Sir Peter MacCallum Department of Oncology - Research Publications
Permanent URI for this collection
Search Results
1 - 3 of 3
-
ItemEVALUATION OF MSA AS A SERUM MARKER IN BREAST-CANCER - A COMPARISON WITH CEA(STOCKTON PRESS, 1988-03)In a blind study, 518 serum samples were assayed for serum levels of mammary serum antigen (MSA) by an enzyme immunoassay (EIA) using the 3E1.2 monoclonal antibody. Using 300 IU as the arbitrary cut off to distinguish normal from abnormal individuals, 75% of patients with primary Stage I carcinoma of the breast (n = 12), 89% of those with Stage II (n = 9) and 93% of those with Stage IV (n = 57) had elevated levels of MSA. A relationship was observed between the level of MSA and stage of disease, and therefore with the extent of tumour burden. Levels of MSA were also determined in a series of 19 patients undergoing chemotherapy for breast cancer. Over a 2-24 month period, the change of MSA levels corresponded with the clinical course of the disease in 17 (89%) cases. MSA levels were also raised in some patients with ovarian, colon, lung and kidney cancer, but the average level was lower than in patients with breast cancer. A comparison of CEA and MSA levels in these patients revealed that MSA was a substantially better marker for breast cancer than CEA. The results of this study demonstrate that MSA levels are elevated in patients with breast cancer and may provide a useful means of following the clinical course of patients with this disease.
-
ItemCOMPARISON OF MAMMARY SERUM ANTIGEN (MSA) AND CA15-3 LEVELS IN THE SERUM OF PATIENTS WITH BREAST-CANCER(STOCKTON PRESS, 1987-12)Serum levels of mammary serum antigen (MSA) and CA15-3 were evaluated in 135 individuals in order to determine their single and combined value in the diagnosis and monitoring of breast cancer. Raised MSA levels (greater than 300 IU) were found in 68% of patients with Stage I and II breast cancer compared to only 3% having raised CA15-3 levels (greater than 40 U ml-1). Of 38 patients with Stage IV breast cancer, 95% had raised levels of MSA and CA15-3 combined with each test individually detecting 82% of those with Stage IV disease. No correlation was found between MSA and CA15-3 levels. Four patients being treated for breast cancer were followed over a 5-17 week period; MSA levels correlated with disease course in 3 and CA-15 in 2. The overall sensitivity, specificity and accuracy in detecting breast cancer were 76%, 91% and 96% for MSA; and 47%, 95% and 97% for CA15-3 respectively. When both tests were used together combined evaluation gave the highest sensitivity (84%) and specificity (100%). MSA seems to be superior to CA15-3 for early breast cancer diagnosis and a combination of the two tests gave the best results for metastatic disease.
-
ItemPURIFICATION AND BIOCHEMICAL-CHARACTERIZATION OF A NOVEL BREAST-CARCINOMA ASSOCIATED MUCIN-LIKE GLYCOPROTEIN DEFINED BY ANTIBODY 3E1.2(STOCKTON PRESS, 1989-04)A member of the high molecular weight glycoproteins of human milk and breast cancer was isolated from the sera, ascites and breast carcinoma tissue of patients with breast cancer using monoclonal antibody 3E1.2. The 3E1.2 defined antigen, termed mammary serum antigen (MSA) was obtained by immunoaffinity chromatography and a solid phase immuno-precipitation technique (SPIT) from serum of patients with metastatic breast cancer. MSA was found to be a high molecular weight glycoprotein with a Mr greater than 300,000 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and a native Mr approximately 1 x 10(6) by gel filtration chromatography; in accord with the published Mr of other high molecular weight glycoproteins obtained from human milk and breast cancer. A high degree of glycosylation of MSA molecule was shown by its poor staining with Coomassie blue but good staining in a PAS-silver stain. In addition, MSA contained N-acetyl neuraminic acid and N-acetyl glucosamine as indicated by its binding to wheat-germ agglutinin. The epitope defined by antibody 3E1.2 is sensitive to treatment by sodium periodate and neuraminidase, implying that both carbohydrate and sialic acid are required for binding of antibody 3E1.2. Sandwich immunoassays demonstrated that MSA+ molecules are likely to express repeated 3E1.2 defined epitopes. Furthermore, MSA was susceptible to degradation by pronase, subtilisin and proteinase K and gave a different peptide profile from that of the PAS-O glycoprotein of human milk. MSA+ molecules were found to carry epitopes for a number of other monoclonal antibodies which were reactive with the PAS-O glycoprotein. It is suggested that MSA has the same core protein as is recognised by antibody DF3 which has been used to clone the same cDNA as was cloned with antibodies HMFG-1, HMFG-2 and SM-3. However, the epitope detected by the 3E1.2 antibody is either absent or weakly expressed on human milk, human milk-fat globule membrane (HMFGM) or deglycosylated HMFGM--all of which react strongly with various anti-HMFG antibodies. The antibody 3E1.2 thus recognises a unique epitope of the high molecular weight glycoproteins of human milk and breast cancer, being found in cancer tissue, serum and ascitic fluid of patients with breast cancer but weakly expressed or absent in human milk.