Cancer Poster Session
The development of laboratory methods of breast cancer screening and monitoring is on a great demand nowadays. The wide-known tests, such as detection of cancer markers like CA-15, CA-19, etc., due to their non - sufficient sensitivity are applied for disease monitoring in Ag-positive patients and can not be used for the initial preclinical breast cancer screening.
Here we present the alternative approach for breast cancer detection, based on the registration of cell immune reaction – in vitro delayed type hypersensitivity in electrophoretic mobility test (EM-test) with neuraminidase - treated membrane antigen preparation. In vitro antigen preparation procedure mimics in vivo early stage cancerogenesis events, that lead to the loss of «social behavior» of the cells /1/.
In our numerous model experiment with different models of spontaneous, induced and transplanted tumors in mice and rats /2/ it was shown that the sensitization of the lymphocytes to the desialilated antigens in the organism may serve as a marker of the malignancy and the lowest level of the positive reaction was approximately 10 5 transformed cells. That formed a strong base for the application of EM-test with NA treated antigens in humans, especially in breast cancer, where the wide screening programs are best developed.
Materials and Methods
We studied the blood specimens from 117 women with malignant and benign breast diseases that obtained diagnostics and treatment in the breast disease department of the Ukrainian Institute of the Oncology and Radiology, Kiev. Besides this the blood of 21 healthy donors was studied. The age of patient and donors was 27 – 87 years. Cancer diagnosis was approved by hystological method, diagnose of benign tumor and mastopathy was approved by hystological, cytological and clinical methods. In patient group there were 872 women with primary diagnosis of breast cancer of stage I – IY, including 14 patients after presurgery radiation.; 21 patient with benign breast diseases (fibroadenoma, fibroadenomatosis), 26 patients after complex treatment (surgery, radio- and chemotherapy) and 16 patients with non-breast cancer.
EM-test was performed according to Broen et. al. /3/ with own modifications /3/. Nearaminidase-treated antigenic membrane preparation were obtained from normal and malignant human breast tissues. Test results were supposed to be positive if the decrease of the electrophoretic mobility of the indicator cells (EM-indices) was equal and/or more than 10% from the control.
The initial step of the clinical investigations was the determination of the operational characteristics of EM-indices, distinguishing positive and negative results. In the study with breast cancer patients and healthy donors (men) it was shown that the test specificity was 83% and sensitivity – 90%: positive prognostic value of 98% and negative prognostic value of 65,5%.
Sensitization to normal desialilated antigens (NDSAg) and cancer desialilated antigens (CaDSAg) were compared in the patients with different tumor stage. The results are shown in the table.
Ag Breast cancer stages I II III IY All NDSAg Positive/total, % 2/2 20/29 18/18 10/11 48/58 Sensitivity 100% 69% 100% 91% 83% EM index, % 85 29.9±6.0 56.3±7.5 37.7±6.3 CaDSAg Positive/total, % - 13/18 9/11 4/4 26/33 Sensitivity - 72% 82% 100% 78% EM index, % - 18,9±3,8 31,2±8,2 52,3±14,3 ----------------------------------------------------------------------During the separate analysis it was shown that the patients with false negative results were, presumable older than 50 years (p <: .1) As can be seen from the results the "normal" antigen preparation seems to be more effective, the "cancer" antigen, presumable, by some loss of the antigenic determinants during the malignization. NDSAg is more hystospecific the CaDSAg: in study of the patient with other types of cancer: lung (4) rectal (4) and stomach (4) cancer cross-reaction was determined with CaDSAg in 3 patients and no cross-reaction was shown with NDSAg. That’s why in further study we used "normal" desialilated antigen preparation.
Next study was to compare the results of EM-testing in patient with- and without pre-surgery irradiation. We detected the correlation between cytocydic effect of radiation in some patients and decline in EM-indices. EM-indices also correlated with the mass volume (for T2 and T3 (P <: ,05). No correlation has been found between EM-indices and the hystolohical grade of malignancy, lymph nodes involvement, methastatic process.
During the study of the lymphocyte sensitization in patients with benign breast diseases it was demonstrated the positive EM-test reaction in 7/9 patients with fibroadenoma (77.8%) and in 8/13 (61,55) patients with fibroadenomatosis (in North America – non-dominant lesion) with reliable difference between these two groups (p <: .05). We suppose this difference is much more like due to the mass volume, than to the different cancer potential of these forms.
The study of the prognostic capacity of NDSAg in recurrence prediction in breast cancer patients after the combined treatment has been held in 26 patients. 50% showed the positive reaction in the range of 13 - 82%. We succeeded to follow up 16 patients during four years: in 13 of them the EM-test indices correlated with the current of the disease. In several cases the positive reaction preceded the clinical manifestation of the metastasis for 1 - 3 years.
Discussion and Conclusion
The results, shown above, summarize total of 18 years of study of the normal desialilated antigens. Initial purpose of the work was the augmentation of tumor cells’ antigenicity by neuraminidase treatment. As it revealed, neuraminidase treatment in special conditions augments not only antigens in the tumor tissue, but also unmasks hidden antigenic determinants on the normal cell surface, that are intimately involved in cancerogenesis in its early stages. Desialilated membrane antigens can be used in the heterogenous systems, that provides the possibility for their application for human cancer immunodetection.
The application of normal desialilated antigens is the most promising for preclinical screening of real, evidence-based high risk groups, were the regular follow-up and possible prescription of such prophylaxis drugs like Tamoxifen and Raloxifen can bring the immediate results by increasing health care standards. Rather time and labor-consuming EM-test procedure may be avoided by the replacement of electrophoretic mobility measurements by lymphokine determination in ELISA test.
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|Novichenko, N.; (1998). Novel Type of Antigen Preparation for Immunodetection of Breast Cancer. Presented at INABIS '98 - 5th Internet World Congress on Biomedical Sciences at McMaster University, Canada, Dec 7-16th. Available at URL http://www.mcmaster.ca/inabis98/cancer/novichenko0442/index.html|
|© 1998 Author(s) Hold Copyright|