By Mothaffar Rimawi, MD, Dan L Duncan Professor, Executive Medical Director, Associate Director for Clinical Affairs, Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine

The past decade brought a dramatic evolution in the field of genetics. The most consequential change was the wide adoption of genetics in cancer medicine. Genetics continues to transform every aspect of cancer care—how clinicians identify patients’ risk for the disease, prevent or delay its onset, and treat it, increasingly with customized therapies as part of precision medicine.

A key factor that helped drive the uptake of genetics in cancer care: more efficient and cost-effective technology. Technology improved dramatically while the cost of sequencing DNA dropped drastically.

Sequencers—the machines we use to sequence DNA—evolved significantly. They became faster and capable of sequencing more samples with each run. Next-generation sequencing became a mainstay in cancer genetics. At the same time, costs dropped precipitously. Sequencing a tumor or germline sample might have cost thousands of dollars previously. Now, sequencing the same tissue might only run a few hundred dollars. More powerful and lower-cost technology enabled the generation of a large amount of data that facilitated the broader use of genetics in cancer medicine.

As the revolution in cancer genetics progresses, St. Luke’s Health is helping to lead the way. Through its partnerships with Baylor College of Medicine—home to the No. 1 NIH-funded genetics department and the nation’s largest clinical genetics program—and the NCI-designated Dan L Duncan Comprehensive Cancer Center at Baylor St. Luke’s Medical Center, SLH is uniquely positioned to be at the forefront of cancer genetics, which can help guide clinical management and facilitate access to clinical trials.

Putting Cancer Genetics Into Practice

At SLH and elsewhere, genetics can play a key role in cancer care in two major ways. First, sequencing the germline DNA inherited from parents can help identify patients with cancer predisposition who may be at increased risk of cancer, allowing physicians to place them under enhanced screening programs or recommend risk-reducing strategies.

Genetics can also help in cancer therapeutics. Sequencing tumor DNA—and, most recently, RNA—can help identify therapeutic targets in tumor cells. It is also possible to detect small amounts of circulating tumor DNA. This can be used for tumor profiling and monitoring for early tumor recurrences. Many other uses and research applications for genetics are in development.

SLH oncologists use genetics to screen for and treat all types of cancer. Many gene mutations in cancers can be present in more than one tumor type, and many of the treatments that target specific pathways can be active in more than one tumor type. Some of the tumors for which the SLH team most often uses genetics as part of screening or treatment include melanoma and breast, lung and colon cancers.

Getting Precise

In recent decades, researchers and physicians have gained invaluable insight into cancer-fueling genomic changes through projects such as The Cancer Genome Atlas program and Therapeutically Applicable Research to Generate Effective Treatments, or TARGET, program. These efforts have driven the development of precision interventions, such as targeted therapies.

Based on tumor profile (DNA and RNA), SLH oncologists select the most effective treatment for that particular tumor at that particular time. Since tumors evolve and change, we perform serial profiling repeatedly to match treatments to the most recent molecular portrait. We often discuss complex cases at our Molecular Tumor Board, which is truly a differentiator for SLH.

A unique service available only at select, highly specialized cancer centers, the Molecular Tumor Board brings together medical oncologists, molecular biologists, medical geneticists, genetic counselors, pharmacists and research team members. Meeting monthly, this group discusses cancer cases that may warrant next-generation sequencing or germline molecular testing. By considering molecular diagnostic data with the full spectrum of patient information, Molecular Tumor Board members draw on their expertise to provide treatment recommendations to patients’ physicians. Board members can also screen patients for clinical trials, many of which now target specific tumor mutations.

Bringing the Future Forward

Where is cancer genetics headed? The next frontier is proteogenomics, which is profiling not only genomics but also proteomics—proteins in cancer cells—and tying them together to create the most comprehensive tumor profile. This requires a lot of work to analyze large amounts of data, usually performed by a team of expert bioinformaticians.

Baylor College of Medicine is a national leader in proteogenomics research, and we have a strong focus on expanding its use in the clinical setting. The use of AI can help expedite this process of analysis and data integrations.

Currently, we concentrate most of our proteogenomics research and clinical trial activity on breast cancer and lung cancer, but we’re looking to expand our investigations into other tumor types. All research takes place according to strict regulations set by the Baylor College of Medicine Institutional Review Board and other regulatory agencies. Our investigators and staff are trained to uphold the highest ethical standards that maintain patient rights, safety and privacy.

Through partnerships with Baylor College of Medicine and the Dan L Duncan Comprehensive Cancer Center, and with support from other clinical programs of excellence at SLH, we provide top-notch care, access to clinical trials and consultative services for complex cases. We take an individualized approach to patient care, and we are always open to partnering with other physicians to help care for their patients.