A prediction model for pathologic N2 disease in lung cancer patients with a negative mediastinum by positron emission tomography.
BACKGROUND
Guidance is limited for invasive staging in patients with lung cancer without mediastinal disease by positron emission tomography (PET). We developed and validated a prediction model for pathologic N2 disease (pN2), using six previously described risk factors: tumor location and size by computed tomography (CT), nodal disease by CT, maximum standardized uptake value of the primary tumor, N1 by PET, and histology.


METHODS
A cohort study (2004-2009) was performed in patients with T1/T2 by CT and N0/N1 by PET. Logistic regression analysis was used to develop a prediction model for pN2 among a random development set (n = 625). The model was validated in both the development set, which comprised two thirds of the patients and the validation set (n = 313), which comprised the remaining one third. Model performance was assessed in terms of discrimination and calibration.


RESULTS
Among 938 patients, 9.9% had pN2 (9 detected by invasive staging and 84 intraoperatively). In the development set, univariate analyses demonstrated a significant association between pN2 and increasing tumor size (p < 0.001), nodal status by CT (p = 0.007), maximum standardized uptake value of the primary tumor (p = 0.027), and N1 by PET (p < 0.001); however, only N1 by PET was associated with pN2 (p < 0.001) in the multivariate prediction model. The model performed reasonably well in the development (c-statistic, 0.70; 95% confidence interval, 0.63-0.77; goodness of fit p = 0.61) and validation (c-statistic, 0.65; 95% confidence interval, 0.56-0.74; goodness-of-fit p = 0.19) sets.


CONCLUSIONS
A prediction model for pN2 based on six previously described risk factors has reasonable performance characteristics. Observations from this study may guide prospective, multicenter development and validation of a prediction model for pN2.
Department of Surgery, Division of Cardiothoracic Surgery, University of Washington, Seattle, Washington, USA.
Farhood
F
Farjah
Feiran
F
Lou
Camelia
C
Sima
Valerie W
VW
Rusch
Nabil P
NP
Rizk
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D008481:Mediastinoscopy; D008875:Middle Aged; D015233:Models, Statistical; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18