Adjuvant chemotherapy improves survival of patients with locally advanced rectal cancer

This study investigated the role and optimal dose and duration of adjuvant (after surgery) chemotherapy (AC) in patients with locally advanced rectal cancer. Researchers suggested that this treatment was associated with improved survival in these patients.

Colorectal cancer is one of the most common cancers worldwide. Colon and rectal cancers are often grouped as a single disease. However, these two diseases have great differences in treatments and in recurrence rates.

Locally advanced rectal cancer is commonly treated with therapy followed by surgery. This therapy can be chemotherapy and/or radiation therapy. This aims to reduce tumor growth to improve tumor elimination rates during surgery.

Treatment guidelines for rectal cancer also recommend AC. This therapy aims to eliminate any cancer cells left behind after surgery. However, prior studies about AC have different results. Some of these studies suggest a benefit associated with this therapy, while others do not. The role of AC in locally advanced rectal tumors is still not clear.

This study included 866 patients with stage 2 and 3 rectal cancer. These patients received chemotherapy/radiotherapy followed by surgery. Then, 417 patients received AC and 449 did not receive AC. The average follow-up was 109 months.

The 6-year disease-specific survival (DFS; from treatment to death caused by the cancer) for all patients was 73.7%. DFS was 79.5% in the AC group and 68% in the non-AC group. The average overall survival was 90.8 months for all patients. 6-year overall survival was 64.3% for the AC group and 49.6% for the non-AC group. Disease-specific survival improved in the AC group after 4 months, when comparing to the non-AC group. No differences were seen between single and multiple-drugs AC.

This study concluded that AC improves the survival of patients with locally advances rectal cancer.

Patients were not randomized to received AC or non-AC. This might have influenced the results.