Improving size, lymph node metastatic rate, breast conservation, and mortality of invasive breast cancer in Rhode Island women, a well-screened population

Abstract

The beneficial impact of screening mammography on breast cancer outcome continues to be debated as demonstrated by guidelines published by the United States Preventive Services Task Force. A previous report from Rhode Island, which has a very high rate of mammographic screening, demonstrated significant improvements in invasive breast cancer presentation and mortality through 2001. This report updates data through 2008 to determine whether previous favorable trends continued. Rhode Island Cancer Registry data regarding invasive breast cancer presentation and mortality in 17,522 female residents diagnosed between 1987 and 2008, inclusive, were analyzed for demographic and pathological factors. Data were analyzed by four time periods: 1987-1992, 1993-1998, 1999-2003, and 2004-2008 and overall. Statistically significant improvements occurred over the four successive time periods, in mean cancer size (23.7, 20.9, 19.6, and 19.3 mm, p < 0.0001), pathologic grade (Grade I: 12, 15, 19, and 17 %; Grade III 57, 41, 36, and 35 %, p < 0.0001), breast conserving surgery (38, 56, 67, and 71 %, p < 0.0001) and mortality (37.3, 31.4, 25.1, and 22.6 per 100,000/year, p < 0.0001). The results showed that high screening rates favorably impacted presentation of and mortality from invasive breast cancer in Rhode Island. From 1987 to 2008, there has been a 39 % decline in breast cancer mortality considering 5 year periods (37.3 vs. 22.6 deaths per 100,000) and 41 % comparing the period from 1990 to 2008, which may exceed the goal of 50 % mortality reduction by 2015 established by the American Cancer Society.