What is the purpose of genetic testing for cancer patients?

Level 2 alterations include molecular changes that may confer benefit from investigational or off-label therapies, as well as molecular changes that may cause resistance to FDA-approved treatments. Level 3 alterations refer to changes with no current therapeutic implications. 3. Test Results According to the researchers’ published findings, among the 1,015 patients who successfully underwent NGS sequencing, 817 patients (80.5%) harbored at least one potentially actionable Level 1 or Level 2 alteration. Of these, 713 patients (70.2%) had somatic molecular alterations in their tumors that could guide targeted or other treatment strategies. Among all Level 1 and Level 2 molecular alterations identified, 962 (94.8% of the total) were detected via DNA sequencing, and 645 (63.4% of the total) via RNA sequencing. 4. Treatment Outcomes Among patients with potentially actionable alterations, 132 patients (16.2%) ultimately received therapy guided by sequencing results. The median time from patient enrollment to initiation of such guided therapy was 3.8 months. Of these 132 patients, 49 (37.1%) achieved clinical benefit, including 19.7% exhibiting exceptional responses—meaning they experienced outstanding therapeutic efficacy. A step-by-step analysis of these results reveals that, if patients undergo standardized genetic testing, the likelihood of obtaining clinically valuable results is actually very high—there is no need to worry that 'testing is futile.' Moreover, if patients follow treatment recommendations derived from test results, the probability of achieving favorable outcomes—or even exceptional responses (the top 10% of best responders)—is also remarkably high. Genetic testing functions like a 'compass' for cancer treatment. Supported by extensive clinical trial data, experts can effectively leverage test results to chart a relatively more appropriate therapeutic course for cancer patients. Such a treatment process is far smoother, more efficient, and higher-quality than empirically trialing targeted drugs—and leads to longer patient survival. Beyond guiding targeted therapy, genetic testing also holds critical significance for chemotherapy selection. For example: patients with ERCC1 mutations are more likely to develop resistance to platinum-based chemotherapy; those with RRM1 mutations may be resistant to gemcitabine; and patients with lower TYMS expression tend to respond better to pemetrexed. Regarding chemotherapy-related adverse effects, genetic testing results also play an important predictive role. Patients with UGT1A1 mutations face higher risks of neutropenia, leukopenia, thrombocytopenia, and diarrhea when treated with irinotecan; patients with GSTP1 mutations may exhibit impaired drug metabolism and reduced dose tolerance—administering standard doses could thus trigger severe systemic adverse reactions. These are merely several representative examples, yet they clearly illustrate the vital guiding role of genetic testing across diverse tumor treatment strategies. Undergoing genetic testing prior to treatment is not—as many patients imagine—a wasteful expense. Rather, it represents clinicians using evidence-based experience to guide patients toward maximum benefit at minimal cost.

Cancer blood tests: Can earlier detection save more lives?

Another complex issue is that—despite early detection—the lethality of certain cancers remains markedly higher than that of others, and the underlying reasons remain unclear. This point was illustrated by a UK National Health Service clinical trial on the CA125 blood test for ovarian cancer, conducted between 2001 and 2011. Although the blood test identified more early-stage ovarian cancer cases, it failed to improve patient survival—due to the inherently high lethality of ovarian cancer. According to GRAIL, this month’s findings suggested a “favourable trend” in the results for some types of cancer later in the trial. If that holds up, the balance of harms and benefits associated with using Galleri is likely to be different for each of the cancers it looks for. That makes the administration of the test a decision to be taken carefully. There are additional dilemmas, too: patients with a fatal cancer may not benefit from an earlier diagnosis, but such knowledge could help researchers improve their knowledge of early-stage cancers. That will not be the end of the story. “GRAIL’s technology is somewhat outdated now,” says Anna Schuh, who leads molecular diagnostics research at Oxford University’s Department of Oncology.

US FDA Advisory Panel Endorses Grail Cancer Test Benefits

13 hours ago

US FDA advisers voted 7-2 that Grail's Galleri blood-based cancer test benefits outweigh risks, paving the way for potential nationwide approval. The test detects multiple cancers from a single blood draw with high specificity, serving as an addition to standard care.

reuters

2026-09-23

US FDA Advisory Panel Endorses Grail Cancer Test Benefits

US FDA Advisory Panel Endorses Grail Cancer Test Benefits

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