FOLFOXIRI-Bev Tied to High Response Rate, Surgical Conversions in Metastatic CRC
By Marilynn Larkin
NEW YORK (Reuters Health) – A combination of fluorouracil, oxaliplatin and irinoctecan plus bevacizumab (FOLFOXIRI-Bev) is associated with a significant overall response rate and probability of surgical conversion in patients with unresectable metastatic colorectal cancer, researchers say.
FOLFOXIRI-Bev is a first-line regimen for metastatic colorectal cancer, but resection rates and overall survival have not been evaluated in published studies, according to Dr. Fausto Petrelli of Piazzale Hospital in Treviglio, Italy and colleagues.
To investigate, the team analyzed data from FOLFOXIRI-Bev studies published between 2010 and 2016. Eleven studies, including 877 patients (ages 56 to 63) who were evaluable for overall response rates, were included.
As reported in JAMA Oncology, online May 25, the objective response rate to the combination was 69%. The rate of overall surgical conversions was 39.1%, whereas the rate of R0 (curative) surgical conversions was 28.1%.
In the six trials with data available, median pooled overall survival was 30.2 months; in nine trials, progression-free survival was 12.4 months.
Dr. Petrelli and coauthor Dr. Gianluca Tomasello told Reuters Health by email, “Interestingly, the results of secondary analyses showed that in patients with disease limited to the liver, overall and R0 resection rates were even higher (62.2% and 54.7%, respectively). Moreover, receiving a high number of chemotherapy cycles (close to 12) seemed to significantly enhance the probability of undergoing secondary liver surgery.”
“Also noteworthy,” they said, is that “data from our analysis are derived from a series of biologically unselected patients, including RAS- or BRAF-mutated cancers. Such biologic characteristics are well established adverse prognostic factors.”
They conclude that “an appropriate selection of patients for such an intensive chemotherapy regimen and a multidisciplinary approach remain crucial to guarantee an optimal integration of highly active upfront treatments with surgical procedures to ultimately improve patients’ long-term outcome.”
Medical oncologist Dr. Avni Desai of Memorial Sloan Kettering Cancer Center in Commack, New York, told Reuters Health by phone that she has used the FOLFOXIRI-Bev regimen, “but not often, because it has more toxicity than just using a combination of two medications.”
“If a patient were borderline and this combination weren’t too toxic for them, it could be a reasonable option,” she added. “But the study just looked at response rate and conversion over a limited time period, so they may not have seen the increased toxicity.”
Dr. Kirk Heyne, a medical oncologist at Houston Methodist Hospital in Houston, said the study “is of marginal significance.”
“What it does accomplish is showing that this four-drug regimen is now more likely to be thought effective at shrinking colon cancer spread than other regimens,” he told Reuters Health by email.
“Not being a randomized trial, it does not prove it,” he observed. “Which patients were selected for the less rigorous studies could also explain these finding.”
“Nor,” he said, “does it answer the ultimate questions: was it worth it? Did anyone truly live longer or better?”
JAMA Oncol 2017.
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