Charlottesville, VA—Could common blood-pressure (BP) drugs have protective effects against colorectal cancer (CRC) mortality? A new study suggests that might be the case.

University of Virginia Health System researchers reviewed outcomes of nearly 14,000 patients with colorectal cancer and identified an association with the use of ACE inhibitors, beta-blockers, and thiazide diuretics with decreased mortality. The report in Cancer Medicine also suggests that patients who were more adherent to their antihypertensive drug regimen consistently were less likely to die from their cancer.

“Cost-effective solutions to prolong cancer survivorship in older patients may lie in commonly used medications,” explained lead author Rajesh Balkrishnan, PhD, of the University of Virginia School of Medicine’s Department of Public Health Sciences. “However, we need further confirmation of these findings through clinical trials.”

The article points out that vascular changes often are observed with cancers, adding that “evidence indicates that antihypertensive (AH) medications may interfere with both tumor vasculature and in recruiting immune cells to the tumor microenvironment based on preclinical models. Extant literature also shows that AH medications are correlated with improved survival in some forms of cancer.”

That information led to noninterventional, retrospective analysis of patients aged 65 years and older with CRC diagnosed from January 1, 2007, to December 31, 2012. The 13,982 participants were drawn from the Surveillance, Epidemiology, and End-Results (SEER)-Medicare database, and the researchers focused on the association between antihypertensive drug use on stage I–III CRC mortality rates in patients who underwent treatment for cancer.

Results indicate that, among these patients, the use of BP medications was associated with decreased cancer-specific mortality (hazard ratio [HR], 0.79; 95% CI, 0.75-0.83). Specifically associated with lower mortality, researchers report, were:
• ACE inhibitors (HR: 0.84, 95% CI, 0.80-0.87),
• Beta-blockers (HR: 0.87, 95% CI, 0.84-0.91), and
• Thiazide diuretics (HR: 0.83, 95% CI, 0.80-0.87)

No comparable benefit was seen with calcium-channel blockers, although they add that an association was also found between adherence to antihypertensive therapy and decreased cancer-specific mortality (HR, 0.94; 95% CI, 0.90-0.98).

“Although further analysis is necessary, this increment of survival may be associated with a higher dose exposure, as a long-term/high-dose exposure to ACE-Is/ARBs was associated with a decreased incidence of CRC mortality,” the report advises.

While calling for more studies, researchers suggest that the use of blood pressure medications “may present a promising, low-cost pathway to supporting CRC treatment for stage I–III cancers.”

They explain that hypoxia and uneven tumor vascularization can contribute to cancer treatment failure by promoting metastases, complicating surgery, and limiting the efficacy of a variety of known cancer therapies.

“Therefore, strategies that normalize tumor vasculature function and hypoxia to normalize the underlying tumor microenvironment may be effective for the optimization of different modalities of cancer patient management,” the authors note.

In addition, the study points out that hypertension is one of the most significant comorbidities suffered by cancer patients, with past studies suggesting that new-onset hypertension occurs in about one-third of cancer patients.

The authors point out that chemotherapy can exacerbate the issues because “hypertension is a known risk factor for chemotherapy-induced cardiotoxicity and has a correspondingly large influence on cancer management approaches.”

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.