吸烟是导致癌症的一个主要原因。

Smoking is a major cause of ___cancer.

医学的进步正在帮助治疗多种类型的癌症。

Advances in medicine are helping to treat many types of ___cancer.

他最近被诊断出癌症，并已开始接受治疗。

He was recently diagnosed with ___cancer and has started treatment.