Modern chemotherapy treatment for advanced colorectal cancer, such as irinotecan, oxaliplatin, and molecular-targeted treatments, are successful in extending the lives of patients by several months – not the case a few years ago when these treatments were unavailable, says a report in The Lancet Oncology September 20th Edition.
Professor Loennidis, University of Ioannina School of Medicine, Greece, and team comment that while prior studies indicated that newer therapies were beneficial, how beneficial they really are was never that clear. The scientists wanted to find out whether some regimens were linked to improved survival rates and delayed disease progression. They also wanted to assess the magnitude of these benefits.
They examined 242 randomized trials to compare systemic treatment regimens in advanced colorectal cancer patients during the last four decades.
The scientists report that for patients who had been expected to survive for one year on fluorouracil and leucovorin, the estimated absolute survival benefit of additional treatment with irinotecan + bevacizumab was eight months – in other words, irinotecan plus bevacizumab gave patients an extra eight months. Patients survived for an extra 4.7 months with the addition of oxaliplatin + bevacizumab or irinotecan + oxaliplatin.
The authors explained that as newer and more intensive treatments have higher toxicity this type of quantification is required to ascertain the incremental survival benefits of each type of chemotherapy compared to older treatments so that toxic effects can be weighed up against improved efficacy.
Although patients are surviving for longer, multidrug combinations often have serious toxic effects, caution the authors. They say additional and longer-term follow-up data on toxicity in different settings is required on these new regimens. “The fluorouracil, leucovorin, irinotecan, plus bevacizumab regimen especially, which has the highest probability to be the best in improving survival according to our analysis, might be complicated by up to 84•9% of grade 3 or 4 adverse events, including a 1•5% chance of gastrointestinal perforation. Existing uncertainties suggest that more data are needed, especially for the newest regimens.”
Written by: Christian Nordqvist