Oestrogen receptor expression in ductal carcinoma in situ of the breast: relationship to flow cytometric analysis of DNA and expression of the c-erbB-2 oncoprotein

Current Approaches to Diagnosis and Treatment of Ductal Carcinoma In Situ and Future Directions

The presentation and treatment of ductal carcinoma in situ (DCIS) has changed substantially over the years. While previously an incidental pathologic finding in more advanced, palpable tumors, the institution of screening mammography has repositioned this disease entity as one largely diagnosed as a non-palpable lesion, often prior to any invasive disease. As DCIS is a precursor to invasive carcinoma, evolution in the approach to treatment has followed in the footsteps of that for invasive disease, including breast conservation therapy, adjuvant radiation, and use of antihormonal therapy. Survival outcomes for DCIS are very high and more recent literature has investigated tailoring therapeutic approaches to avoid overtreatment. Two important areas of ongoing clinical debate concerning overtreatment include use of preoperative MRI and the role of adjuvant radiation. The heterogeneity of the disease makes it difficult to differentiate lesions that would benefit from more aggressive treatment from those in which overtreatment could be avoided. Clinical characteristics, such as histologic appearance, age at diagnosis, and margin status at tumor excision have been established as moderate predictors of disease recurrence, but none has provided strong enough evidence as to guide consensus decisions on adjuvant therapy. Continuing research seeks to define the genetic and molecular characteristics that can predict disease course and serve as the potential targets for novel therapeutic agents. While several markers have shown promise in differentiating tumor aggressiveness, there is still much to be discovered about the precise mechanisms of disease progression and how this can be applied clinically to optimize treatment.

Biology and treatment of ductal carcinomain situ

Ductal carcinoma in situ (DCIS) is responsible for 25% of screen-detected breast cancers. Various prognostic classifications are in use, including the Van Nuys Prognostic Index and the European Organisation for Research and Treatment of Cancer grading system (well, intermediate or poorly differentiated) based on cytonuclear pattern. This has been modified in screening programs to low, intermediate and high grade. In comparison with normal epithelium, DCIS has a tenfold increase in growth and 15-fold increase in apoptosis. Patients with extensive or multifocal DCIS need mastectomy and sentinel node biopsy, together with reconstruction, if requested. Microinvasion associated with DCIS is an indication for sentinel node biopsy. Randomized trials have confirmed the value of breast irradiation after wide excision, in terms of DCIS relapse and progression to invasive disease. Patients with estrogen receptor-positive DCIS benefit from adjuvant tamoxifen after breast-conserving surgery.

Steroid-coupled liposomes for targeted delivery to tumor

The steroidal receptors play a key role in protein synthesis and maintain the homeostasis in normal and diseased state, including tumorigenesis at the target tissues when overactivated. Thus steroidal receptors may act as potential targets for selective delivery of different therapeutic agents as they are overexpressed by a number of endocrinal tumors. The selective delivery of these agents may be a better treatment strategy for endocrinal cancer as it may also result in cytosolic and nuclear delivery of cytotoxic agents. In this review, the targeting potential of steroidal receptors for the drug or bioactive(s) delivery is discussed. The ligands that have been proven to be effective for specific steroidal receptors can be used as vectors for carrying the drug or drug-delivery system to the desired site of drug action in an optimum concentration. This strategy will not only minimize the undesired side effects associated with nonspecific delivery of drug, but will also maximize the drug utilization. Ligand-conjugated liposomes as a carrier of bioactives prevent passive diffusion of the encapsulated drug to normal cells, increase the time of circulation and reduce the undesirable side effects of a drug.

The role of HER2 in early breast cancer metastasis and the origins of resistance to HER2-targeted therapies

The HER2 gene encodes the receptor tyrosine kinase HER2 and is often over-expressed or amplified in breast cancer. Up-regulation of HER2 contributes to tumor progression. Many aspects of tumor growth are favorably affected through activation of HER2 signaling. Indeed, HER2 plays a role in increasing proliferation and survival of the primary tumor and distant lesions which upon completion of full transformation cause metastases. P185(HER2/neu) receptors and signaling from them and associated molecules increase motility of both intravasating and extravasating cells, decrease apoptosis, enhance signaling interactions with the microenvironment, regulate adhesion, as well as a multitude of other functions. Recent experimental and clinical evidence supports the view that the spread of incompletely transformed cells occurs at a very early stage in tumor progression. This review concerns the identification and characterization of HER2, the evolution of the metastasis model, and the more recent cancer stem cell model. In particular, we review the evidence for an emerging mechanism of HER2(+) breast cancer progression, whereby the untransformed HER2-expressing cell shows characteristics of stem/progenitor cell, metastasizes, and then completes its final transformation at the secondary site.

Correlation of HER-2 over-expression with clinico-pathological parameters in Tunisian breast carcinoma

BACKGROUND

Breast carcinoma is a disease with a tremendous heterogeneity in its clinical behavior. Newer prognostic factors and predictors of response to therapy are needed. The aim of this study was to evaluate the expression of HER-2, estrogen receptor (ER) and progesterone receptors (PR) in breast carcinoma and to compare it with other prognostic parameters such as histological type and grade, tumor size, patients' age, and lymph node metastases.

