The San Antonio Breast Cancer Symposium (SABCS) is an annual international conference directed towards academicians, private physicians and researchers with more than 7,000 in attendance from 90 countries. The purpose of the symposium is to relay breaking news, trial updates, advances in biology and practice-changing guidelines in breast cancer care and management.
Breastlink sends a team of physicians and researchers to SABCS every year to gather critical updates and research advances. We then disseminate the results to patients, referring physicians and the Breastlink medical team. Last year, for example, the results of the ATLAS trial delivered at the 2012 SABCS extended the duration of Tamoxifen from 5-years to 10-years in certain groups of breast cancer patients. This year, a number of important findings were discussed:
In Prevention News:
The results of the preventive trial of anastrozole for post-menopausal women (IBIS-II) were favorable. Women taking the aromatase inhibitor (AI) had a 53 percent reduction in the risk of developing breast cancer compared to women who did not get the drug. There was a 10 percent increase in musculoskeletal symptoms bu less than 2 percent increase in fractures for women on the AI.
Interpretation: There are now more pharmacologic options available to high-risk women who want to lower their risk of breast cancer.
In Local Therapy News:
1. Radiation after lumpectomy: PRIME 2 trial results. This compared lumpectomy and hormonal therapy with and without radiation for women with invasive ER+ breast cancer 65 and older. At 5 years follow-up, recurrence was only 4.1 percent for women randomized to NO radiation compared to 1.3 percent with radiation. There was no difference in survival between the groups.
Interpretation: radiation therapy benefits all groups of women with invasive breast cancer, but for some the benefit may be very small.
2. Surgery for Stage IV breast cancer. There were two randomized trials, one from India and another from Turkey, evaluating the benefit of surgery on the primary breast cancer for women who presented with metastatic breast cancer. No clear benefit in survival with surgery was identified in either trial at this point in time for the majority of patients.
In Adjuvant Therapy News (Bisphosphonates and Bevacizumab):
1. The Benefit of Bisphosphonates. Bisphosphonate therapy is commonly given to women with osteoporosis or women at risk of bone cancer metastasis from breast cancer. A meta-analysis by the EBCTCG reviewed 22 randomized trials of bisphosphonate treatment in 17,791 women with early breast cancer. With 10 years of follow-up data, post-menopausal women who were randomized to bisphosphonate treatment had a 34 percent decreased risk of bone metastasis and 17 percent decreased risk of death from breast cancer compared to women who were not given the drug.
Interpretation: Newly diagnosed post-menopausal women with any invasive breast cancer are now recommended to start this a bisphosphonate regimen with their adjuvant therapy.
2. Adding bevacizumab to HER2-directed chemotherapy: Reporting from the BETH trial, researchers found no substantial benefit from adding bevacizumab to trastuzumab-based chemotherapy after curative surgery. An increase in adverse events, including hypertension, was associated with the bevacizumab arm. This study helps to put the final nail in the coffin regarding bevacizumab’s role in treating breast cancer – both metastatic as well as localized.
In Neoadjuvant Therapy News:
1. Predicting trastuzumab treatment failure: The German Breast Cancer Group reported that HER2-positive, hormone receptor-positive breast cancer with mutations in the PI3K/AKT pathway may respond poorly to chemotherapy and combined anti-HER2 therapy prior to surgery in comparison to those without the mutation. This group is currently conducting the NeoPHOEBE trial using an inhibitor of PI3K, buparlisib.
2. Adding platinum chemotherapy: For triple negative breast cancer, combining carboplatin to neoadjuvant therapy improved the likelihood of finding no evidence of disease at the time of surgery, as reported from the CALGB 40603 study. This complete response rate has a known correlation with improved survival. From the same analysis, adding bevacizumab, “Avastin,” to pre-surgery chemotherapy carried no added benefit.
In Tumor Biology News:
1. Tumor infiltrating lymphocytes (TILs): Two separate reports demonstrated prognostic and predictive relevance to finding TILs within the breast cancer stroma. Patients whose tumors were HER2 over-expressed or triple negative had a better prognosis when higher levels of TILs were seen. Implications from these studies include the possible inclusion of TIL analysis into the AJCC (American Joint Committee on Cancer) staging for triple negative breast cancer as well as further uncovering trastuzumab’s role as a possible immune modulator when used with chemotherapy.
There were many other important presentations, sessions and posters that were presented, including data on NSABP-B32 10-year update on occult sentinel lymph node metastasis, sentinel lymph node biopsy and neoadjuvant chemotherapy, gene-mutation testing and panel testing, fertility treatment and breast cancer risk, to name a few.