Some mastectomies not needed, study suggests

The findings suggest that some of the patients had a higher risk to develop the disease, especially those who were younger than 40 years old, African-American and those whose abnormal cells contained molecular markers typically found in advanced forms of cancers with poorer prognoses.

A new study of 136,000 adults found light to moderate drinking was associated with an increased risk of breast cancer in women and several other cancers in male smokers. This type of cancer makes up nearly 20 to 25 percent of all diagnosed breast cancer in the US.

It looked at the medical records of over 100,000 women diagnosed with DCIS between 1988 and 2011 and assessed whether treatments had an impact and how many patients were still alive after 10 and 20 years.

However, for others, the findings from the study suggested aggressive treatment, such as lumpectomies, lumpectomies with radiology and mastectomies, is often not necessary.

DCIS is a well-known risk factor for breast cancer, but doctors have disagreed on whether to treat it. Light drinking have been linked to a minimal increase of risk of all cancers but daily drinking, even just a glass have been found to increase the risk of breast cancers in women.

JUDY WOODRUFF: And I just want to clarify again for our audience who is watching, we’re throwing around the term DCIS, which, again, most – it stands for the least advanced stage of cancer, also known as stage zero.

“It is therefore appropriate to consider these as de facto breast cancers and not as pre-invasive markers predictive of a subsequent invasive cancer”, Narod’s team wrote.

With the discovery that treatment of very early stage cancers has not reduced mortality from the disease significantly, some researchers are questioning the effects of what they describe as over-diagnosis and over-treatment.

Women diagnosed before the age of 35 had a 17 times greater than normal risk of dying from breast cancer, Dr. Steven Narod of Women’s College Hospital and the University of Toronto found.

The research authors recommended women not exceed one drink a day in order to keep their cancer risk as low as possible.

But a massive new study has the medical community rethinking its approach to treatment, and has led to questions about whether thousands of women are undergoing unnecessary surgery and radiation treatment. Scientists also need to figure out how much treatment – if any – is needed for most women diagnosed with DCIS so patients don’t undergo unneeded surgeries and therapies. Golshan said two studies in Europe are examining what happens when women with the same diagnosis are randomly assigned to different interventions – for example, if the patients are simply observed vs. given treatment.

The study did identify a subset of women with DCIS who were at a higher risk. That may lead some women to skip radiation, Narod said.

I think what it does tell us is that, to date, physicians have been pretty good at selecting low-risk DCIS, which can be treated minimally with lumpectomy alone.

More broadly, the study highlights a recurring theme in cancer research: Screening has allowed doctors to detect tumours earlier but hasn’t always enabled them to distinguish between the ones that will be fatal and the ones that are slow-growing and may not affect someone’s health.