PATIENTS AND METHODS

This is a retrospective study conducted in the department of pathology at Sfax University Hospital. Confirmed 155 Cases of breast carcinoma were reviewed in the period between January 2000 and December 2004. We used immunohistochemistry to evaluate the expression of HER-2, ER, and PR receptor and Chi-square and Fisher exact test to correlate immunohistochemical findings with prognostic parameters for breast carcinoma such as patients' age, tumor size, histological type, histological grade and lymph node status.

RESULTS

The mean age of patients was 51.5 years, ranging from 22 to 89 years. 80 (51.6%) of the patients were below 50 years. The percentage of expression of HER-2, ER and PR was 26, 59.4, and 52.3%, respectively. HER-2 was over-expressed (3+) in 18.1% of the cases, was inversely related to ER expression (p = 0.00) and to PR expression (p = 0.048). This over-expression was also associated with a high tumor grade with marginal significance (p = 0.072). A negative correlation was noted between ER and PR expression and SBR grade (p = 0.000) and ER and age (p = 0.002).

CONCLUSION

HER-2 over-expression was observed in 18.1% of Tunisian breast carcinoma affecting female patients. This group presents apparently an aggressive form of breast carcinoma with high histological grade and negative ER.

Pathobiological features of breast tumours in the State of Kuwait: a comprehensive analysis

Background

Breast cancer accounts for 30.3% of all cancer types in Kuwaiti women. Death occurs in approximately 43% of these patients. Our goal was to conduct a comprehensive analysis of the pathobiological characteristics of the tumours in an attempt to determine any particular trend that could be present.

Methods

One hundred and sixty-six cases were included in this study. All the pathology reports and paraffin blocks pertaining to these cases were collected. Four micrometer sections were taken from each block, and immunostaining against Her-2, ER, and PgR was performed. Both the proportion and intensity of immunostaining were scored according to the Allred's method, and typing of the tumour was done according the WHO criteria regarding tumour classification. Grading of invasive carcinomas was done according to the modified Bloom-Richardson-Elston's method, and tumour stage was determined according to the criteria set by the American Joint Committee on Cancer.

Results

The mean age of the patients below 55 years was 40, as compared to 68 for those above 55 (p < 0.0001). More than half of the cases were in the right breast, and were surgically treated by total mastectomy with axillary clearance. The majority of the tumours had irregular (stellate) margins, was invasive, and had a surrounding breast tissue of adenosis or fibrocystic type. Their mitotic index was 10–20 or >20 with a marked to moderate nuclear pleomorphism. They were mostly grade II or III, sized 2–5 or > 5 cm, had absent or scanty tumour lymphocytes, and were stage II or III. The in situ tumours were mainly ductal carcinoma (DCIS) of which comedo and cribriform were the major histological subtypes. The major histological subtypes of the invasive tumours were ductal-not otherwise specified, lobular, and tubular/cribriform. In this study, we also found a significant (p < 0.05) association between over expression of Her-2, lack of expression of ER and some of the characteristics mentioned above.

Conclusion

Breast cancer in Kuwait seems to be more aggressive than what is currently seen in Europe, North America, Australia, and parts of Asia. Further investigations regarding the features observed in this study need to be performed.

Ductal carcinoma in situ--current management

This article summarizes the modern evidence-based management of ductal carcinoma in situ. The data addressing the surgical issues, including indications for mastectomy and the use of sentinel node biopsy, are presented. The randomized trials examining the role of radiation therapy after breast-conserving surgery and the use of tamoxifen in ductal carcinoma in situ are discussed. Factors to consider in developing a management strategy for the individual patient are elucidated in the final section.

The Value of the Van Nuys Prognostic Index in Ductal Carcinoma In Situ of the Breast: A Retrospective Analysis

The Van Nuys Prognostic Index 1996 (VNPI), based upon tumor size, pathological grade and tumor margins, is a guideline for the treatment of ductal carcinoma in situ (DCIS). It was thought to strongly decrease overtreatment. In 2003, age was added to the index as a fourth prognostic factor. We examined changes in treatment modality after applying the VNPI retrospectively and investigated if the addition of age to the Index causes a shift in treatment. The influence of each prognostic factor on disease-free survival (DFS) was calculated. We performed a retrospective file study of DCIS patients treated between 1985 and 2003 at the University Hospital, Antwerp. Patients were assigned a Van Nuys Score 1996 and 2003. The influence of tumor size, pathological grade, tumor margins and age on DFS was calculated with the Kaplan-Meier method and the log-rank test. We identified 104 DCIS cases with a median follow-up of 36 months. Twelve patients showed recurrence (11.5%), of whom seven were invasive (58%). Seventeen of the 29 women diagnosed before 1997 were undertreated according to the VNPI 1996 and six of them showed recurrence. The remaining three recurrences were correctly treated. Seventy-five patients diagnosed after 1997 were all treated according to the VNPI 1996 and only three had a recurrence. The introduction of age caused no significant shift in treatment modalities. Significant differences in DFS were seen between large (>41 mm) and small (<15 mm) tumors (p = 0.0074), old (>60 years) and young (<40 years) patients (p = 0.024) and Van Nuys Subgroup 2 and 3 (p = 0.04). Tumor margins and pathological grade showed no significant difference in DFS. The VNPI can be a useful tool in the treatment of DCIS. However, this Index is not evidence-based, using a relatively small retrospective series of patients. The validity of the modified VNPI must be prospectively confirmed with large numbers of DCIS patients.

