Top Line: Are your patients receiving adjuvant CDK4/6 inhibitors following definitive management of ER+ breast cancer?
The Study:This editorial suggests it’s probably overkill for most women strictly meeting trial eligibility. Although CDK4/6 inhibitors improve outcomes in metastatic ER+ breast cancer, their adjuvant use is undermined by substantial toxicity, high discontinuation rates, financial burden, and trial-design flaws—including lack of guaranteed post-progression CDK4/6 therapy for control patients and heavy censoring that may falsely favor the experimental arms. With no proven overall survival benefit and biologic data suggesting possible acceleration of endocrine resistance, the current evidence does not justify prescribing adjuvant CDK4/6 inhibitors. This counterpoint contends persistent post-treatment benefit contradicts concerns about inducing resistance and concludes their magnitude of benefit and low number need to treat (13 to prevent one recurrence at 5 years and 8 at 10 years) represent a major therapeutic advance that should be considered standard for appropriately selected patients rather than withheld on speculative grounds.
TBL: A woman’s desire to be aggressive versus minimalist may drive the decision on this one. | Tannock, J Clin Oncol 2025 & de Laurentiis, J Clin Oncol 2025
The Study:This editorial suggests it’s probably overkill for most women strictly meeting trial eligibility. Although CDK4/6 inhibitors improve outcomes in metastatic ER+ breast cancer, their adjuvant use is undermined by substantial toxicity, high discontinuation rates, financial burden, and trial-design flaws—including lack of guaranteed post-progression CDK4/6 therapy for control patients and heavy censoring that may falsely favor the experimental arms. With no proven overall survival benefit and biologic data suggesting possible acceleration of endocrine resistance, the current evidence does not justify prescribing adjuvant CDK4/6 inhibitors. This counterpoint contends persistent post-treatment benefit contradicts concerns about inducing resistance and concludes their magnitude of benefit and low number need to treat (13 to prevent one recurrence at 5 years and 8 at 10 years) represent a major therapeutic advance that should be considered standard for appropriately selected patients rather than withheld on speculative grounds.
TBL: A woman’s desire to be aggressive versus minimalist may drive the decision on this one. | Tannock, J Clin Oncol 2025 & de Laurentiis, J Clin Oncol 2025