Predicting response to treatment in cancer that has spread

This study looked at whether measuring a specific enzyme, lactate dehydrogenase (LDH), in tissue can help predict the way in which a person’s cancer may progress following treatment. 

A common treatment option for patients with colorectal cancer (CRC) that has spread to other areas of the body (metastatic CRC) is bevacizumab (Avastin). This drug, an angiogenesis inhibitor, slows the growth of new blood vessels, helping slow the spread of cancer. It is often given with chemotherapy. The benefits of this treatment combination for all patients have yet to be determined.

LDH is an enzyme ound in our body tissues. LDH levels have been found to predict cancer growth and spread in patients.

The current study examined whether LDH levels could predict prognosis in patients treated with chemotherapy and bevacizumab. 

370 patients were included in this study. Each patient had their LDH levels measured before treatment. Patients were marked as having a low LDH level if it was below normal and high if above. Patients were randomly assigned to two treatment groups. Group A received a combination of chemotherapy and bevacizumab. Patients in Group B were given chemotherapy only.

Patients were checked every 8 weeks to determine how their tumors were responding to treatment. Patients were followed for an average of 36 months.

Patients with a high LDH level had a lower progression-free survival (PFS, the time following treatment before the disease progresses) time of 8.1 months compared with 9.2 months for thse with low LDH levels. Patients with a low LDH level had an average overall survival (time from treatment until death from any cause) time of 25.2 months compared with 16.1 for those with a high LDH level.

In patients with high LDH, Group A had a higher PFS rate (9.1 months) compared to Group B (6.9 months). Overall survival rates for both groups were the same.

PFS did not differ between treatment groups for those with low LDH. Overall survival was higher for Group B (26.4 months) compared to Group A (22.6 months).

In Group B, 30.5% of patients with high LDH found their cancer began growing again compared to 12.1% of those with a lower LDH level. The number of Group A patients whose cancer grew was similar in for those with high and low LDH.

Patients with a low LDH were 55% more likely to survive for the duration of the trial and 37% less likely to have their cancer progress during that time.

This study concluded that LDH levels are a useful predictor of how a patient’s cancer might progress. It also found that bevacizumab improved outcomes for patients with high LDH.

Larger trials should be undertaken to fully understand the usefulness of LDH levels and bevacizumab.

Discuss measuring your LDH level and bevacizumab with your doctor.