HER2 protein overexpression in estrogen receptor-positive ductal carcinoma in situ of the breast: frequency and implications for tamoxifen therapy

Recent clinical data have suggested that the efficacy of tamoxifen in reducing the risk of local recurrence following lumpectomy and radiation therapy in patients with ductal carcinoma in situ (DCIS) is limited to patients with estrogen receptor (ER)-positive lesions. However, it is currently not known if HER2 protein overexpression might be associated with reduced tamoxifen benefit in patients with ER-positive DCIS, as has been suggested in patients with ER-positive invasive breast cancer and in preclinical models. Moreover, the frequency of HER2 overexpression in ER-positive ductal carcinoma in situ has not been previously evaluated in detail. To address this issue, we studied ER expression and HER2 overexpression in 148 cases of DCIS using a sensitive double immunostaining technique and assessed the frequency of ER expression and HER2 overexpression in relation to each other and in relation to DCIS grade. Overall, ER expression was seen in 114 cases (77%) and HER2 protein overexpression was seen in 42 cases (28%). Of 114 ER-positive ductal carcinoma in situ, 14 (12%) showed concurrent HER2 protein overexpression, and all 14 of these DCIS lesions were of high nuclear grade. In addition, in all 14 ER-positive DCIS cases that showed HER2 overexpression, double immunostaining demonstrated that ER and HER2 protein were coexpressed by the same neoplastic cells. We conclude that a subset of ER-positive DCIS show concomitant overexpression of HER2 protein. Whether or not HER2 overexpression is associated with a diminished response to tamoxifen in patients with ER-positive DCIS will require investigation in clinical outcome studies.

Estrogen receptor mutations in human disease

As early as the 1800s, the actions of estrogen have been implicated in the development and progression of breast cancer. The estrogen receptor (ER) was identified in the late 1950s and purified a few years later. However, it was not until the 1980s that the first ER was molecularly cloned, and in the mid 1990s, a second ER was cloned. These two related receptors are now called ERalpha and ERbeta, respectively. Since their discovery, much research has focused on identifying alterations within the coding sequence of these receptors in clinical samples. As a result, a large number of naturally occurring splice variants of both ERalpha and ERbeta have been identified in normal epithelium and diseased or cancerous tissues. In contrast, only a few point mutations have been identified in human patient samples from a variety of disease states, including breast cancer, endometrial cancer, and psychiatric diseases. To elucidate the mechanism of action for these variant isoforms or mutant receptors, experimental mutagenesis has been used to analyze the function of distinct amino acid residues in the ERs. This review will focus on ERalpha and ERbeta alterations in breast cancer.

Ductal carcinoma in situ, complexities and challenges

The incidence of ductal carcinoma in situ (DCIS), a noninvasive form of breast cancer, has increased markedly in recent decades, and DCIS now accounts for approximately 20% of breast cancers diagnosed by mammography. Laboratory and patient data suggest that DCIS is a precursor lesion for invasive cancer. The appropriate classification of DCIS has provoked much debate; a number of classification systems have been developed, but there is a lack of uniformity in the diagnosis and prognostication of this disease. Further investigation of molecular markers should improve the classification of DCIS and our understanding of its relationship to invasive disease. Controversy also exists with regard to the optimal management of DCIS patients. In the past, mastectomy was the primary treatment for patients with DCIS, but as with invasive cancer, breast-conserving surgery has become the standard approach. Three randomized trials have reported a statistically significant decrease in the risk of recurrence with radiation therapy in combination with lumpectomy compared with lumpectomy alone, but there was no survival advantage with the addition of radiotherapy. Two randomized trials have suggested an additional benefit, in terms of recurrence, with the addition of adjuvant tamoxifen therapy, although in one trial the benefit was not statistically significant. Current data suggest that tamoxifen use should be restricted to patients with estrogen receptor-positive DCIS. Neither trial demonstrated a survival benefit with adjuvant tamoxifen. Ongoing and recently completed studies should provide information on outcomes in patients treated with lumpectomy alone and on the effectiveness of aromatase inhibitors as an alternative to tamoxifen.

