|The following article features coverage from the ASCO Gastrointestinal Cancers Symposium 2022. Click here to read more of Cancer Therapy Advisor’s conference coverage.|
In an analysis of patients receiving 6 months of oxaliplatin-based adjuvant chemotherapy for stage III colon cancer, early treatment discontinuation (ETD) was associated with a significant decrease in disease-free survival (DFS) and overall survival (OS). In contrast, early oxaliplatin discontinuation (EOD) was not associated with a decrease in DFS or OS.
These results were presented at the ASCO Gastrointestinal Cancers Symposium 2022 by Claire Gallois, MD, of Hopital Européen Georges Pompidou in Paris.
Dr Gallois and colleagues performed a pooled analysis of 11 clinical trials to evaluate factors associated with ETD or EOD and the prognostic impact of ETD and EOD in patients with stage III colon cancer.
The study population included patients who were treated with a combination of leucovorin, fluorouracil, and oxaliplatin (FOLFOX) or capecitabine plus oxaliplatin (CAPOX), prescribed for a duration of 6 months, and who participated in 1 of 11 adjuvant trials.
ETD was defined as discontinuation before 75% of planned chemotherapy cycles were completed. EOD was defined as stopping oxaliplatin before 75% of planned cycles were completed while continuing capecitabine or fluorouracil.
Of the 10,444 patients analyzed, 20.9% had ETD — 17.8% in the FOLFOX group and 27.2% in the CAPOX group (P <.001). Of 7243 patients, 18.8% had EOD — 17.4% in the FOLFOX group and 21.4% in the CAPOX group (P <.001).
Patients with ETD or EOD were significantly more likely to be women, 65 years of age or older, and have an Eastern Cooperative Oncology Group performance status of 1 or higher. In addition, ETD was associated with having a body mass index less than 18.5 kg/m2.
Multivariate analyses revealed that ETD was associated with a reduction in DFS (hazard ratio [HR], 1.61; 95% CI, 1.48-1.75; P <.0001) and OS (HR, 1.73; 95% CI, 1.57-1.91; P <.0001).
EOD (stopping oxaliplatin before 75% of planned cycles) was not associated with a decrease in DFS (HR, 1.07; 95% CI, 0.95-1.20; P =.2758) or OS (HR, 1.13; 95% CI, 0.99-1.30; P =.0804). However, patients who received less than 50% of the planned oxaliplatin cycles did have worse DFS (HR, 1.35; 95% CI, 1.10-1.65; P =.0182).
Patients with ETD were more likely than those without ETD to experience grade 3 or higher gastrointestinal toxicities (nausea, vomiting, and diarrhea). Patients with EOD were more likely than those without EOD to experience grade 3 or higher peripheral sensory neuropathy.
Based on these results, Dr Gallois concluded that, in patients with a 6-month adjuvant regimen, maintaining the planned number of treatment cycles seems important. However, she recommended stopping oxaliplatin in patients with grade 2 or higher neurotoxicity. For patients with grade 1-2 neurotoxicity, stopping oxaliplatin after 3 months is likely a valid option that will not impair clinical outcomes, Dr Gallois said.
Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
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Gallois C, Shi Q, Meyers JP, et al. Prognostic impact of early treatment discontinuation and early oxaliplatin discontinuation in patients treated with 6 months of oxaliplatin-based adjuvant chemotherapy for stage III colon cancer: An ACCENT/IDEA pooled analysis of 11 trials. Presented at ASCO GI 2022; January 20-22, 2022. Abstract 11.