Retrospective study on the pattern of treatment choice of metastatic hormone receptor positive breast cancer.

E. Aboelkheir*¹, A. Ashour¹, S. Fadel¹, W. Arafat¹.

¹Clinical Oncology, Alexandria University, Alexandria, Egypt.

Introduction

The standard treatment of hormone receptor positive Her2 negative metastatic breast cancer is endocrine therapy with or without targeted therapy (e.g., CDK4/6inhibitors and mTOR inhibitors) reserving chemotherapy for whose tumors appear to have either visceral crisis or to be resistant to HT.

Method

Retrospective study using patient files of adult female diagnosed and treated at Clinical Oncology Department, Alexandria Main University Hospitals during the period from January 2010 to December 2019. All information was obtained regarding patient, disease, treatment characteristics and treatment outcomes.

Results

611 patients with HR+ MBC were identified. 67.5% those patients received CT as first-line treatment (CT-first group) while 32.5% patients were treated with a first-line HT (HT-first group). Patients in the CT-first group were younger (median age 50 versus 54 years, p < 0.001) and more frequently in pre-menopausal status (51.8% versus 38.5%, p = 0.003) as compared to patients in the HT-first group. Number of recurrent cases in CT-first group was less than number of patients in HT-first group (64.7% versus 77.5%, p= 0.002), Also, patients in the CT-first group had more metastatic sites (≥2 in 72.5% versus 48.2%, p < 0.001) and a greater visceral only involvement than patients in the HT-first group (35.8% versus16.7%). Notably, chemotherapy was offered in the first 5years to 74% of all studied patients. But chemotherapy was offered less in the second 5years to 60.4% patients. Regarding HR+/Her2- MBC patients with no visceral crisis; The PFS was longest in the HT group and shortest in the CT group (20.6 vs. 11.7 months, respectively; p =0.028). The median OS was highest in HT-first group and shortest in CT first group (57.7 months vs. 35.8 months; p=0.09)), this difference didn't reach statistical significance.

Conclusion

There is significant change in practice pattern in choosing the first line treatment between the first and last 5 years. Also, this study showed that predictors of the preferential use of CT as first-line treatment were younger age, premenopausal state, denovo metastatic disease, multiple metastatic sites, and visceral metastases. Despite the poor prognostic factors of CT first line group, those patients had overall clinical outcomes similar to or even lower than those of patients treated with the reverse sequence, so no added benefit.