This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Which of the following is not useful as a screening method ? 
Select and explain. 
A. Pap smear for cervical cancer, B. CA-125 for ovarian cancer, C. Office endometrial washing for endometrial cancer, D. USG in endometrial cancer
B: CA-125 for ovarian cancer
Answer: B: CA-125 for ovarian cancer 
Explanation: Ans. is 'b' i.e., CA-125 for ovarian cancer o Endometrial cancer screening : i) Pap smear (Not much useful; only recommended for cervical cancer) ii) Ultrasonography iii) Office endometrial washings iv) Colour flow imaging o Ca-125 in not useful in screening ovarian cancers because : i) CAl25 increases only in late stages of cancer ii) CAl25 gives a lot of false positive results iii) CAl25 with USG is a good screening test