms was identical, as well as those with distant metastases. The median DFS was 3.4 years in the standard arm and the median OS was 3.4 years. In the intervention arm, the median DFS was 3.8 years and the median OS was 4.1 years.

Reference

Chaukar D, Prabash K, Rane P, et al. Prospective phase II open-label randomized controlled trial to compare mandibular preservation in upfront surgery with neoadjuvant chemotherapy followed by surgery in operable oral cavity cancer. J Clin Oncol. 2022;40(3):272-281. doi:10.1200/JCO.21.00179