Identification of second malignancies on effusions and fine-needle aspirates using a panel of monoclonal antibodies

The longer survival of neoplastic patients achieved through improvements of therapeutic regimens has increased the relative risk of developing a second primary tumour (SPT). In this context, conventional cytopathology can define tumour histotype only in a small fraction of cases. In this study, we have evaluated whether selected combinations of monoclonal antibodies (MAbs) to tumour-associated antigens (TAAs) can increase the accuracy of conventional morphology in detecting second primary tumours (SPTs) in two particularly difficult areas of cytodiagnosis, namely that of effusions and pulmonary fine-needle aspirates (FNAs). The immunocytochemical (ICC) analysis of 334 cytological specimens demonstrated that the use of our selected panel of MAbs could allow a more efficient identification of SPTs in comparison with conventional morphology. This diagnostic improvement was statistically significant (P < 0.0001). The present findings show that the immunophenotyping of effusions and FNAs, providing a more accurate and objective identification of SPTs, may have significant therapeutic and epidemiological relevance.

Spontaneous canine mammary tumors. A model for monoclonal antibody diagnosis and treatment of human breast cancer

BACKGROUND

The increasing availability of monoclonal antibodies to human breast tumor-associated antigens offers a new means to evaluate whether antigenic similarities exist between human and animal breast tumors. The study of the biology of spontaneous mammary tumors in the dog, one of the most frequent neoplasias in this domestic animal, may be of interest in providing an experimental model for the clinical management of human breast cancer.

EXPERIMENTAL DESIGN

In order to assess whether antigenic similarities do occur between human and canine breast cancer, in the present study we have evaluated the immunohistochemical reactivity of two normal mammary glands and 62 benign and malignant canine breast tumors with a panel of six MoAbs, (HMFG2, MBr1, B72.3, B6.2, X-10, B1.1) recognizing distinct human breast tumor-associated antigens.

RESULTS

The results of the present study indicate that mammary neoplasias in dogs display an antigenic phenotype comparable to that observed in female and male human breast lesions. As has already been demonstrated in humans, only three among the six monoclonal antibodies tested (B72.3, B6.2, and X-10) appear to discriminate benign from malignant canine mammary tumors.

CONCLUSIONS

These findings demonstrate that (a) this veterinary tumor may represent a suitable model for imaging and immunotherapy studies of human breast carcinoma and (b) the triplet of reagents capable of distinguishing selectively transformed glandular epithelium may be useful in the immunocytochemical presurgical diagnosis of these canine neoplasias.

Immunocytochemical diagnosis of amelanotic metastatic melanoma using monoclonal antibodies HMB-45 and Ep1-3

The analysis of fine-needle aspirates and effusions has proved to be a valuable tool for the cytological identification of metastatic melanoma. Nevertheless, while malignant pigmented cells can be easily detected on cytological specimens, their identification may be very difficult in patients bearing amelanotic lesions. In the present study we have evaluated whether this limitation can be overcome using two monoclonal antibodies (mAbs) HMB45 and Ep1-3, which are highly specific for the melanocyte lineage. These reagents were assayed in immunocytochemical tests performed on cytological material obtained from 50 patients with a past history of melanoma and 463 bearing metastases from a cryptic primary tumour. These mAbs, employed in combination with a panel of monoclonal reagents with well-defined tumour specificity, may improve the accuracy of the conventional cytopathological diagnosis of melanoma metastases in the two groups of patients.

Antigenic modulation of metastatic breast and ovary carcinoma cells by intracavitary injection of IFN-alpha

Antigenic modulation of major histocompatibility and tumour associated antigens was observed in neoplastic cells obtained from patients with pleural and abdominal effusions of breast and ovary carcinomas following a single intracavitary dose of 18 x 10(6) U recombinant IFN-alpha. This regimen resulted in antigenic modulation in seven out of 11 tested cases, suggesting a potential, although limited, responsiveness of at least a fraction of breast and ovary carcinoma cells to in situ biomodification with IFN-alpha.

Immunocytodiagnosis of atypical hyperplasia and endometrial carcinoma in post-menopausal women

In the present study we have evaluated whether monoclonal antibodies (MAbs) B72.3 and AR-3 which display, on histological preparations, a differential reactivity with normal and transformed endometrium, could be a useful adjunct to endometrial cytology in the identification of pre-neoplastic and neoplastic conditions. Immunocytochemical (ICC) tests, using the 2 reagents, were performed on normal cycling endometrium and on hyperplastic and malignant lesions collected by the endocyte technique both from 86 surgically resected specimens and from 62 postmenopausal symptomatic and asymptomatic outpatients. The results obtained showed that the combination of the 2 MAbs can complement conventional morphology in the identification of pre-malignant atypical lesions and endometrial carcinoma of unclear cytological features, thus allowing a selection of those patients who are candidates for fractional curettage.

Selected monoclonal antibodies can increase the accuracy of cytodiagnosis of neoplastic effusions of cryptic origin expanded in a short term culture

The use of a selected panel of monoclonal antibodies (MoAb) to tumor associated antigens (TAA) in immunocytochemical (IIC) tests has been shown, in a preliminary study, to be a powerful diagnostic tool for the identification of the primary solid tumor causing metastatic effusion. Despite this improvement in a minority of neoplastic fluids a number of different causes may still determine false negative (FN) immunocytochemical diagnoses. The aim of the present study was to confirm the diagnostic accuracy of this panel of MoAb. This was done by analyzing in IIC tests a larger number of effusions and by evaluating whether the expansion in short term culture of those fluids with an uncertain malignant morphology could provide an adequate cellular substrate for immunocytodiagnosis. The analysis of 314 effusions confirmed the results of the pilot study and demonstrated that the combination of short term culture and immunocytochemical assays can further increase the sensitivity of this novel diagnostic procedure from 84.3% to 95.3%.

The use of a panel of monoclonal antibodies can lower false-negative diagnoses of peritoneal washings in ovarian tumors

A correct surgical staging of ovarian carcinoma and the identification of persistent microscopic disease at second-look surgery largely rely on the cytologic examination of peritoneal washings (PW). Nevertheless, the morphologic analysis of these fluids frequently provides false-negative findings. As shown in other areas of cytodiagnosis, monoclonal antibodies (MoAb) to tumor-associated antigens may be a useful adjunct to overcome the limitations of conventional cytopathologic examination of PW. To evaluate this question, immunocytochemical tests were done using a panel of four MoAb to ovarian carcinoma-associated antigens (B72.3, MOv18, MOv19, and OC-125) to analyze 117 PW sampled during initial surgical staging and 121 PW harvested at second-look operations. The results of this study showed that immunocytochemical tests using the combination of the four reagents could improve cytodiagnosis more than 15% in both groups of PW. Thus a significant fraction of patients could be correctly staged and treated or become potentially curable by second-line salvage therapy.