Tumor Testing: Finding the Right Key for Your Lock
In the November issue of O, The Oprah Magazine, there is an article by Katherine Hobson titled “Take That, Lung Cancer!” Hobson discusses the latest breakthroughs in screening and treatment for lung cancer, including targeted therapies that match a drug to a tumor’s cancer-causing mutation “in the same way you find the right key for a lock.”
What a perfect description for tumor-based genetic testing (also called somatic testing). Instead of treating all lung cancer patients with generic chemotherapy, doctors are performing genetic testing on tumors to unlock the most appropriate targeted treatment options.
In addition to Hobson’s article, two academic papers were recently published on somatic testing, which you can read here and here. As precision medicine and our understanding of the genetics of tumors grows, we’ll be hearing a lot more about this.
Here are a few takeaways:
- When someone is diagnosed with cancer, it’s now common to do genetic testing on the tumor itself to find out what treatment the tumor may respond best to, whether that person is a candidate for a clinical trial, and/or the aggressiveness of the tumor and likely prognosis.
- When doing this type of tumor testing, germline (hereditary) genetic findings are sometimes suspected or discovered; however, somatic testing is not powered to detect germline mutations, so these findings must be confirmed with a new blood sample and a new germline test.
- Discovering these germline findings for patients with tumors is critical because:
- it may mean the patient is a candidate for different therapies,
- it may mean the patient is at increased risk for other cancers,
- it means the patient’s family members are at risk.
- Current guidelines say (1) that patients should be told before they have somatic testing that evidence of an underlying germline finding may be found and (2) that if a BRCA finding is suspected based on somatic testing, germline testing should be offered. We have observed that both guidelines are overlooked in many clinical scenarios, meaning patients and their families are not getting the information they need.
The bottom line:
Somatic testing is being done more and more routinely, and the potential of underlying germline findings should not be ignored. Germline information can be incredibly beneficial for the patient and his/her entire family. Ignoring these findings presents a liability to the patient, the patient’s family, the health care provider, the laboratory, and the health system. Payers should encourage genetic counseling and testing for these suspected underlying germline findings.
My Gene Counsel developed Living Lab Reports to help patients and clinicians understand these findings, their options for additional testing, and why this is critical to the patient and their entire family. We are also working with partners to bridge the gap between somatic and germline testing.