The value of monoclonal antibody B72.3 for the diagnosis of breast carcinoma: experience with the first commercially available source

Comparative study of monoclonal antibody B72.3 and gross cystic disease fluid protein-15 as markers of apocrine carcinoma of the breast

Gross cystic disease fluid protein-15 (GCDFP-15) is a commonly used apocrine marker; however, its expression was recently found to decrease in infiltrating, larger, or metastasizing apocrine carcinomas of the breast. In the breast, monoclonal antibody (MAb) B72.3 has been reported to be useful as an apocrine marker although it is used for that purpose much less frequently than GCDFP-15. In the search for a more consistent apocrine marker, immunoreactivity for MAb B72.3 was examined in apocrine carcinomas at different stages and compared with GCDFP-15. 47 of 51 apocrine carcinomas (92%) and 9 of 62 ordinary carcinomas (15%) were MAb B72.3 positive, while 39 of 51 apocrine carcinomas (76%) and 13 of 62 ordinary carcinomas (21%) were GCDFP-15 positive. Thus, both sensitivity and specificity were higher for MAb B72.3. Furthermore, unlike GCDFP-15, MAb B72.3 exhibited positivity irrespective of infiltrating status, tumor size, or metastatic status. There was no correlation between MAb B72.3-immunoreactivity and GCDFP-15-expression. The combined usage of MAb B72.3 with GCDFP-15 was useful to confirm the diagnosis of apocrine carcinoma, especially for advanced tumors, with only two cases being negative for both MAb B72.3 and GCDFP-15. Whether these two cases should be differentiated from ordinary apocrine carcinomas remains to be investigated.

Cytomorphology of fibrocystic change, high-risk proliferative breast disease, and premalignant breast lesions

In a prospective study using mammographically guided fine needle aspirates in 100 nonpalpable breast lesions, the author's group assessed the reliability of a cytological grading system to define the cytological features of proliferative and nonproliferative breast disease and to differentiate between benign, premalignant and malignant breast lesions. We developed a cytological grading system evaluating the aspirates for the cellular arrangement, the degrees of cellular pleomorphism and anisonucleosis, presence of myoepithelial cells and nucleoli and the status of the chromatin pattern. This grading system, now recognized as the Masood Cytology Index, is commonly used as a surrogate end point biomarker in chemoprevention trials.

Intracytoplasmic lumina in human oviduct epithelium

Intracytoplasmic lumina (ICL) in human oviduct epithelium were investigated with transmission electron microscopy. ICL were found in 43 out of 60 cases examined. They were ultrastructurally characterized by microvilli lining the lumina, periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining-positive finely granular material in the lumina, and secretory vesicles in the cytoplasm surrounding the lumina. Although ICL were observed at various heights within the epithelium, they were mainly seen in basally located cells that did not face the oviduct lumen. Various stages of formation and development of ICL were observed in the basally located epithelial cells with secretory activities. Primary ICL were originated in the cytoplasm where the secretory granules were aggregated with smooth-surfaced tubular vesicles. Electron microscopic observations after PA-TCH-SP staining revealed that ICL were formed by fusion of the secretory granules with the tubular vesicles. ICL were enlarged into round profiles by further fusion of secretory granules and tubular vesicles, and subsequently opened to the oviduct lumen, or fused to each other to develop into large extracellular cysts within the epithelium.

Diagnosis of breast carcinoma with radiolabeled monoclonal antibodies (MoAbs) to carcinoembryonic antigen (CEA) and human milk fat globulin (HMFG)

The current study attempted to assess the potential proficiency of radioimmunodetection (RAID) of primary, residual, multicentric, and recurrent breast carcinoma using two radiolabeled murine monoclonal antibodies (MoAbs), anti-human milk fat globulin (HMFG1) labeled with iodine (123I) and anti-carcinoembryonic antigen (CEA) labeled with technetium (99Tc). Thirteen patients with suspicious clinical and/or mammographic primary or recurrent breast carcinoma were studied in a phase I-II prospective, consecutive, nonrandomized, noncontrolled study. Five patients received intravenous infusion with 0.5-2.0 mg anti-CEA MoAb type CYT 380 labeled with 99Tc [13-22 millicurie (mCI)] and 8 patients received intravenous infusion with 0.25-1.0 mg anti-HMFG1 MoAb (Unipath, U.K.) labeled with 123I (4-17 mCI). Both MoAbs used in this study demonstrated ability to bind specifically to breast cancer lesions, resulting in successful RAID in 10 of 12 of studied patients (5 of 5 patients in the anti-CEA-99Tc and 5 of 7 in the anti-HMFG-123I group--accuracy 83.3%). One patient was excluded due to protocol violation. Seven patients had true-positive scans when correlated with surgery (sensitivity 87.5%). The MoAb scans accurately diagnosed lesions in 3 of the 4 primary invasive breast carcinomas confirmed histologically. Presence of residual carcinoma following wide excision was established in 1 of 2 patients and presence of soft tissue metastases in 3 patients. Three patients had true-negative scan (specificity 75%): 2 patients presented with suspicious mammographic recurrence postlumpectomy and 1 patient had questionable soft tissue recurrence. One patient with primary breast carcinoma had a false-negative scan and another had a false-positive scan in the presence of fibrosis following lumpectomy and radiation therapy. No adverse reactions were noted in the patients studied. RAID findings were confirmed by immunohistochemistry in 6 of 9 cases studied. Our data suggest that radiolabeled MoAbs used in this study are potentially useful diagnostic agents for evaluation of primary or recurrent breast carcinoma, particularly in the areas where conventional methodology is limited.

Epithelial Proliferative Lesions and Carcinomas in Fibroadenomas of the Breast

Sixteen cases of fibroadenomas with epithelial proliferative lesions (EP lesions) with histologic features resembling those of epithelial hyperplasia, sclerosing adenosis, and microglandular adenosis, and four cases of carcinomas in fibroadenomas (CA lesions) were studied histopathologically and immunohistochemically. The CA lesions included one intraductal carcinoma, two invasive ductal carcinomas, and one lobular carcinoma in situ. The histologic features of the EP lesions and CA lesions were fundamentally the same as those of carcinomas commonly observed in the mammary gland. Immunohistochemically, smooth muscle actin was useful in the detection of myoepithelial cells, particularly in EP lesions of the adenosis type (sclerosing adenosis or microglandular adenosis), and in distinguishing carcinoma. The differences between EP lesions and CA lesions of sites of immunoreactivity to CA15-3, CEA, and EMA were also helpful for differential diagnosis.