Consequences of Discontinuing a 4/6 Cyclin D-Dependent Kinase Inhibitor During Endocrine Treatment in Hormone-Sensitive Metastatic Breast Cancer Patients in the Context of the COVID-19 Outbreak

Clin Breast Cancer. 2023 Jan;23(1):32-37. doi: 10.1016/j.clbc.2022.10.006. Epub 2022 Oct 13.

Abstract

Background: The impact of some hasty medical decision made during the first wave of the Coronavirus Disease 2019 (COVID-19) remains unknown. We have evaluated the consequences of one of these precautionary measures: the withdrawal of the cyclin D-dependent kinases 4/6 inhibitor (CDK4/6i) in patients whose metastatic disease was controlled by a combination of endocrine treatment and CDK 4/6i.

Method: This study was noninterventional, retrospective, multicentric, and included 60 patients with HR+ HER2- metastatic disease. Their disease was controlled with the combination of endocrine treatment and CDK 4/6i. The CDK 4/6i was stopped for two months during the first COVID-19 outbreak. A univariate analysis was performed to assess the risk factors associated with disease progression.

Results: During this therapeutic break, 22 (37 %) patients had a radiological and/or clinical disease progression. Among them, the CDK 4/6i was re-introduced to 16 patients (n = 16/22; 73 %). A new line of treatment (chemotherapy or targeted therapy) was initiated due to the rapid symptomatic tumor progression in four patients (n = 4/22; 18 %). Two patients (n = 2/22) died in visceral crisis before another anti-tumoral treatment was introduced. In univariate analysis, the presence of liver metastases increased the risk of metastatic disease progression during the withdrawal of the CDK 4/6 (OR = 6.6; 95 % CI 1.87-23.22; P= .0033).

Conclusion: Progression was observed in 37% of patients during the two-month treatment interruption of the CDK 4/6i. A prolonged CDK 4/6i treatment interruption in patients with clinical benefit on endocrine treatment does not seem to be a reasonable option in light of these results.

Keywords: CDK4/6 inhibitors; COVID-19; Disease progression; Hepatic metastases; Treatment withdrawn.

MeSH terms

  • Antineoplastic Agents* / therapeutic use
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Breast Neoplasms* / pathology
  • COVID-19*
  • Cyclin-Dependent Kinase 4 / antagonists & inhibitors
  • Cyclin-Dependent Kinase 6 / antagonists & inhibitors
  • Disease Progression
  • Female
  • Hormones
  • Humans
  • Neoplasm Metastasis
  • Protein Kinase Inhibitors* / administration & dosage
  • Retrospective Studies

Substances

  • Antineoplastic Agents
  • Cyclin-Dependent Kinase 4
  • Cyclin-Dependent Kinase 6
  • Hormones
  • Protein Kinase Inhibitors