Optimal management of ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) represents a breast lesion that is diagnosed with increasing frequency, mainly due to the wide use of screening mammography. Today, DCIS comprises 15-25% of all breast cancers detected at population screening programs. Consequently, the concepts of properly managing such patients assume a greater importance in everyday practice. Mammographically detected microcalcifications are the most common presentation of DCIS. Despite recent technological advances (including Stereotactic-guided directional vacuum-assisted biopsy), mammographically guided wire biopsy remains the "gold-standard" for obtaining a histological diagnosis in patients with non-palpable, mammographically detected DCIS. Management options include mastectomy, local excision combined with radiation therapy, and local excision alone. Given that DCIS is a heterogeneous group of lesions rather than a single entity, and because patients have a wide variety of personal needs that must be addressed during treatment selection, it is obvious that no single approach will be appropriate for all forms of DCIS or for all patients. Careful patient selection is of key importance in order to achieve the best results in the management of the individual patient with DCIS. Axillary lymph node dissection is unnecessary in the treatment of pure DCIS, but it is indicated when microinvasion is present. In these cases, sentinel lymph node biopsy may be an excellent alternative. In the NSABP B-24 trial, tamoxifen reduced both the invasive and non-invasive breast cancer events in either breast by 37%. Nearly all patients who develop a non-invasive recurrence following breast-sparing surgery are cured with mastectomy, and approximately 75% of those with an invasive recurrence are salvaged. Selected patients initially treated by lumpectomy alone may also undergo breast-conservation therapy at the time of relapse according to the same strict guidelines of tumor margin clearance required for the primary lesion; radiation therapy should be given following local excision. The use of systemic therapy in patients with invasive recurrence should be based on standard criteria for invasive breast cancer.

Ductal carcinoma in situ

DCIS is a heterogeneous disease whose natural history is poorly defined. Screening mammography has increased the detection rate of DCIS, but we remain unable to identify cases of DCIS that will not progress to invasive carcinoma during an individual's lifetime. Genomics holds great promise in this regard, but prospective studies with long-term follow-up will be needed before concluding that a subset of DCIS is clinically insignificant. The varying intensity of treatment options for DCIS, ranging from mastectomy to excision, RT, and tamoxifen to excision alone, reflects the uncertainty about the natural history of DCIS as well as differing physician values regarding the impact of local recurrence. The extent of DCIS within the breast is the major determinant of whether the patient is a candidate for a breast-conserving approach, and contraindications to the use of breast conservation treatment and to the use of irradiation have been defined. The clinical decision-making process in DCIS would benefit greatly from improvements in our ability to convey information about the long-term risks and benefits of therapy, as well as the tradeoffs in health-related quality of life, to patients, and to incorporate their preferences into the decision-making process.

Oestrogen receptor negativity as a marker for high-grade ductal carcinoma in situ of the breast

AIMS

To compare the morphological and immunohistochemical characteristics of oestrogen receptor (ER)-negative and ER-positive ductal carcinoma in situ (DCIS) of the breast, in an attempt to establish more objective criteria for the classification of DCIS.

METHODS AND RESULTS

Sections of 64 cases of in-situ carcinoma of the breast were stained for ER, progesterone receptors (PgR), androgen receptors (AR), c-erbB-2 and p53, using the immunoperoxidase technique. The cases included 60 DCIS and four lobular carcinoma in situ (LCIS). Four DCIS lesions were associated with foci of microinvasion. The 60 DCIS cases included 31 high grade, 23 intermediate grade and six low grade. Twenty-four DCIS cases (40%) were ER-negative and 36 were positive. ER negativity was significantly associated with high nuclear grade (88% versus 27% for ER-positive cases, P < 0.001), PgR negativity (100% versus 25%, P < 0.001), c-erbB-2 positivity (79% versus 14%, P < 0.001) and p53 positivity (58% versus 6%, P < 0.001). There was no difference between ER-negative and -positive DCIS as regards AR expression, with 91% of cases in each group being AR-positive. Of the four cases of DCIS with microinvasion, three were ER- and PgR-negative, all four were c-erbB-2-positive and AR-positive and one was p53-positive. None of the four LCIS was ER, PgR or AR-negative and none was c-erbB-2- or p53-positive.

CONCLUSIONS

There is a highly significant direct relationship between ER negativity in DCIS and high nuclear grade, PgR negativity and c-erbB-2 and p53 positivity. We suggest that immunohistological assessment of ER status may help in providing a more objective way of classifying DCIS.

Differences in the pathologic and molecular features of intraductal breast carcinoma between younger and older women

BACKGROUND

Patients diagnosed with ductal carcinoma in situ (DCIS) at a young age appear to have a different natural history and biology, including a higher local relapse rate, than patients diagnosed later in life. The current study compared various pathologic and molecular features of DCIS arising in a cohort of young women with those of DCIS arising in a cohort of older women to identify potential biologic differences between these two populations of patients.

METHODS

The study population consisted of 20 patients age < 42 years and 34 patients age > 60 years who were treated at Yale University School of Medicine with breast-conserving therapy (BCT) and whose archival paraffin blocks were available and had sufficient tumor for staining. The original slides from each case were reviewed and the most representative specimen block from each case was processed for immunohistochemical staining. Pathologic characteristics evaluated for each case included histology, grade, and presence of necrosis. Paraffin-embedded sections were immunohistochemically evaluated for expression of HER-2/neu, estrogen receptor (ER), progesterone receptor (PR), bcl-2, cyclin D1, Ki-67, and p53.

RESULTS

Although there was no difference in pathologic features of the tumors between the two groups, HER-2/neu was found to be overexpressed in a greater percentage of the younger population (P = 0.06). There was no apparent difference in expression of the other markers. Of note, HER-2/neu expression was correlated with high nuclear grade (P = 0.004), necrosis (P = 0.06), and ER and PR negativity (P = 0.01 and P = 0.03, respectively) in the combined population.

