ECOG performance status as a predictor of adjuvant chemotherapy (AC) toxicities in stage III colorectal cancer (CRC) patients.

Abstract

789 Background: Toxicities acquired from AC can greatly impact quality of life. ECOG performance status is a clinical factor that is frequently considered in AC treatment decision-making, but its associations with common toxicity outcomes remain unclear. Methods: We reviewed a cohort of 371 CRC patients treated with adjuvant monotherapy (Capecitabine) or combination therapy (FOLFOX or CAPOX) within 12 weeks of curative resection at the British Columbia Cancer Agency, and determined the associations between ECOG (0, 1, ≥ 2) and toxicity outcomes. We also categorized toxicities into early, intermediate, or late based on their time of onset. Results: Among 371 patients, median age was 65 years, 52% were men, and 45%, 41%, and 14% were ECOG 0, 1, and ≥ 2, respectively. In this cohort, 41% received monotherapy and 59% received combination therapy. There was a trend of decreased toxicity for specific side effects, such as nausea, vomiting, and diarrhea, with each additional treatment cycle. For monotherapy, ECOG was found on univariate analyses to be associated with several toxicities including early onset hand foot syndrome and early onset anemia (both P < 0.05). When compared to ECOG 0, multivariate analyses showed that patients with worse ECOG were more likely to develop early hematological toxicities (ECOG 1, OR 2.75, 95% CI 1.01-7.49, P= 0.04; ECOG ≥ 2, OR 4.38, 95% CI 1.24-15.49, P= 0.02). ECOG ≥ 2 patients also had higher odds of experiencing late hematological toxicities (OR 4.52, 95% CI 1.05-19.52, P= 0.04) and neuropathy (OR 5.73, 95% CI 1.25-26.14, P= 0.02). In univariate analyses of combination therapy, ECOG was associated with early gastrointestinal and late hematologic toxicities (both P < 0.05). On multivariate analyses, however, ECOG was predictive of only early hematologic toxicities (ECOG 1, OR 2.13, 95% CI 1.05-4.32, P= 0.04; ECOG ≥ 2, OR 3.85, 95% CI 1.18-12.6, P= 0.03). Further analyses did not show any consistent correlations between ECOG and other toxicity outcomes. Conclusions: Although specific toxicities appear to decrease with each successive cycle of AC, poor ECOG is associated with an increased likelihood of certain side effects that can further inform AC discussions.