SEATTLE – Adjunct testosterone improved short-term cardiac function in head, neck, and cervical cancer patients undergoing standard treatment in a small randomized trial from the University of Texas Medical Branch, Galveston.
The finding suggests that testosterone might counteract the cardiotoxic effects of chemotherapy, reducing “the incidence of chemotherapy-induced remodeling. It might also have rehabilitation implications and make patients better surgical candidates. Further investigation is warranted,” said investigator Albert Chamberlain, MD, an endocrine research fellow at the university. Although the results were positive, follow-up was short; years-long data are needed to know if testosterone really protects the heart from chemotherapy damage.
Dr. Albert Chamberlain
Dr. Chamberlain’s team looked into the issue because “many current chemotherapy drug classes have cardiotoxicity that progresses subclinically for a long time” before problems emerge. “Testosterone is known to cause vasodilation in both large and resistance arteries,” which might help prevent damage. “With that in mind, we decided to” investigate testosterone’s impact on cardiac performance during chemotherapy, he said at the International Conference on Head and Neck Cancer, held by the American Head and Neck Society.
Five women and one man were randomized to weekly intramuscular 100 mg testosterone injections for 7 weeks; six men and four women were randomized to placebo injections. They were all recently diagnosed with stage IIIB, IV, or recurrent head and neck cancer, or cervical cancer, and were undergoing concomitant standard-of-care chemotherapy or chemoradiation. Cardiac function was measured blindly by transthoracic echocardiogram at baseline and the end of the study.
The testosterone group had significantly improved stroke volumes (+18.2% versus –2.6%, P = 0.01), ejection fractions (+6.2% versus –1.8%, P = 0.02), and cardiac output (+1402.2 mL/min versus –16.8mL/min, P = 0.011). Heart rate, arterial pressure, end-diastolic volume, and end-systolic volume remained unchanged in both groups, so the improved systolic function was attributed to reduced vascular resistance in the testosterone group (–26.5% versus +3.9% in the placebo group, P = 0.001).
Systolic improvements remained as cardiac index increased 27.6% in the testosterone group versus 2.8% in the placebo group. Testosterone didn’t seem to have any negative impacts on diastolic function. A placebo patient had a stroke, but there were no other adverse events in the study.
Although improved stroke volume is likely due to the reduced afterload, “increased contractility cannot be eliminated as a potential contributing factor. End diastolic volume remained unchanged in both groups, [suggesting] that preload is unlikely to be the mechanism for increased stroke volume,” Dr. Chamberlain said.
This study was funded by the National Cancer Institute. Dr. Chamberlain reported having no relevant disclosures.