How many names for a rose: inconsistent classification of multiple foci of lung cancer due to ambiguous rules.
OBJECTIVE
Stage classification is important because it allows consistent definition of patient groups, and thus provides a foundation for comparison of outcomes. For patients with multiple pulmonary foci of lung cancer, however, the classification rules are ambiguous and confusing.


METHODS
We surveyed experts and clinicians who regularly evaluate patients with lung cancer to see how similar or different their interpretation of the official stage classification was for such patients.


RESULTS
We found a great deal of inconsistency in how four clinical scenarios were classified. No method of classification was chosen by a majority when there were more than two choices allowed by the classification rules. In a scenario with pulmonary foci of cancer of different histologic types, 86% classified this as separate primary cancers and 14% as multifocal lung cancer.


CONCLUSIONS
The marked variability in classification must be taken into account when interpreting reported outcomes of patients with multiple pulmonary foci of lung cancer.
General Surgery Resident, Yale School of Medicine, PO Box 208062, New Haven, CT 06520-8062, United States.
Annabelle
A
Fonseca
Yale School of Medicine, Thoracic Surgery, PO Box 208062, New Haven, CT 06520-8062, United States. Electronic address: frank.detterbeck@yale.edu.
Frank C
FC
Detterbeck
D000230:Adenocarcinoma / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D003951:Diagnostic Errors; D006801:Humans; D008175:Lung Neoplasms / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D066231:Surgeons; D011795:Surveys and Questionnaires
Adenocarcinoma; Lung cancer; Multi foci; Non-small cell lung cancer; Stage classification; TNM