American Board of Internal Medicine (ABIM) Certification Practice Exam

Which stage of non-small cell lung cancer is characterized by a solitary tumor without regional lymph node involvement?

1. I

2. II

3. III

4. IV

The correct answer is: I

The stage of non-small cell lung cancer characterized by a solitary tumor without regional lymph node involvement is Stage I. In this stage, the cancer has not yet spread beyond the lung and the tumor is typically localized, meaning it is confined to one area of the lung without any evidence of lymphatic or distant spread. Stage I non-small cell lung cancer is categorized into two sub-stages (IA and IB) based on the size and characteristics of the tumor. In both sub-stages, there is no regional lymph node involvement or distant metastasis. This is crucial for determining the appropriate treatment and prognosis, as early-stage cancers generally have better outcomes and a higher chance for successful surgical intervention. In contrast, the other stages involve varying degrees of lymph node involvement (Stage II and Stage III) or metastasis (Stage IV), indicating a more advanced disease that requires different therapeutic approaches. Understanding the staging is essential for guiding treatment decisions and predicting patient outcomes.