Breast cancer staging systems were developed in the 1920s and 1930s to determining the extent to which a cancer has developed by growing and spreading. The first case-controlled study on breast cancer epidemiology was done by Janet Lane-Claypon, who published a comparative study in 1926 of 500 breast cancer cases and 500 controls of the same background and lifestyle for the British Ministry of Health. Radical mastectomies remained the standard of care in the USA until the 1970s, but in Europe, breast-sparing procedures, often followed by radiation therapy, were generally adopted in the 1950s. In 1955 George Crile Jr. published "Cancer and Common Sense" arguing that cancer patients needed to understand available treatment options. Crile became a close friend of the environmentalist Rachel Carson, who had undergone a Halsted radical mastectomy in 1960 to treat her malign breast cancer. The US oncologist Jerome Urban promoted superradical mastectomies, taking even more tissue, until 1963, when the ten-year survival rates proved equal to the less-damaging radical mastectomy. Carson died in 1964 and Crile went on to published a wide variety of articles, both in the popular press and in medical journals, challenging the widespread used of the Halsted radical mastectomy. In 1973 Crile published "What Women Should Know About the Breast Cancer Controversy". When in 1974 Betty Ford was diagnosed with breast cancer, the options for treating breast cancer were openly discussed in the press. During the 1970s, a new understanding of metastasis led to perceiving cancer as a systemic illness as well as a localized one, and more sparing procedures were developed that proved equally effective.