Reduced-dose of doublet chemotherapy combined with anti-EGFR antibodies in vulnerable older patients with metastatic colorectal cancer: Data from the REVOLT study

Objectives: To assess the toxicity patterns and effectiveness of doublet chemotherapy when administered at reduced doses of 20% (FOLFOX or FOLFIRI) in combination with anti-EGFR antibodies (cetuximab or panitumumab) in old, vulnerable patients with metastatic colorectal cancer (mCRC). Patients and methods: We performed a retrospective observational study of RAS and BRAF wild-type, vulnerable patients aged ≥70 years with previously untreated mCRC. The primary endpoint was safety, and secondary endpoints were overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Results: One hundred and eighteen patients were collected from 14 selected Italian centres. The median age was 75 (range, 70-85). Geriatric screening by G8 tool gave a score ≤ 14 in all patients. In total, 75 and 43 patients received FOLFOX or FOLFIRI, respectively, in combination with panitumumab (53%) or cetuximab (47%). The overall incidence of grade (G) 3-4 neutropenia was 11.8%, and for skin rash 11%. The most frequent adverse events were G1-2 skin rash (49.1%), G1-2 diarrhea (21.1%) and G1-2 nausea (17.7%). The ORR was 57.3%. Stable disease was observed in 29.1% of patients, with a disease control rate of 86.4%. With a median follow-up of 18 months, the median PFS was 10.0 months (95% confidence interval [CI]: 8.5-11.4), while the median OS was 18.0 months (95% CI: 16.0-19.9). No statistically significant difference was observed between the regimens in terms of ORR, PFS (p = 0.908), and OS (p = 0.832). Conclusion: This study shows that with an appropriate design, including reduced doses, vulnerable older patients best tolerate chemotherapy when combined with anti-EGFR antibodies.