American Society of Clinical Oncology (ASCO): Update from Recent Meeting

Top Highlights from Natalie Mandolfo, our Board Mission Chair

July 5, 2011

At the recent American Society of Clinical Oncology (ASCO) meeting held in Chicago, IL  from June 3-7th, 2011, breast cancer was the topic of many great discussions. Below are just a few of the top highlights:

Exemestane Significantly Reduces Risk of Invasive Breast Cancer in High-Risk, Postmenopausal Women: A large randomized double-blind phase III trial has shown that in postmenopausal women who are at increased risk of developing breast cancer, the aromatase inhibitor exemestane (Aromasin) reduces this risk by 65 percent compared with placebo.

Adding Regional Nodal Irradiation Decreases Recurrences in Women with Early Breast Cancer: Interim analysis data from a randomized Phase III trial showed that, in women with node-positive or high-risk node-negative breast cancer, additional radiation treatment to the regional lymph nodes (regional nodal irradiation, or RNI) improves disease-free survival, reducing cancer recurrences both near the tumor site and in other parts of the body.

A Short Course of Hormone Replacement Therapy (HRT) Does Not Appear to Increase Breast Cancer Risk for BRCA1 / 2 Carriers after Undergoing Risk Reducing Salpingo-Oophorectomy (RRSO): In an analysis of 1,299 BRCA1 or BRCA1 mutation carriers  there was no significant difference in the incidence of breast cancer in women who underwent risk reducing salpingo-oophorectomy (RRSO: removal of ovaries and fallopian tubes) and received HRT compared to those who underwent RRSO and did not receive HRT. Of 321 women who had undergone RRSO, the incidence of breast cancer was 14% in those who received HRT (20 of 144 women) and 12% in those who never received HRT (22 of 177 women) which was not a statistically significant difference. Some experts believe that this data may suggest that short term HRT to control menopausal symptoms could be considered for BRCA 1 / 2 carriers undergoing RRSO for ovarian and breast cancer risk reduction. This study also supports findings of previous studies that have shown definitively that oophorectomy reduces ovarian and breast cancer incidence in these women and reduces their mortality due to those cancers.

Cigarette Smoking Again Shown to Increase  A Woman’s Risk of Breast Cancer:  Data that was part of the Breast Cancer Prevention Trial of the National Surgical Adjuvant Breast and Bowel Project (where women with high risk for breast cancer were assigned to either receive tamoxifen or placebo for prevention) has continued to be studies and after over 8 years of evaluation researchers recently announce that compared to the 55% of women in the study who had never smoked,  there a significant increase in risk for breast cancer in women who were smokers (the risk increased as the years of smoking increased).  While that original data from this prevention trial (known commonly as the BCPT trial some of you may have participated in) has been discussed for many years, many may remember a clear benefit was demonstrated for women who took Tamoxifen versus Placebo in reducing the risk of developing breast cancer.

Resource: ASCO daily news, Wrap Up Edition 2011; ASCO News online