Modern practice is shifting away from routine Prophylactic Cranial Irradiation (PCI) for extensive-stage small cell lung cancer. This change is driven by a key Japanese study where patients, screened with baseline MRI, showed a survival trend favoring observation with serial MRIs over PCI, challenging a long-standing treatment paradigm.

Despite strong data favoring pre-surgical systemic therapy, a surgeon argues that many patients will continue to undergo surgery first. This is due to real-world factors like surgeons being the point of diagnosis, urgent symptoms requiring rapid intervention, and patient preferences to have the tumor removed immediately.

Unlike rare biomarkers that necessitate a 'test-and-wait' approach, IB6 is expressed in over 80-90% of NSCLC tumors. This ubiquity could make pre-screening unnecessary for drugs like Sigvotatug Vedotin, allowing clinicians to initiate targeted therapy much faster and for a broader patient population.

When a sentinel lymph node biopsy is skipped, radiation oncologists lack crucial staging information. This can make them hesitant to recommend less-invasive partial breast radiation, even if a patient otherwise qualifies. They may instead recommend whole breast radiation to treat any potential, unconfirmed microscopic disease in the axilla.

The success of perioperative osimertinib means oncologists cannot choose the optimal strategy (targeted therapy vs. chemoimmunotherapy) for resectable lung cancer without first knowing the patient's EGFR, ALK, and PD-L1 status. This elevates biomarker profiling from a metastatic-setting tool to a critical first step in early-stage disease.

While primarily known for guiding radiation, surgeons place clips in the lumpectomy cavity for their own future reference. These markers are critical for guiding re-excision if margins are positive and help radiologists accurately monitor the surgical site for recurrence on future mammograms, distinguishing scar tissue from new concerns.

Experts warn against over-interpreting a single negative ctDNA test after surgery, clarifying that these patients still face a significant 25-30% risk of recurrence. The biomarker's true prognostic power comes from serial testing that shows a patient remains persistently negative over time.

Dr. Radvanyi advocates for a paradigm shift: treating almost all cancers with neoadjuvant immunotherapy immediately after diagnosis. This "kickstarts" an immune response before standard treatments like surgery and chemotherapy, which are known to be immunosuppressive, can weaken the patient's natural defenses against the tumor.

While a positive ctDNA test clearly signals the need for adjuvant therapy, a negative result is less actionable for deciding initial treatment. The key prognostic value comes from being *serially* undetectable over time, information that is not available when the immediate post-surgery treatment decision must be made.