Effective January 2025, the 9th edition staging for NSCLC splits N2 into N2A (single station) and N2B (multiple stations). It also divides M1C metastatic disease into M1C1 (multiple mets, single organ) and M1C2 (multiple mets, multiple organs). This reshuffles stage groupings, particularly for stages 2 and 3.
When diagnosing a cancer of unknown primary, immunohistochemistry (IHC) markers are key. CK7 positivity in adenocarcinoma typically points to an origin above the diaphragm, such as the lung. Conversely, CK20 positivity is more prevalent in adenocarcinomas originating below the diaphragm, like the GI tract.
Despite the success of perioperative chemo-immunotherapy, it is contraindicated for patients with resectable NSCLC harboring EGFR or ALK driver mutations. These molecular markers predict limited benefit from immune checkpoint inhibitors (ICIs), and NCCN guidelines explicitly recommend against using ICI in this population in favor of targeted therapies.
For resectable, driver-negative NSCLC, clinicians must choose from four Category 1 chemo-immunotherapy options without direct comparative data. This includes one neoadjuvant-only regimen (Checkmate 816) and three full perioperative strategies. The choice requires multidisciplinary discussion, and the selected immunotherapy agent must not be switched mid-course.