Background Flashcards
Small cell lung cancer (SCLC) accounts for what % of new lung cancer Dx in the United States? What % of lung cancer deaths?
14% (31,000 cases/yr) of new lung cancer diagnosed in 2017 is SCLC, accounting for ∼25% of lung cancer deaths annually.
What % of SCLC is linked to smoking?
Nearly all cases of SCLC are linked to smoking.
What is the median age of Dx of SCLC? What % of pts are >70 yo at Dx?
The median age of SCLC Dx is 64 yrs, with 25% of pts presenting at age >70 yrs.
What % of pts with SCLC presents with metastatic Dz?
67% of SCLC pts present with mets, most commonly to the contralat lung, contralat or bilat malignant pleural effusion, liver, renal, adrenals, bone, BM, and brain.
What are the pathologic characteristics of SCLC?
Small round blue cells of epithelial origin with neuroendocrine differentiation, ↑ mitotic count, and ↑ N/C ratio
What are the markers that characterize SCLC?
Markers that characterize SCLC include S100, synaptophysin+, chromogranin+, and neurotensin + EGFR–.
What pathology finding is often associated with SCLC?
Crush artifact
What are some common neurologic and endocrine paraneoplastic syndromes associated with SCLC?
Neurologic: Lambert–Eaton syndrome (antibody to presynaptic voltage-gated calcium channels), encephalomyelitis, sensory neuropathy (anti-Hu antibody)
Endocrine: Cushing Dz (↑↑ ACTH), SIADH (↑↑ ADH)
What is the most common chromosomal abnormality associated with SCLC but not seen with extrapulmonary small cell carcinomas?
Deletion of 3p (95% of cases, particularly 3p14–25 region, with inactivation of at least 3 tumor suppressor genes, including FHIT and RASSF1A)
What is the most common genetic alteration seen in SCLC?
Amplification of the bcl-2/C-myc family of oncogenes is most common but likely is not the initiating event. Other common abnormalities include loss of p16, loss of Rb, and mutation in p53.
