FRIDAY, July 13, 2007 (HealthDay News) -- For patients battling advanced colorectal cancer, beginning treatment with a single chemotherapy drug is gentler than starting out with a combination of medicines and just as effective, according to two studies in the July 14 issue of The Lancet medical journal.
The findings challenge current clinical practice that favors using combination therapy right from the start, the researchers say.
In the first study, a British team from the University of Leeds divided more than 2,100 patients with advanced colorectal cancer into three groups. The first group received single-drug treatment with fluorouracil for as long as it controlled their disease, followed by single-drug treatment with irinotecan. The second group received fluorouracil followed by combination treatment (fluorouracil plus irinotecan or oxaliplatin), while the third group received combination therapy from the outset.
Patients in the first group had the shortest survival times, while patients in the second and third groups had similar overall survival times. Single-treatment fluorouracil produced the least toxic effects. All three groups had similar quality of life scores.
The authors said their study "produced a surprising result which challenges accepted standard treatment approaches in advanced colorectal cancer therapy," and provides patients with "the knowledge that a decision to opt for staged treatment approach, starting with less toxic therapy and keeping active agents in reserve, entails minimal, if any, compromise in survival."
In the second study, researchers at University Nijmegen Medical Center in the Netherlands randomly assigned 820 advanced colorectal cancer patients to receive either sequential treatment with capecitabine, irinotecan and oxaliplatin; or combination treatment of capecitabine plus irinotecan followed by capecitabine plus oxaliplatin.
Both groups of patients had similar overall survival rates.
"Our results show that, for patients with advanced colorectal cancer, combination treatment with all effective cytotoxic drugs was no better than their sequential use," the study authors wrote. "Progression-free survival over all subsequent treatment lines was not significantly different between the study groups. Additionally, sequential treatment was associated with less toxicity during first-line treatment than was combination therapy."
The findings "indicate that sequential treatment remains a valid treatment option for these patients," the researchers concluded.
The American Cancer Society has more about chemotherapy.