Medicine: Mammogram Muddle

More than 250,000 women 35 years old and older have taken part over the past three years in a breast-cancer detection program conducted by the American Cancer Society and the National Cancer Institute. Because any cancerous tumors they may have are detected early, say the sponsors, these women presumably will have a lower-than-average rate of mortality from breast cancer, which will kill some 32,000 in the U.S. this year. Last week the screening program became the center of a major medical storm stirred by a group of doctors who warned that X rays used in the screening might actually increase the...