In a nutshell
This study compared the effectiveness and safety of S-1 (tegafur/gimeracil/oteracil) and oxaliplatin (Eloxatin) combined with bevacizumab (Avastin) or with cetuximab (Erbitux) in patients with previously untreated advanced colorectal cancer with wild-type KRAS. This study concluded that the safety and effectiveness of SOX+bevacizumab tented to be better compared to SOX+cetuximab for patients with wild-type KRAS advanced CRC.
Some background
Patients who are diagnosed with metastatic colorectal cancer (mCRC) have disease that has spread to other areas. Genetic changes in the KRAS protein can often occur to promote mCRC growth and spread. mCRC tumors that do not have these genetic changes are known as KRAS wild-type mCRC.
FOLFOX (folinic acid, fluorouracil, oxaliplatin) and FOLFIRI (folinic acid, fluorouracil, irinotecan) chemotherapies are the recommended first-line therapies for advanced CRC. However, receiving these therapies comes with considerable discomfort for patients. Therefore, oral drugs such as S-1 agents have been considered as an option to treat these patients. This consists of a combination of tegafur, gimeracil, and oteracil potassium. Previous studies have shown its antitumor activity against advanced CRC.
Bevacizumab and cetuximab are targeted therapies. They have been shown to improve the outcomes of patients with CRC when added to chemotherapy. Although chemotherapy for mCRC has improved, the standard chemotherapy regimens for patients with RAS wild-type mCRC are still unclear.
Methods & findings
This study involved 45 patients with mCRC. Patients had wild-type KRAS CRC and did not previously receive any treatments for CRC. Patients were randomly assigned into 2 groups. Group 1 included 22 patients who received S-1 and oxaliplatin (SOX) plus bevacizumab. Group 2 included 23 patients who received SOX plus cetuximab. The average follow-up time was 19.9 months for group 1 and 12 months for group 2.
Overall, 59.1% of patients in group 1 and 43.5% of patients in group 2 responded to treatment. The disease control rate (the tumor does not grow or spread) was 90.9% for group 1 compared to 91.3% for group 2. These differences were not statistically significant.
The average overall survival was 25.3 months for group 1 compared to 15.5 months for group 2. Patients in group 1 were 40% more likely to have a better survival than patients in group 2.
The average survival without cancer worsening was longer for group 1 (11.7 months) compared to group 2 (5.5 months). Patients in group 1 were 44% more likely to survive without cancer worsening than patients in group 2.
Nerve damage was the most common side effect in both groups.
The bottom line
This study concluded that the safety and effectiveness of SOX+bevacizumab tented to be better compared to SOX+cetuximab for patients with wild-type KRAS advanced CRC.
The fine print
This study included a very small number of participants. Further larger studies are needed.
Published By :
BMC cancer
Date :
Aug 23, 2021
