Association of Survival With Maintenance Therapy in Patients With Metastatic Breast Cancer After First-line Chemotherapy

Study Overview
=================
Brief Summary
-----------------
To investigate the benefits and risks of maintenance chemotherapy (MCT), maintenance endocrine therapy (MET) and none maintenance therapy after first-line treatment of metastatic breast cancer (MBC).

Detailed Description
-----------------
There are several options for MBC patients who are responding to chemotherapy, to continue treatment with a fix number of cycles or until disease progression which also known as maintenance chemotherapy (MCT), to stop chemotherapy and take a watch and wait strategy, or to stop chemotherapy and start the maintenance endocrine therapy (MET) for hormone receptor (HR) positive patients. Since the role of maintenance therapy in prolonging the overall survival (OS) and progression-free survival (PFS) of MBC was controversial in previous studies, the investigators performed a systematic review of randomized controlled trials to detect the association of survival with maintenance therapy in patients with MBC after first-line chemotherapy. And the investigators further performed a multi-center retrospective real-world study to evaluate these two maintenance modalities.

Official Title
-----------------
Association of Survival With Maintenance Therapy in Patients With Metastatic Breast Cancer After First-line Chemotherapy

Conditions
-----------------
Metastatic Breast Cancer

Intervention / Treatment
-----------------
* Drug: Capecitabine
* Drug: Liposomal doxorubicin
* Drug: Gemcitabine
* Drug: Fulvestrant
* Drug: Anastrozole
* Drug: Letrozole


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients with pathologically clear invasive breast cancer between 2003 and 2018; Female,18-75 years old; Measurable metastatic lesion according to RECIST 1.1 evaluation criteria; The first-line chemotherapy regimen is a breast cancer combination or single-agent chemotherapy regimen recommended by the NCCN guidelines; First-line chemotherapy is effective (according to RECIST1.1 evaluation criteria, the efficacy is evaluated as complete response (CR), partial response (PR), or steady state (SD)); After the last cycle of first-line chemotherapy, patients should still be in a state of no progress for at least 4 weeks; Patients' Karnofsky performance status (KPS) scores were ≥70. Exclusion Criteria: Unmeasurable metastatic lesion according to RECIST 1.1 evaluation criteria.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| MCT Group<br>People who received chemotherapy as a maintenance therapy after first-line chemotherapy reaching a state of no progress for at least 4 weeks. One patient only received one of the intervention drugs for maintenance therapy. | Drug: Capecitabine<br>* 1000-1250 mg/m 2 PO twice daily days 1-14, cycled every 28 days<br>* Other names: Maintenance Chemotherapy;Drug: Liposomal doxorubicin<br>* 50 mg/m 2 IV day 1, cycled every 28 days<br>* Other names: Maintenance Chemotherapy;Drug: Gemcitabine<br>* 800-1200 mg/m 2 IV days 1, 8, and 15, cycled every 28 days<br>* Other names: Maintenance Chemotherapy;|
| MET Group<br>People who received endocrine therapy as a maintenance therapy after first-line chemotherapy reaching a state of no progress for at least 4 weeks. One patient only received one of the intervention drugs for maintenance therapy. | Drug: Fulvestrant<br>* 500mg IH Days 0, 14, 28, then every 28 days<br>* Other names: Maintenance Endocrine Therapy;Drug: Anastrozole<br>* 1mg PO qd<br>* Other names: Maintenance Endocrine Therapy;Drug: Letrozole<br>* 2.5mg PO qd<br>* Other names: Maintenance Endocrine Therapy;|
| Observation Group<br>People who didn't receive any maintenance therapy after first-line chemotherapy reaching a state of no progress for at least 4 weeks. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall Survival (OS) | From enrollment to death (for any reason) | Estimated 36 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Progression free survival (PFS) | From enrollment to progression or death (for any reason) | Estimated 18 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Metastatic Breast Cancer, Maintenance Chemotherapy, Maintenance Endocrine Therapy, Overall Survival, Safety