The Probability of Malignancy in Solitary Pulmonary Nodules. Application to Small Radiologically Indeterminate Nodules

Arch Intern Med. 1997 Apr 28;157(8):849-55.

Abstract

Background: A clinical prediction model to identify malignant nodules based on clinical data and radiological characteristics of lung nodules was derived using logistic regression from a random sample of patients (n = 419) and tested on data from a separate group of patients (n = 210).

Objective: To use multivariate logistic regression to estimate the probability of malignancy in radiologically indeterminate solitary pulmonary nodules (SPNs) in a clinically relevant subset of patients with SPNs that measured between 4 and 30 mm in diameter.

Patients and methods: A retrospective cohort study at a multispecialty group practice included 629 patients (320 men, 309 women) with newly discovered (between January 1, 1984, and May 1, 1986) 4- to 30-mm radiologically indeterminate SPNs on chest radiography. Patients with a diagnosis of cancer within 5 years prior to the discovery of the nodule were excluded. Clinical data included age, sex, cigarette-smoking status, and history of extrathoracic malignant neoplasm, asbestos exposure, and chronic interstitial or obstructive lung disease; chest radiological data included the diameter, location, edge characteristics (eg, lobulation, spiculation, and shagginess), and other characteristics (eg, cavitation) of the SPNs. Predictors were identified in a random sample of two thirds of the patients and tested in the remaining one third.

Results: Sixty-five percent of the nodules were benign, 23% were malignant, and 12% were indeterminate. Three clinical characteristics (age, cigarette-smoking status, and history of cancer [diagnosis, > or = 5 years ago]) and 3 radiological characteristics (diameter, spiculation, and upper lobe location of the SPNs) were independent predictors of malignancy. The area (+/-SE) under the evaluated receiver operating characteristic curve was 0.8328 +/- 0.0226.

Conclusion: Three clinical and 3 radiographic characteristics predicted the malignancy in radiologically indeterminate SPNs.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Diagnosis, Differential
  • Female
  • Humans
  • Logistic Models
  • Lung Diseases / diagnosis
  • Lung Neoplasms / diagnosis*
  • Lung Neoplasms / diagnostic imaging
  • Lung Neoplasms / pathology
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Probability
  • ROC Curve
  • Radiography
  • Retrospective Studies
  • Risk Factors