Cancer risk relatively low with DAPT regardless of drug used

December 14, 2015 – The DCRI’s Matthew Roe, MD, MHS, found that few acute coronary syndrome patients develop neoplasms while on dual antiplatelet therapy.

Relatively few acute coronary syndrome (ACS) patients develop neoplasms while on dual antiplatelet therapy (DAPT), and the frequency of neoplasm detection was similar regardless of which antiplatelet agents were used, according to a new study by DCRI researchers.

The study is the latest analysis of results from the Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes (TRILOGY ACS) study led by the DCRI’s Matthew Roe, MD, MHS (pictured), and E. Magnus Ohman, MD. The results were published online this month in the European Heart Journal.

matthew-roe-newsThe interaction between cancer and cardiovascular disease is complex and only partially understood. Earlier studies have arrived at different conclusions about the risk of cancer associated with long-term cardiovascular therapies.

In this study, the researchers collected data on cancer history and pre- and post-randomization cancer-screening procedures for ACS patients who were randomized to DAPT (aspirin plus either prasugrel or clopidogrel) from the original TRILOGY ACS trial. That trial was a double-blind, randomized trial that compared prasugrel to clopidogrel in ACS patients with unstable angina or non-ST elevation myocardial infarction managed without revascularization.

Over three years, the trial enrolled 9,326 patients from 52 countries. Of these patients, 9,240 received at least one dose of the study drug and were analyzed for this study. Median treatment exposure was 15 months; median follow-up was 17 months.

In the current study, the researchers looked at each patient’s history of prior neoplasm occurrence and any cancer-screening tests or procedures performed before and after randomization.

“We found that cancer screening rates were much higher in North America and Western Europe compared with other regions, a finding that we believe confounded the ascertainment of neoplasm events given that geographic region was one of the strongest predictors of neoplasm development,” Ohman said.

The researchers found 187 distinct new, non-benign neoplasm events in 170 participants who received at least one dose of study drug (1.8 percent incidence rate). There was no statistical difference in neoplasm development observed between patients who received prasugrel versus those who received clopidogrel.

The researchers also found that rates of cardiovascular death, myocardial infarction, or stroke were higher among those patients who experienced a neoplasm event (18.2 percent) versus those who did not (13.5 percent). Additionally, the detection of new, non-benign neoplasm events was also associated with high rates of permanent study drug discontinuation and bleeding events (both before and after neoplasm detection).

“We implemented a novel data collection and ascertainment process for neoplasm events in a global cardiovascular outcomes trials on a scale that had never been done beforehand,” Roe said. “These findings are groundbreaking and will inform future efforts to understand the potential cancer risks of long-term cardiovascular drug therapies.”