Q: Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.
Question: Does population-based prostate-specific antigen testing in the UK lead to a stage migration of prostate cancer?
Answer: Population-based PSA testing resulted in a significant downward stage and grade migration, and most such cancers were of low stage and grade, which could lead to risks of over-treatment for some men.
A:
yes