Accuracy of classification of invasive lobular carcinoma on needle core biopsy of the breast.

Although the UK National Institute for Health and Care Excellence guidelines recommend that in patients with biopsy-proven invasive lobular carcinoma (ILC), preoperative MRI scan is considered, the accuracy of diagnosis of ILC in core biopsy of the breast has not been previously investigated. Eleven pathology laboratories from the UK and Ireland submitted data on 1112 cases interpreted as showing features of ILC, or mixed ILC and IDC/no special type (NST)/other tumour type, on needle core biopsy through retrieval of histology reports. Of the total 1112 cases, 844 were shown to be pure ILC on surgical excision, 154 were mixed ILC plus another type (invariably ductal/NST) and 113 were shown to be ductal/NST. Of those lesions categorised as pure ILC on core, 93% had an element of ILC correctly identified in the core biopsy sample and could be considered concordant. Of cores diagnosed as mixed ILC plus another type on core, complete agreement between core and excision was 46%, with 27% cases of pure ILC, whilst 26% non-concordant. These data indicate that there is not a large excess of expensive MRIs being performed as a result of miscategorisation histologically.

Immunohistochemical analysis of cancer stem cell markers in invasive breast carcinoma and associated ductal carcinoma in situ: relationships with markers of tumor hypoxia and microvascularity.

We performed immunohistochemical analysis of 3 cancer stem cell-related markers (CD44(+)/CD24(-/low), aldehyde dehydrogenase [ALDH]-1, CD133) in 94 invasive ductal carcinomas and assessed relationships with markers of hypoxia (carbonic anhydrase IX [CAIX]), tumor microvessel density (CD31), and clinicopathologic variables. Overall, 10% of tumors were CD44(+)/CD24(-/low), 13% were ALDH-1(+), 25% were CD133(+), 35% were immunonegative, and 1 tumor was immunopositive for all 3 markers. Associated ductal carcinoma in situ (DCIS) was present in 48% of tumors. Marker immunopositivity was detected in DCIS in 13% (CD44(+)/CD24(-/low)), 7% (ALDH-1(+)), and 32% (CD133(+)) of these tumors and was more likely present in DCIS when also detected in the invasive compartment (P = .03, P = .001, and P = .009, respectively). CD44(+)/CD24(-/low) cells were more common in progesterone receptor-negative tumors (P < .01), and ALDH-1(+) cells were more common in estrogen receptor-negative tumors (P < .01). CD133(+) cells were more common in patients younger than 50 years (P < .05) and in high grade (P < .01), localized (P < .05), and estrogen receptor-negative (P < .001), progesterone receptor-negative (P = .02), and triple-negative breast cancers (P < .001). CD44(+)/CD24(-/low) (P = .06) and CD133(+) (P = .02) tumor cells were more common in CAIX(+) versus CAIX(-) tumors, whereas ALDH-1(+) tumors had a higher mean microvessel density than did ALDH-1(-) tumors (P = .002). No significant relationships were observed between the markers studied and survival for 5 years. Our study demonstrated the presence of cancer stem cell marker-positive tumor cells in DCIS as well as invasive breast cancer and showed that CD44(+)/CD24(-/low) and CD133(+) cells were more frequently observed in hypoxic regions of tumor, whereas ALDH-1(+) cells more commonly colocalized to tumors with high microvessel density.