Smooth or attached solid indeterminate nodules detected at baseline CT screening in the NELSON study: cancer risk during 1 year of follow-up.
OBJECTIVE
To retrospectively determine whether baseline nodule characteristics at 3-month and 1-year volume doubling time (VDT) are predictive for lung cancer in solid indeterminate noncalcified nodules (NCNs) detected at baseline computed tomographic (CT) screening.


METHODS
The study, conducted between April 2004 and May 2006, was institutional review board approved. Patient consent was waived for this retrospective evaluation. NCNs between 5 and 10 mm in diameter (n = 891) were evaluated at 3 months and 1 year to assess growth (VDT < 400 days). Baseline assessments were related to growth at 3 months and 1 year by using chi(2) and Mann-Whitney U tests. Baseline assessments and growth were related to the presence of malignancy by using univariate and multivariate logistic regression analyses.


RESULTS
At 3 months and at 1 year, 8% and 1% of NCNs had grown, of which 15% and 50% were malignant, respectively. One-year growth was related to morphology (P < .01), margin (P < .0001), location (P < .001), and size (P < .01). All cancers were nonspherical and purely intraparenchymal, without attachment to vessels, the pleura, or fissures. In nonsmooth unattached nodules, a volume of 130 mm(3) or larger was the only predictor for malignancy (odds ratio, 6.3; 95% confidence interval [CI]: 1.7, 23.0). After the addition of information on the 3-month VDT, large volume (odds ratio, 4.9; 95% CI: 1.2, 20.1) and 3-month VDT (odds ratio, 15.6; 95% CI: 4.5, 53.5) helped predict malignancy. At 1 year, only the 1-year growth remained (odds ratio, 213.3; 95% CI: 18.7, 2430.9) as predictor for malignancy.


CONCLUSIONS
In smooth or attached solid indeterminate NCNs, no malignancies were found at 1-year follow-up. In nonsmooth purely intraparenchymal NCNs, size is the main baseline predictor for malignancy. When follow-up data are available, growth is a strong predictor for malignancy, especially at 1-year follow-up.
Xu
Dong Ming
DM
Department of Radiology, University Medical Center Groningen, Hanzeplein 1, Postbus 30.001, 9700 RB Groningen, the Netherlands.
van der Zaag-Loonen
Hester J
HJ
Oudkerk
Matthijs
M
Wang
Ying
Y
Vliegenthart
Rozemarijn
R
Scholten
Ernst T
ET
Verschakelen
Johny
J
Prokop
Mathias
M
de Koning
Harry J
HJ
van Klaveren
Rob J
RJ
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D018287:Carcinoma, Large Cell / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D054893:Cone-Beam Computed Tomography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D033162:Incidental Findings; D016015:Logistic Models; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D015588:Observer Variation; D016017:Odds Ratio; D012189:Retrospective Studies; D012306:Risk; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D036542:Tomography, Spiral Computed; D047368:Tumor Burden