Cellular and molecular aspects of neoplastic progression in the mammary gland

Correlation between nuclear grade and biological prognostic variables in invasive breast cancer

BACKGROUND

Grading of carcinomas is an estimation of differentiation. Nuclear grading is the cytological evaluation of tumor nuclei in comparison with the nuclei of normal mammary epithelial cells. Because nuclear grading does not involve an assessment of the growth pattern of the tumor, it applies not only to invasive ductal carcinoma but also to other subtypes of breast carcinoma.

METHODS

A total of 215 primary breast carcinomas obtained from the Affiliated Kihoku Hospital of Wakayama Medical College were enrolled in our present study. Nuclear grade was evaluated according to the criteria of the National Surgical Adjuvant Study of Breast Cancer (NSAS-B) protocol. Immunohistochemistry was also performed to determine Bcl-2, p53, c-erbB-2, estrogen receptor (ER) and MIB-1 expression in paraffin-embedded tissues for all cases.

RESULTS

Thirty-two (14.9%) of the patients were graded as 1,124 (57.7%) as 2, and 59 (27.4%) as 3. Nuclear grade displayed a negative correlation with Bcl-2 expression (r=-0.308, p<0.0001), and a positive correlation with c-erbB-2 overexpression (r= 0.172, p=0.0117) and tumor proliferative index labeling by MIB-1 (r=0.485, p<0.0001).

CONCLUSIONS

These results imply that nuclear grade is related to the characteristics of tumor biology, indicating that the morphology and biology of breast cancer are tightly linked. Our present results also suggest that adding the nuclear grade to the pathological diagnosis of invasive breast carcinoma may be clinically useful for predicting tumor behavior, for example aggressiveness, and for prognostication.

Early onset Pneumocystis carinii pneumonia after allogeneic peripheral blood stem cell transplantation

Pneumocystis carinii (P. carinii) is one of the major opportunistic pathogens responsible for hematopoietic stem cell transplantation (HSCT)-related pneumonias. Although trimethoprim-sulfamethoxazol (TMP/SMX) prophylaxis has been shown to prevent almost all P. carinii infections, 1%-2% of patients may still experience this complication. P. carinii pneumonia (PCP) is usually a late complication in patients receiving TMP/SMX prophylaxis, with most cases occurring later than 2 months post-transplant. We report a patient who developed early onset PCP after allogeneic peripheral blood stem cell transplantation (PBSCT) from an HLA-identical sibling donor. On day 12, the patient complained of dyspnea and cough. A chest X ray showed infiltrates in right upper lobe with bilateral pleural effusion. By the findings of Grocott stain on bronchoalveolar lavage fluid obtained on day 14, he was diagnosed as having PCP. Intravenous TMP/SMX failed to improve the lesion. This is the earliest onset PCP in the literature after HSCT despite the prophylactic administration of TMP/SMX before transplant.

Eight-year surveillance of non-albicans Candida spp. in an oncology department prior to and after fluconazole had been introduced into antifungal prophylaxis

From 1989 until 1996, during the last 8 years, the proportion of Candida (C.) krusei, and other non-albicans Candida spp. isolated from surveillance cultures and from sterile body sites, was analyzed among 13,758 admissions in a National Cancer Institute. During these admissions a total of 9,042 isolates were prospectively collected from surveillance cultures, and 126 from blood cultures. The proportion of C. krusei among all organisms was 12.7% to 16.5% in 1989 through 1991, i.e., before fluconazole was introduced into prophylactic protocols. After the introduction of fluconazole into prophylaxis in acute leukemia in 1992 the incidence of C. krusei was 7.9% to 8.6% during 1994 to 1996. After 5 years of using this drug for prophylaxis, the incidence of C. krusei was lower than before this drug was introduced in our institute. Among yeasts, the most frequently isolated pathogen was still Candida albicans (72.2% of all isolated fungal organisms). Among molds, Aspergillus spp. was the most frequently isolated agent. Analyzing the etiology of proven fungal infections (fungemias) confirmed by positive blood cultures, C. albicans was the most common causative organism in 53.8% of cases. The incidence of fungemia due to Torulopsis (C.) glabrata and C. krusei before and after fluconazole introduction did not change. Of 126 organisms isolated from blood cultures, there was no increase in T. (C.) glabrata or C. krusei after introduction of fluconazole for prophylaxis and therapy, and the quoted 6.4% of fungemic episodes remained stable with an incidence of 1 fungemia/year since 1991. The proportion of C. krusei and C. glabrata among Candida spp. was decreasing in our center between 1989 and 1996. Also, the proportion of non-albicans Candida spp. among isolates decreased from 25.7% in 1990 to 11.9% in 1996.

Histological grade in invasive ductal carcinoma of breast correlates with the proliferative activity evaluated by BrdU: an immunohistochemical study including correlations with p53, c-erbB-2 and estrogen receptor status

Thirty cases of invasive ductal carcinoma of the breast were classified to histological subtype according to the General Rules for Clinical and Pathological Recording of Breast Cancer of the Japanese Breast Cancer Society and histologically graded using the Nottingham method and the correlation of histology with proliferative activity was investigated using bromodeoxyuridine (BrdU). In addition, the overexpression of p53 protein, c-erbB-2 oncoprotein and estrogen receptor (ER) were immunohistochemically examined in order to discuss the relationship with histological subtype and histological grade. Histological grade correlated positively to the BrdU labeling index (LI) and overexpression of p53. High grade carcinoma demonstrated c-erbB-2 more frequently and exhibited a low incidence of ER. However, no significant relationship was found between BrdU LI, overexpression of p53 and c-erbB-2 and histological subtype. These results suggest that the histological grade does represent the proliferative activity of tumor cells and that adding the histological grade to the pathological diagnosis in invasive ductal breast carcinoma may be useful from the clinicopathological aspect concerning tumor behavior.

Comparative pathology of mammary tumorigenesis in transgenic mice

Mammary tumors arise in transgenic mice bearing growth factors, proto-oncogenes, oncogenes and tumor suppressor genes. The tumors arise from hyperplasias. The tumor natural history and histogenesis are oncogene specific. Interactions between oncogenes may impede or accelerate tumorigenesis.

C-erbB-2 immunostaining: problems with interpretation

AIMS

To assess the consistency and reproducibility of assessment of c-erbB-2 immunostaining, and to examine some of the problems relating to inter- and intraobserver variability in the documentation of positive staining; to profile the spectrum of cytoplasmic and membranous staining in a wide range of tumour types.

METHODS

A total of 283 neoplasms were examined for immunohistochemical expression of the c-erbB-2 oncoprotein. Three independent observers were required to assess intensity both of membrane and cytoplasmic staining on a three point and then a four point scale. Extent of positive staining was also assessed on a two point scale. A minimum of two weeks elapsed between assessments using the differing scales.

RESULTS

Positive membrane staining was documented by one or more observers in 16.6% of tumours examined. This positivity was largely restricted to bladder, renal, and breast tumours. The overall level of disagreement as to the presence or absence of membranous staining was 11.3%. Cytoplasmic staining was identified in 55.5% of tumours studied. The level of disagreement as to the presence or absence of cytoplasmic staining was 26.5%.

CONCLUSIONS

Intraobserver variability was minimal, indicating that each pathologist was adhering to internal reproducible standards. Interobserver variability was greater, indicating that the interpretation of c-erbB-2 immunostaining may require set guidelines. It is suggested that assessment should be referenced to a standard positive control, that a three tier system for grading of intensity and a two tier system for grading of extent should be adopted, and that the evaluation should be agreed by at least two pathologists. The presence of cytoplasmic staining should continue to be routinely recorded until its biological role and clinical implications are fully understood.

What's new in breast cancer? Molecular perspectives of cancer development and the role of the oncogene c-erbB-2 in prognosis and disease

The oncogene c-erbB-2 is frequently amplified in human breast carcinoma. The c-erbB-2 gene is present as a single copy in normal cells, and has been mapped to chromosome 17 in the region 17q 12-21.32. c-erbB-2 encodes a transmembrane glycoprotein known as p185. The intracellular component of p185 has tyrosine kinase activity; the extracellular domain has a structure resembling a growth factor receptor. c-erbB-2 amplification, p185 overexpression and levels of transcribed c-erbB-2 specific messenger RNA have been studied in a large number of breast carcinomas using a variety of techniques. In general, overexpression of p185 oncoprotein reflects various levels of DNA amplification, though in some cases amplification can be detected in the absence of overexpression of p185 and similarly overexpression of p185 can be present without detectable levels of c-erbB-2 amplification. This findings suggests that multiple mechanisms may be responsible for overexpression. c-erbB-2 amplification and/or overexpression occurs in almost all cases of high grade duct carcinoma in-situ, but has been reported in only 10%-40% of infiltrating duct carcinoma. c-erbB-2 amplification or overexpression occurs rarely in invasive lobular carcinoma, and has not been detected in ductal or lobular epithelial hyperplasia, or in atypical ductal or atypical lobular hyperplasia. It is generally believed that c-erbB-2 amplification/overexpression is an important independent prognostic indicator in breast carcinoma, identifying a subset of patients with poor prognosis tumours, particularly if axillary node metasases are present. However, many unanswered questions remain regarding c-erbB-2 and its role in breast cancer development and progression. The causes of c-erbB-2 amplification are unknown. There is no evidence of mutations in the human gene which might cause amplification or overexpression. The significance of the differences in levels of c-erbB-2 amplification/overexpression in in-situ duct carcinoma and associated invasive duct carcinoma has not been established. Amplification or overexpression have not been reported in atypical duct hyperplasia, a proposed precursor of duct carcinoma in-situ, yet overexpression occurs almost always in high grade duct carcinoma in-situ. c-erbB-2 may play a critical role in the development of a clonal in-situ, proliferation of high histological grade, yet does not obviously influence the acquisition of an invasive phenotype. We would postulated that this instability in amplification/overexpression is of biological significance, and if better understood may aid in the study of progression of human breast carcinoma.

Immunohistochemical overexpression of C-erbB-2 in the prognosis of breast cancer

Immunohistochemical c-erbB-2 protein overexpression was detected in 34 of 124 (27.4%) paraffin-embedded breast cancer specimens. Although no difference was seen between the c-erbB-2 positive and negative groups in 5-year disease-free survival, 5-year overall survival was significantly less favorable in the c-erbB-2 positive group. Furthermore, patients graded as having positive c-erbB-2 staining and aneuploid DNA showed significantly poorer survival than those in other categories. The significant prognostic factors, determined by a multivariate analysis, were nodal status and c-erbB-2 overexpression. Our findings therefore suggest that c-erbB-2 expression is a prognostic factor in breast cancer and that it could be useful in the determination of postoperative adjuvant therapy.

Melanocyte tumor progression is associated with changes in angiogenesis and expression of the 67-kilodalton laminin receptor

BACKGROUND

A number of experimental studies have substantiated changes in angiogenesis and in laminin/laminin-receptor interactions during tumorigenesis and tumor progression. However, these observations have never been verified objectively in tissues from a well-defined model of tumor progression.

METHODS

Tissues from 97 proliferative lesions of the melanocyte lineage defining distinct steps in tumor progression were investigated immunohistochemically for changes in angiogenesis and expression of the laminin receptor (67-kilodalton molecule).

RESULTS

Although the microvessel number was low in common nevi, it increased significantly in nevi with architectural disorder with varying degrees of melanocytic atypia (termed "nevi with ADMA"), and these changes persisted during transformation. Progression to primary melanomas was accompanied by a high microvessel number and progression to metastases by another significant increase. The number and diameter of microvessels were significantly higher at the lesion base than at the adjacent dermis of primary melanomas and higher in the lesion than in the adjacent tissue of metastatic foci. Expression of the laminin receptor, evaluated as percentages of positive lesions and positive cells per lesion, underwent upregulation in the course of progression. Changes in expression were associated mostly with nevi with ADMA, transformation, and deepening of the tumors into the dermis.

CONCLUSIONS

These in situ data suggest that more frequent interactions between melanocytic cells and their microvasculature via adhesion protein laminin occur during tumor progression.

Overexpression of HER-2/neu and its relationship with other prognostic factors change during the progression of in situ to invasive breast cancer

Using permanent-section immunohistochemistry, we investigated the role of HER-2/neu in the development and progression of human breast cancer by measuring its overexpression in a series of hyperplastic (n = 30), dysplastic (n = 15), and malignant neoplastic (n = 708) lesions of ductal epithelium and by evaluating the relationships between overexpression and clinicopathologic features known to have prognostic significance in these lesions. The neoplasms included pure ductal carcinoma in situ (DCIS; n = 59) and infiltrating ductal carcinoma (IDC; n = 649). The latter were all node negative and stratified into IDC combined (n = 237) or not combined (n = 412) with a "significant amount" of DCIS (defined as DCIS greater than or equal to 10% of total tumor cellularity). Overexpression of HER-2/neu was not observed in any of the hyperplastic or dysplastic lesions. In contrast, it was present in 56% of pure DCIS and in 77% of the comedo subtype of this group. Only 15% of IDC overexpressed HER-2/neu. However, the rate of overexpression was significantly higher in the subset of IDC combined with DCIS compared with the subset of IDC not combined with DCIS (22% v 11%, respectively; P less than .0001). These results are consistent with the hypothesis that HER-2/neu plays a more important role in initiation than in progression of ductal carcinomas. They also suggest that overexpression decreases within individual tumors as they evolve from in situ to increasingly invasive lesions or, alternatively, that many invasive carcinomas arise de novo (ie, without progressing through a significant in situ stage) by mechanisms not involving HER-2/neu. In addition, overexpression of HER-2/neu was associated with several poor prognostic features (younger patient age, premenopause, negative estrogen receptor status, negative progesterone receptor status, and high nuclear grade) in the subset of IDC combined with DCIS. With one exception (negative estrogen receptor status) these associations were lost in IDC not combined with DCIS, also suggesting that the role of HER-2/neu changes during the progression of human breast cancer.

Nuclear and flow cytometric characteristics associated with overexpression of the c-erbB-2 oncoprotein in breast carcinoma

The overexpression of the c-erbB-2 oncoprotein is now thought by most authors to be associated with adverse prognosis in breast carcinoma. In this study, we investigate the relationship between overexpression of the c-erbB-2 oncoprotein and nuclear size by morphometry in a series of 150 human breast carcinomas, comprising 65 cases of ductal carcinoma in situ (DCIS) and 85 cases of invasive adenocarcinoma. The mean nuclear size for c-erbB-2 positive cases of DCIS was 54.8 micron 2 and invasive carcinoma was 52.1 micron 2 respectively, in contrast with 41.6 micron 2 and 42.5 micron 2 for c-erbB-2 negative cases of DCIS and invasive carcinoma respectively. Flow cytometric examination of DNA in a subset of 91 of these tumours showed no association between tumour cell aneuploidy and c-erbB-2 overexpression. S-phase fraction could be calculated on 20 cases of DCIS and 48 invasive carcinomas. There was a strong association between c-erbB-2 overexpression, S-phase fraction (p less than 0.001) and proliferative index (p less than 0.001) in 20 cases of DCIS. A weak association of S-phase fraction and c-erbB-2 overexpression was seen in 48 invasive carcinomas (p = 0.047). This study confirms the subjective impression that there is a relationship between large tumour cell nuclear size and an overexpression of the c-erbB-2 oncoprotein, and also shows an association with increased tumour cell proliferation.

Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up

Morphological assessment of the degree of differentiation has been shown in numerous studies to provide useful prognostic information in breast cancer, but until recently histological grading has not been accepted as a routine procedure, mainly because of perceived problems with reproducibility and consistency. In the Nottingham/Tenovus Primary Breast Cancer Study the most commonly used method, described by Bloom & Richardson, has been modified in order to make the criteria more objective. The revised technique involves semiquantitative evaluation of three morphological features--the percentage of tubule formation, the degree of nuclear pleomorphism and an accurate mitotic count using a defined field area. A numerical scoring system is used and the overall grade is derived from a summation of individual scores for the three variables: three grades of differentiation are used. Since 1973, over 2200 patients with primary operable breast cancer have been entered into a study of multiple prognostic factors. Histological grade, assessed in 1831 patients, shows a very strong correlation with prognosis; patients with grade I tumours have a significantly better survival than those with grade II and III tumours (P less than 0.0001). These results demonstrate that this method for histological grading provides important prognostic information and, if the grading protocol is followed consistently, reproducible results can be obtained. Histological grade forms part of the multifactorial Nottingham prognostic index, together with tumour size and lymph node stage, which is used to stratify individual patients for appropriate therapy.

c-erbB-2 oncoprotein expression in primary and advanced breast cancer

Immunoreactivity for c-erbB-2 oncogene product expression has been investigated in patients with breast cancer using the polyclonal antibody 21N. Three series of patients were studied, 602 presenting with primary operable cancer, 57 with stage 3 and 123 with stage 4 disease. Representative tissue sections of each primary tumour were stained using a standard immunoperoxidase technique. Invasive tumour membrane immunoreactivity was assessed and identified in 15% of patients with primary operable cancer and 20% in the advanced breast cancer group. The results demonstrate a relationship between poorer survival and oncogene expression in all three patient groups. Patients in the primary operable cancer group with membrane oncoprotein expression had a poorer outcome, 35% 10-year survival, compared with those in which membrane expression was absent, 55% 10-year survival. The median survival of patients with stage 3 disease with c-erbB-2 membrane positivity was 17 months compared to 24 months with membrane negativity. In stage 4 disease median survival with membrane expression was 8.8 months compared to 19.7 months with no membrane expression. In addition in the series of primary cancers a correlation existed between histological grade and membrane immunoreactivity. Multivariate analysis showed histological grade to be a more powerful prognostic factor than c-erbB-2 protein expression. In conclusion, this study demonstrates, in a large series of patients presenting to one centre, that c-erbB-2 protein expression is a prognostic indicator in patients with primary operable and advanced breast disease.

Immunohistochemical demonstration of c-erbB-2 protein in mammary ductal carcinoma in situ

The presence of the c-erbB-2 protein, demonstrated immunohistochemically with antibody 21N, has been studied in 72 cases of pure mammary ductal carcinoma in situ. Sixty-one percent of cases showed positive staining. The protein was always present in large-cell comedo type of ductal carcinoma in situ, and never in small-cell cribriform/micropapillary type of ductal carcinoma in situ. When nuclear size was measured, staining was associated with tumors containing cells with large nuclei measuring up to 20 mu, and was never present in lesions containing cells with small nuclei measuring 10 mu or less. In tumors of mixed histopathologic type of ductal carcinoma in situ, variable staining was seen; the cells with small nuclei never stained, while the majority of cells with large nuclei reacted positively. The possible relevance of these findings to the biologic behavior of DCIS is discussed.

Bone marrow purging with mafosfamide--a critical survey

Autologous bone marrow transplantation (ABMT) is increasingly used to consolidate remissions, primarily in hematological disease. Various purging strategies have been developed to minimize the risk of reimplantation of tumor cells with the bone marrow autotransplant. Pharmacological purging with the oxazaphosphorine derivative mafosfamide has been studied extensively, and recent clinical data suggest that purging with mafosfamide may translate into superior remission duration if compared to nonpurged ABMT in acute leukemia. Chemical and experimental data relevant to mafosfamide-purging and clinical results are reviewed, with special emphasis on safety aspects.