Comparison of fifteen immunoassays for the measurement of serum MUC-1/CA 15-3 in breast cancer patients.

BACKGROUND: Quality control results for serum MUC-1/CA 15-3 assays have always shown large discrepancies. METHODS: This multicentre study of 15 methods (labelled M1-M15) measured coded sera from 35 patients with breast cancer without recurrence (group 1), 46 patients at 1st metastasis (group 2), and 39 patients with advanced metastases (group 3). Results were compared using parametric statistics, ANOVA, principal component analysis, and receiver operating characteristic (ROC) curves. RESULTS: Mean MUC-1/CA 15-3 concentrations varied widely (75.1-303.0 U/mL, 24.8%) among methods. The false positive (FP) rate for group 1 was 8/521 (1.5%); for group 2 and group 3 false negative (FN) results were 21/680 (3.1%) and 11/583 (1.9%), respectively. Using the ROC cut-offs, we found no FPs for group 1 and no FNs for group 3. However, group 2 showed 16 FNs. All p-values for Pearson's correlation were <0.0001 between methods, except for M11. When comparing methods using different antibodies, discordance rates reached a maximum of 15.2%. Principal component analysis revealed a grouping of methods using: CanAg monoclonal antibodies (mAbs) (M2, M7 and M12); Centocor/Fujirebio mAbs (M3-M6, M8-M10, M14-M15) and Biomira mAbs (M1 and M13); and Centocor/Fujirebio mAbs (M11). CONCLUSIONS: Results were more consistent among methods using the same antibody type. Principal component analysis showed that antibody type was the strongest determinant of immunoassay results.

A soluble lymphocyte activation gene-3 (sLAG-3) protein as a prognostic factor in human breast cancer expressing estrogen or progesterone receptors.

In contrast to the long-held belief that breast cancer is a weakly immunogenic tumor, accumulating evidence indicates an immune infiltrate is an invariable finding in breast cancers, raising hopes that immunotherapy for breast cancers may succeed in targeted patients, specifically those with either regional or minimal residual disease. However, no immunologically related prognostic factor has yet been established that may help to define subsets of patients who are more prone to respond to immunotherapy. High levels of soluble LAG-3 protein (sLAG-3) in sera has previously been shown to be associated, as a Th1 marker, to resistance to tuberculosis in large series of patients. We therefore hypothesized that, if cell-mediated immune mechanisms are indeed important for improved prognosis, high levels of sLAG-3 might be correlated with improved survival in some subsets of breast cancer patients. Studying a cohort of 246 patient's sera collected in 1994 at time of first diagnosis, we found that both disease-free and overall survival rates were greater in patients with estrogen or progesterone receptor positive tumor cells who had detectable levels of sLAG-3 at diagnosis versus patients with undetectable sLAG-3 levels. These results indicate that sLAG-3 may be a valuable marker for prognosis in some subsets of breast cancers and, more importantly, that cell-mediated mechanisms such as Th1 responses do have an impact on survival, a pre-requisite before the setting-up of immunotherapy protocols as a form of adjuvant therapy for breast cancer.

Longitudinal changes in serum HER-2/neu oncoprotein levels in trastuzumab-treated metastatic breast cancer patients.

BACKGROUND: To evaluate longitudinal variations of serum HER-2/neu extracellular domain (sHER-2) in metastatic breast cancer patients receiving combined trastuzumab treatment. PATIENTS AND METHODS: Thirty-three patients were monitored by serial sHER-2 ELISA (Oncogene Science). Results were compared to time to progression (TTP) and survival from treatment initiation. Non parametric statistical tests were used. RESULTS: Median sHER-2 before first injection was 41.37 ng/ml (range 7.54-1597.00 ng/ml, n=32). Mean sHER-2 levels differed significantly between responders (n=20) and non responders (n=13) (p<0.0001). Median TTP (266 days, range 35-1000 days) was unrelated to clinico-biological variables at diagnosis or number and site of metastases before treatment. Patients with pre-treatment sHER-2 levels < or = 30 ng/ml (n=14) had a significantly longer TTP than the group with sHER-2 > 30 ng/ml (n=18) (p=0.0346) and sHER-2 levels were of prognostic value for overall survival from first injection (p=0.0150). CONCLUSION: Our results show that monitoring serum HER-2/neu levels during metastatic breast cancer can provide a real time assessment of a woman's HER-2/neu status and can provide important information for therapeutic decisions.

