Take for example nasopharyngeal cancer, to which Chinese are specially susceptible. Nasopharyngeal cancer originates near the base of the skull, close to vital organs, so there's little room for safety to make surgery more practicable. In addition, nasopharyngeal cancer is extremely likely to spread to the lymph nodes in the neck or other more remote areas of the body, so it is difficult to get all of the cancer with surgery.
以華人好發的鼻咽癌為例，鼻咽癌的原發部位接近顱底和其他重要器官，沒有寬廣的安全範圍可供切除，再加上鼻咽癌極易發生頸部淋巴結轉移和遠隔轉移，外科手術不容易清除乾淨，因此預後不佳。