The Metastatic Breast Cancer Project (MBCproject) is an ongoing research study that directly engages patients (pts) through social media and advocacy groups, and empowers them to share their samples, clinical information, and experiences. The goal is to create a publicly available dataset of linked genomic, clinical, and pt-reported data to enable research. In collaboration with pts, advocates, and advocacy groups, a website (MBCproject.org) was developed that allows pts with metastatic breast cancer (MBC) anywhere in the US or Canada to register. From 10/20/15-6/1/21, 6100 patients with MBC registered for the MBCproject. Registered pts are sent an online consent form that asks for permission to obtain and analyze their medical records and samples. Consented pts are sent a saliva and/or blood kit and asked to mail back a saliva sample, which is used to extract germline DNA, and/or a blood sample, which is used to extract germline DNA and cell free DNA (cfDNA). We contact participants’ medical providers to obtain medical records and a portion of their stored tumor biopsies. 3456 pts receiving care at over 1700 different institutions have consented to share medical records and tumor/saliva/blood samples and to have genomic analysis performed. Whole exome sequencing (WES) is performed on tumor DNA, germline DNA, and cfDNA; transcriptome sequencing (RNA-seq) is performed on tumor RNA. Medical records and pt-reported data are abstracted to create a detailed clinical record for each pt. Table 1 highlights clinical data collection, biospecimen acquisition, and genomic data generation to date. Examples of clinicogenomic analyses are shown in Table 2. De-identified linked genomic, clinical, and pt-reported data is shared regularly via public databases (mbcproject.org, cBioPortal, dbGaP, NCI Genomic Data Commons). To date, this data has been cited in over 40 publications. Study updates are shared with participants regularly. The MBCproject continues to enroll new patients, generate additional data, and perform integrated clinical and genomic analyses with the goal of building a dataset that is representative of patients with MBC. We have partnered with over 30 non-profit breast cancer advocacy groups. We also have several community engagement efforts underway to more directly reach patients in underrepresented communities, including partnerships with faith-based organizations and colleges/universities, as well as targeted engagement with the African American community. In addition, in partnership with Latinx patients, advocates, and researchers, a Spanish-language version of the MBCproject was launched in June 2021. Partnering directly with pts rapidly enables thousands of pts to remotely share tumors, blood, saliva, and medical records to accelerate research. The resulting publicly shared clinically annotated dataset is a resource that allows researchers to identify patients with specific phenotypes, who have often been challenging to identify with traditional approaches.

Clinical data collection, biospecimen acquisition, and genomic data generation:Number
Consent signed (US & CA) 3456 pts 
Patient-reported data collected (demographics, diagnosis details, receptor status, clinical experiences, pathology details, sites of metastasis, treatments with start and stop dates 3456 pts 
Medical record received from clinical institution 1365 pts 
Saliva sample received from pt 2124 pts 
Blood sample received from pt 1114 pts 
Tumor samples received from clinical institution 631 tumor samples from 398 pts 
WES from germline complete 505 germline samples 
WES from tumor (primary and metastatic) samples complete 429 tumor samples 
RNA-seq from tumor (primary and metastatic) samples complete 351 tumor samples 
ULP-WGS from cfDNA (taken in metastatic setting) complete 953 blood samples 
WES from circulating tumor DNA (taken in metastatic setting) complete 144 blood samples 
Clinical data collection, biospecimen acquisition, and genomic data generation:Number
Consent signed (US & CA) 3456 pts 
Patient-reported data collected (demographics, diagnosis details, receptor status, clinical experiences, pathology details, sites of metastasis, treatments with start and stop dates 3456 pts 
Medical record received from clinical institution 1365 pts 
Saliva sample received from pt 2124 pts 
Blood sample received from pt 1114 pts 
Tumor samples received from clinical institution 631 tumor samples from 398 pts 
WES from germline complete 505 germline samples 
WES from tumor (primary and metastatic) samples complete 429 tumor samples 
RNA-seq from tumor (primary and metastatic) samples complete 351 tumor samples 
ULP-WGS from cfDNA (taken in metastatic setting) complete 953 blood samples 
WES from circulating tumor DNA (taken in metastatic setting) complete 144 blood samples 

CohortConsented (US & CA)Tumor WES completeTumor RNA-seq complete
Pts diagnosed < 40 yrs of age 1146 152 92 
De novo MBC 1207 158 109 
Late recurrence (>5 years after dx) 909 91 41 
Long term survivors (MBC > 10yrs) 163 13 
Resistance to CDK4/6 inhibitors 709 148 39 
NED at time of f/u survey 430 54 45 
Triple Negative Breast Cancer 330 46 32 
Patients with 2 or more tumor biopsies/cfDNA samples collected by the MBCproject 298 108 82 
CohortConsented (US & CA)Tumor WES completeTumor RNA-seq complete
Pts diagnosed < 40 yrs of age 1146 152 92 
De novo MBC 1207 158 109 
Late recurrence (>5 years after dx) 909 91 41 
Long term survivors (MBC > 10yrs) 163 13 
Resistance to CDK4/6 inhibitors 709 148 39 
NED at time of f/u survey 430 54 45 
Triple Negative Breast Cancer 330 46 32 
Patients with 2 or more tumor biopsies/cfDNA samples collected by the MBCproject 298 108 82 

Citation Format: Nikhil Wagle, Corrie Painter, Elana Anastasio, Mary McGillicuddy, Esha Jain, Tania G. Hernandez, Brett N. Tomson, Beena Thomas, Daniel Abravanel, Dewey Kim, Sara Balch, Alyssa L. Damon, Shahrayz Shah, Rafael Ramos, Delia Sosa, Ilan Small, Colleen Nguyen, Sarah Winnicki, Taylor Cusher, Parker Chastain, Michael Dunphy, Jorge Gomez Tejeda Zanudo, Netsanet Tsegai, Lauren Sterlin, Ulcha F. Ulysse, Imani Boykin, Oyin Alao, Todd R. Golub. The metastatic breast cancer project: Generating the clinical and genomic landscape of metastatic breast cancer through patient-partnered research [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-19-01.