Significance of Anemia in Outcomes After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Approximately one quarter of patients receiving neoadjuvant chemoradiotherapy (NCRT) for locally advanced rectal cancer will be anemic at presentation. The outcomes of these anemic patients have historically been less favorable. We assessed the potential of anemia to act as an independent biomarker for a poor prognosis in patients with locally advanced rectal cancer.

We performed a retrospective, observational study of consecutive patients with locally advanced rectal adenocarcinoma who underwent NCRT from 2004 to 2009 at 3 English National Health Service trusts. The main outcomes were Rectal Cancer Regression Grade, mortality rate, and disease-free survival. These were compared between the anemic and nonanemic patients.

A total of 273 patients were included. Of these patients, 63 (23%) had a hemoglobin level of < 120 g/L (anemic) at presentation. The Rectal Cancer Regression Grades were higher (less regression) in the anemic patients than in the nonanemic patients (χ² = 10.14; P = .006). A subgroup analysis stratified by disease stage at presentation demonstrated less tumor regression in anemic patients with Dukes stage C disease (Dukes stage B, χ² = 4.31, P = .12; Dukes stage C, χ² = 5.36, P = .07). After adjusting for age, gender, and initial Dukes stage, the anemic patients demonstrated greater mortality rates than the nonanemic patients (hazard ratio, 1.73; 95% confidence interval, 1.05-2.86). The consistency with which the 2 independent reviewers were able to generate the rectal cancer regression grades from the historic pathology reports varied. Also, the subgroup analyses in the present study were often limited by low power.

The present large UK study examined patients receiving NCRT for magnetic resonance imaging-proven, locally advanced rectal adenocarcinoma. Our findings have demonstrated that patients who were anemic at presentation have higher regression grades (less regression) in response to the treatment than nonanemic patients. This trend appeared to persist despite radiologic disease stage at presentation. Anemia at presentation was also associated with increased mortality rates compared with that of nonanemic patients.