A novel method for prediction of long-term outcome of women with T1a, T1b,and 10-14 mm invasive breast cancers: a prospective study

Background Women with small mammographically detected breast cancers genera lly have good long-term outcomes, but a few with T1a (1-5 mm) and T1b (6-10 mm) tumours will eventually die from breast cancer. We investigated whethe r Women at high risk of breast-cancer death could be identified with mammog raphic criteria and differentiated from women with small cancers of the bre ast and good outcomes. Methods We prospectively applied mammographic classifications of tumour typ e to a consecutive series of 343 mammograms of invasive breast cancers of s ize 1-14 mm, Classifications were: stellate (spiculated) mass with no calci fications; circular or oval lesions with no calcifications; spiculated or c ircular lesions with non-casting-type calcifications; and casting-type calc ifications. Findings 20-year survival for women with 1-14 mm invasive tumours with cast ing-type calcifications was 55%. 14% of 138 women with 1-9 mm tumours had c asting-type calcifications-on mammography, which accounted for 73% of ail b reast-cancer deaths (p<0.001). T1a, T1b, and 10-14 mm tumours with casting- type calcifications behaved as if they were larger lesions, since the rate of death was similar to that for women with advanced high-grade tumours, Mo st women who died were node-negative. The long-term survival of women who h ad tumours of 1-9 mm with no casting-type calcifications was about 95%. Interpretation Mammographic classification seemed to reliably predict good and bad long-term outcomes for survival in tumours of 14 mm or smaller, and especially for those smaller than 10 mm. The implications for therapy are substantial.