ESMO Congress 2023 | OncologyPRO

Abstract 410P

Background

Breast cancer represents a major public health issue in which numerous therapeutic advances have been made, particularly for those with HER2 overexpression. The standard of care until mid-2022 has been based on the combination of Trastuzumab - Pertuzumab - Docetaxel in first line, followed by T-DM1 in second line. Limited data are available on survival outcomes of patients receiving these treatments in a real-life setting. We aimed to analyse them in this study.

Methods

We searched the French PMSI (French National Hospital Discharge Summary Database) database and extracted 10,408 patients treated with Pertuzumab between 2014 and 2021, with a C50* code (coding for breast cancer) and with an index stay in a public or private non-profit hospital. We then extracted administrative data, comorbidities, types of metastases and survival. We collected and analyzed the same data for patients receiving T-DM1 after Pertuzumab.

Results

Median survival for patients treated with Pertuzumab was not reached at time of analysis (February 2023). Survival rate at 5 years was 61.9 % (CI95% [60.6, 63.1]). Several risk factors were identified : an intensive care unit stay, age and a code for hydroelectrolytic disorders, metastases (particularly cerebromeningeal, liver, bone, and lung metastases), infection, diabetes, undernutrition and cytopenias. Median survival for patients treated with T-DM1 after Pertuzumab was 2.8 years (CI95% [2.65,2,99]), with a 5-year survival rate of 36.9% (CI95% [34.6 , 39.4]). Risk factors were : a code for liver or cerebromeningeal metastases, undernutrition, and age.

Conclusions

To our knowledge, this is the largest real-life cohort of patients with breast cancer treated with Pertuzumab followed by T-DM1, and our results are consistent with available data, both from the lead CLEOPATRA and EMILIA studies and other retrospective studies.