Breast cancer updates

By Dr. Ananya Mandal, MDMar 22 2011

Stress association with breast cancer

Many survivors of breast cancer cite stress as a link to the cancer despite no scientific proof of a connection. Experts believe that the root cause here are the lifestyle-related issues - such as smoking and obesity - where there is a clear link to the cancer.

This came from research which took in the views of almost 1,500 Australian breast cancer survivors. The study showed that just over four in 10 (43.5 per cent) believed there was a factor which contributed to their cancer and, among these women, more than half (58.1 per cent) blamed stress. The women also pointed to previous use of hormone therapy (17 per cent), a family history of cancer (9.8 per cent). Two per cent attributed their cancer to other lifestyle factors. Women aged under 40 were more likely to believe there was a reason for their breast cancer.

Christine Bennett, chair of the Bupa Health Foundation Steering Committee which part-funded the study said, “It is concerning that only two per cent of the women in the study attributed their breast cancer to lifestyle factors such as diet, exercise and alcohol consumption...There is scientific evidence that being overweight, smoking and excessive alcohol are risk factors.”

The Bupa Health Foundation and Well-Being after Breast Cancer Study and was led by Robin Bell, Deputy Director of the Women's Health Research Program at Monash University and Alfred Hospital. According to Professor Bell it showed women often responded to a breast cancer diagnosis with a new resolve to improve their overall health, usually through improved exercise. This could do good she added but warned that women should be wary of making changes which could be counter-productive in the fight against cancer - such as removing all dairy products from the diet. “Cutting out dairy products may remove some fat from the diet but it could have a negative effect on the bone health of women who, due to some cancer treatments, are already at risk of osteoporosis,” Prof Bell said.

Speaking on those who blamed stress she said, the women could also feel a sense of mistaken guilt that they should have acted sooner. “If doctors are aware of this guilt, they will be in a better position to help women address their feelings and overcome their distress,” Prof Bell said.

The research is published in the March edition of the journal Psycho-Oncology.

Heart disease drug & breast cancer

Another new study on more than 2 million Danes has shown that women taking the heart drug digoxin have an increased risk of breast cancer. Digoxin, marketed as Lanoxin and Digitek, is used by people with heart failure or with abnormal heart beats. But it can also act like the female hormone estrogen in the body, leading researchers to wonder if it might up cancer risk the same way estrogen treatment does in older women.

The study showed that about two percent of the women who took digoxin at any point eventually developed breast cancer. Former users had the same risk as those who had never taken the drug, while those currently on it were about 40 percent more likely to get breast cancer.

That extra risk is “worth noting,” said Dr. Timothy Lash of Aarhus University Hospital in Denmark, a breast cancer expert an independent observer. But he added that it's less impressive when you consider how few women actually developed the disease. In the U.S., about one in eight women develop breast cancer at some point, according to the American Cancer Society.

The study was led by Dr. Robert Biggar of Statens Serum Institut in Copenhagen, Denmark, whose team tapped into two different country-wide databases. About 100,000 women age 20 and older took digoxin at some point during the course of the study, which tracked women for an average of 12 years. The risk of breast cancer was highest in women who were in their first year of taking digoxin. Then it dropped off, but slowly crept up again after 3 years or more on the drug.

In a note the researchers write in the Journal of Clinical Oncology that this study can't prove that digoxin, actually causes breast cancer in some women. And even if it does, the heart benefits might still outweigh that risk. Dr. Lash said, “It might be worth talking with their doctor about the trade off, (but) maintaining heart health is an important consideration.”

Tamoxifen for five years improves outcome in breast cancer

A new study has shown that women boost their chances of surviving breast cancer if they complete their full five-year course of tamoxifen. This drug is one of the most important in fighting breast cancer but many women stop taking it after two years as they experience side effects.

The large study has now found breast cancer returned in 46% of women who stopped taking it early, compared to 40% who completed the course. Senior author Dr Allan Hackshaw said, “Taking it for five years offers the best chance of surviving cancer.”