Avoiding Adjuvant Prophylactic Neck Irradiation in Lateralized Oral Cavity Cancer (APRON)

Area of Science:

• Oncology
• Radiation Oncology
• Head and Neck Cancer Research

Background:

• Oral cavity squamous cell carcinoma (OCSCC) is a prevalent cancer in India, often diagnosed at advanced stages.
• Current adjuvant treatment involves surgery followed by radiotherapy (RT), frequently with elective nodal irradiation (ENI) even in node-negative cases.
• There is a need to de-escalate treatment to minimize toxicity while maintaining efficacy.

Purpose of the Study:

• To evaluate if limiting elective nodal irradiation (ENI) is non-inferior to standard adjuvant RT in carefully selected OCSCC patients.
• To assess the safety and efficacy of moderate hypofractionation (50 Gy/20 fractions) in the adjuvant setting.
• To improve functional outcomes and reduce treatment-related morbidity in OCSCC management.

Main Methods:

• A single-arm, phase II trial (APRON study) included adult patients with lateralized OCSCC (bucco-alveolar or oral tongue) after margin-negative resection and adequate nodal dissection.
• Primary endpoint: regional control at 2 years. Secondary endpoints: swallowing function, recurrence-free survival, toxicity, and quality of life.
• Statistical analysis included the Clopper-Pearson method and propensity score matching with historical controls for non-inferiority testing.

Main Results:

• The study is ongoing, evaluating regional control at 2 years as the primary endpoint.
• Secondary endpoints assess swallowing function, survival rates, toxicity, and quality of life.
• Dosimetry comparisons and analysis of moderate hypofractionation are also included.

Conclusions:

• The APRON study aims to provide evidence for de-escalated adjuvant strategies in OCSCC.
• Limiting ENI in well-selected patients may reduce treatment morbidity while preserving oncologic control.
• This approach has the potential to improve functional outcomes and preserve regional immune function.