Hi, Thanks for writing in. Cancer is an important condition and chemotherapy should be given only after confirmation. Please tell your father to visit a cancer hospital and then get examined in detail. If there is doubt then please have imaging investigation and biopsy done. It is best to clarify even the smallest doubt of cancer before taking chemotherapy. Without confirmation no one should take chemotherapy as it can cause serious side effects and damage. First he should get a CT scan or MRI scan done and then a biopsy. In this way the cells from cheeks will be studied under microscope and any abnormal cancer cells picked up. There is usually no doubt in finding a cancer on biopsy. If not conclusive then a repeat biopsy is to be done. Doing a PET scan is advised if doubt persists and this tells a cancer in most cases. Please do not worry.