What is the best treatment for HR+ breast cancer? [2023] - Lavasani - MOASC

Dr. Sayeh Lavasani presented breast cancer research updates at MOASC Spotlight On Oncology, covering hormone-positive, metastatic, and HER2+ breast cancer, highlighting key findings, treatment options, and the potential for de-escalation strategies.


Dr. Sayeh Lavasani, MD, MSc, FRCPC, an Associate Clinical Professor in the Division of Hematology Oncology at the Department of Medicine, UCI Health, presented updates on breast cancer research during the MOASC (Medical Oncology Association of Southern California) Spotlight On Oncology. Here's a breakdown of the key topics discussed:

Presenter Disclosures: Dr. Lavasani's disclosures include associations with Daichii Sankyo, Seagen, Sermonix, and Astrazeneca for honorarium, institutional research funding, consultation, and speaker engagements.


  • Hormone Positive Breast Cancer: Early Stage (NATALEE)

  • Metastatic Breast Cancer: SONIA

  • HER2+ Breast Cancer: PHERGain (Cortes et al.)

Key Highlights:

  • Hormone Positive Breast Cancer - NATALEE Study:

    • Improvement in Invasive Disease-Free Survival (IDFS) across all subgroups.

    • Consistent improvement in Disease-Free Survival (DDFS).

    • Positive trend in Overall Survival (OS) with a follow-up duration of 30.4 months.

    • Referencing MonarchE Study by Johnston et al., JCO 2020.

  • Metastatic Breast Cancer - SONIA Trial:

    • Discussion on first-line treatment options involving CDK4/6 inhibitors (CDK4/6i) in AI-resistant cases.

    • Highlighting AI alone vs. AI + CDK4/6i outcomes.

    • AI-alone approach yielded similar outcomes to AI + CDK4/6i in first-line treatment of Hormone Receptor positive Metastatic Breast Cancer (MBC).

    • Considerations regarding the delay of CDK4/6i treatment based on patient subsets and biomarker selection.

    • Noting the lack of survival data for Palbociclib vs. Ribociclib and Abemaciclib.

    • Insights on reduced toxicities with CDK4/6i in second-line treatment, but with grade 3 or higher toxicities in 42% of cases.

    • Quality of Life (QOL) findings based on FACT-B total score.

    • Citing AI Resistant Trials and various references for further context.

  • HER2+ Breast Cancer - PHERGain Trial:

    • Discussion on the PHERGain trial, focusing on chemotherapy de-escalation in HER2-positive early breast cancer (EBC).

    • Evaluation of the 3-year Invasive Disease-Free Survival (iDFS) outcomes.

    • Mention of T-DXd HER2 low expression (Enhertu).

    • Presenting De-Escalation strategies in HER2+ early-stage BC.

    • Emphasizing the potential benefits of neoadjuvant therapy involving HP +/- weekly Paclitaxel.

    • Highlighting pCR (pathological complete response) rates and their translation to improved outcomes.

    • Referencing ADAPT (West German Study Group) and other relevant studies.

Take-Home Points:

  • The NATALEE study demonstrated improved IDFS, DDFS, and OS with adjuvant Ribociclib combined with NSAI in HR+ BC of stage 2 and 3.

  • The SONIA trial indicated comparable outcomes between AI alone and AI + CDK4/6i in first-line treatment of HR+ MBC.

  • The potential for PET scans to predict pCR to HP without chemotherapy in neoadjuvant HER2+ breast cancer treatment, aiding in de-escalation strategies.