The study, which appears in the Journal of the American Medical Association (JAMA) Oncology this week, found that women treated for ductal carcinoma in situ, a group of abnormal cells found in the milk duct, were not significantly less likely to die of breast cancer than women on average.

He suggests the research shows it is the former, though it is a curable form of cancer in the vast majority of cases.

Women with the diagnoses were treated with a lumpectomy (a surgical treatment that removes a lump from the breast), lumpectomy with radiation therapy, or mastectomy (full surgical removal of the breast). However, researchers studied 100,000 women diagnosed with DCIS for 20 years, and found 97% of them did not die from breast cancer after undergoing treatment. The death rates were twice as high for those younger than 35 and in blacks – but still lower than those with more common invasive breast cancer. This factor comes into focus while analyzing results of the study in relation to prostate, colon and breast cancers. They reviewed age at diagnosis, race/ethnicity, pathologic features, date of second primary breast cancer, cause of death, and survival.

Narod’s research is what is called an observational study. Study researchers recruited men and women who were moderate alcohol drinkers, two glasses for men and three for women. These rates, however, were still lower than those for women with more invasive stages of breast cancer. The researchers then assessed the total cancer risk as well as the known alcohol-related types of cancers, which included colorectal cancer, female breast cancer, oral cavity, esophagus, pharynx, liver, and larynx cancer.

An editorial accompanying the article argues the findings should lead to a dialing back of the way women diagnosed with DCIS are treated.

Dr. Laura Esserman, of the University of California San Francisco, said to stop thinking of DCIS as a single condition to help determine treatment.

In the 1980s, women with DCIS numbered only in the hundreds, but about 240,000 women received diagnosis of invasive breast cancer each year. We now know that breast cancer encompasses a range of behaviors, from aggressive to indolent; the latter are more likely to surface with screening.

Risk for death in patients observed was compared with the general population, with Cox proportional hazard analysis performed to estimate hazard ratio for death from DCIS by age at diagnosis, clinical features, ethnicity, and treatment option.

According to Professor Sir Ian Gilmore, the chair of the Alcohol Health Alliance UK, “This research confirms the results of previous studies showing that there is no such thing as a safe level of drinking when it comes to the risk of cancer”.