Serum HER-2 extracellular domain (ECD) before the first metastasis in 128 breast cancer patients.

We studied the serum HER-2 extracellular domain (sHER-2) before the first metastases in 128/701 breast cancer patients diagnosed and followed-up in our institution who developed metastases as the first relapse. sHER-2 was measured by an enzyme-linked immnunosorbent assay and CA 15.3 by an immunoradiometric assay. Non-parametric statistics were used. sHER-2 and CA 15.3 before and after primary treatment were measured in a previous part of the study. Before first metastases, 45% of the samples were over 12 microg/l of sHER-2 (cut-off) and were significantly related to sHER-2 values before and after primary treatment (P = 0.0350 and P < 0.0001 respectively). Concordance with CA 15.3 was 56.25 % (weak correlation, rho = 0.263). sHER-2 levels differed according to the sites of the metastases (P = 0.0199), the highest levels were found in liver and lung metastases. A median sHER-2 lead time of 254 days was found for 18/28 (64.3 %) patients before first metastasis. Pre-metastatic sHER-2 levels showed strong univariate (Kaplan-Meier method, P = 0.0014) and multivariate prognostic values (Cox model, P < 0.0001) for survival after first metastasis. In recurrent breast cancer, elevated levels of sHER-2 enabled an early detection of occult metastases and the identification of patients with a high probability of shortened survival.

Two prognostic groups of inflammatory breast cancer have distinct genotypes.

PURPOSE: The prognosis of inflammatory breast cancer (IBC) remains poor despite the use of multimodality treatments, with a 10-year survival rate of not >30%. Clinicopathological and biological predictors of outcome are inadequate in this setting. Analysis of loss of heterozygosity (LOH) can provide a molecular portrait of the genetic alterations underlying stepwise cancer progression. We tested the value of LOH patterns as diagnostic and prognostic markers in IBC. EXPERIMENTAL DESIGN: In a previous study of 64 patients with IBC who were treated homogeneously between 1988 and 1999, we determined LOH frequencies at 71 loci located in 20 chromosomal regions associated with primary breast cancer. Six of these regions bore alterations that were less frequent in non-IBC. In the present study, we sought correlations between these molecular data and the clinicopathological features and clinical outcome of the same 64 patients. RESULTS: With the exception of stage IV disease, extensive breast inflammation at first clinical examination was the main factor associated with poor outcome (P = 0.00065 versus localized inflammation). The overall frequency of LOH was also higher in this group (P = 0.000073). LOH patterns differed between patients with localized and extensive breast inflammation. CONCLUSION: Patients with IBC can be separated into two major prognostic groups on the basis of initial clinical signs, which appear to be subtended by different molecular alterations.

Luteinizing hormone receptor status and clinical, pathologic, and prognostic features in patients with breast carcinomas.

