What is the medical term meaning cancer?

It can be cancer/o or it can be carcin/o.

I put the forward slash for the reason that its a root Word and it can be combined with suffixes.

Like: carcinoma which means cancerous tumor.
Cancer is a pretty broad term. Carcinoma is a general term for cancer. However, there are many different types of cancers with specific terms; such as, melanoma which is a type of skin cancer, leukemia which is a general term for bone marrow cancer (and there are many types of leukemia).