CASE 34
A patient of yours has just undergone surgery at your local hospital for cancer of the colon. You agreed to act as a surgical assistant for this operation. After completion of the surgery, the surgeon reminds you to draw a carcinoembryonic antigen (CEA) level. Why did the surgeon do this? What is this measurement? What is the significance of measuring this in this population?
QUESTIONS FOR GROUP DISCUSSION
1. What are the two most common colorectal cancers in which heredity plays a role? Explain why a mutation in a gene encoding proteins that play a role in DNA mismatch repair might make a person more susceptible to colon cancer.
2. Describe the clinical manifestations of colon cancer and the screening tests that are used for early detection.
6. Carcinoembryonic antigen (CEA) is an oncofetal antigen. What is its function? Given its function, what role might it play in embryogenesis? What role might it have in adults when it is re-expressed in malignant tissues?
8. Explain the term magic bullet as it refers to tumor therapy. Describe approaches that are used in attempts to achieve this.
9. Describe, in general terms, the assay for measuring CEA levels in a patient. Discuss why there is, to date, no well-described cell-mediated immune assay available for CEA detection. How might you approach this problem to develop an assay?
