Worsening Anaemia Signals Poorer Outcomes In Men Treated For Advanced Prostate Cancer

Researchers from the Oregon Health & Science University Cancer Institute and Southwest Oncology Group have identified a new method of determining how men with advanced prostate cancer will respond to treatment. They found that worsening anaemia during the first three months of hormonal therapy for prostate cancer that has spread predicts shorter survival and earlier relapse.

“These results suggest that by monitoring anaemia during the first three months of treatment, we can provide men with a better idea of how well they will fare,” said principal investigator Tomasz Beer, M.D., director of the prostate cancer research program in the OHSU Cancer Institute. Beer presented results of this study at the 101st Annual Meeting of the American Urological Association in Atlanta on Tues., May 23.Researchers also found that race alone was not a strong predictor of survival or disease progression. However, they found that men with the same haemoglobin levels before treatment experienced significantly different overall and progression-free survival depending on whether they were black or white. Haemoglobin levels in the blood are measured to monitor anaemia. Lower levels of haemoglobin are considered anaemic. “Outcomes for prostate cancer have always been worse for black men than their white counterparts and the reasons behind this have not been fully understood,” Beer said. “Differences in anaemia could help us understand why blacks do worse and maybe make it possible to do something about it.”Overall, researchers found that anaemic blacks fare worse than anemic whites and that blacks with high baseline hemoglobin fare better than whites with similar hemoglobin levels.”Our study was not designed to answer questions about this complex and novel finding, but we are examining a number of hypotheses,” Beer said. Anaemia is common among newly diagnosed prostate cancer patients with metastatic disease. Approximately one-fourth of these men are anaemic. Previous studies have shown that men who are anaemic prior to treatment experience shorter survival and are prone to early relapse. One recent study has shown that a decrease in haemoglobin after one month of treatment predicts early relapse in men with high-risk prostate cancer that has not spread. “Relatively little was known about hemoglobin change after the beginning of hormonal therapy for advanced prostate cancer,” Beer said. “We were interested in learning how changes in anaemia during early treatment impact survival for these men because there are ways of treating anaemia. There may be opportunities to study whether treating anaemia would improve survival, making it a modifiable risk factor.”Androgen deprivation, or hormonal therapy, is the standard treatment for prostate cancer that has spread beyond the gland. It blocks the production of male hormones that can promote prostate cancer growth. This common treatment for advanced prostate cancer wipes out most male hormones found in the body. It also is known to reduce red cell production, making anaemia one of its adverse effects.”We believed that different men would respond to hormonal therapy differently and that these different responses in haemoglobin could be an independent prognostic factor for men with advanced prostate cancer,” Beer said. “We also believed that the effect of anaemia on outcomes may vary by race.”Beer and his colleagues tested this hypothesis in a retrospective analysis of SWOG 8894, a randomized study of orchiectomy versus orchiectomy plus flutamide in previously untreated metastatic prostate cancer. Of the 1,286 subjects enrolled in SWOG 8894, data from 817 subjects were available for this analysis, which included a number of other traditional risk factors beyond haemoglobin, including performance status, Gleason score and disease extent. The median pretreatment hemoglobin was 13.7 g/dL before treatment and 12.8 g/dL after treatment. Overall, the mean change in haemoglobin between the baseline measurement and three-month follow-up was a decrease of 0.54 g/dL. Subjects whose haemoglobin dropped by 1.6 g/dL or more had a 31 percent higher risk of death than those whose haemoglobin increased by more than .3 g/dL.”We now know that baseline haemoglobin and three-month haemoglobin change are prognostic, even after taking into account these other risk factors,” Beer said. “Further study is needed to fully understand the underlying biology of this affect and to determine if reversing anaemia can improve survival in patients with advanced prostate cancer.”(Source: Oregon Health & Science University Cancer Institute: May 2006.)