Anaemia in half, iron deficiency in fifth of HK patients with advanced prostate cancer

Anaemia affects 52.4 percent, while iron deficiency is present in 20.7 percent of Hong Kong patients with advanced prostate cancer (CaP), according to findings from a local cohort.

Anaemia is widely associated with advanced CaP, particularly in metastatic stages treated with androgen deprivation therapy (ADT), however, its exact prevalence remains largely unknown, with reports ranging between 13–78 percent. [Rev Urol 2004;6:1-4] Therefore, researchers from the Chinese University of Hong Kong investigated the incidence of anaemia in a local cohort of CaP patients and reviewed potential associated factors with the aim of enhancing recognition of this common comorbidity and facilitating timely management.

Overall, 82 eligible patients (mean age, 74.2 years) were recruited between September and December 2022 from a CaP clinic within a general urology unit and included in the study. At the time of analysis, 25.6 percent of patients had metastatic hormone-sensitive CaP, while 13.4 percent had castration-resistant CaP (CRPC). Anaemia was defined as per WHO criteria, ie, haemoglobin level <13 g/dL, while iron deficiency was defined as ferritin level <100 μg/L or transferrin saturation <20 percent. Iron deficiency anaemia was classified as the coexistence of both anaemia and iron deficiency. [Hong Kong Med J 2025;doi.org:10.12809/hkmj2411653]

Anaemia was identified in 52.4 percent of patients, while another 20.7 percent of patients had iron deficiency without anaemia. Among individuals with anaemia, 14.0 percent had iron deficiency anaemia, 7.0 percent had B12 deficiency, and 16.3 percent had folate deficiency.

The impact of anaemia in CaP extends beyond quality of life (QoL)–related symptoms and is associated with worse overall and progression-free survival. [Am J Transl Res 2018;10:3877-3886] Anaemia-induced hypoxia within cancer colonies reduces reactive oxygen species levels, which leads to dimerization of hypoxia-inducible factor 1 alpha and beta, resulting the transcription of treatment resistance-associated oncogenes and, ultimately, the development of CRPC. [Int J Radiat Oncol Biol Phys 2005;63:25-36] “These findings highlight the importance of early identification and prompt treatment of CaP-related anaemia in the outpatient setting to preserve long-term oncological outcomes in advanced CaP treatment,” stressed the researchers.

Univariate analysis identified castrated state (odds ratio [OR], 1.99; p=0.002), metastatic disease (OR, 1.78; p=0.004), and hypoalbuminaemia (OR, 2.05; p=0.015) as statistically significant predictors of anaemia. Multivariate analysis showed that patients in castrated state (ie, those receiving ADT) had a higher likelihood of iron deficiency (OR, 1.30; p=0.006). Testosterone has been suggested to promote the generation of renal erythropoietin, therefore, ADT-induced lack of testosterone may impair haematopoiesis and contribute to anaemia. [Am J Transl Res 2018;10:3877-3886]

In addition, iron deficiency was reported in more than half of the CRPC patients (OR, 2.55; p=0.017). “Chronic kidney disease and metastatic status were not significantly associated with iron deficiency, although slight trends were observed. Other factors, including patient age, prostate-specific antigen level at diagnosis or follow-up, performance status, and International Society of Urological Pathology grade group, were not associated with iron deficiency,” reported the researchers.

As highlighted in several multicentre reviews of Asian CaP cohorts, the consequences of anaemia can be profound and include metabolic complications or diminished glycaemic control. [Int Urol Nephrol 2022;54:993-1000; Prostate 2023;83:801-808; Sci Rep 2020;10:18060] “Increased awareness of CaP-related anaemia, which is readily treated with intravenous iron or erythropoietin, could improve QoL and long-term patient outcomes,” noted the researchers.

“Physicians are encouraged to monitor the development of anaemia after initiation of CaP treatment,” they advised.