Tumor-associated antigen TAG-72: Correlation of expression in primary and metastatic breast carcinoma lesions

Abstract

Variability of tumor-associated antigens among and within human tumor cell groups presents a potential problem in the development and optimization of immunodiagnostic and therapeutic procedures for cancer. We determined the degree of expression of a tumor-associated antigen in the primary and metastatic lesions of 23 patients with infiltrating ductal carcinoma; this was accomplished using monoclonal antibody B72.3, an IgG1 generated against membrane-enriched fractions of human metastatic breast carcinomas and reactive with a 220,000-400,000 d glycoprotein complex, termed TAG-72, and the avidin-biotin complex immunoperoxidase method on fixed tissue sections. Sixteen of the 23 breast carcinomas (70%) demonstrated MAb B72.3 reactivity (range 5% to 100% of tumor cells staining). Reactivity of lymph node metastases was present in 14 of 21 patients (67%). MAb reactivity in metastases to distant sites, including bone, adrenals, liver, skin and effusions, was present in 10 of 18 patients (56%). In one patient, neither the primary carcinoma nor the metastasis to the lymph node demonstrated reactivity. There was a statistically significant positive correlation between MAb B72.3 reactivity in both primary and lymph node metastases (Kendall's Correlation Coefficient = 0.60, p = 0.0006) and between lymph node and distant metastases (Kendall's Correlation Coefficient = 0.48, p = 0.02) of the same patient. No correlation existed between antibody reactivity seen in the primary and that found in the distant lesions of that patient. These studies thus demonstrate that monoclonal antibody B72.3 can detect expression of a tumor-associated antigen in both primary and metastatic infiltrating ductal carcinoma lesions, and may prove valuable in the understanding of tumor biology of metastases and as a means for diagnosing occult disease.

Breast epithelial antigen levels and breast tumor antigen content

“…This delay did not seem of consequence, since other authors have demonstrated the antigenic content seems to remain similar in breast cancer metastatic tissue when compared to the original primary tumor [16]. A similar case can be made for NPGP detected by Mc5.…”

“…A similar case can be made for NPGP detected by Mc5. This antigen is the same antigen bound by DF3 in previous studies [16]. When binding of Mc5 to 9 primary breast tumors was compared to the binding of Mc5 to their metastases, the scoring indexes were not different statistically from each other as tested by t-test, U-test, and ANOVA (unpublished results).…”

Sialyl-Tn in Cancer: (How) Did We Miss the Target?

“…The numbers on the top of the bars indicate the number of samples used for each study. References are indicated at the base of each bar, including [56,57,58,59,60,61,62] that are not quoted elsewhere in the text. SCC: Squamous cell carcinoma, AC: adenocarcinoma.…”

The Role of Sialyl-Tn in Cancer

“…Early studies identified the sTn as a marker for diagnosis and prognosis in cancer, and later work focused on using sTn as a potential therapeutic target. sTn neo- or over-expression has been described in many types of epithelial cancer including: gastric [ 5 ], colon [ 6 ], breast [ 7 , 8 ], lung [ 9 ], oesophageal [ 10 ], pancreatic [ 11 ], prostate [ 12 , 13 ], bladder [ 14 ], and endometrial cancer [ 15 ]. Studies suggest that sTn expression has primarily been detected at the apical or luminal surface of tissue and tends to occur in early carcinogenesis [ 16 ].…”