Colon and Rectal Cancers - Medications

Medications

Chemotherapy uses drugs that kill cancer cells throughout the body. There are two situations in which chemotherapy is used:

• The adjuvant setting. Adjuvant refers to the use of chemotherapy after surgery in patients with Stage III tumors and selected patients with high-risk Stage II tumors (disease that is potentially curable). The goal of this therapy is to eliminate any cancer cells that surgery may have missed, thereby preventing recurrence and increasing the chance of cure. Patients of all ages, including the elderly, can benefit.
• In metastatic disease. In patients with metastatic disease (where the cancer has spread to other parts of the body) the goal of chemotherapy is to shrink tumors, improve symptoms and quality of life, and to lengthen life.

In the adjuvant setting, there are some differences in chemotherapy treatments between colon and rectal cancers:

• Chemotherapy for Stage II patients is considered standard care for Stage II rectal cancer but is under debate for colon cancer.
• Chemotherapy is standard for patients with Stage III colon cancer. Chemotherapy is also standard for patients with Stage III rectal cancer but is used in combination with radiation.

Chemotherapy for Stage II Patients with Colon Cancer. Adjuvant chemotherapy for Stage II colon cancer is controversial. Such patients tend to have a good outcome after surgery, and the positive effects of chemotherapy have been difficult to demonstrate. To date, the survival advantage of adjuvant chemotherapy in this group has been reported to be only in the range of 2%. However, better trials are still needed to confirm or refute the benefits in specific patient groups.

Although not yet known with certainty, some data suggest that certain Stage II patients may be at higher risk of recurrence and would theoretically benefit from adjuvant therapy. These include patients with the following conditions:

• Cancers that have obstructed the bowel
• Cancers that have perforated the wall of the colon
• Cancers that have adhered to structures outside the intestine.