Evaluating the timing of chemotherapy plus bevacizumab for patients with colorectal cancer and liver metastasis

This study investigated whether chemotherapy plus bevacizumab (Avastin) before and after or after surgery improves the survival of patients with colorectal cancer (CRC) and operable liver metastasis (LM; cancer spread to the liver). Researchers suggested that chemotherapy and bevacizumab before and after surgery improved the overall survival of these patients.

CRC is one of the most common cancers worldwide. A significant number of patients present with metastatic (spread to other parts of the body) disease at diagnosis. The liver is the most common site for metastasis and is found in 30 to 60% of patients. Surgery of LM is the only curative option. However, almost two-thirds of patients have a recurrence of LM. Therefore, chemotherapy such as FOLFOX (folinic acid, 5-fluorouracil, and oxaliplatin) or FOLFIRI (folinic acid, 5-fluorouracil, and irinotecan) can be given. In advanced cases, chemotherapy is only of limited effectiveness. Therefore, the addition of other agents to the therapy, before and/or after surgery, improves the treatment outcomes.

Bevacizumab is a targeted therapy that stops the ability of the tumor to grow and spread. Prior studies showed that bevacizumab improves effectiveness outcomes and response rate as first-line treatment in metastatic CRC. Therefore, it is also expected that this agent improves tumor shrinkage before surgery. However, the effects of chemotherapy plus bevacizumab before and after surgery in patients with CRC and LM are not clear.

This study included information about 76 patients with CRC and LM. All participants received either 6 cycles of FOLFOX or FOLFIRI with bevacizumab before and after surgery (group 1) or 12 cycles of FOLFOX or FOLFIRI after surgery (group 2). Patients were followed up for 5.4 years.

The average survival without cancer worsening of all patients was 37.4 months. Survival without cancer worsening was slightly higher in group 1 (45.8 months) compared to group 2 (28.9 months). However, this difference was not statistically significant. The overall survival was significantly longer in patients from group 1. These patients had a 40% improvement in the odds of a better overall survival.

In patients from group 1 with an increased level of carcinoembryonic antigen (CEA levels of 5 ng/ml or there was a 51% improvement in the odds of a better overall survival compared to group 2. CEA is a protein in the blood that is high in certain types of cancer including CRC.

Patients in group 1 with more than 2 liver metastases had a 45% improvement in the odds of a better overall survival compared to those in group 2.

No difference between both groups was seen in complications after surgery or side effects during therapy.

This study concluded that treatment with chemotherapy plus bevacizumab before and after surgery improved overall survival in patients with CRC and LM.

This study included a limited number of participants. Further studies with a bigger population are necessary. Roche, the manufacturer of bevacizumab funded this study.