Hypertension may be a novel independent risk factor for the biochemical recurrence of prostate cancer (PCa) after radical prostatectomy, a new study suggests. The study also confirmed previous research showing that obesity increases the risk.
Of 1,428 men who underwent RP, 107 (8%) experienced biochemical recurrence after a median follow-up period of 3.6 years. Hypertension and obesity were associated with a significant 51% and 37% increased risk of biochemical recurrence, respectively, after adjusting for age, surgical margin status, tumor stage, Gleason score, and metabolic syndrome features, researchers reported online ahead of print in Prostate Cancer and Prostatic Disease. The presence of both conditions was associated with a significant twofold increased risk.
The investigators, led by Ramsey Asmar, MD, of the University of Michigan Medical School and Comprehensive Cancer Center in Ann Arbor, noted that their finding of a link between obesity and PCa biochemical recurrence is consistent with a previous study led by Stephen J. Freedland, MD, then at Johns Hopkins University School of Medicine in Baltimore, but now at Duke University Medical Center in Durham, N.C. The study by Dr. Freedland and his colleagues showed that moderately and severely obese PCa patients had a twofold significantly increased risk of post-RP biochemical recurrence, after controlling for preoperative characteristics (J Clin Onc 2004;22:446-453). In addition, in the past decade, Dr. Asmar’s team pointed out, a consistent association has been observed between higher body mass index and prostate cancer aggressiveness, progression, and mortality.
“Our observation may be explained at least in part by the fact that surgery is more technically challenging in the obese or morbidly obese patient, or due to delayed detection of depressed PSA concentrations among obese men,” the authors wrote. “However, our increased recurrence rate was independent of surgical margin status, arguing in favor of a biological mechanism by which obesity confers risk.”
With regard to the finding of an independent association between hypertension and increased risk of biochemical recurrence, Dr. Asmar and his collaborators said their findings are consistent with those of a study by Jennifer M. Post, MD, of Wayne State University in Detroit (Prostate Cancer 2011;2011:245642), which found that hypertension was associated with a significant twofold increased risk of biochemical recurrence following RP.
In a discussion of study limitations, Dr. Asmar’s group acknowledged that patient comorbidities may not have been accurately reported. They noted, for example, that they were unable to account for patients who failed to report a history of hypertension or diabetes to their medical providers.
“This study nicely corroborates multiple prior studies which found obesity correlated with poor outcome after surgery,” said Dr. Freedland, Associate Professor of Surgery at Duke and editor of Prostate Cancer and Prostatic Disease.
The finding of a significant association between hypertension and poor outcome is novel, Dr. Freedland told Renal & Urology News. The effect of hypertension on biochemical recurrence of PCa previously has not been well studied and requires validation, he said. “However, as hypertension is part of the metabolic syndrome—along with obesity—these data add to the growing body of literature that metabolic disturbances appear to be associated with more aggressive prostate cancer.”