TABLE III.

Stereotypes in lung cancer^a

	Squamous	Adenocarcinoma		Large-cell
		Current or ex-smoker	Never-smoker
Pathology	Typical	bac component; may be mucinous; ttf-1 helpful	Any bac component will be non-mucinous; ttf-1 helpful	Heterogonous; may have neuroendocrine features
Demography	Often an older male, heavy (ex-) smoker	Male > female	Female > male; any age; common in East Asian individuals	Often an older male, heavy smoker
Clinical	Often proximal primary, may cavitate, paraneoplastic hypercalcemia, clubbing prominent, hemoptysis risk high	Primary may be more distal; can have clubbing; brain metastases, especially if female or elevated ldh	Primary may be distal, can be multifocal; tendency to brain metastases; do not have clubbing	Aggressive cancer; may metastasize to brain
Molecular	ras mutated type rare; EGFR mutated type nonexistent (?); egfr overexpression (by ihc) common; egfr fish+ ±25%; higher ts levels	ras mutated type approximately 45% in North America (approximately 17% in Asia), especially poorly differentiated; EGFR mutated type occurs, but <10% in North America (approximately 30% in Asia); lower ts levels; incidence of egfr fish+ (approximately 25% ?)	EGFR mutated type occurs in approximately 60% Asian individuals, and approximately 30% Caucasian individuals; especially well differentiated; activating codon 12/13; KRAS mutations do not occur; lower ts levels; non-classical ras mutations may occur; significance (?)	ras mutation incidence unclear, may be rare; no EGFR mutations; TS levels (low, unless neuroendocrine subtype); egfr fish (?)

^aThe relationships between clinical stereotypes, histology, and biomarkers are generally tentative. This table should be used with caution; it is intended to provide clues when definitive histologic or biomarker data (or both) are unavoidably lacking.

bac = bronchioloalveolar carcinoma; ttf-1 = thyroid transcription factor-1; ldh = lactate dehydrogenase; ihc = immunohistochemistry; fish = fluorescence in situ hybridization; ts = thymidylate synthase.