CHICAGO — An influential U.S. government advisory panel is dropping its opposition to routine prostate cancer screening in favor of letting men decide for themselves after talking with their doctor. The new draft guidelines released Tuesday echo those of several leading medical groups, but they don't make the decision any easier for men: With their doctor's help, they have to decide whether to take an imperfect PSA test that has a small chance of detecting a deadly cancer and a larger chance of triggering unneeded worry and treatment with serious side effects. "This isn't a one-size-fits-all" recommendation, said the panel's chair Dr. Kirsten Bibbins-Domingo, a San Francisco internist who already follows the advice and discusses the potential pros and cons with her patients.