PIV and PILE scores predict the clinical outcome in patients with metastatic breast cancer treated with CDK4/6 inhibitors.

AIMS AND OBJECTIVES

Cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) therapy, the standard of care for metastatic hormone receptor-positive (HR +)/human epidermal growth factor receptor 2 (HER2) negative breast cancer (BC), has profoundly affected many cell types, including tumor cells, Tregs, cytotoxic T cells, and stem and progenitor cells. Therefore, it is reasonable to assume that the pretreatment status of tumor immunity may have predictive value in CDK4/6i efficacy.

METHODS

A total of 404 patients were included in the analysis. The scores of the panimmune-inflammatory values (PIV) and PILE (PIV-LDH-ECOG), a candidate PIV-based scoring system, were calculated within one week before the initiation of CDK4/6i plus endocrine therapy (ET).

RESULTS

The median overall survival (OS) was 69.0 months (95% CI 51.1-86.8). The low-PIV subgroup had significantly longer progression-free survival (PFS) [23.9 vs. 18.8 months; HR = 1.817, 95% CI = 1.113-2.965, p = 0.017] and OS [73.6 vs. 37.7 months; HR = 2.338, 95% CI = 1.122-4.871, p = 0.023] than the high-PIV subgroup. In the low-risk PILE subgroup, PFS [37.0 vs. 15.8 months; HR = 2.751, 95% CI = 1.736-4.361, p < 0.001] and OS [73.6 vs. 35.1 months; HR = 3.854, 95% CI = 1.855-8.005, p < 0.001] were greater than in the high-risk PILE subgroup. The low-risk PILE subgroup was associated with a significantly better disease control rate (DCR) than the high-risk PILE subgroup (87.2% and 75.0%, p = 0.004). In the analysis of 112 patients treated with ET in the metastatic stage before CDK4/6i as a control group, PIV and PILE were not independent prognostic indicators.

CONCLUSIONS

Our study demonstrated that PIV and PILE scores could be predictive biomarkers for the treatment efficacy of CDK4/6is.