Healthcare

As part of the prospective Women Health Initiative (WHI) Observational Study, the researchers determines the association between self-reported alcohol intake and the risk for postmenopausal breast cancer.

According to their findings that reported in August 23, 2010 of the Journal of the National Cancer Institute, alcohol consumption was directly associated with an overall risk for invasive breast cancer, invasive lobular carcinoma, and hormone receptor-positive tumors.

The study involve 87,724 participants enrolled from 1993 to 1998. During follow-up through September 2005, total 2294 participants were diagnosed with invasive breast cancer.

The study authors, Christoper I. Li, MD, PhD, from Fred Hutchinson Cancer Research Center in Seattle, washington, and colleagues write, “Alcohol consumption is a well-established risk factor for breast cancer.”
According to them, “This association is thought to be largely hormonally driven, so alcohol use may be more strongly associated with hormonally sensitive breast cancers. Few studies have evaluated how alcohol-related risk varies by breast cancer subtype.”

According to the investigators, the association between alcohol intake and breast cancer was stronger for certain types than for others.
They said that for women who drank at least 7 alcoholic beverages per week, the risk for hormone receptor-positive invasive lobular carcinoma was nearly double compared to people who never drink alcoholic beverages.
However, for the risk of hormone receptor-positive invasive ductal carcinoma was not statistically significantly increased.
The difference in hazard ratios (HRs) per drink per day among current drinker was 1.15.

Absolute rates of hormone receptor-positive lobular cancer were 5.2 per 10,000 years among never-drinkers and 8.5 per 10,000 person-years among current drinkers.
For hormone receptor-positive ductal cancer, absolute rates were 15.2 and 17.9 per 10,000 person-year, respectively.

Despite several limitations in this study such as observational design with possible residual confounding, and assessment of alcohol use only at baseline, so that extensive measurement errors or changes in alcohol use could affect the study conclusion. Also, data on tumor characteristics were based on information abstracted from local pathology reports, which may have led to an unknown degree of misclassification because of variations in histology and hormone-receptor assessment across in the United States, the authors concluded, “This study provides prospective evidence that the relationship between alcohol use and breast cancer risk varies by breast cancer subtype, with risk most pronounced for invasive lobular and hormone receptor-positive tumors.”
And added, “Hence, alcohol is another established breast cancer risk factor that appears to be differentially associated among breast cancer subtypes, and this pattern of associated risk indicates that tumors defined by both histology and hormone receptor status have somewhat different etiologic determinants. These findings highlight the importance of incorporating breast cancer subtype information in etiologic studies of the disease.”