Silver Linings: Some Treatments for Comorbidities May Help Prevent Cancer

Comorbidities can sometimes get in the way of cancer treatment, but the world of oncology also has something to gain from its interconnection with these conditions: Some of the medications used to treat various comorbidities, such as hypertension, diabetes and osteoporosis, may actually have a favorable impact on the likelihood of cancer, or its spread or recurrence.

“It’s no coincidence that risk factors for heart disease, stroke and cancer are fairly similar,” explains Howard Bailey, director of the University of Wisconsin Carbone Cancer Center and an expert on chemoprevention. While scientists are still unraveling the fine details, it’s clear that inflammation and a misfiring metabolism are at the root of many common health problems. It makes sense that drugs that help repair these issues could have benefits beyond the targeted conditions.

The other advantage of these medications is that they are already taken by hundreds of thousands of people. The first rule of medicine is “do no harm,” and that’s particularly true when devising preventive measures. Because these medications are clearly tolerated by so many people, they are considered generally safe. An added benefit: The longer they are in use, the more likely we are to figure out new uses.

Here are some recent findings on chemoprevention:

> Statins: In two studies presented at a major oncology conference this year, researchers reported that statins such as Lipitor (atorvastatin) and Crestor (rosuvastatin), indicated for the prevention of heart disease and stroke, improved the survival of women with breast, bowel and ovarian cancers, and of men with advanced prostate cancer, by 40 percent. For instance, in one of the studies, 55 of 709 women who took statins died of breast cancer (0.18 percent), while 200 of 2,443 women not using statins died of the disease (0.31 percent). And the rate of death dropped by a relative 55 percent for women with bone cancer who took the drugs, meaning that 15 of the 709 women taking statins died of bone cancer (0.05 percent), while 100 of the 2,443 not taking statins (0.16 percent) died from the disease.

> Bisphosphonates: These bone-strengthening drugs, used to treat osteoporosis, include Fosamax (alendronate sodium) and Reclast (zoledronic acid). According to a group of researchers in England, such drugs helped prevent the spread of breast cancer to bones in mice, halting the disease. This year, in a review of 26 trials of 19,000 women with breast cancer, investigators found that bisphosphonates reduced the absolute risk of dying from the disease by 2 to 3 percent among postmenopausal women in the first decade following diagnosis.

> Metformin: Researchers are studying whether this diabetes drug can help prevent cancers including colorectal, prostate, endometrial and breast. The idea came from studies of people with diabetes, which showed that participants who took metformin had a lower incidence of cancer than those who took different types of drugs to control their diabetes.

> Aspirin: This nonsteroidal anti-inflammatory drug (NSAID) and others in its class, such as ibuprofen — when used regularly — may reduce breast cancer growth. A study of more than 4,000 women starting at least a year after their diagnosis with stage 1 to 3 breast cancer found that those who took aspirin two to five times a week had a lower risk of breast cancer death than non-aspirin takers. Women in the group who didn’t take aspirin had about a 1 percent chance each year of dying of breast cancer. Those who took aspirin two to five times a week faced a 0.3 percent risk of dying of breast cancer each year. Taking aspirin more frequently — six to seven days a week — appeared slightly less beneficial; these women faced a 0.43 percent annual risk of breast cancer death. Also decreased among aspirin users was the risk of the cancer’s spread. Despite these encouraging findings, this treatment is not considered standard, and women should ask their doctors before beginning any regimen of NSAIDs. A large prospective randomized trial of aspirin in breast cancer survivors is planned.

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> Blood pressure drugs: A clinical trial is now testing a concept that worked well in mouse models — that the angiotensin-converting enzyme (ACE) inhibitors often used to control hypertension, such as Lotensin (benazepril) and lisinopril, can, when combined with chemotherapy, help delay tumor growth and extend survival. The phase 2 trial, which is enrolling, is testing the drug losartan plus FOLFIRINOX chemotherapy followed by short-term proton beam radiation in patients with locally advanced, unresectable pancreatic cancer (NCT01821729).