What is the rationale for using concurrent chemoradiation in head and neck cancer?

• A. Synergistic effect of chemo as a radiosensitizer, improving local control and survival
• B. Chemotherapy reduces radiation dose
• C. Radiation eliminates chemotherapy toxicity
• D. Chemoradiation is only palliative

Answer: (A)

Concurrent chemoradiation relies on the ability of certain chemotherapy drugs to act as radiosensitizers, making tumor cells more vulnerable to radiation. Chemotherapy disrupts DNA repair and enhances radiation-induced DNA damage, so the combination yields greater tumor kill than radiation alone. This leads to improved local control of the cancer in the head and neck region, which often translates into better overall survival for locally advanced disease. The systemic component of chemotherapy also helps address microscopic metastatic disease that radiation cannot reach, offering a broader disease control benefit. While this approach increases acute and late toxicities due to the combination, it is not used to reduce the radiation dose, and radiation does not eliminate chemotherapy toxicity. Chemoradiation is not limited to palliative care—it is commonly used with curative intent in suitable patients to improve outcomes.