CET Cancer Registry Data Collection 2 — Questions and Answers
Question 1: Which coding system is used to classify cancer primary sites and histologies in cancer registries?
- ICD-O-3 (Correct answer)
- CPT-4
- ICD-10-CM
- SNOMED-CT
Correct answer: ICD-O-3
ICD-O-3 (International Classification of Diseases for Oncology, 3rd Edition) is the standard coding system for classifying cancer by site (topography) and cell type (morphology).
Question 2: In ICD-O-3 morphology codes, what does a behavior code of '/2' indicate?
- In situ (Correct answer)
- Malignant, primary site
- Benign
- Uncertain behavior
Correct answer: In situ
A behavior code of /2 indicates carcinoma in situ, meaning cancer cells are present but have not invaded surrounding tissue.
Question 3: What does 'laterality' code '2' represent for a paired organ in ICD-O-3?
- Left side (Correct answer)
- Right side
- Bilateral
- Midline
Correct answer: Left side
In ICD-O-3, laterality code 2 represents the left side of a paired organ such as the lung, kidney, or breast.
Question 4: What is the 'primary site' in cancer registry terminology?
- The organ or tissue where the cancer first developed (Correct answer)
- The largest tumor mass regardless of location
- The first site of distant metastasis
- The organ most affected by treatment side effects
Correct answer: The organ or tissue where the cancer first developed
The primary site is the organ or tissue of origin where the malignancy first arose, regardless of where it subsequently spread.
Question 5: Which ICD-O-3 histology code range represents adenocarcinomas?
- 8140–8389 (Correct answer)
- 8000–8049
- 8050–8089
- 8700–8790
Correct answer: 8140–8389
Adenocarcinomas, which are glandular malignancies, are coded in the 8140–8389 range within the ICD-O-3 morphology classification.
Question 6: In cancer registry data, what does 'grade' describe?
- Degree of cellular differentiation compared to normal cells (Correct answer)
- Stage of disease spread throughout the body
- Physical size of the tumor mass
- Speed at which the tumor is growing
Correct answer: Degree of cellular differentiation compared to normal cells
Grade reflects how closely cancer cells resemble normal cells (differentiation), ranging from well-differentiated (Grade 1) to undifferentiated (Grade 4).
Question 7: Which ICD-O-3 topography code represents the colon?
- C18 (Correct answer)
- C16
- C20
- C15
Correct answer: C18
C18 in ICD-O-3 topography represents the colon; C16 is stomach, C20 is rectum, and C15 is esophagus.
CET Cancer Registry Data Collection 2
Which coding system is used to classify cancer primary sites and histologies in cancer registries?