Association of the imaging characteristics of desmoplasia on digital breast tomosynthesis and the Ki-67 proliferation index in invasive breast cancer

Abstract

Aim To evaluate the imaging characteristics of desmoplasia on digital breast tomosynthesis (DBT) and their association with the Ki-67 index. Methods Seventy-seven malignant spiculated breast masses were analyzed in terms of tumor size, length and width of spicules, coverage of tumor margin with spicules, and the number of spicules. The Ki-67 index was obtained from surgically removed tumor specimens. Results The average spicule length was significantly negatively associated with a high Ki-67 (P=0.005, odds ratio [OR] 0.252, 95% confidence interval [CI] 0.094–0.676), ie, the lesions with longer spicules had a 3.968 times lower odds of having a high Ki-67 than the lesions with shorter spicules. The average spicule width at the base was significantly positively associated with Ki-67 (P=0.004, OR 3.939, 95% CI 1.520–10.209), ie, the lesions with thick spicules had a 3.939 times higher odds of having a high Ki-67 than the lesions with thin spicules. The lesions with more than 20 spicules and those with partially spiculated margins more frequently had a high Ki-67 than those with fewer spicules and fully spiculated margins, but the differences were not significant. Conclusion The spiculation analysis could be used as a non-invasive method providing information about malignant lesions. The tumor proliferative activity, and therefore the patient’s prognosis, might be predicted before biopsy directly from DBT images.