CONCLUSIONS

The current study data suggested that HER-2/neu overexpression in younger patients may characterize a biologic difference in their tumor and may partially contribute to their higher risk of recurrence. Further studies are needed to assess whether this difference holds independent of grade and to evaluate the prognostic significance of HER-2/neu overexpression in DCIS.

Ductal carcinoma in situ of the breast in Singapore: recent trends and clinical implications

BACKGROUND

Breast ductal carcinoma in-situ (DCIS) is increasingly being diagnosed as a result of screening mammography and better pathological recognition. With this and the rising breast cancer incidence in Singapore, DCIS is poised to become a bigger part of surgical practice. Principles of screening, diagnosis and management of DCIS have also been rapidly evolving. Against this background, a clinicopathological audit of recent cases of DCIS in our centre was performed.

METHODS

Thirty-eight cases of DCIS diagnosed in the period 1997-2000 were retrospectively analysed. Histological examination and immunohistochemical studies for oestrogen and progesterone receptor expression were performed.

RESULTS

In the present study, DCIS was most common in the group of patients who were <50 years (58%) as compared to an American series' where the corresponding group were > or =60 years (36%). Compared to a previous local study a decade ago, the present series showed that: (i) DCIS constituted a higher proportion of all breast cancers (6.4% vs 3.7%); (ii) a larger proportion of patients had disease detected by mammography (47% vs 10%); (iii) conservative breast excision was the only definitive surgery in 39% of cases (vs approximately 30%); and (iv) the mean size of lesions is smaller (13.5 mm vs 24.4 mm). Histologically, 26% of tumours were high grade, 71% had necrosis while 32% were oestrogen receptor (ER) and progesterone receptor (PR) negative. High grade tumours were associated with the presence of necrosis (P = 0.018), ER negativity (P = 0.015) and PR negativity (P = 0.001).

CONCLUSIONS

This study reveals interesting trends of DCIS in Singapore. The sizeable proportion of hormone receptor-negative tumours may have implications for the hormonal adjuvant therapy of DCIS.

Histopathological and cell biological factors of ductal carcinoma in situ before and after the introduction of mammographic screening

With the introduction of mammographic screening the incidence of ductal carcinoma in situ (DCIS) has increased to 10-15% of all breast cancers. The aim of this study was to investigate whether there were any morphological and cell biological differences between DCIS detected during the pre-screening (n = 39) as opposed to the screening period (n = 120). We could not demonstrate any statistically significant differences between the pre-screening and the screening period with regard to nuclear grade, presence of necrosis, the Van Nuys classification system, growth pattern, or cell biological factors (estrogen and progesterone receptors, c-erbB-2, p53, DNA ploidy status, Ki67, and Auer classes). These findings suggest that DCIS tumors detected during the two time periods have a similar malignant potential. DCIS detected during the screening period was further divided into the prevalence period versus the period thereafter, and symptomatic versus screening-detected asymptomatic cases. More cases with diffuse growth patterns were seen during the prevalence period than after the prevalence period, and screening-detected asymptomatic DCISs were more often 15 mm or smaller in diameter than DCISs detected symptomatically.

Androgen receptor expression in ductal carcinoma in situ of the breast: relation to oestrogen and progesterone receptors

AIMS

Ductal carcinoma in situ (DCIS) of the breast has been diagnosed increasingly since the advent of mammographic screening. In contrast to the situation in invasive breast carcinoma, there are no reports on androgen receptor (AR) status in DCIS and few reports on oestrogen (ER) and progesterone (PR) receptors.

METHODS

AR expression was examined in 57 cases of DCIS of the breast and correlated to the degree of differentiation and ER/PR status using immunohistochemical methods.

RESULTS

AR positivity was noted in 19 of the cases, whereas the other 38 cases were negative. There was no significant association between AR expression and the degree of differentiation of DCIS; three of the 13 well differentiated DCIS cases, 10 of the 19 intermediately differentiated cases, and six of the 25 poorly differentiated cases were positive (p = 0.093). However, a strong association was shown between the expression of ER (p < 0.0001) and PR (p = 0.002) and the degree of differentiation of DCIS. In addition, no significant association was found between the expression of AR and the expression of ER (p = 0.26) or PR (p = 0.57) in DCIS of the breast.

CONCLUSIONS

A large number of cases of DCIS of the breast express AR and this may be associated with apocrine differentiation, which may impact on accurate typing of DCIS. Moreover, the expression of AR (but not ER or PR) in DCIS does not appear to be associated with the degree of differentiation.

