The prognostic role of haemoglobin in patients undergoing concurrent chemo-radiation for anal cancer

Background: Concurrent chemo-radiation (CT-RT) is a standard therapy for squamous cell carcinoma of anal canal. Different clinical and biological factors may potentially affect outcome. We investigated the prognostic role of baseline hemoglobin (Hb) in a cohort of anal cancer patients submitted to CT-RT with 5-fluorouracil and mitomycin C. Methods: Up to 161 patients with clinical stage T1-T4/N0-N3/M0 were treated. Response was assessed at 6 weeks and thereafter at 3, 6 and 12 months. Two different approaches were used:a)simultaneous integrated boost following RTOG 05-29 indications;b)first sequence of 45Gy/25 fractions to the pelvis followed by 9–14.4 Gy/5–8 fractions to the macroscopic disease. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Results: On multivariate analysis, pre-treatment Hb level had a significant correlation to OS (HR:0.53;95% CI:0.33–0.87; p = 0.001), but not to PFS (HR:0.78;95% CI:0.53–1.15; p = 0.12) Patients with pre-treatment Hb ≥ 12 g/dl had 5-year PFS and OS of 82.2%, compared to 29.3% and 32.8% for those below the threshold. The likelihood to achieve a complete remission increased by 5.6% for every single-unit (g/dl) increase in baseline Hb level over 11 g/dl. On multivariate analysis, response to treatment had a significant correlation to PFS (incomplete vs complete response – HR:5.43;95% CI: 2.75–10.7; p < 0.0001) and OS (HR: 6.96;95% CI:2.96–16.5; p < 0.0001). Conclusions: We showed that baseline Hb level is a strong indicator for poor response to RT-CT in anal cancer patients. A close clinical monitoring for incomplete response to treatment should be advised in patients with low pretreatment Hb. The hypothesis that the preservation of adequate Hb level during treatment may lead to a better outcome needs prospective evaluation.