VA National Precision Oncology Program

As the nation’s largest integrated health care system with about 50,000 new cancer diagnoses per year, providing care for over 400,000 veterans with cancer and a robust research portfolio, the US Department of Veterans Affairs (VA) is well positioned to be a leader in both clinical and research in oncology. The VA National Precision Oncology Program (NPOP), which provides tumor sequencing and consultative services, is a key component of VA oncology assets.

Case Presentation

As the mission of the VA is to “care for him who shall have borne the battle,” it is fitting to begin with the story of a US Army veteran in his 40s and the father of 2 young children who developed progressive shortness of breath, cough, and weight loss over a period of 8 months. He was diagnosed with metastatic lung adenocarcinoma in 2016, and standard testing of his tumor showed no alteration of the EGFR and ALK genes. He was treated with whole brain radiation and had begun treatment for carboplatin and pemetrexed chemotherapy with mixed tumor response.

Subsequently, his tumor was tested through NPOP, using a multigene next-generation sequencing (NGS) assay panel, which showed the presence of an abnormal fusion between the EML4 and ALK genes. The chemotherapy was discontinued and oral crizotinib precision therapy was started. The patient had an excellent response in all sites of disease (Figure 1). He was able to return to work and school.

In July 2017, his medication was switched to alectinib for asymptomatic progression in his brain, and there was further response. In September 2019, he was treated with precision intensity-modulated radiotherapy (IMRT), targeting a single brain metastasis as there were no other sites of cancer progression and no cancerrelated symptoms. He finished school and continues to work.

Precision Oncology

Oncology is a relatively young medical field. The early medical treatments for cancer were developed empirically against hematologic malignancies, particularly leukemias. Cytotoxic chemotherapeutic agents as a group have modest effects on most solid tumors, and even modern genomics has had limited ability to predict differential benefit in patients with advanced-stage carcinomas. As a result, the medications are used in a nonprecision manner in which all patients with the same cancer diagnosis and stage receive the same treatment. This is due in part to our limited understanding of both the pathophysiology of cancer and the mechanism of action of cytotoxic agents.The paradigm of precision oncology, in contrast, utilizes unique, patient-specific molecular characteristics to guide prescribing of antineoplastic agents (Figure 2). These molecular characteristics are frequently tumoral but also may be nontumoral, such as germline genetic variants and even nonhuman, such as the gut microbiome as has been proposed as predictive of response to immune checkpoint inhibitors. ^1,2

One of the first examples of precision oncology was tumor testing for the estrogen receptor in breast cancer, which distinguishes breast tumors sensitive to hormonal treatments from those that are resistant. ³ In 2004, somatically acquired mutation of the EGFR gene was found to be associated with response to EGFR tyrosine kinase inhibitors such as gefitinib and erlotinib, and subsequently it was shown that patients without these mutations derived no benefit from use of these drugs. ⁴ Thus, the precision oncology paradigm is using a molecular diagnostic as part of the indication for an antineoplastic agent, resulting in improved therapeutic efficacy and often reduced toxicity.