Every year, the San Antonio Breast Cancer Symposium (SABCS) hosts one of the most important breast cancer conferences in the world. Experts across various specialties gather to share updates in cutting-edge breast cancer treatments and interventions. At the 2015 SABCS, Breastlink joined the discussion to share research we’ve been working on with patients in Orange County.

I had the opportunity to present a research poster and host a discussion on the results of a Breastlink study that I led: “Multi-gene panel testing and the cancers identified in patients at risk for hereditary breast cancer.” Dr. John Link presented a research poster based on another study we conducted: “The Breast Cancer Index as a Tool in Decision Making for Adjuvant Hormonal Therapy in Early Luminal Breast Cancer: Initiation, Withdrawal and Continuance.”

Dr. Nimmi Kapoor’s Poster

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Dr. John Link’s Poster

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Hereditary Breast Cancer, Cancer-Related Genes & Cancer Types

In one study, we looked at the relationship between pathogenic gene mutations and the biology of cancers in women at risk for hereditary breast cancer. Understanding cancer biology can help us to optimize screening, prevention and treatment in patients with a genetic predisposition for cancer.

Multigene panel testing offers additional information about the relationship between genetics and cancer biology. Earlier genetic tests evaluated only genes BRCA1 and BRCA2, but multigene panel testing can evaluate up to 43 cancer-related genes for pathogenic mutations and variants of uncertain significance (VUS).

Our study included data from 500 patients who received panel testing for between 5 and 43 cancer-related genes. These patients met NCCN testing guidelines and all had a personal or family history of breast and/or ovarian cancer. A total of 32 patients (6.4%) tested positive for at least 1 pathogenic mutation and a total of 81 (16.2%) tested positive for VUS.

Pathogenic mutations were most commonly detected in BRCA2 (30.3%), CHEK2 (21.2%), MUYTH (9.1%), PALB2 (9.1%), BRCA1 (6.1%), and ATM (6.1%). A majority of patients testing positive for a pathogenic mutation were diagnosed with ER-PR-positive invasive ductal carcinoma. Patients with non-BRCA mutations were more likely to have a family history of ovarian cancer than patients with BRCA mutations.

Multigene panel testing is still relatively new to clinical settings and we are uncovering new knowledge about breast cancer biology and genetics every day. However, as we collect more data, additional information about biology and genetics will help us to improve breast health care and cancer treatment.

The Breast Cancer Index & Treatment Decision Making

In another study, we investigated how the breast cancer index affected treatment decision-making in women with early-stage luminal breast cancers. The Breast Cancer Index (BCI) is genomic biomarker test that assesses risk of recurrence and predicts likelihood of benefit from extended endocrine therapy.

Women with early-stage luminal cancers have traditionally been treated for 5 to 10 years with adjuvant endocrine therapy. Benefits to endocrine therapy vary and around one-third of women on endocrine therapy suffer side effects and quality of life issues. With the ability to assess risk and likelihood to benefit, many women can avoid these issues.

In our study, we collected information from our first 100 patients tested with BCI. Results were analyzed for three groups of patients:

  • Patients who were considering adjuvant therapy (n=14).
  • Patients 6 months to 4 years post-diagnosis considering discontinuation of therapy (n=54).
  • Patients with more than 4 years of post-diagnosis therapy considering extended therapy (n=32).

Out of 100 patients tests, 93 made treatment decisions in line with BCI predictive results. Most women were found to have a low risk of recurrence and a low likelihood of benefit from adjuvant therapy. Of these, all but one chose not to pursue endocrine therapy. Similarly, all patients with a high risk of recurrence and high likelihood to benefit continued or extended therapy. Overall, around two-thirds elected against initiation or continuation of therapy.

Results to our study show that BCI provides important information to assist many breast cancer patients in treatment decision making. Breast cancer clinics can use BCI results to personalize care and help many women avoid unnecessarily suffering side effects of treatment.

It was exiting to be part of the stimulating dialogue at the 2015 San Antonio Breast Cancer Symposium. Breastlink is committed to working with breast cancer researchers to advance effective treatments and we are proud to share our own results with some of the world’s leading breast cancer experts.