San Antonio Breast Cancer Symposium

av Balazs Acs, 10– 14 december 2019

I attended the 42nd Annual San Antonio Breast Cancer Symposium (SABCS), the largest annual breast cancer meeting in the world. This year’s meeting breast cancer symposium more than 7,500 attendees from 90 countries. The event presented a balance of clinical, basic and translational research in breast cancer.
Please find here are some key highlights from studies presented at SABCS 2019:

  1. The Destiny-Breast01 Phase II trial (n=184) investigated a new HER2-targeted antibody-drug conjugate that called trastuzumab deruxtecan (T-DXd). T-DXd has a monoclonal antibody targeting HER2 and topoisomerase 1 inhibitor as the payload. The trial showed that T-DXd yielded durable objective responses in patients with HER2-positive breast cancer who were heavily pretreated, including with T-DM1. The importance of this study is that resistance to anti-HER2 drugs develops almost inevitably and currently we do not have a standard of care for these patients once resistance occurs.
  2. The HER2CLIMB II trial (n=612) compared the tyrosine kinase inhibitor called tucatinib in combination with trastuzumab and capecitabine to trastuzumab and capecitabine alone in patients with pretreated HER2-positive metastatic breast cancer with or without brain metastases. Tucatinib is an investigational oral tyrosine kinase inhibitor that is highly selective for HER2 with minimal inhibition of EGFR. The tucatinib arm of the trial demonstrated significantly improved progression-free survival and overall survival.
  3. Previous studies showed that combining endocrine therapy with CDK4/6 inhibitors, resulted in similar response rates to chemotherapy for advanced breast cancers. The SOLTI-1402/CORALLEEN trial (n=106) investigated the efficacy of the CDK4/6 inhibitor ribociclibin combination with the aromatase inhibitor letrozole in patients with high-risk, luminal B, stage I to III operable breast cancer. Neoadjuvant ribociclib and letrozole in high-risk Luminal B breast cancer achieves similar rates of Risk of Relapse (ROR)-low disease at surgery as multi-agent chemotherapy. Future studies in high-risk early breast cancer evaluating the survival outcomes and quality of life of this combination in the absence of cytotoxic therapy are justified.
  4. In the KEYNOTE-522 trial, the authors examined the effect of adding the immune checkpoint inhibitor pembrolizumab to neoadjuvant chemotherapy and adjuvant therapy in patients with early-stage triple negative breast cancer (TNBC). Treatments targeting the PD-1/PD-L1 pathway were previously shown to be effective for patients with metastatic TNBC. The study enrolled 1,174 patients, aged 18 years or older, with previously untreated, non-metastatic TNBC. It was previously reported at European Society of Medical Oncology 2019 meeting that patients in the pembrolizumab plus chemotherapy arm had a significantly higher rate of pCR compared to patients in the chemotherapy alone arm (64.8 percent vs. 51.2 percent), regardless of PD-L1 expression. The latest data presented here included subgroup analyses of patients with lymph node involvement. They showed that among patients whose cancers had spread to the lymph nodes, 64.8 percent of those in the pembrolizumab plus chemotherapy arm had a pCR, compared to 44.1 percent in the chemotherapy only arm. High rates of pCR were also observed in patients with stage III disease. This result suggests that adding pembrolizumab to neoadjuvant chemotherapy is beneficial for patients with the most aggressive disease and the highest unmet need.
  5. Menopausal hormone therapy with estrogen plus progestin (for postmenopausal women with an intact uterus) and estrogen alone (for postmenopausal women with prior hysterectomy) continues to be used by millions of women worldwide. However, menopausal hormone therapy influence on breast cancer incidence and mortality remains uncertain. Long-term follow-up results from two large, randomized, placebo-controlled Womens Health Initiative (WHI) trials in postmenopausal women showed that the use of estrogen alone as menopausal hormone therapy decreased breast cancer incidence and death with persistent results after discontinuation of use, while estrogen plus progestin increased breast cancer incidence with persistent results after discontinuation of use.
    Please find below my personal participation to SABCS2019:
    The San Antonio Breast Cancer Symposium is the largest and most prestigious congress focusing on breast cancer. I was able to learn state-of-the-art information and new perspectives regarding breast cancer diagnostics and therapy. I was also getting to know the most current issues about my research area designating the landmarks of my future studies.
    My research studies presented at SABCS 2019 got very positive comments, so they are ready for publication. Please let me know, if you would like to have the electronic version of my posters.
    My PI and I have also participated in Research Working Group meetings at SABCS 2019. Regarding the international Ki67 in Breast Cancer Working Group project, the latest study is ready to publish, and we have been assigned to write this manuscript. At the international Tumor Infiltrating Lymphocyte in Breast Cancer Working Group (TIL working group), we have been asked to participate in writing a guideline how to use machine learning in clinical trials. Furthermore, we have been also asked to perform an international study involving hundreds of pathologists to score PD-L1 and TILs in TNBC. Our duty will be to build an algorithm for automated PD-L1 scoring so to compare it with semi-quantitative assessment of pathologists. This study is going to be launched in February 2020.
    SABCS 2019 – it was a successful and fruitful conference providing professional development, achievements and future collaborations. I am very grateful for this travel support that has great impact on building research collaborations and achieving professional goals as well.