The eighth edition of the AJCC Cancer Staging Manual now stratifies the T descriptor for lung cancers by each increasing 1.0 cm increment, up to 5.0 cm, with an additional category for tumor greater than 7.0 cm. Bias in pathologic versus radiologic measurements may impact tumor staging.
The gross pathologic measurements of 493 resected lung adenocarcinomas were compared with presurgical computed tomography radiologic measurements. Also, pathologic tumor measurement data from the Surveillance, Epidemiology, and End Results (SEER) program database were examined.
The distribution of pathologic measurements showed clustering at 0.5-cm increments, with 43.0% of pathologic measurements falling on 0.5-cm increments compared to only 20.3% of radiologic measurements. This pathologic measurement clustering was also observed for both 591,691 resected lung cancers and 3,597,685 tumors of any type from the SEER database.
Compared to radiologic measurements, gross pathologic measurements cluster around whole- and half-cm values. This measurement bias could lead to incorrect pathologic tumor staging and influence clinical treatment plans.