What is the predictor for invasion in non-palpable breast cancer with microcalcifications?

To assess the presence of invasion in non-palpable breast cancer with microcalcifications.

We investigated 157 patients with non-palpable breast cancer with microcalcifications, who had undergone stereotactic core biopsy or vacuum-assisted breast biopsy and operation at the Cancer Institute Hospital between 1995 and 2001. We investigated the correlation between the area of calcification (maximum range of microcalcifications measured in mm by direct mammography), morphology of calcification on mammography, histological subtype of intraductal carcinoma (comedo or non-comedo) and frequency of invasion, and lymph node metastasis. The chi-square test was used in the statistical analysis and p values less than 0.05 were considered statistically significant.

Invasion was observed in 33 of 157 pts (21%), of whom 23 showed minimal invasion, which is less than 0.5 cm in greatest diameter. The risk of invasion was 13% within 10 mm of the microcalcifications (n =70), 25% from 11 to 30 mm (n =59), and 32% more than 31 mm from the microcalcifications (n =28). The risk of invasion was 16% for punctate-round and amorphous type (n =87) microcalcifications, and 27% for pleomorphic and linear-branching types (n =70)(p =0.092). In addition, invasion was found 10% of the time within 10 mm of punctate-round and amorphous type microcalcifications, and 20% of the time at 11 mm or more. On the other hand, invasion was found 15% of the time within 10 mm of pleomorphic and linear-branching type microcalcifications, and 37% of the time at 11 mm or more. In 72 cases of intraductal carcinoma diagnosed by pathological examination, invasion was found in 10 of 31 (32%) comedo type intraductal carcinomas and in 5 of 41 (12%) non-comedo types (p =0.0379). There were 5 cases (3.2%) with axillary lymph node metastasis, all of which widely extended more than 21 mm from the microcalcifications.

The risk of invasion was 10% within 10 mm of punctate-round and amorphous type microcalcifications, and 37% at more than 11 mm of pleomorphic, linear-branching microcalcifications.