44

These results indicate the existence of..oat-SCLC-leukemia common tumor-asso- ciated antigens. The Mo-Abs are useful

in the diagnosis of oat-SCLC or acute leukemia.

Significance of Carbohydrate Antigen 19.9 (CA19-9) as a Tumor Marker for Lung

Carcinomas. Kurata, M., Takeda, A., Tachibana . H., Muromoto, H., Chin, K., Tanaka, K., Ka- gioka, H., Kubo**, K. **Div. Thoracic Surgery, **Div. Internal Medicine Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan.

CA19-9, a new tumor marker which has been defined by a monoclonal antibody, was assayed in 83 cases of pulmonary dis- ease, including 58 cases of lung cancer, and its significance as a tumor marker for lung cancer was studied in compari- son with the values for Carcinoembyonic Antigen (CEA) assayed at the same time.

CA19-9 was assayed using a Centocor CA19-9 RIA kit and a value of 38 or more was considered positive. CEA was assayed by means of the sandwich method and a value of 2.6 or more, or 5.1 or more, was considered positive.

Lung Cancer Benign Pulmonary (58 cases) Diseases Including

COLD (25 cases) CEA> 2.6 35(60%) 9 (36%) CEA> 5.1 24(41%) 1 (4%) CAI~-9>38 20(35%) 3 (12%)

CA19-9 was found to yield false posi- tives less often than CEA. CA19-9 tested positive in lung cancer cases as follows: adenocarcinoma 41% (ll/27~cases), squa- mous cell carcinoma 21% (3/14 cases), lar- ge cell carcinoma 30% (3/10 cases), and small cell carcinoma 43% (3/7 cases). CA19-9 value for the tumors was general- ly higher than for the blood. There were also cases in which CA19-9 tested high (positive) for the tumor but normal (negative) for the blood.

Tissue Polypeptide Antigen (TPA), Carci- noembryonic Antigen (CEA), and CA-50: A Useful Tumour Marker Combination for Non- Small Cell Lung CarcSnomas (NSCL~). Nilsson~ S., Brodin ~, O., Sil~n ~, A, Lindholm , L. i. Department of Oncology, Akademiska Sjukhuset, University of Upp- sala, S.751 85 Uppsala. 2. Sangtec Medi- cal, Box 200 45, S-161 20 Bromma. 3. Department of Medical Microbiology, Sahl- grenska Sjukhuet, University of G6teborg, S-413 45 G6teborg, Sweden.

There is a need for better tumour mar- kers in the management of NSCLC. In this study TPA, a protein related to cytokera-

tins, CEA, and Ca-50, a tumour associated

ganglioside antigen, were investigated. Sera from

51 patients with NSCLC were drawn prior to therapy and stored at -80°C until analysis. The tumour mar- kers were quantified by the use of radio immuno- assays. The upper normal limits used were 90U/I, 5 ug/l, and 17 U/l for TPA, CEA, and Ca-50, respec- tively. The mean TPA value for 31 patients with limited disease (L~was 107 U/1, whereas that of 9 patients with extensive disease (ED) was 216 U/l. The difference between the two groups was signifi- cant according to Mann-Whitney's U-test. About 70% of the patients had elevated levels with re- spect to TPA. Among the patients in the TPA nega- tive group, about every second showed elevated CEA levels, and in the TPA-CEA negative group, almost every third patient showed elevated Ca-50 levels. Consequently, close to 80% of the patients with NSCLC had elevated serum levels with respect to at least one of the three antigens prior to therapy. The antigens seemed to follow the course of the disease fairly well. Thus this tumour mar- ker combination seems to be of potential value in the management of the disease.

~bnoclonal Antibodies to Non-Small Cell Lung Car- cinomas. Namikawa, S., Rao, U., Chen, S., Pollard, C., Takita, H., Bankert, R.B. Roswell Park Memorial Institute, Buffalo, New York.

Three different monoclonal antibodies, 5C7, 5E8, and IF10 generated against primary adenocarcinoma, squamous cell carcinoma and large cell carcinoma of lung, respectively were assayed on fresh frozen tissue obtained from 36 lung cancers and 40 con- trol specimens employing double antibody immuno- peroxidase technique. Intensity of positive reac- tion and its pattern of distribution was roughly quantitated and also simultaneously compared to the pattern of distribution of keratins AEland AE 3 (Hybritech) and antikeratin and CEA (D/IKO) and preliminary findings are reported. Cross sections occurred but antibodies did not react with sarco- mas, melanoma and lymphomas. Antibody 5C7 reacted strongly with well differentiated adenocarcinoma and large cell carcinoma and with less intensity with squamous cell carcinoma. Intensity of stain- ing appeared to be proportional to the differen- tiation of the neoplasm. 5E8 also reacted with all cell types of lung cancer, but higher scores were obtained with squamous cell carcinoma. On the con- trary, about 60% of well differentiated adenocar- cinoma were negative, iF10 reactions were stron- gest with the poorly differentiated adenocarci- noma/large cell group. No significant differences in staining reactions of primary or metastatic lung carcinoma was found. Interesting findings were focal areas of positivity with Caltitonin (Histotech) in four cases of squamous cell carci- noma of lung and ~HCG in a single case of large cell carcinoma. Correlation of above findings with clinical behavior of the tumors will be presented.

A Canine Lung Cancer ~bdel. Benfield, J., Harmnond, W., DeCaro, L., Paladugu, R.

Pak, H., Teplitz, R.. City of Hope National Medical