Shifting from clinician-ordered to pathologist-initiated reflex testing for NSCLC biomarkers combines diagnosis and molecular analysis into one workflow. This operational change minimizes delays, increases testing rates, and optimizes the use of small biopsy samples, getting actionable results to oncologists faster.

To reduce treatment delays, pathologists should initiate biomarker testing reflexively. Waiting for a medical oncologist to order tests at a first visit is a system failure, wasting critical time and risking the need to retrieve archived samples.

Dr. Deb Schrag suggests the main challenge for new molecular cancer screening technologies is not invention, but implementation. The critical task will be deploying these tools at a population scale and effectively managing the logistical challenge of distinguishing true positives from false alarms.

In community SCLC care, molecular strategies are not monolithic. Genomic alteration testing (NGS) is ready for immediate use and can identify targets today. In contrast, neuroendocrine subtyping is still investigational and not yet clinically actionable, pending results from research studies.

The novel target DLL3 is a promising avenue for treating NECs, but its therapeutic efficacy is highly dependent on expression levels. Early trial data for a DLL3 T-cell engager showed a 40% response rate in high-expressing tumors versus just 3% in low-expressors, mandating biomarker testing for patient selection.

For certain therapies like Enhertu, eligibility is based on immunohistochemistry (IHC), not NGS. Labs must run HER2 IHC in parallel because NGS, as a population-based test, can miss intratumoral heterogeneity (small clusters of positive cells) that IHC can detect, thus identifying more eligible patients for targeted therapy.

While Next-Gen Sequencing (NGS) provides genetic data, IHC directly measures the protein, is faster, cheaper, and requires less tissue. This makes it more scalable for routine clinical use, especially with small biopsy samples. High-level IHC loss correlates well with genetic loss seen on NGS.

When the FDA approves a new biomarker-linked therapy, an in-house pathology lab actively queries its historical database of all prior NGS tests to identify past cases with the relevant genetic alteration. They then proactively contact the oncologists for these patients, uncovering new treatment options that were previously unavailable.

While high DLL3 expression is a key predictor for most T-cell engagers, early data for the tri-specific antibody Gossetamic shows responses in both high and low DLL3 prostate neuroendocrine carcinomas. This suggests the biology of prostate NECs may differ, questioning if DLL3 expression is a universal biomarker for all extrapulmonary neuroendocrine carcinoma subtypes.