3-month chemo may be sufficient for most patients with colon cancer
Three vs 6 months of adjuvant oxaliplatin-based chemotherapy may be sufficient for colon cancer with low risk of recurrence and has the advantage of fewer side effects, according to the IDEA* trial which pooled data from six phase III trials.
“This is extremely important work that will affect the lives of many of my patients,” commented ASCO expert Dr Nancy Baxter from St Michael’s Hospital in Toronto, Ontario, Canada. “Today, up to 60 percent of my patients with stage III colon cancer will be able to stop after 3 months of therapy and get on with their lives and have a lower risk of permanent problems, such as numbness of their hands and feet.”
Researchers compared 3 months vs 6 months of adjuvant oxaliplatin-based therapy in patients with node-positive stage III colon cancer who underwent surgery. The median duration of follow-up was 39 months. [ASCO 2017, abstract LBA1)
“With 12,834 patients from 12 countries included in the study, this is the largest collaboration of its kind in gastrointestinal oncology,” said
principal investigator Dr Axel Grothey from the Mayo Clinic Cancer Center in Rochester, Minnesota, US.
For all patients, the rate of disease-free survival (DFS) at 3 years appeared comparable between 3 and 6 months of chemotherapy (74.6 percent vs 75.5 percent, hazard ratio [HR], 1.07). The type of chemotherapy regimen used affected the difference in 3-year DFS between courses (75.9 percent vs 74.8 percent; HR, 0.95 with CAPOX [capecitabine/oxaliplatin] and 73.6 percent vs 76 percent; HR, 1.16 with FOLFOX [leucovorin, fluorouracil, oxaliplatin]). However, the difference was relatively small in both regimens.
In a subset of patients with lower risk of cancer recurrence (1-3 nodal involvement but has not spread to the bowel wall; 60 percent of patients in the study), the difference in DFS was very small (83.1 percent vs 83.3 percent for 3 and 6 months of chemotherapy). “Three months of chemotherapy will likely become the new standard of care in this group of patients with lower recurrence risk,” said Grothey.
When it comes to treatment-related serious adverse effects, nerve damage (Grade 2 or higher) was consistently higher in those receiving 6 months vs 3 months of chemotherapy (48 percent vs 17 percent with CAPOX; 45 percent vs 15 percent with FOLFOX).
Aside from nerve damage, longer chemotherapy translates to more diarrhoea and fatigue, more doctor appointments and blood draws, and time away from work, said Grothey.
“Patients with higher-risk colon cancer, however, should discuss these results with their doctor to see if a shorter course of therapy would be right for them, taking into account their preference, age, and ability to tolerate chemotherapy.”
The IDEA trial was funded by the US National Institutes of Health and other non-commercial entities in participating countries. “Who is interested in shortening the duration of therapy from a commercial perspective? These trials can only be conducted with a publicly funded clinical trial system,” said Grothey.