Geisinger MyCode® detects BRCA2 mutation prior to abdominal panniculectomy allowing for DIEP flap breast reconstruction

Thyroidectomy Outcomes in Patients Identified With RET Pathogenic Variants Through a Population Genomic Screening Program

Importance

Population-based genomic screening can facilitate early detection of medullary thyroid carcinoma (MTC) in patients with pathogenic/likely pathogenic (P/LP) RET variants.

Objective

To evaluate the clinical treatment and patient outcomes after identification of P/LP RET proto-oncogene variants associated with the risk of MTC via a population genomic screening program.

Design, Setting, Participants

This retrospective cross-sectional study was completed between June 1, 2016, and May 31, 2022, for a mean follow-up period of 22.4 months (range, 2-76 months). The study included patients who were identified as having P/LP RET variants through a population genomic screening program at a rural tertiary care center and who underwent thyroidectomy after results disclosure.

Main Outcomes and Measures

The outcomes of interest were preoperative evaluation and treatment-related outcomes. Measures included imaging and laboratory findings, extent of surgery, pathologic diagnosis, and staging.

Results

Seventy-five patients were identified as having P/LP RET variants exclusively through genomic screening. Twenty of these patients (27%; 11 women [55%] and 9 men [45%]; median age, 48 years [range, 22-73 years]) underwent total thyroidectomy; 13 of these patients (65%) also had a central neck dissection. No patients had clinically apparent disease at the time of surgery. Pathologic findings indicated MTC for 12 patients and papillary thyroid carcinoma in 2. Of patients with MTC, 10 had stage I disease, 1 had stage II disease, 1 had stage III disease, and none had stage IV disease. Based on postoperative surveillance imaging and laboratory results, no patient had evidence of recalcitrant disease.

Conclusions and Relevance

In this cross-sectional study, all malignant neoplasms identified on surgical pathology were clinically occult, with surgical intervention based solely on the identification of the P/LP RET variant via population genomic screening. This finding suggests that genomic screening may provide opportunities for early detection and treatment of MTC, with the potential for improved patient outcomes.

Leveraging population-based exome screening to impact clinical care: The evolution of variant assessment in the Geisinger MyCode research project

Exome and genome sequencing are increasingly utilized in research studies and clinical care and can provide clinically relevant information beyond the initial intent for sequencing, including medically actionable secondary findings. Despite ongoing debate about sharing this information with patients and participants, a growing number of clinical laboratories and research programs routinely report secondary findings that increase the risk for selected diseases. Recently, there has been a push to maximize the potential benefit of this practice by implementing proactive genomic screening at the population level irrespective of medical history, but the feasibility of deploying population-scale proactive genomic screening requires scaling key elements of the genomic data evaluation process. Herein, we describe the motivation, development, and implementation of a population-scale variant-first screening pipeline combining bioinformatics-based filtering with a manual review process to screen for clinically relevant findings in research exomes generated through the DiscovEHR collaboration within Geisinger's MyCode® research project. Consistent with other studies, this pipeline yields a screen-positive detection rate between 2.1 and 2.6% (depending on inclusion of those with prior indication-based testing) in 130,048 adult MyCode patient-participants screened for clinically relevant findings in 60 genes. Our variant-first pipeline affords cost and time savings by filtering out negative cases, thereby avoiding analysis of each exome one-by-one, as typically employed in the diagnostic setting. While research is still needed to fully appreciate the benefits of population genomic screening, MyCode provides the first demonstration of a program at scale to help shape how population genomic screening is integrated into routine clinical care.