Baseline anaemia increases locally advanced rectal cancer mortality in older patients undergoing preoperative chemoradiation.

The median diagnosis age of rectal cancer (RC) is 70 years old. The standard of care for locally advanced RC (LARC) is preoperative chemoradiation (CRT) followed by surgery. Anaemia is a frequent condition in older patients but is not a pure consequence of ageing. The patients aged 65 years or over, with clinical stage II/III LARC, and treated with preoperative concurrent CRT were retrospectively reviewed. Baseline haemoglobin (Hb) levels were collected. One hundred and seven patients enrolled in this study, but 17 were excluded in relation with treatment disruption. Fifty-seven (63.3%) males and 33 (36.7%) females completed preoperative CRT whose median age at diagnosis was 73. Twenty-five (27.8%) patients presented with anaemia at rectal cancer diagnosis, and median Hb was 13.5 g/dL (IQR = 1.45) and 11.2 g/dL (IQR = 1.35), for non-anaemic and anaemic patients, respectively. For the enrolled older population, only 2 patients reported acute grade 3 toxicity. Baseline anaemia tended to decrease the LARC-free interval and was associated with a significantly higher hazard of all-cause and LARC mortality, approximately 5 times (HR = 5.25; 95% CI 1.48-18.66) and 10 times (HR = 10.09; 95% CI 2.40-42.48), respectively. Patients older than 75 presented a significantly negative impact on overall survival (OS) and LARC-specific survival (HR = 6.20, 95% CI 2.00-19.22; and HR = 7.61, 95% CI 2.08-27.87, respectively). Conversely, no significant impact was found for age-adjusted Charlson comorbidity index on OS, LARC-specific survival and LARC-free interval. Overall and LARC-specific survival were significantly lower for the baseline anaemic older patients and for those aged 75 years or over.