Evaluating the effectiveness and safety of adding oxaliplatin (3 months vs 6 months) to 6 months of fluoropyrimidine after surgery in patients with stage II or III colon cancer.

This study evaluated the effectiveness and safety of adding oxaliplatin (Eloxatin; 3 months vs 6 months) to 6 months of fluoropyrimidine therapy such as 5-Fluorouracil (Adrucil) or capecitabine (Xeloda) as adjuvant (treatment after surgery) treatment in patients with stage II or III colon cancer. The data showed that adding 3 months of oxaliplatin to 6 months of fluoropyrimidine treatment could be considered an alternative adjuvant treatment option in patients treated with capecitabine plus oxaliplatin.

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. CRC involves the final part of the intestines, colon, or rectum. The first choice for the treatment of CRC is usually surgery. Often, patients are given chemotherapy after surgery to make sure any remaining cancer cells are killed. This is called adjuvant chemotherapy (AC).

The current standard treatment for patients with stage 3 CRC is surgery followed by 6-months of FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) or CAPOX (capecitabine and oxaliplatin) treatment. However, many patients develop peripheral sensory neuropathy (PSN; weakness, numbness, and pain in the hands and feet) during the 6 months of this therapy. A shorter 3-month FOLFOX/CAPOX treatment was shown to be as effective and safe as the 6-month treatment for patients with stage 3 CRC. However, the optimal duration of adding oxaliplatin (3 months vs 6 months) to 6 months of fluoropyrimidine AC in order to diminish PSN without compromising the effectiveness in patients with stage II or III colon cancer is still unknown.

This study involved 1788 patients with high-risk stage II and stage III colon cancer. Patients were randomly assigned into 2 groups. Group 1 included 893 patients who received 3 months of oxaliplatin with 6 months of fluoropyrimidine therapy. Group 2 included 895 patients who received 6 months of oxaliplatin with 6 months of fluoropyrimidine therapy. The average follow-up time was 78.7 months.

After 3 years, 84.7% of the patients in group 1 were alive without any signs or symptoms of cancer compared to 83.7% of the patients in group 2. After 5 years, 82.2% of the patients in group 1 were alive without any signs or symptoms of cancer compared to 81.6% of the patients in group 2

Fewer patients (58.3%) in group 1 experienced PSN compared to group 2 (69.5%).

Among patients with stage III CRC treated with capecitabine plus oxaliplatin, after 3 years, patients in group 1 were 29% more likely to survive without any signs or symptoms of cancer than patients in group 2.

This study concluded that adding 3 months of oxaliplatin to 6 months of fluoropyrimidine AC could be considered an alternative adjuvant treatment option in patients with stage III CRC treated with capecitabine plus oxaliplatin.

The patients knew which treatment they were getting. This study only included patients treated at institutions in Korea.