NEW YORK (Reuters Health) – A multinational study has shown that progression-free survival in elderly patients with untreated metastatic colorectal cancer (CRC) is improved significantly when bevacizumab is added to capecitabine chemotherapy, and treatment is well tolerated.
While overall survival was not improved significantly, “the study was not sufficiently powered to detect differences in overall survival,” the researchers report in the Lancet Oncology online September 10.
The authors point out that the majority of metastatic colorectal cancers occur in older patients, but this population is underrepresented in clinical trials. This, and the perception that the elderly are at increased risk for toxic side effects, has led to reservations about combining bevacizumab with chemotherapy for elderly patients.
To investigate further, Dr. David Cunningham, with the Royal Marsden Hospital in London, UK, and colleagues in ten countries conducted the AVEX trial involving 280 patients aged 70 or older (median age 76 years) with metastatic CRC who were deemed not be candidates for combination chemotherapy with irinotecan or oxaliplatin, or for curative resection of metastases. The patients were randomized to receive capecitabine alone or with bevacizumab.
Median progression-free survival, the primary endpoint, was significantly longer in the bevacizumab-capecitabine group at 9.1 months, compared with 5.1 months in the capecitabine-only arm (hazard ratio, 0.53; p<0.0001), the investigators found.
Corresponding figures for median overall survival were 20.7 months and 16.8 months, which, as mentioned, was not statistically significant (hazard ratio, 0.79; p=0.18).
Rates of treatment-related serious adverse events were 14% and 8% in the two groups, respectively, according to the report. “Although concern has previously been raised about the safety of bevacizumab in elderly patient populations, we identified no new safety signals,” Dr. Cunningham and colleagues note.
“In conclusion,” they write, “our data suggest that bevacizumab plus capecitabine represents an additional therapeutic option in elderly patients with metastatic colorectal cancer, particularly in those who are unsuitable for upfront oxaliplatin-based or irinotecan-based combination regimens.”
An editorialist wonders if the APEX trial establishes a new standard of care of elderly patients with metastatic colorectal cancer. “Most oncologists would agree that it does,” suggests Dr. Stefan Kubicka, with the Cancer Center Reutlingen in Germany.
SOURCE: Bevacizumab plus capecitabine versus capecitabine alone in elderly patients with previously untreated metastatic colorectal cancer (AVEX): an open-label, randomised phase 3 trial
SOURCE: Low-toxicity treatment for colorectal cancer in elderly people
Lancet Oncol 2013.