Hypoxia reduces hormone responsiveness of human breast cancer cells

Resistance to hormonal therapy frequently occurs following successful treatment in breast cancer. The mechanism responsible for this acquired resistance is still unknown. It has been suggested that a hypoxic tumor microenvironment promotes malignant progression of cancer, i.e., hypoxia may promote estrogen-independent growth (a more malignant phenotype) of breast cancer. To clarify this hypothesis, the effects of hypoxia on the growth responses to hormonal agents and the expression levels of estrogen receptor (ER)-alpha and progesterone receptor (PgR) were investigated in two human breast cancer cell lines, ML-20 and KPL-1. The expression level of ER-alpha was significantly decreased by hypoxia (1% O(2)) in a time-dependent manner in both cell lines. Hypoxia also significantly reduced the growth-promoting effect of estradiol (E2) and the growth-inhibitory effects of an antiestrogen, ICI 182 780, and a progestin, medroxyprogesterone acetate, in both cell lines. In addition, hypoxia markedly suppressed the induction of PgR mRNA and protein by E2 in both cell lines. To clarify further the effect of hypoxia on ER-alpha expression, the expression levels of hypoxia-inducible factor-1 alpha (HIF-1 alpha), a marker of hypoxia and ER-alpha were immunohistochemically examined in 36 breast cancer specimens. ER-alpha expression (both its proportion and intensity) was significantly lower in nuclear HIF-1 alpha-positive tumors than in negative tumors. These findings indicate that hypoxia down-regulates ER-alpha expression as well as ER-alpha function in breast cancer cells. These processes may lead to an acquired resistance to hormonal therapy in breast cancer.

Immunohistochemical analysis on biological markers in ductal carcinoma in situ of the breast

BACKGROUND

The increasing use of mammographic screening has led to an increased detection of ductal carcinoma in situ (DCIS) of the breast. The detailed biological characteristics of DCIS and a new classification of DCIS based on these characteristics are needed.

METHODS

Immunohistochemical studies were performed to assess the expression of c-erbB-2 (ErbB-2), estrogen receptor (ER), p53 and proliferative activity (Ki-67) in 65 patients with pure DCIS and 60 with invasive ductal carcinoma (IDC). We classified pure DCIS tumors using three classifications, the architectural, Nottingham, and Van Nuys classifications.

RESULTS

ErbB-2, ER and p53 staining was positive in 34%, 66% and 21% of patients with DCIS, respectively, and 58%, 42% and 33% in patients with IDC, respectively. Ki-67 stained positively in 1.5% of patients with DCIS and 11.2% of patients with IDC. The comedo type showed a high rate of positive ErbB-2 and p53 staining. The cribriform and papillary types showed a high rate of positive ER staining. Under the Van Nuys classification, ErbB-2, p53 and Ki-67 expression were highest in the group with high nuclear grade and lowest in the group with non-high nuclear grade without necrosis.

CONCLUSION

Although the biological markers of IDC tended to suggest aggressive behavior more so than those of DCIS, these differences were based on the histological sub-type, comedo or non-comedo. The Van Nuys classification best defined the subgroups of DCIS with a distinct expression pattern of biological markers, and the best candidates for breast-conserving surgery.

Cell biological factors in ductal carcinoma in situ (DCIS) of the breast-relationship to ipsilateral local recurrence and histopathological characteristics

All cases of ductal carcinoma in situ (DCIS) diagnosed from 1987 to 1991 in the Southern Health Care Region of Sweden, and operated upon with breast conserving treatment (BCT) with (n=66) or without (n=121) postoperative radiation (RT) were clinically followed, morphologically re-evaluated and analysed for cell biological factors (immunohistochemical assays or DNA flow cytometry). Median age at diagnosis was 58 years (range 29--83 years) and median follow-up was 62 months. Oestrogen (ER)- and progesterone receptor (PR)-negativity, c-erbB-2 overexpression, low bcl-2 expression, p53 accumulation, DNA non-diploidy and high Ki67, were strongly associated with high grade DCIS, and comedo-type necrosis. In contrast, significant associations to growth pattern (not diffuse versus diffuse) were seen only for c-erbB-2 and PgR. There was also a strong relationship between the cell biological factors, and a summary cell biological index based on principal component analysis was introduced (CBI-7). In the group that had not received postoperative RT, 31 ipsilateral local recurrences occurred (13 invasive, 18 DCIS). Ipsilateral recurrence-free interval (IL-RFI) was in univariate analyses significantly, or almost significantly, shorter for patients showing p53 accumulation, high Ki67 or low bcl-2, compared with patients with normal p53, low Ki67 and high bcl-2. The prognostic importance of the remaining cell biological factors was less pronounced. On the other hand, the index CBI-7, was a strong predictor for recurrence.

Pathobiologic findings in DCIS of the breast: morphologic features, angiogenesis, HER-2/neu and hormone receptors

With the increasing incidence of ductal carcinoma in situ (DCIS) of the breast and its relationship to invasive breast carcinoma, it is important to understand the biology of this entity. We report on a hospital-based survey of 219 case subjects with DCIS of the breast without associated invasive carcinoma diagnosed between 1982 and 1994. The cases of DCIS were analyzed for architectural type, size, nuclear grade, necrosis, calcification, periductal fibrosis, neovascularization, estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu expression. Periductal neovascularization was associated with tumor size, microcalcifications, periductal fibrosis, and HER-2/neu overexpression. Expression of ER and PR was observed in 60 and 62% of the cases, respectively, and HER-2/neu overexpression in 28% of the cases. ER and PR expression were both inversely associated with comedo histology and nuclear grade. HER-2/neu overexpression was positively associated with comedo histology, high nuclear grade, and periductal neovascularization and was inversely correlated with both ER and PR expression. High nuclear grade was positively associated with comedocarcinoma, necrosis, microcalcification, and periductal fibrosis. The role of these molecular/pathologic markers in the biology of DCIS and their potential clinical implications are discussed.

