CEACAM5 and adenocarcinoma: Matsuoka et al. [7] showed a relationship between histologic subtype and the usefulness of CEA as a prognostic indicator in NSCLC patients with pathologic stage I, showing that a high preoperative CEA level was associated to shorter disease-free survival and lower 5-year survival rate in adenocarcinoma compared to the squamous histology in whom it was not predictive of survival nor recurrence.