Common blood pressure drugs may raise risk of cancer

ARBs are commonly taken by patients suffering from hypertension and heart problems. On analyzing data from previous studies that involved some 60,000 people, researchers found that the drugs raised the risk of cancer by 1.2 percent. It included lung cancer, breast cancer and prostrate cancer.

The risk of cancer is small, but significant
"The increased risk of new cancer occurrence is modest but significant," said lead author Dr. Ilke Sipahi and his colleagues from Case Western Reserve University in Cleveland.

The small risk is very significant because these drugs are used widely and therefore they may be responsible for numerous new cases of cancer every year.

However, the drugs were not linked with increased rate of death from cancer, but that is probably because cancer is a slowly progressing disease and the consequences may not be completely recorded in relatively short-term studies.

My message for the patients who are currently on ARBs is they should not stop taking these medications on their own because they have beneficial effects -- lead author Dr. Ilke Sipahi

About 85 percent of patients in the trials were reported to be on German drugmaker Boehringer Ingelheim's telmisartan, which is sold under the trade name- Micardis, and has annual sales of over $1.5 billion.

Among the patients who had been taking these medications for over four years, one extra case of cancer was detected in every 105 people.

No need to ditch the drugs immediately
However, experts do not see the need to cut down on the drugs immediately, but they suggest that concerned patients should consult their physicians. Also, they have called for deeper investigation to determine the adverse effects of ARBs.

“My message for the patients who are currently on ARBs is they should not stop taking these medications on their own because they have beneficial effects,” said Dr. Sipahi. “They need to make a decision with their physicians about the potential risks and whether they need to switch.”

The study was published in the medical journal, Lancet Oncology on Monday.

German drug maker defends its drug
Boehringer Ingelheim spoke up against the findings of the study, insisting that the results were in contradiction of the “internal safety data” they have.

Though no firm reason could be established for the risk of increased cancer with ARBs, it is suspected that the drugs may be responsible for blood vessel growth in tumors.

In a piece of writing accompanying the study, Dr. Steven Nissen, a cardiologist at the Cleveland Clinic, said that the findings were "disturbing and provocative, raising crucial drug safety questions for practitioners and the regulatory community."