Biological features of premalignant disease in the human breast

Most human invasive breast cancers (IBCs) arise from preexisting benign lesions. There are many types of benign lesions in the human breast and only a few appear to have significant premalignant potential (atypical hyperplasias and in situ carcinomas). These lesions are relatively common and only a small proportion progress to IBC. They are currently defined by their histological features and their prognosis is imprecisely estimated from indirect evidence based on epidemiological studies. Although lesions within specific categories look alike, they must possess morphologically silent biological differences motivating some to remain stable and others to progress. Understanding the biological changes responsible for the development and progression of premalignant disease is a very active area of medical research. Progress in this area may provide new opportunities for breast cancer prevention by providing strategies to treat premalignant lesions before they develop or become cancerous. A large number of biological features have been evaluated in this setting during the past decade. This review discusses a few features that appear to be particularly important and have been studied in a relatively comprehensive manner.

Ductal carcinoma in situ (DCIS) of the breast: evolving perspectives

Ductal carcinoma in situ (DCIS) of the breast is an early, localized stage of carcinoma in the process of multistep breast carcinogenesis. The incidence of DCIS is increasing, mainly due to screening mammography, which results in diagnosing the disease in an increasing proportion of asymptomatic patients. Consequently, clinicians are being confronted with growing numbers of women who present with DCIS of the breast; thus, the concepts of managing such patients are assuming greater importance. The most common presentation is calcifications on mammography. DCIS is a biologically and morphologically heterogeneous disease. If left untreated, a significant proportion of these tumours will evolve into invasive cancer. However, when appropriately treated, the prognosis of DCIS is excellent. Optimal management of DCIS remains controversial. The goal in the treatment of patients with DCIS is to control local disease and prevent subsequent development of invasive cancer. For several decades, total mastectomy was the treatment of choice for DCIS and it should still be considered the standard of care, to which more conservative forms of treatment must be compared. Mastectomy is associated with a risk for chest wall recurrence of approximately 1%. Axillary lymph node dissection is not routinely recommended in the management of DCIS. However, mastectomy probably represents overtreatment in a substantial number of patients, especially those with small, mammographically detected lesions. Local excision alone has been suggested in carefully selected patients, whilst the rest of the patients undergoing breast-conservation surgery should be treated with breast irradiation. There is evidence that breast-conservation therapy is an effective option in the management of selected patients with DCIS. The use of radiotherapy after lumpectomy significantly decreases the rate of recurrence. Nuclear grade, presence of comedo necrosis, and margin involvement are the most commonly used predictors of the likelihood of recurrence. There is no role for adjuvant chemotherapy in the management of this disease. The role of tamoxifen in the treatment of DCIS is not clearly defined; tamoxifen should be given only in patients enrolled in clinical trials. Following breast-conservation therapy, about 50% of the tumours recur as invasive cancer. Most patients with recurrent disease can be treated effectively, usually by salvage mastectomy, but also in selected cases by breast-conservation therapy.

Carcinoma in situ of the breast: correlation of histopathology to immunohistochemical markers and DNA ploidy

In a consecutive and unselected series of 178 cases of carcinoma in situ of the breast (CIS), comprising both ductal (DCIS) and lobular type (LCIS), and a series of 48 cases of invasive carcinoma (IC) with predominance of DCIS, the association between histopathology, immunohistochemical markers (ER, PgR, MIB-1, c-erbB-2, and p53), and DNA ploidy was investigated, in order to discriminate biologically different groups. In DCIS, significant correlation was shown between large nuclear size and comedonecrosis, both of which showed also strong association to DNA aneuploidy, high proliferation activity, low steroid receptor content, and overexpression of c-erbB-2 and p53 factors that may indicate an aggressive behavior. Small nuclear CIS, whether LCIS or DCIS, on the contrary, were DNA diploid with low proliferation, and no cases showed overexpression of c-erbB-2 and p53. Heterogeneity with respect to the investigated parameters was also a frequent finding that may reflect a development complexity. In IC, comparison of the DCIS and the invasive component showed similar patterns. No significant differences were shown between DCIS without and with invasion. This may indicate that none of the investigated parameters on its own are essential for the event of invasion.

Tamoxifen for prevention of breast cancer: report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study

BACKGROUND

The finding of a decrease in contralateral breast cancer incidence following tamoxifen administration for adjuvant therapy led to the concept that the drug might play a role in breast cancer prevention. To test this hypothesis, the National Surgical Adjuvant Breast and Bowel Project initiated the Breast Cancer Prevention Trial (P-1) in 1992.

METHODS

Women (N=13388) at increased risk for breast cancer because they 1) were 60 years of age or older, 2) were 35-59 years of age with a 5-year predicted risk for breast cancer of at least 1.66%, or 3) had a history of lobular carcinoma in situ were randomly assigned to receive placebo (n=6707) or 20 mg/day tamoxifen (n=6681) for 5 years. Gail's algorithm, based on a multivariate logistic regression model using combinations of risk factors, was used to estimate the probability (risk) of occurrence of breast cancer over time.

