Breast carcinoma with basal phenotype: mammographic findings.
OBJECTIVE
Basal phenotype has been found to be an independent poor prognostic factor for breast cancer. The aim of this study was to assess the mammographic appearance of screening-detected breast carcinoma with the basal phenotype.


METHODS
A series of 1,944 consecutively enrolled patients with operable invasive breast cancer underwent immunohistochemical analysis with cytokeratin 5/6 and cytokeratin 14 markers to identify tumors exhibiting basal phenotype characteristics. Among those patients, 356 women with breast cancer were common to a prospectively collected database of screening-detected cases of breast cancer. The predominant mammographic appearance and any associated features were reported by experienced image readers blinded to phenotype status. A chi-square test was used to assess difference between the mammographic appearances of a group of tumors with the basal phenotype and those of a group with the nonbasal phenotype.


RESULTS
Forty-one (12%) of the screening-detected tumors had basal phenotypic expression, and these were compared with 309 (88%) nonbasal tumors. Basal-phenotype tumors were significantly more likely to manifest as an ill-defined mass (basal phenotype, 25 [61%] of 41 tumors; nonbasal phenotype, 75 [24%] of 309 tumors; p < 0.001) or with comedo calcification (basal phenotype, nine [22%] of 41 tumors; nonbasal phenotype, 30 [10%] of 309 tumors; p = 0.019). Nonbasal-phenotype tumors were more likely to manifest as a spiculated mass (nonbasal phenotype, 150 [49%] of 309 tumors; basal phenotype, eight [20%] of 41 tumors; p < 0.001). The low rate of spiculation in basal tumors was independent of histologic grade.


CONCLUSIONS
Screening-detected breast tumors with a basal phenotype have a mammographic appearance different from that of nonbasal tumors. This finding may explain the good prognostic value of mammographic spiculation reported in previous studies.
Luck
Angela A
AA
Nottingham International Breast Education Centre, Nottingham City Hospital, Hucknall Rd., Nottingham NG5 1PB, United Kingdom. angela.luck@uhb.nhs.uk
Evans
Andrew J
AJ
James
Jonathan J
JJ
Rakha
Emad A
EA
Paish
E Claire
EC
Green
Andrew R
AR
Ellis
Ian O
IO
D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010641:Phenotype; D011379:Prognosis; D011446:Prospective Studies
D014408:Biomarkers, Tumor