Cancer Biochemistry and Tumor Markers MCQs

Biochemistry · 33 free questions with answers & explanations.

1. The Warburg effect in cancer cells describes aerobic glycolysis. The primary molecular advantage this confers to rapidly proliferating tumour cells is:
2. A 55-year-old male with hepatocellular carcinoma has serum AFP of 850 ng/mL. AFP is elevated because it is:
3. Succinate dehydrogenase (SDH) subunit B mutation in hereditary paraganglioma-pheochromocytoma syndrome leads to accumulation of succinate. Succinate is classified as an oncometabolite because it:
4. PSA (prostate-specific antigen) is a serine protease of the kallikrein family. Its biological function in semen is to:
5. The Warburg effect in cancer cells refers to preferential aerobic glycolysis over oxidative phosphorylation. Which enzyme, when overexpressed in cancer cells, is a key driver of this phenotype by diverting pyruvate away from the mitochondria?
6. IDH1 and IDH2 mutations in gliomas and AML produce 2-hydroxyglutarate (2-HG), an oncometabolite. The primary mechanism by which 2-HG drives oncogenesis is:
7. AFP (alpha-fetoprotein) is elevated in which of the following clinical scenarios EXCEPT:
8. In the intrinsic pathway of apoptosis, cytochrome c release from mitochondria is triggered by pro-apoptotic BAX/BAK proteins. Cytochrome c then binds APAF-1 and procaspase-9 to form which structure?
9. Cancer cells preferentially utilise aerobic glycolysis (Warburg effect) even in the presence of adequate oxygen. Which biochemical advantage does this confer on the tumour?
10. IDH1 and IDH2 gain-of-function mutations in gliomas and AML produce a novel oncometabolite. Which metabolite is produced and what is its principal oncogenic mechanism?
11. Bcl-2 overexpression, commonly seen in follicular lymphoma due to t(14;18), promotes tumour cell survival by:
12. Carcinoembryonic antigen (CEA) is a tumour marker used in monitoring colorectal carcinoma. Which statement about CEA is MOST accurate?
13. The RAS proto-oncogene product is a GTPase involved in the MAPK proliferative signalling cascade. Oncogenic point mutations at codons 12 or 13 of KRAS lead to persistent tumour cell proliferation because:
14. The Warburg effect describes aerobic glycolysis in cancer cells. Beyond simply producing more ATP, the primary metabolic advantage of aerobic glycolysis for rapidly proliferating cancer cells is:
15. IDH1/IDH2 mutations in glioma and AML result in the production of 2-hydroxyglutarate (2-HG) instead of alpha-ketoglutarate. 2-HG is classified as an oncometabolite because it:
16. A 62-year-old man with hepatocellular carcinoma has AFP of 4,500 ng/mL. He is considered for liver transplant under Milan criteria. Which biochemical characteristic of AFP makes it a reliable marker of hepatocellular carcinoma recurrence post-transplant?
17. In the intrinsic apoptotic pathway, cytochrome c released from mitochondria forms the apoptosome. The direct molecular function of the apoptosome is:
18. CA-125 is elevated in a 55-year-old woman found to have a pelvic mass. The specificity of CA-125 for epithelial ovarian cancer is limited because CA-125 can be elevated in benign conditions. The most common benign gynaecological condition causing false-positive CA-125 elevation is:
19. The Warburg effect in cancer cells describes aerobic glycolysis. The PRIMARY advantage this metabolic reprogramming provides to rapidly proliferating cancer cells (beyond ATP) is:
20. IDH1 and IDH2 mutations in gliomas and AML produce the oncometabolite 2-hydroxyglutarate (2-HG). The MECHANISM by which 2-HG drives tumorigenesis is:
21. AFP (alpha-fetoprotein) is elevated in hepatocellular carcinoma. However, which combination of tumor markers and associated cancers is INCORRECTLY paired?
22. In the intrinsic apoptotic pathway, cytochrome c release from mitochondria leads to apoptosome formation. The PRECISE molecular event triggered by cytochrome c in the cytosol is:
23. The Warburg effect in cancer cells describes aerobic glycolysis: glucose is preferentially converted to lactate even when oxygen is present. Which metabolic advantage does this confer on rapidly proliferating tumour cells?
24. IDH1 and IDH2 mutations in gliomas and AML produce a neomorphic enzyme that generates 2-hydroxyglutarate (2-HG) instead of alpha-ketoglutarate. 2-HG causes epigenetic dysregulation by acting as a competitive inhibitor of which class of enzymes?
25. A 65-year-old man has PSA of 18 ng/mL. To distinguish benign prostatic hyperplasia (BPH) from prostate cancer, the free-to-total PSA ratio is measured. In which direction does this ratio shift in prostate cancer compared to BPH?
26. Cytochrome c release from the mitochondria into the cytoplasm is a pivotal step in intrinsic apoptosis. It forms the apoptosome by binding which protein to activate caspase-9?
27. A woman has elevated serum CA-125 and is suspected of having ovarian carcinoma. Which primary limitation reduces CA-125 utility as a screening marker in the general population?
28. The Warburg effect in cancer cells refers to:
29. IDH1/IDH2 mutations found in gliomas and AML produce the oncometabolite 2-hydroxyglutarate (2-HG), which causes cancer by:
30. Alpha-fetoprotein (AFP) is elevated in all of the following EXCEPT:
31. p53 tumour suppressor protein is called the 'guardian of the genome' because it:
32. Which tumour marker combination is most specific for monitoring response to treatment in a patient with epithelial ovarian cancer?
33. BCL-2 overexpression in follicular lymphoma protects cancer cells from apoptosis by: