Antigenic phenotype of the lymphocytic component of medullary carcinoma of the breast

Prospective study on the expression of cancer testis genes and antibody responses in 100 consecutive patients with primary breast cancer

To determine the expression of cancer testis (CT) genes and antibody responses in a nonselected population of patients with primary breast cancer, we investigated the composite expression of 11 CT genes by RT-PCR in fresh biopsies of 100 consecutive cases of primary breast carcinoma and by immunohistology in selected RT-PCR-positive cases. Antibody responses against 7 CT antigens were analyzed using recombinant antigen expression on yeast surface. In 98 evaluable cases, SCP-1 and SSX-4 were expressed most frequently (both 65%), followed by HOM-TES-85/CT-8 (47%), GAGE (26%), SSX-1 (20%), NY-ESO-1 (13%), MAGE-3 (11%), SSX-2 (8%), CT-10 (7%), MAGE-4 (4%) and CT-7 (1%). One CT gene was expressed by 90% of the cases; 79% expressed > or =2, 48% > or =3, 29% > or =4, 12% > or =5, 6% > or =6, 3% > or =7, 2% > or =8 and one case coexpressed 9 antigens. Of 100 serum samples screened for CT antigen-specific antibodies, antibodies against NY-ESO-1 were detected in 4 patients, against SCP-1 in 6 patients and against SSX-2 in 1 patient, while no antibodies were detected against MAGE-3, CT-7 and CT-10. Expression of CT genes or antibody responses was not correlated with clinical parameters (menopausal status, tumor size, nodal involvement, grading, histology and estrogen receptor status) or the demonstration of CT gene expression at the protein level, by immunohistology. Our results show that breast carcinomas are among the tumors with the most frequent expression of CT antigens, rendering many patients potential candidates for vaccine trials.

Immunophenotype of lymphocytic infiltration in medullary carcinoma of the breast

Medullary carcinoma (MC) of the breast is characterized by large anaplastic cells and infiltration by benign lymphocytes. Patients with this pattern of breast carcinoma are considered to have a better prognosis than those with other histological subtypes. We reviewed cases of primary breast carcinoma that were surgically resected between 1990 and 2004. Of these, 13 cases of medullary carcinoma of the breast with lymphocyte infiltration were reported. Tests for CD3, CD4, CD8, CD20, CD56, TIA-1, and granzyme B were performed on paraffin sections. We found that the MC contained very few NK cells, as assessed by their reactivity with the CD56 antibodies. However, MC had a significantly greater percentage of CD3, CD8, TIA-1, and granzyme B lymphocytes infiltrating the stroma of the tumor. Furthermore, more CD8-positive than CD4-positive T-cell lymphocytes were present within the tumor cell nests in MC, as opposed to the proportion in usual ductal carcinoma. The infiltrating cytotoxic/suppressor T cells in MC represent host resistance against cancer, and the high grading of the T-cell infiltration could explain, in part, a key mechanism controlling the good prognosis for this type of tumor and solve the pathological paradox of MC.

Medullary carcinoma, provocative now as then

The recent observation that studies of BRCA1-associated tumors contain a high proportion of medullary carcinomas and ductal carcinomas with medullary features has re-introduced pathologists to an old diagnostic problem. The term "medullary carcinoma" dates to the 19th century, but the modern entity was introduced in 1949 by Moore and Foote, who described a carcinoma with a lymphoid infiltrate, a favorable prognosis, and low frequency of metastasis. Almost three decades later, Ridolfi et al proposed specific criteria for diagnosis, resulting in an entity with an even more favorable prognosis and a lower incidence. The reproducibility and clinical relevance of the diagnosis have been questioned recently, and new criteria have been proposed and compared. The tumors typically express cytokeratin 7, often vimentin and S100-protein, but not cytokeratin 20. The usual ones are positive for p53 and negative for estrogen receptor, Her2/neu, and bcl-2. Medullary carcinomas express e-cadherin and beta-catenin more often than ordinary high-grade ductal carcinomas, and the former have genetic differences from the latter. The lymphoid infiltrate of medullary carcinomas is related to beta-actin fragments exposed by apoptotic cells. The present review discusses historical and recent developments and emphasizes diagnostic criteria.

Translocation of an intracellular antigen to the surface of medullary breast cancer cells early in apoptosis allows for an antigen-driven antibody response elicited by tumor-infiltrating B cells

Tumor-infiltrating lymphoplasmacytic cells are a key feature of medullary carcinoma of the breast (MCB), a distinct subtype of human breast cancer that, despite cytologically anaplastic characteristics, has a more favorable prognosis than other types of breast cancer. Since it has been proposed that the improved clinical outcome is due at least in part to the presence of a prominent lymphoplasmacytic cell infiltrate in the tumor stroma, we recently examined the tumor-infiltrating B cell response in MCB and showed that it is oligoclonal and directed against an intracellular protein translocated to the cell surface upon MCB cell apoptosis. Human Abs cloned from MCB lymphoplasmacytic infiltrate-derived phage display libraries and reflecting the dominant part of the response were used to identify the target Ag as actin. Here, we have characterized in detail the cloned human IgG Abs and the translocation process of actin to the cell surface of apoptotic MCB cells. Our analysis shows that the cloned Abs bind specifically and with high affinity to actin, as determined by ELISA and surface plasmon resonance. Sequence analysis revealed that the Abs are highly somatically mutated, with high replacement to silent ratios, indicative of an Ag-driven, affinity-matured response. Interestingly, the tumor-infiltrating B cells in half the MCB patients mainly exhibited an IgG2 response, while IgG1 dominated in the others. To gain insight to the molecular events that may elicit such an Ab response, we examined the translocation of actin to the cell surface of apoptotic MCB cells using flow cytometry and laser scanning cytometry. Our results show that actin becomes exposed on the cell surface of a large proportion of apoptotic MCB cells as an early apoptotic event. We propose that the Ab response against actin produced by tumor-infiltrating B lymphoplasmacytic cells is Ag-driven, affinity-matured, and elicited due to the increased rate of apoptosis occurring within the MCB tumor that facilitates the translocation and proteolytic fragmentation of intracellular proteins.

The tumor-infiltrating B cell response in medullary breast cancer is oligoclonal and directed against the autoantigen actin exposed on the surface of apoptotic cancer cells

Medullary carcinoma of the breast (MCB) is a morphologically and biologically distinct subtype of human breast cancer that, despite cytologically anaplastic features, has a more favorable prognosis than other types of breast cancer at similar stages of differentiation. It has been proposed that the improved clinical outcome is due, at least in part, to the presence of a prominent lymphoplasmacytic cell infiltrate in the tumor stroma. We studied the B lymphoplasmacytic cell infiltrates in MCB to determine the role of the antibody response produced by the local infiltrating cells. Oligoclonal predominance among tumor-infiltrating B cells in a panel of MCB patients was observed, suggesting that certain B cell clones were expanded, possibly in response to specific tumor-associated stimuli. IgG antibody phage-display libraries were generated from MCB-infiltrating lymphoplasmacytic cells of two patients, and MCB-reactive monoclonal antibodies were retrieved by selection on fresh-frozen MCB tissue sections. Analysis by mass spectrometry revealed that the antigen targeted by the dominant clones in the oligoclonal B lymphoplasmacytic response in both patients was not a cancer-specific antigen but the cytoskeletal protein beta-actin. MCB exhibits an increased rate of apoptosis, and apoptotic MCB cells were shown to expose actin on the cell surface, permitting its recognition by the humoral immune system. Further, actin fragments, similar to those observed after cleavage with the apoptotic protease granzyme B, were observed in MCB tissue. Our results indicate that the major antibody response produced by tumor-infiltrating B lymphoplasmacytic cells are autoimmune in nature and a consequence of the perturbed state of increased MCB apoptosis caused by granzyme B-induced T cell cytotoxicity and/or intrinsic cellular factors of MCB cells.

Antigenic characterization of medullary carcinoma of the breast: HLA-DR expression in lymph node positive cases

Medullary carcinoma of the breast has attracted attention because of its relatively good prognosis, in spite of its high cytologic grade. It has, by definition, a consistent, florid tumor infiltrating lymphocyte (TIL) population, probably the result of cytotoxic T-lymphocytes recognizing tumor cells in an HLA-DR-restricted manner. HLA-DR tends to be more highly expressed on primary medullary carcinoma cells than on ductal carcinoma cells; however, the MHC-class II antigenicity of the tumor cells themselves has not been analyzed extensively, and as yet there has been no comparative study of HLA-DR expression in medullary and ductal carcinomas metastatic to lymph nodes. Eleven cases of medullary carcinoma and 15 cases of ductal carcinoma, primaries, and respective lymph node metastases were analyzed by immunoperoxidase staining for HLA-DR and lymphocytes antigens. Polymerase chain reaction (PCR) analysis to identify HLA-DR subtypes from the paraffin blocks was performed on selected cases of primaries and nodal metastases of both tumor types. Immunoperoxidase staining for HLA-DR antigen revealed a marked difference in antigen expression between medullary and ductal carcinomas. In the medullary carcinomas, the mean percentage of cells staining for HLA-DR was 74.5% in the primary tumors and 67.3% in the nodal metastases. For the ductal carcinomas, the mean percentage of cells staining was 17.7% in the primaries and 7% in the metastases. There was a tendency for the level of HLA-DR expression to remain high in medullary carcinoma metastatic to nodes, whereas whatever HLA-DR was present within ductal primaries tended to diminish when cells metastasized to regional nodes. PCR analysis of the HLA-DR within the two tumor types revealed no emerging subtype or variant that could be associated with either the medullary or the ductal carcinomas. Medullary carcinoma cells express much greater quantities of HLA-DR, on the whole, than ductal carcinomas. Expression of HLA-DR is retained on medullary carcinoma cells that have spread to lymph nodes, whereas the smaller quantities of HLA-DR present within ductal primaries tend to diminish even further when the tumor cells are found in lymph nodes. No discernible HLA-DR mutations or predominant subtypes emerged on PCR analysis, and the authors therefore conclude that it is the quantity and not the quality of HLA-DR expression in medullary carcinoma that maintains the characteristic TIL infiltrate, not seen in ductal carcinomas.

Lymphoepithelioma-like carcinoma of the breast: lack of evidence of Epstein-Barr virus infection

AIMS

Six cases of lymphoepithelioma-like carcinomas of the breast were studied in order to better define the morphology of this type of breast tumour and to see if these neoplastic lesions are related to Epstein-Barr virus (EBV) infection by analogy with histologically similar tumours located in other organs.

METHODS AND RESULTS

The cases were studied with immunohistochemistry using several antibodies and with in-situ hybridization method employing different types of nucleotides in four cases. The cases presented the distinctive morphology of the lymphoepithelioma-like carcinomas as seen in other organs. Specifically Rigaud and Schminke's patterns of growth were observed. In addition, at the edge of the neoplastic lesions, a lymphoepithelial lobulitis was seen. In-situ hybridization failed to reveal any positivity for EBV genome.

CONCLUSION

Lymphoepithelioma-like carcinoma is a specific type of breast tumour, but its relation to EBV has yet to be proven. The differential diagnosis with medullary carcinoma is discussed.

HLA-DR and beta 2 microglobulin expression in medullary and atypical medullary carcinoma of the breast: histopathologically similar but biologically distinct entities

AIMS

To examine the expression of HLA-DR and beta 2 microglobulin in medullary carcinoma and atypical medullary carcinoma of the breast to determine if the effective presentation of tumour antigens to the immune system can differentiate between these two histopathologically similar entities.

METHODS

Expression of HLA-DR and beta 2 microglobulin was examined by immunohistochemical methods in five samples of medullary carcinoma of the breast, which has a relatively favourable prognosis, six samples of atypical medullary carcinoma of the breast, which has a prognosis closer to that of regular invasive duct carcinoma, and 20 samples of invasive duct carcinomas, 10 with an accompanying lymphocytic infiltrate.

RESULTS

A positive and significant correlation was found between tumour type and both HLA-DR and beta 2 microglobulin expression. Expression was most prominent in medullary carcinoma, followed by atypical medullary carcinoma and invasive duct carcinoma with and without lymphocytic infiltrates. The mean intensity and percentage of HLA-DR tumour immunostaining were significantly higher in medullary carcinoma than in the other three tumour groups, as was the mean intensity of beta 2 microglobulin immunostaining. Mean percentage of beta 2 microglobulin immunostaining was significantly higher in medullary carcinoma than in invasive duct carcinoma without lymphocytic infiltrates, and showed a trend to increase from invasive duct carcinoma with lymphocytic infiltrates to atypical medullary carcinoma and medullary carcinoma.

CONCLUSIONS

Medullary carcinoma and atypical medullary carcinoma of the breast differ in their expression of HLA-DR and beta 2 microglobulin. The relatively favourable prognosis of medullary carcinoma of the breast may be related to effective tumour antigen presentation to the immune system through MHC-I and MHC-II expression. Immunotherapy aimed at MHC-I and MHC-II induction might have a beneficial effect in breast cancer.

Age distribution of histologic types of breast carcinoma

The large number of cases in the Surveillance, Epidemiology and End Results (SEER) program of the US National Cancer Institute allowed a detailed analysis of the age distribution of the histologic types of invasive breast carcinoma. Between ages 50 and 85 years in females, the age-specific incidence rate shows little change for medullary, inflammatory and apocrine carcinomas; is about doubled for Paget's disease and for ductal, lobular, tubular and metaplastic carcinomas; and increases to 4 to 8 times the menopausal level for mucinous, papillary and signet-ring-cell carcinomas. The peri-menopausal break on the age-incidence curve is most marked for carcinomas of predominantly lobular origin and virtually absent for carcinomas of predominantly ductal origin. In males, the age distribution of papillary carcinoma is similar to that of all types combined, whereas that of mucinous carcinoma is skewed towards older ages, as in females.

Flow cytometric analysis of tumour infiltrating lymphocyte activation and tumour cell MHC class I and II expression in breast cancer patients

The primary tumour cells and tumour infiltrating lymphocytes (TILs) of 31 breast cancer patients have been analysed by dual colour flow cytometry to determine whether the phenotype and/or activation status of the TILs bears any relationship to the expression of MHC antigens on the tumour cells. The phenotype and activation status of 5000 TILs were studied using Mabs to CD4, CD8, HLA DR, CD25 (the low affinity inducible IL-2 receptor) and the transferrin receptor and related to Class I and Class II MHC expression on 5000 primary tumour cells. On the tumour cells, Class I MHC expression ranged from 1-74%, averaging 12.9%. HLA DR expression ranged from 1-69% averaging 14.3%. When the phenotypic proportions of the lymphocytic infiltrate were analysed there was found to be a correlation between tumour expression of Class I MHC and the proportion of both CD4+ (P less than 0.05) and CD8+ (P less than 0.02) T cells within the tumour. No such relationship was found with the MHC Class II antigen. When TIL activation markers were analysed, the percentage of CD8+ TILs positive for HLA DR expression correlated strongly with the expression of Class I (P less than 0.001) and Class II (P less than 0.001) antigens on the tumour cells. The percentage of CD4+ TILs positive for HLA DR expression also correlated significantly, but less strongly with the expression of Class I (P less than 0.01) and Class II (P less than 0.02) antigen expression on the tumour cells. The percentage of CD4+ TILs positive for CD25 expression correlated with both Class I (P less than 0.05) and Class II (P less than 0.03) expression on the tumour cells while the percentage of CD8+ TILs positive for CD25 did not. The percentage of TILs bearing the transferrin receptor showed no measurable correlation with the expression of either class of MHC antigen on the tumour. The data suggest that MHC expression on the tumour cells has a selective effect on the response capacity of different parts of the immune system.

Flow cytometric analysis of tumour infiltrating lymphocytes in breast cancer

In 31 patients with carcinoma of the breast the phenotype and activation status of tumour infiltrating lymphocytes (TILs) was analysed by flow cytometry. The predominant cells, in all patients, were T lymphocytes and in the majority of cases CD8+ (cytotoxic/suppressor) T lymphocytes were present in greater numbers than CD4+ (helper) T lymphocytes. There was no relationship between the degree of lymphocytic infiltration and either tumour stage or grade but there appeared to be an inverse correlation with the levels of oestrogen receptor (ER) in the tumour (P less than 0.01). Both populations of T cells had significantly higher numbers of cells carrying HLA DR (class II major histocompatibility antigen) than the equivalent populations in peripheral blood from the same patient group (P less than 0.001). The transferrin receptor was found on similar numbers of CD8+ T cells in peripheral blood and among the tumour infiltrating lymphocytes while more of the CD4+ T cells infiltrating the tumour were found to carry this receptor (P = 0.034). The Tac (CD 25) antigen was also on similar numbers of CD8+ T cells from both peripheral blood and the tumour but was on fewer of the CD4+ T cells in the tumour with respect to peripheral blood (P = 0.029). In both TILs and blood lymphocytes, the Tac antigen was consistently present on greater numbers of CD4+ T lymphocytes than on the CD8+ T lymphocytes (P less than 0.001) and as this is a component of the interleukin 2 (IL-2) receptor this may be of relevance to the use of IL-2 in TIL cancer therapy.

Relationship between eosinophil density and T-cell activation markers in lymph nodes of patients with Hodgkin's disease

Hodgkin's disease (HD) is characterized morphologically by a variable infiltration of tissues by eosinophilic granulocytes. The lesions also contain numerous T cells, predominantly of the CD4+ immunophenotype. To investigate whether the presence or absence of tissue eosinophilia is related to the immunophenotype of the T cells, we studied 43 cases of HD (28 nodular sclerosing, ten mixed cellularity, and five unclassifiable) for the relative numbers of lymphocytes positive for CD2, CD3, CD4, CD5, CD8, CD25, CD38, T9, TQ1, HLA-DR, and beta F1, and for the number of eosinophils in tissue sections. By univariate and multivariate analysis, we determined that there was an inverse relationship between the number of eosinophils and the presence of TQ1+ (P less than .0005) and CD25+ (P less than .0005) lymphocytes. In addition, we observed that TQ1 stained the Reed-Sternberg cells in these lesions. We also determined that the T cells expressed HLA-DR more frequently in the nodular sclerosis subtype than in other subtypes of HD (P less than or equal to .0001). We therefore conclude that the degree of tissue eosinophilia in the lymph nodes of patients with HD may be explained, at least in part, by the immunophenotype of the T cells present in the affected lymph nodes.

What's new in the local immune response in cancer?

Malignant tumors in humans are commonly associated with an inflammatory infiltrate. The mechanisms that account for the accumulation of T-lymphocytes and macrophages--these cells comprise the major components of tumor infiltrates--in the vicinity of a growing tumor are not fully understood. Tumor specific and immunogenic antigens could not be demonstrated in most solid tumors of humans, in contrast to several experimental tumor models. Thus it is not proven in human malignancies that neoantigens expressed on malignant cells are the signal which initiates an inflammatory response that, immunohistologically, is comparable to mononuclear infiltrates present in allograft rejection. A variety of nonspecific factors including lymphokines released by tumor cells may also account for the accumulation of inflammatory cells at the tumor site. The difficulties to evaluate the functional role of the "local immune response" for tumor and host are even greater. Most tumors progress in the presence of mononuclear infiltrates. Do they progress in spite of or because of the action of the local immune response? Clinical, immunopathological, and experimental data suggest that both is right, and that at least four distinct properties of tumor-associated immune reactions exist: Regression, Selection, Modulation and Progression. These distinct properties will be discussed below, using mainly the malignant melanoma of the skin as a model for a malignant tumor in humans.

Experimental model for locally recurring mammary tumors. Development, morphology, karyotype, growth kinetics, and experimental metastatic potential

A rat model was established for evaluating the biology of locally recurring mammary tumors after surgical resection of the primary tumor. Eight distinct cell lines were independently derived from primary tumors and local recurrences after surgical removal of 13762NF rat mammary adenocarcinoma clone MTF7(T20). In vivo tumor doubling times between the "parental" MTF7(T20) cell line, primary tumor-derived cell lines sc1 and sc3, and the local recurrence (LR) sublines varied after the inoculation of 10(6) tumor cells into the mammary fat pad of female Fischer 344 rats. Doubling times were shorter for LR3, and LR4, LR5, and LR6 than their primaries sc3 and MTF7(T20), respectively, and longer for LR1 and LR1a than their primary tumor sc1. The LR sublines varied considerably for their experimental metastatic potentials. Both increases and decreases in metastatic potential were seen compared to MTF7(T20), sc1, and sc3. Karyotype analysis by G-banding revealed the presence in the LR sublines of several marker chromosomes, previously identified in MTF7 at tissue cultures 11 and 35. Two new chromosome markers were identified: M54, shared by MTF7(T20), sc1, LR4, LR5 and LR6, and M55, shared by MTF7(T20), sc1, LR1, sc3, LR3, LR4, and LR6. These data indicate that local tumor regrowth after surgical excision of the primary tumor in this model most likely selects the growth of tumor cell subpopulations already present within the primary tumor. Differences in growth kinetics, karyotype, and metastatic potential between the parental MTF7(T20), primary tumors sc1 and sc3, and their LR sublines may reflect in vivo influences on the phenotypic diversity generated during the development of local mammary tumor recurrences after surgical treatment of the primary tumor.