Laryngeal cancer affects the larynx or voice box, which is important for breathing, talking and swallowing. Hypopharynx cancer affects the gullet – the lower part of the throat that surrounds the larynx. Treatment of early cancers, through radiotherapy or laser surgery is often successful and preserves most functions. More advanced cancers are treated with chemotherapy and radiotherapy which can cause more loss of function. when this fails or for very advanced tumours, surgery involves removing the voice box.