Patterns of use and tolerance of anti-epidermal growth factor receptor antibodies in older adults with metastatic colorectal cancer

Background Limited data are available regarding the tolerance of anti-epidermal growth factor receptor (EGFR) antibodies among elderly patients with metastatic colorectal cancer (mCRC). We retrospectively reviewed our experience of treating elderly patients with mCRC with these agents between 2004 and 2011.

Methods Patients with mCRC ≥ 65 years treated with anti-EGFR agents were included in this analysis. We recorded demographic and disease characteristics, treatment regimen and duration, KRAS status, and overall survival (OS). Toxicity evaluation included common hematologic and nonhematologic toxicities seen with these agents.

Results One hundred seventeen patients were included, with a median age at treatment initiation of 73 years (range, 65-86 years), 59% of male sex, 82% with colon primary tumors, and 51% with metastatic disease at presentation. Median time on anti-EGFR treatment was 2.4 months. Older age at treatment initiation was associated with use of anti-EGFR antibody as monotherapy versus combination therapy (P =.0009). Worse performance status (PS) at treatment initiation was associated with a shorter overall survival (OS) (P =.013) and shorter treatment duration (P =.01). The incidence of hematologic/nonhematologic grade ≥ 3 was 36% and 15%, respectively. No association was found between age and presence of grade ≥ 3 toxicity. Longer treatment duration and better PS at treatment initiation were the only factors associated with higher incidence of grade 3 toxicity.

Conclusion Our data demonstrate that anti-EGFR antibodies can be used in older patients with mCRC, with toxicity profiles similar to those reported in large phase III studies of younger patients. Advanced age was associated with receipt of anti-EGFR agents as monotherapy but did not impact treatment outcomes in this population.