OCN Cancer Biology and Pathophysiology 2

Question 1

TNM staging for solid tumors classifies cancers based on which three factors?

Accepted Answer

Tumor size/extent, lymph Node involvement, and Metastasis

Answer

TNM staging uses primary tumor extent (T), regional lymph node involvement (N), and distant metastasis (M) to classify cancer stage and guide treatment.

Question 2

Which oncogene is frequently amplified in HER2-positive breast cancer, making it a therapeutic target?

Accepted Answer

ERBB2 (HER2/neu)

Answer

ERBB2 gene amplification produces excess HER2 protein on the cell surface, driving uncontrolled cell proliferation in HER2-positive breast cancer.

Question 3

Tumor grade refers to which pathological characteristic?

Accepted Answer

How differentiated (similar to normal tissue) the cancer cells appear under microscopy

Answer

Tumor grade reflects the degree of cellular differentiation: low grade (well differentiated) cells look like normal cells, while high grade (poorly differentiated) cells are more abnormal and aggressive.

Question 4

Lynch syndrome (hereditary non-polyposis colorectal cancer) is caused by mutations in which genes?

Accepted Answer

Mismatch repair genes (MLH1, MSH2, MSH6, PMS2)

Answer

Lynch syndrome is caused by germline mutations in DNA mismatch repair genes, leading to microsatellite instability and increased risk of colorectal, endometrial, and other cancers.

Question 5

Which tumor marker is most specific for monitoring colorectal cancer recurrence?

Accepted Answer

Carcinoembryonic antigen (CEA)

Answer

CEA is the most widely used tumor marker for monitoring colorectal cancer response to treatment and surveillance for recurrence after resection.

OCN Exam Practice Test

OCN Exam Practice Test

OCN Cancer Biology and Pathophysiology 2