The recent guidelines issued by the American College of Radiology and the Society of Breast Imaging on Monday recommend that Mammograms should begin at 40 for women with an average risk of breast cancer and by 30 for high-risk women, contradicting controversial guidelines from a U. S. advisory panel last year.

Dr. Phil Evans of the University of Texas Southwestern Medical Center in Dallas and president of the Society for Breast Imaging, said the guidelines are based on the latest clinical trial data.

"The significant decrease in breast cancer mortality, which amounts to nearly 30 percent since 1990, is a major medical success and is due largely to earlier detection of breast cancer through mammography screening," said Dr. Carol Lee of Memorial Sloan-Kettering Cancer Center in New York.

The recommendations contradicted the conventional message about the need for routine best cancer screening starting at the age of 40, triggering a rebellion from breast cancer specialists who argued the guidelines would befuddle women and would result in more deaths from breast cancer.

For high-risk women who cannot get an MRI, often due to claustrophobia, a breast ultrasound should be used instead, Evans advised.

However the two groups did not consider the ill effects associated with routine screening at an earlier age, such as false positive results, which they were trying to balance.