BACKGROUND: It has been established that pregnancy protects against breast carcinoma, and animal models have shown that human chorionic gonadotropin (hCG) mimics this effect by inhibiting the initiation and progression of experimental breast carcinoma. Luteinizing hormone (LH)/hCG receptors (LHR) have been characterized in several human breast carcinoma cell lines and in a limited number of breast carcinoma biopsy specimens. These observations led to the suggestion that hCG may be used as a means of prevention and possibly treatment in patients with breast carcinoma. METHODS: The authors used immunocytochemistry to analyze tumors from 160 patients who were followed for a median of 2539 days. Using a cut-off value of 18% immunolabeled cells in each tumor, 72% of tumors were identified as LHR positive. The LHR-positive tumors were found more frequently in premenopausal women, who had tumors with greater cell differentiation and positive estrogen receptor alpha status. Infiltrating lobular carcinomas were positive for LHR more frequently compared with infiltrating ductal carcinomas. There was no correlation between LHR status and lymph node invasion, tumor size, or progesterone receptor status. RESULTS: Patients with LHR-positive tumors had a longer metastasis free survival, although the statistical significance was slight (P = 0.07), most likely due to the limited number of events in the patients studied. Conversely, there was no difference between patients with LHR-positive or LHR-negative tumors in the local recurrence free interval. CONCLUSIONS: LHR status seems to be related in part to the degree of differentiation in breast tumors, confirming experimental evidence of the effect of hCG on mammary tissue. The presence of LHR is a tumor characteristic that largely is independent of other clinical and pathologic tumor features. It may be of interest in the future to correlate the presence of LHR with a possible therapeutic response in individual patients to hCG.

Evidence of chromosome regions and gene involvement in inflammatory breast cancer.

Inflammatory breast cancer (IBC) is a rare but particularly aggressive form of primary breast cancer. In contrast to noninflammatory breast cancer (non IBC), the molecular alterations underlying IBC are poorly known. We postulated that the kind and frequency of these alterations might differ between IBC and non IBC and account for its particular aggressiveness. We investigated allelic losses associated with primary breast cancer (on chromosome arms 1p, 3p, 6p, 6q, 7q, 8p, 9p, 11p, 11q, 16q, 17p and 17q) by analyzing 71 microsatellite markers in 66 cases of IBC. Loss of heterozygosity (LOH) was frequent, with a mean fractional allelic loss (FAL) index of 52%. Relative to published data on non IBC, allelic loss was particularly frequent at 3p21-p14, 6p, 8p22, 11q, 13q14 and 17q21, suggesting the presence of genes that are markedly altered in IBC. In contrast, the DNA amplification levels of ERBB2, MYC and CCND1, as measured by real-time quantitative PCR, did not differ between IBC and non IBC.

Correlation between MIB-1 and other proliferation markers: clinical implications of the MIB-1 cutoff value.

BACKGROUND: Cell proliferation is a major determinant of the biologic behavior of breast carcinoma. MIB-1 monoclonal antibody is a promising tool for determining cell proliferation on routine histologic material. The objectives of this study were to compare MIB-1 evaluation to other methods of measuring cell proliferation, with a view to refining the cutoff used to classify tumors with low and high proliferation rates in therapeutic trials. METHODS: One hundred eighty-five invasive breast carcinomas were evaluated for cell proliferation by determining monoclonal antibody MIB-1 staining, histologic parameters (Scarff-Bloom-Richardson grade and mitotic index) on paraffin sections, S-phase fraction (SPF) by flow cytometry, and thymidine-kinase (TK) content of frozen samples. RESULTS: There was a high correlation (P = 0.0001) between the percentage of MIB-1 positive tumor cells and SPF, TK, histologic grade, and the mitotic index. Multivariate analyses including MIB-1 at 5 different cutoffs (10%, 15%, 17% [median], 20%, 25%) and the other proliferative markers showed that the optimal MIB-1 cutoff was 25% and that the mitotic index was the proliferative variable that best discriminated between low and high MIB-1 samples. A MIB-1 cutoff of 25% adequately identified highly proliferative tumors. Conversely, with a MIB-1 cutoff of 10%, few tumors with low proliferation were misclassified. CONCLUSIONS: The choice of MIB-1 cutoff depends on the following clinical objective: if MIB-1 is used to exclude patients with slowly proliferating tumors from chemotherapeutic protocols, a cutoff of 10% will help to avoid overtreatment. In contrast, if MIB-1 is used to identify patients sensitive to chemotherapy protocols, it is preferable to set the cutoff at 25%. The MIB-1 index should be combined with some other routinely used proliferative markers, such as the mitotic index.