Highlights from the San Antonio Breast Cancer Symposium

BCRF shares updates from the largest scientific meeting on breast cancer research.

The San Antonio Breast Cancer Symposium (SABCS) on December 4-8 welcomed over 7,500 physicians, researchers, patient advocates and healthcare professionals from over 90 countries. In the field of cancer research, SABCS is among three major annual meetings that provide a forum for researchers across all disciplines to present new and emerging data to the scientific community for open discussion, feedback and debate.

SABCS is unique in its singular focus on breast cancer research. The conference features sessions on clinical trial updates, breast cancer biology and genetics, drug discovery, survivorship and quality of life. As in past years, BCRF research staff attended the meeting to hear the latest in breast cancer research at the scientific symposia and to meet BCRF investigators at the poster sessions. Joined by members of BCRF  communications team, we conducted live interviews with BCRF investigators on topics ranging from quality of life to metastasis, breast cancer in men and emerging therapies.

Here are some highlights from BCRF investigators who presented at the meeting.

Liquid biopsy predicts recurrence in estrogen receptor (ER)- positive breast cancer 

BCRF investigator Dr. Joseph Sparano reported that detecting a single circulating tumor cell (CTC) in women five to seven years after a diagnosis of hormone receptor-positive breast cancer increased the risk of recurrence within two years. 

To perform the study, investigators used a commercially available blood test to detect CTCs in the blood of breast cancer patients who had completed surgery as well as five years of endocrine (anti-estrogen) therapy. The study included 546 patients in the original trial conducted by the ECOG-ACRIN breast cancer trial group with support from BCRF.

Out of the trial participants, 4.8 percent of patients had a positive CTC result. CTCs were detected more often in patients with ER-positive breast cancer (5.8 percent) compared to ER-negative breast cancer (4.3 percent).

At a median follow up of just over one and a half years, the investigators reported that a positive CTC result increased the risk of recurrence within two years by 20-fold in patients with ER-positive breast cancer, but was not predictive in patients with ER-negative disease.

While the study’s findings are dramatic, Dr. Sparano cautioned, “We need more clinical trials to confirm the clinical utility of the assay.” Click here to watch Dr. Sparano’s full interview with BCRF on Facebook. Read more about the study in the ASCO Post.

Immunotherapy improves progression free survival in Herceptin-resistant, HER2-postive breast cancer patients

BCRF investigator Dr. Sherene Loi presented an early analysis from the PANACEA trial that investigated the effect of adding anti-PD-LI immunotherapy (Keytruda) to Herceptin in patients with advanced HER2-positive breast cancer that had progressed on Herceptin.

The Phase Ib/II study primarily assessed safety and efficacy of combining Keytruda with Herceptin. Investigators reported that the combination was well tolerated. Analysis on the effect of the combination on tumor progression revealed that the presence of the Keytruda target protein, PD-L1 was a key determinant to response. In patients whose tumors expressed PD-L1, the overall survival at 12 months was 65 percent compared to 12 percent in patients whose tumors did not express PD-L1.

This is an important finding because it provided a tumor marker that may predict patients most likely to response to the combination therapy.

“This proof-of-principle study suggests that immune evasion is a mechanism of resistance to trastuzumab and contributes to disease progression in advanced HER2-positive breast cancer,” Dr. Loi told AACR.

Another finding from the study demonstrated that immune cells called tumor infiltrating lymphocytes (TILs) were much less prevalent in the metastatic tumors than the primary tumor, and primarily found only in tumors with PD-L1. 

Updates on the International Male Breast Cancer Study identifies key differences in male vs. female breast cancer.

Male breast cancer represents about one percent of all breast cancers – and one percent of all cancers in men. Due to the disease’s rarity, clinical trials have been difficult to complete for lack of participants and this has affected our understanding of the disease and how best to treat men with breast cancer. 

To tackle this problem, BCRF investigator Dr. Fatima Cardoso leads the International Male Breast Cancer Study – the largest study in the world on male breast cancer – which reported new results in three presentations at SABCS. Findings include:

• Like breast cancer in women, male breast cancer is most often ER-positive and a luminal subtype. However, HER2-positive and triple negative breast cancers much more rare in men than in women.
• Despite the majority of male breast cancers being hormone receptor positive, many men do not receive the appropriate treatment for ER-positive breast cancer, including radiation therapy or the option of breast conserving surgery .
• The most prevalent risk factor for male breast cancer is a hereditary mutation in the BCRA2 gene, but as in female breast cancer, being overweight or obese, smoking, and alcohol consumption (more than one drink/day) also increases the risk of breast cancer in men.
• In an initial retrospective analysis of 152 male breast cancers, study investigators identified two subgroups of male breast cancer that could be further subclassified.

To gain more insight into these findings, BCRF spoke Dr. Cardoso in this Facebook Live interview.  

Acupuncture is shown to relieve symptoms of joint pain from aromatase inhibitor treatment.

BCRF investigator Dr. Dawn Hershman reported results from the fist large multicenter study demonstrating the effectiveness of acupuncture to reduce joint pain caused by aromatase inhibitors (AI).

AIs are the most common treatment for ER-positive breast cancer in postmenopausal women. To be effective at reducing the risk of recurrence, they are prescribed for five to seven years. However, joint pain associated with AI may cause women to discontinue their therapy prematurely.

The study was conducted by the SWOG breast cancer trials group with support from BCRF. It was the first to rigorously test an acupuncture intervention for AI-induced pain. To do so, 226 patients with early stage, ER-positive breast cancer were randomized into three groups. Group one (110 patients) received true acupuncture therapy according to a very specific point prescription; Group two (59 patients) received a sham acupuncture, which involved superficially inserting needles in non-acupoints; Group three participants (57 patients) were on a wait list for acupuncture, but did not receive true acupuncture until data from the three groups were analyzed.

The strength of the study to detect the true effect of acupuncture comes from the study design and inclusion of a sham (fake) acupuncture group. Neither the study participants nor study staff knew which women were assigned to either group.

Dr. Hershman and her colleagues reported that the true acupuncture group experienced a significant reduction in pain than either of the other two groups. The effect was sustained 12 weeks after the 12-week intervention ended, indicating the potential for long lasting results.  

“We hope that these data will not only encourage health-care practitioners to discuss acupuncture as a complementary therapy for patients receiving aromatase inhibitors, but that they will also enhance payers’ willingness to reimburse these patients for acupuncture,” Dr. Hershman told AACR.

BCRF interviewed Dr. Ann Partridge about this and other studies on breast cancer in young women. You can listen to the full interview here and read more about the acupuncture story in the ASCO Post.

Continue to follow BCRF on more news from SABCS.