Study teases out physician intent and preferences for CRC regimen selection

Fluorouracil, oxaliplatin(Drug information on oxaliplatin) (Eloxatin), and bevacizumab(Drug information on bevacizumab) (Avastin) for first-line therapy is preferred in metastatic colon cancer. But chemotherapy use can vary depending on patient age and the therapy’s toxicity profile, said researchers from Duke University Medical Center in Durham, N.C. What remains a bit of a mystery is how oncologists settle on one treatment plan over another.

As patients with colon cancer continue to live longer, they are exposed to more lines of chemotherapy with different agents. Yet no published study has examined community-based treatment patterns for metastatic colorectal cancer patients in the U.S., wrote S. Yousuf Zafar, MD, and colleagues from the division of medical oncology and the department of medicine as well as the department of biostatistics and bioinformatics.

Dr. Zafar's group conducted a two-part retrospective review of patients whose colon cancer was diagnosed between 2003 and 2006. Data were abstracted using patient sociodemographics, disease stage, medication dosage, clinicians’ reasons for choosing or discontinuing a therapy, and adverse events. They also looked at the chemotherapeutic regimens chosen: either FOLFOX or FOLFIRI. Patients were excluded if they had been part of a research protocol during first-line or second-line treatment (J Oncol Pract 5:228-233, 2009).

After examining 738 patient records, 400 patients were eligible for inclusion in the study and, of those, 110 made up the population of phase II of this review (see Table). The mean age of the patients was 57.9 years, and the majority of patients receiving any chemotherapy were younger than 70, the authors reported.

For most patients (64%), first-line therapy consisted of FOLFOX plus bevacizumab. FOLFIRI plus bevacizumab was the most common second-line regimen (13% of patients). The most often used third-line regimen was irinotecan(Drug information on irinotecan) (Camptosar) plus cetuximab(Drug information on cetuximab) (Erbitux) (21% of patients).

“As treatment progressed from first to third line, the use of bevacizumab, 5-FU, and oxaliplatin decreased, whereas the use of irinotecan increased,” the author stated.