Chemotherapy is a systematic treatment method that uses chemical drugs in cancer therapy. The primary goals of this treatment, varying according to the type and stage of cancer, include: curing the disease, preventing tumor spread (metastasis), slowing its growth, destroying cancer cells that may have spread from the initial organ to other parts of the body, and alleviating symptoms associated with the disease.

Chemotherapy is sometimes administered as a standalone treatment, but more often it is used in conjunction with other treatment modalities such as surgery or radiotherapy. These combinatorial approaches can be sequential or concurrent, depending on the stage and spread of the disease. For example, chemotherapy may be applied to shrink a tumor before surgery (neoadjuvant treatment) or to prevent the recurrence of microscopic cancer cells that may have remained in the body after surgery (adjuvant treatment). Similarly, chemotherapy can be included in treatment protocols before, after, or concurrently with radiotherapy (concomitant chemoradiotherapy). These integrated treatment strategies aim to optimize treatment success.