IS THERE A DIFFERENCE BETWEEN PATIENTS UNDER 65 AND PATIENTS AGE 65 AND OVER IN THE EFFECT AND SAFETY OF CDK 4/6 INHIBITOR + ENDOCRINE THERAPY?


Semiz H. S., Keskinkılıç M., Yavuzşen T.

İzmir Eğitim ve Araştırma Hastanesi Tıp Dergisi, vol.26, no.4, pp.372-378, 2022 (Peer-Reviewed Journal)

Abstract

Introduction: Metastatic breast cancer (MBC) has a significant mortality and morbidity rate despte all development in treatment modalities. The clinical course of MBC could be differnt in geriatric (≥65 years old) and non-geriatric (<65 years old) population. Toxicities due to targeted therapies could be different in geriatric population. We aimed to investigate whether there is a difference between the treatment characteristics of CDK 4/6 inhibitor + ET use in the geriatric and non-geriatric populations.  Material and Method: HR-positive HER-2 negative MBC patients using CDK 4/6 inhibitors + ET were included. Data about sociodemographic, histopathologic and treatment modalities of patients collected from hospital database retrospectively.  Results: In our study, which included 81 patients, 29% (n=17) of the patients were ≥65 years. Median OS in the non-geritric group was 17.5 months (95% CI; 15.6-19.5), and 17 months (95% CI; 15.2-19.8) in the geriatric group. There was no statistically significant difference between geriatric and non-geriatric patients in terms of survival. PFS in the non-geriatric group was 14.3 months (95% CI; 12.2-16.3), 15.4 months in the geriatric group (95% CI; 12.9-17.7).PFS was longer numerically in the geriatric group than in non-geriatric group. But this was not statistically significant. The treatment response rate was almost 2 times higher in the geriatric group than the nongeriatric group (87.6% vs 48.4%, respectively)(p=0.047). The incidence of side effects was similar in both groups, while dose reduction was performed in 35.3% of the geriatric group, 17.2% of the non-geriatric group. However, this was not statistically significant (p=0.242).  Conclusion: In our study, OS was similar in both groups, while PFS was longer in the geriatric group. Contrary to the literature, the response rate was higher for geriatric group, while the incidence of side effects was similar in both groups.