SUNDAY, June 3, 2012 (HealthDay News) -- Treating advanced-stage colon cancer patients with a combination of chemotherapy and the tumor-targeting drug Avastin appears to prolong survival among those who have already undergone the combination therapy at an earlier stage of disease, new German research finds.
Avastin (bevacizumab) works by interfering with the growth of blood vessels that tumors require to grow and spread.
In the United States, Avastin already is used in combination with chemotherapy as the standard of care for both initial treatment and second-line treatment, which is for patients who require additional treatment for progressing disease.
The current study's specific finding that Avastin is beneficial as a second go-round for patients with advanced disease could alter the way patients in Europe are treated, given that typically the combined therapy is used either as a first- or second-line treatment, but not both.
"These findings confirm what many physicians and researchers have long suspected: that extended bevacizumab treatment provides meaningful benefits for patients with advanced colorectal cancer without adding significant side effects," Dr. Dirk Arnold, director of the Hubertus Wald Tumor Center at the University Cancer Center of University Clinic Eppendorf in Hamburg, said in a news release from the American Society of Clinical Oncology.
Arnold added that Avastin also could prove useful as a mainstay drug for advanced patients who may have built up resistance to their first-round chemotherapy.
"By simply switching chemotherapy drugs when the cancer progresses and continuing with bevacizumab, we can make second-line treatment even more powerful," he suggested.
Arnold and his colleagues are scheduled to present their findings Sunday at the American Society of Clinical Oncology meeting in Chicago.
In all, 820 patients with inoperable colon cancer that had spread to areas outside the initial tumor region participated in the study from 2006 to 2010. All had been treated with one chemotherapy drug and Avastin as a first-line treatment. When it came time for a second-line treatment, some patients received a different chemo drug plus Avastin, while the others received chemo plus a placebo.
The result: Those treated with the Avastin-chemo combination experienced better median overall survival times (more than 11 months versus less than 10 months) and better progression-free survival (almost 6 months versus about 4 months).
Dr. Frank Sinicrope, professor of medicine and oncology at the Mayo Clinic in Rochester, Minn., characterized the study findings as "especially important."
"This prospective study supports prior evidence for continuing bevacizumab after progression of standard first-line chemotherapy containing bevacizumab," he said.
And that, Sinicrope added, suggests that the German team's observations have "practice-changing implications for advanced [colon] cancer patients."
The drug, made by Roche, comes with a hefty price tag -- more than $8,000 a month, according to published reports.
Arnold has acted as a consultant or adviser to Roche.
Last year, the U.S. Food and Drug Administration rescinded its approval of Avastin to treat advanced breast cancer, saying the risks outweigh the benefits for that use.
Data and results presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.
The National Cancer Institute has more about colon cancer.