prognostic impact of the neutrophil/lymphocyte ratio (nlr) in the treatment of first-line metastatic or locally advanced breast cancer treated with cdk4/6 inhibitor.

Conditions: Breast Cancer; Metastatic Breast Cancer

Summary: the impact of the inflammatory microenvironment in predicting the benefit of a cdk4/6 inhibitor in the treatment of locally advanced or first line metastatic breast cancer has not yet been studied. we propose a multicenter prospective study to confirm the prognostic value of pre-therapy nlr on progression-free survival of patients initiating treatment with a cdk4/6 inhibitor combined with hormonal therapy for locally advanced or metastatic hr-pos / her2-neg breast cancer. we will also evaluate other markers of inflammation and their prognostic and predictive value for a better response to cdk4/6 inhibitor therapy in combination with hormone therapy in these patients. specific blood tests (lymphocyte typing) will be performed during treatment with cdk4/6.

the impact of the inflammatory microenvironment in predicting the benefit of a cdk4/6 inhibitor in the treatment of locally advanced or first line metastatic breast cancer has not yet been studied. we propose a multicenter prospective study to confirm the prognostic value of pre-therapy nlr on progression-free survival of patients initiating treatment with a cdk4/6 inhibitor combined with hormonal therapy for locally advanced or metastatic hr-pos / her2-neg breast cancer. we will also evaluate other markers of inflammation and their prognostic and predictive value for a better response to cdk4/6 inhibitor therapy in combination with hormone therapy in these patients. specific blood tests (lymphocyte typing) will be performed during treatment with cdk4/6.

Eligibility criteria:
inclusion criteria: * patients with locally advanced or metastatic hr-positive, her2-negative breast cancer * patients who are scheduled to receive first-line metastatic cdk4/6 inhibitor therapy in combination with hormone therapy as per the marketing authorization * patients who have not received previous anti-neoplastic therapies for metastatic or advanced disease (chemotherapy, targeted therapy or hormonal therapy). however, it will be possible to have initiated 1st line hormonal therapy within 4 to 6 weeks prior to inclusion. * prior radiotherapy allowed even in metastatic disease. in case of radiotherapy treatment, side effects attributable to the treatment must be resolved. * postmenopausal patients or patients with suppressed ovarian function * patient with measurable or non-measurable disease (according to recist v1.1 criteria) * adequate organ and marrow function to allow prescription of cdk 4/6 inhibitor therapy * age of patient ≥ 18 years * willingness and ability to comply with scheduled visits, treatment plan, biologic tests and other trial procedures including assessments requested for inclusion * patient affiliated with a social security plan * informed consent signed prior to any specific study-related procedures exclusion criteria: * men (no marketing authorization for cdk4/6 inhibitors in men in france) * previous systemic treatment for metastatic disease (chemotherapy, hormone therapy, etc.) * previous treatment with a cdk4/6 inhibitor (adjuvant or for metastatic disease) * locally advanced or relapsed breast cancer for which curative treatment would be considered * her2-positive tumor status on either the primary or relapsed tumor as defined by asco criteria * patient with advanced, symptomatic visceral extension who may be at risk for a potentially fatal short-term complication ("visceral crisis") and who requires treatment with chemotherapy * patients who are deprived of their liberty, under guardianship, or subject to a legal protection measure or who are unable to express their consent * patients who cannot undergo the trial follow-up for geographical, social or psychopathological reasons

Keywords: cdk4/6 lymphocyte typing neutrophil/lymphocyte ratio (nlr)