Table 4. Characteristics of Prevalent versus Incident Lung Cancers.

	Size & CT Densityat Enrollment	Size & CT Densityat Diagnosis	Mean Time Priorto Diagnosis	Histology	Stage at Diagnosis	Median Disease-Free Survival After Diagnosis,& Outcomes
All cancers (33) (includes 3 synch. primaries)	10.8 mm9 SN 14 SSN	18.6 mm19 SN 14 SSN	39.8 mths	26 adeno2 squamous3 small cell2 NSCLC	26 Stage I2 Stage II4 stage IV	42 (range 6–113) mths5 expired (lung ca.)4 recurrences (local)1 lost to f/u
Prevalence cancers dx <6 mths (10)	19.1 mm7 SN3 SSN	21.6 mm7 SN3 SSN	2.4 mths	9 adeno1 NSCLC	7 Stage I2 Stage II1 Stage IV	81.5 (11–113) mths2 expired (lung ca.)1 recurrence (local)
Prevalence cancers dx >6 mths (13)	12.8 mm2 SN11 SSN	20.1 mm7 SN6 SSN	50.3 mths	12 adeno1 squamous	13 stage I	47 (5–96) mths1 expired (lung ca.)3 recurrences (local)1 expired (cva)
Incidence cancers (10)	Not presenton initial CT	13.6 mm5 SN5 SSN	63.5 mths	5 adeno1 squamous3 small cell1 NSCLC	6 stage I3 stage IV	13 (6–33) mths2 expired (lung ca)1 lost to f/u

^*Numbers equal 33 cancers in 30 patients, since three patients had more than one diagnosis of lung cancer (synchronous or second primaries).

Abbreviations: adeno = adenocarcinoma, NSCLC = non-small cell lung cancer not otherwise specified, SN = solid nodule, SSN = sub-solid nodule, ca. = cancer, cva = cerebrovascular accident.