Demonstration of Mucinous-Like Carcinoma-Associated Antigen in Bone Marrow and Lymph Node Biopsies from Patients with Breast Carcinoma

Evaluation of the Expression of Tissue DF-3 and MCA and the Corresponding Serum Values in Patients with Breast Carcinoma

Two specific monoclonal antibodies for breast tissue (DF3 and MCAb-12) and the corresponding tumor markers CA15-3 and MCA in serum have been evaluated in 50 patients with breast cancer and in 15 controls. The expression of these antigens in tissue was poorly correlated with the common prognostic parameters. Their presence in serum was associated with an altered distribution of the antigens in the cell. The expression of these antigens in tissue enables us to select patients for serological follow-up and to evaluate tumor differentiation from a functional point of view.

Mucin-Like Carcinoma-Associated Antigen (MCA) in Breast Cancer: Clinical Experience at the National Cancer Institute of Milan

Mucin-like Carcinoma-associated Antigen (MCA) is a glycoprotein belonging to the mucin family; it is defined by the monoclonal antibody b-12. Mucins represent an interesting group of tumor markers and are widely utilized in the clinical monitoring of neoplastic patients. These molecules show a certain degree of tissue specificity and MCA is preferentially associated with breast tissue.

Several studies have demonstrated that patients with breast cancer usually have high MCA serum levels. In this paper the experience of the National Cancer Institute of Milan with the clinical use of MCA in breast cancer patients is reported. The observed sensitivity of the MCA test was poor in patients with early-stage disease, while it was acceptable in patients with advanced breast cancer. MCA concentrations appeared to be directly related to disease spread. A clear relationship was seen between MCA levels and lymph-nodal status. The highest MCA plasma levels were observed in patients with metastatic disease. In this group of patients the sensitivity of the test on the basis of a cut-off of 11 U/mL was 52%.

Detection of occult micrometastases in non-small cell lung carcinoma by reverse transcriptase-polymerase chain reaction

BACKGROUND

The 5-year survival rate following surgical resection of Stage I or Stage II non-small cell lung carcinoma (NSCLC) is 30% to 50%, probably because of undetected occult micrometastases (OMs) at the time of surgery. Other investigators have detected OMs in bone marrow and histologically negative lymph nodes from patients with NSCLC using immunohistochemical staining to cytokeratins and cell surface glycoproteins.

STUDY OBJECTIVE

To develop and evaluate an assay based on the reverse transcriptase-polymerase chain reaction (RT-PCR) for the detection of OMs in NSCLC.

PATIENTS

Twenty-eight patients with benign or malignant thoracic pathology. Samples of primary tumors and lymph nodes were collected at the time of surgical resection or mediastinoscopic lymph-node biopsy.

RESULTS

Using RT-PCR to detect messenger RNA (mRNA) transcripts for MUC1 (a cell surface glycoprotein present in lung tissue but absent from normal lymph nodes), OMs were identified in 33 of 88 lymph nodes determined to be free of tumor by hematoxylin and eosin staining. Eleven of 11 control mediastinal lymph nodes from patients without malignancy failed to express detectable MUC1 transcripts. Dilutional experiments demonstrate that the assay can detect one MUC1-positive NSCLC cell in 1x10(7) MUC1-negative cells. A comparison of our RT-PCR assay to immunohistochemistry specific for the MUC1 glycoprotein suggests that RT-PCR may be more sensitive than immunohistochemistry for the detection of NSCLC OMs.

CONCLUSIONS

This study demonstrates that RT-PCR for MUC1 mRNA can detect the presence of MUC1 mRNA in histologically negative lymph nodes from patients with NSCLC. The prognostic significance of these findings is currently unknown.

Immunohistochemical evaluation of lymph node micrometastases from breast cancer

The lymph node micrometastasis was retrospectively immunohistochemically investigated in 185 patients with node-negative breast cancer and compared with the routine conventional findings. The monoclonal antibodies to epithelial membrane antigen (EMA) and mucinous-like carcinoma antigen (MCA) were used. Of 19 EMA-positive cases, 16 were false positive. Therefore only 3 cases were found to show staining with both EMA and MCA. The patients are all living and well and free of recurrence. No micrometastasis was immunhistochemically demonstrated in 11 node-negative breast cancer patients with subsequent metastases. The results of the present study indicate that the detection rate containing occult cells afforded by conventional routine evaluation is sufficient, at least in Japanese.