AOCNP Cancer Diagnosis, Staging, and Workup — Questions and Answers
Question 1: According to the TNM staging system, which descriptor indicates that cancer cells have spread to regional lymph nodes?
- T2
- M1
- N1 (Correct answer)
- G2
Correct answer: N1
In the TNM system, N describes regional lymph node involvement (N0 = no nodes, N1+ = regional node spread). T describes primary tumor size/extension, M describes distant metastasis, and G describes histologic grade. N1 specifically indicates spread to regional lymph nodes, which is a critical staging determinant affecting treatment planning.
Question 2: A patient is newly diagnosed with diffuse large B-cell lymphoma (DLBCL). Which staging system is most appropriate for this hematologic malignancy?
- TNM (tumor-node-metastasis) staging
- Lugano classification (modified Ann Arbor staging) (Correct answer)
- FIGO staging
- Dukes classification
Correct answer: Lugano classification (modified Ann Arbor staging)
The Lugano classification, a refinement of the Ann Arbor staging system, is used for lymphomas including DLBCL. It uses Stages I–IV based on nodal and extranodal involvement and incorporates PET-CT findings. TNM is used for solid tumors. FIGO is for gynecologic cancers. Dukes classification is an older system for colorectal cancer.
Question 3: When interpreting a pathology report, a tumor is described as 'poorly differentiated.' What does this histologic grade indicate about the tumor's behavior?
- The tumor closely resembles normal tissue and likely grows slowly
- The tumor shows moderate resemblance to normal tissue
- The tumor bears little resemblance to normal tissue and is likely more aggressive (Correct answer)
- The tumor has not yet invaded beyond the basement membrane
Correct answer: The tumor bears little resemblance to normal tissue and is likely more aggressive
Histologic grade reflects how closely tumor cells resemble normal cells. Poorly differentiated (high-grade, Grade 3) tumors have lost most normal cell characteristics, indicating more aggressive behavior and typically worse prognosis. Well-differentiated tumors (Grade 1) closely resemble normal tissue. Moderately differentiated = Grade 2. Invasion beyond the basement membrane relates to staging, not grading.
Question 4: Which serum tumor marker, when significantly elevated at diagnosis of a testicular mass, is most specific for non-seminomatous germ cell tumors (NSGCTs)?
- CA-125
- PSA (prostate-specific antigen)
- AFP (alpha-fetoprotein) (Correct answer)
- CEA (carcinoembryonic antigen)
Correct answer: AFP (alpha-fetoprotein)
AFP is characteristically elevated in non-seminomatous germ cell tumors (embryonal carcinoma, yolk sac tumor) and is not produced by pure seminomas. Its elevation helps differentiate NSGCT from pure seminoma, which is critical because treatment approaches differ. CA-125 is used for ovarian cancer. PSA for prostate cancer. CEA is a non-specific marker used in colorectal, lung, and breast cancers.
Question 5: A bone marrow biopsy is required to complete staging for which of the following cancers?
- Stage II non-small cell lung cancer
- Multiple myeloma (Correct answer)
- Localized prostate cancer (PSA < 10, Gleason 6)
- Stage I endometrial cancer
Correct answer: Multiple myeloma
Bone marrow biopsy is an essential diagnostic and staging tool for multiple myeloma (and other plasma cell dyscrasias), as plasma cell percentage in the marrow is a diagnostic criterion and prognostic factor per IMWG criteria. Lung, prostate, and endometrial cancers at the stages described do not routinely require bone marrow evaluation as part of standard staging workup.
Question 6: A patient with a 2.5 cm breast mass has biopsy confirming invasive ductal carcinoma. Imaging shows 2 ipsilateral axillary lymph nodes with malignant features and no distant metastasis. What is the clinical TNM stage?
- Stage IIA (T2 N1 M0)
- Stage IIB (T2 N1 M0) (Correct answer)
- Stage IIIA (T2 N2 M0)
- Stage IV (T2 N1 M1)
Correct answer: Stage IIB (T2 N1 M0)
Per AJCC 8th edition, a primary tumor 2–5 cm (T2) with metastasis in 1–3 ipsilateral axillary lymph nodes (N1) and no distant metastasis (M0) classifies as Stage IIB. Stage IIA would be T0-T2 N1 M0 only if T0-1; with T2 and N1, the anatomic stage is IIB. Stage IIIA requires N2 (4–9 nodes) with T2, or T3 with N1. Stage IV requires distant metastasis (M1).
AOCNP Cancer Diagnosis, Staging, and Workup
According to the TNM staging system, which descriptor indicates that cancer cells have spread to regional lymph nodes?