CHICAGO – When it comes to oxaliplatin-based therapy for stage III colon cancer patients with low recurrence risk, 3 is preferable to 6 months and may also be preferable in those with higher recurrence risk – particularly if they are receiving oxaliplatin with capecitabine (CAPOX), according to findings from a prospective pooled analysis of data from six phase III trials.
The findings have immediate practice-changing implications, according to Axel Grothey, MD, of the Mayo Clinic Cancer Center, Rochester, Minn.
The preplanned analysis of the concurrently conducted trials (the International Duration Evaluation of Adjuvant chemotherapy [IDEA] collaboration), which included 12,834 patients receiving either oxaliplatin with fluorouracil and folinic acid (FOLFOX) or CAPOX, showed that, at a median follow-up of 39 months, the overall 3-year disease-free survival (DFS) rates differed by only 0.9% between those receiving 3 vs. 6 months of therapy (DFS, 74.6% and 75.5%, respectively). The difference between the groups was not statistically significant (estimated disease-free hazard ratio, 1.07), Dr. Grothey reported during a press briefing at the annual meeting of the American Society of Clinical Oncology.
However, grade 2 or greater neurotoxicity was greatly reduced, occurring in 17% vs. 48% of FOLFOX patients treated for 3 vs. 6 months, respectively, and in 15% vs. 45% of CAPOX patients treated for 3 vs. 6 months, respectively.
When outcomes were analyzed based on risk of recurrence, low-risk patients (those with T1-3 N1 disease) had 3-year disease-free survival rates of 83.1% and 83.3% with 3 vs. 6 months of therapy, and high-risk patients (T4 or N2 disease) had 3-year disease-free survival of 62.7% vs. 64.4% with 3 vs. 6 months of therapy.
When outcomes were analyzed by regimen, the FOLFOX patients (about 60% of the patient population) had 3-year DFS of 73.6% and 76.0% with 3 vs. 6 months of therapy, and the CAPOX patients had 3-year DFS of 75.9% and 74.8%, respectively.
In this video interview, Dr. Grothey discusses the findings, as well as the importance of federal funding for cancer research, which is underscored by the findings.
He also discusses the IDEA Collaboration consensus based on the results, which calls for 3 months of therapy in low-risk patients and for an individualized approach based on tolerability of therapy, patient preference, assessment of recurrence risk, and treatment regimen (CAPOX vs. FOLFOX) in higher-risk patients.
“We now have very important, very solid data to engage patients in discussion [about] how to individualize the duration of therapy,” he said.
Dr. Grothey reported having no relevant disclosures.