RESULTS

Tamoxifen reduced the risk of invasive breast cancer by 49% (two-sided P<.00001), with cumulative incidence through 69 months of follow-up of 43.4 versus 22.0 per 1000 women in the placebo and tamoxifen groups, respectively. The decreased risk occurred in women aged 49 years or younger (44%), 50-59 years (51%), and 60 years or older (55%); risk was also reduced in women with a history of lobular carcinoma in situ (56%) or atypical hyperplasia (86%) and in those with any category of predicted 5-year risk. Tamoxifen reduced the risk of noninvasive breast cancer by 50% (two-sided P<.002). Tamoxifen reduced the occurrence of estrogen receptor-positive tumors by 69%, but no difference in the occurrence of estrogen receptor-negative tumors was seen. Tamoxifen administration did not alter the average annual rate of ischemic heart disease; however, a reduction in hip, radius (Colles'), and spine fractures was observed. The rate of endometrial cancer was increased in the tamoxifen group (risk ratio = 2.53; 95% confidence interval = 1.35-4.97); this increased risk occurred predominantly in women aged 50 years or older. All endometrial cancers in the tamoxifen group were stage I (localized disease); no endometrial cancer deaths have occurred in this group. No liver cancers or increase in colon, rectal, ovarian, or other tumors was observed in the tamoxifen group. The rates of stroke, pulmonary embolism, and deep-vein thrombosis were elevated in the tamoxifen group; these events occurred more frequently in women aged 50 years or older.

CONCLUSIONS

Tamoxifen decreases the incidence of invasive and noninvasive breast cancer. Despite side effects resulting from administration of tamoxifen, its use as a breast cancer preventive agent is appropriate in many women at increased risk for the disease.

ERBB2 oncogene in human breast cancer and its clinical significance

We reveiwed the relationships between ERBB2 amplification and/or overexpression in human breast cancer and the clinicopathological parameters described in the literature (97 studies involving 22,616 patients) in order to draw conclusions regarding its clinical interest. The mean of ERBB2 positivity (26%, ranging from 5 to 55%) is not dependent on the method used to evaluate ERBB2 amplification or overexpression. Despite the discrepancies observed between the different studies, several associations between ERBB2 positivity and the classical clinicopathological parameters were noted. There are clear relationships between ERBB2 positivity and the lack of steroid receptors, the histological subtypes of mammary tumours (ductal invasive and in situ), worse histological and nuclear grades, aneuploidy and high rate of proliferation. In univariate analyses, ERBB2 is strongly associated with poor prognosis. All these data indicate that ERBB2 is a marker of aggressiveness of the tumour. However, ERBB2 does not retain a clinical prognostic significance in multivariate analyses, since it is associated with several strong prognostic parameters. When considering the prognostic value of ERBB2 in relation to treatment, a significantly worse survival of the treated patients is noted in ERBB2 positive patients. This suggest that ERBB2 could be a marker of reduced response to chemotherapy and hormonal treatment. With respect to the tumour response to treatment, the results, provided as yet by pilot studies, remain controversial and further investigations are necessary to evaluate the predictive value of ERBB2. Finally, new therapeutic approaches targeting the cells overexpressing ERBB2 have been developed.

Assessment of hormone dependence of comedo ductal carcinoma in situ of the breast

BACKGROUND

Ductal carcinoma in situ (DCIS) represents 20%-30% of breast cancers detected by clinical screening (i.e., mammography). More than 50% of DCIS lesions may be estrogen receptor negative and, therefore, hormone independent. However, the role of estrogen in the natural history of DCIS is unknown.

PURPOSE

A novel in vivo (i.e., xenograft) model was developed to determine to what degree DCIS lesions depend on estrogen for growth.

METHODS

Specimens of breast tissue were collected from 52 women during diagnostic or therapeutic surgical procedures. Portions of each specimen were randomly selected and analyzed by histology and thymidine labeling (to measure cell proliferation). The remainder of each specimen was implanted into five to 18 athymic BALB/c nu/nu mice (depending on the amount of tissue available), with eight pieces of approximately 2 mm x 2 mm x 1 mm implanted at different locations on the back of each mouse. Half of the mice received implants containing estrogen (2 mg 17 beta-estradiol), and the other half received placebo implants. Levels of cell proliferation in xenografts, recovered after 14, 28, 42, or 56 days in the mice, were measured by thymidine labeling or by immunohistochemistry through use of an antibody specific for the Ki-67 nuclear antigen. Immunohistochemistry was also used to measure the levels of estrogen receptor in the tissue specimens. Serum 17 beta-estradiol levels in the mice were measured by radioimmunoassay.

RESULTS

Initial levels of cell proliferation were approximately 10-fold higher in 10 specimens with estrogen receptor-negative, comedo (i.e., more malignant in appearance) DCIS than in four specimens with estrogen receptor-positive DCIS (mean proliferation indices: 22% versus 1.9%, respectively; two-sided P < .001). Xenografts from the majority of specimens survived up to 56 days in the mice and maintained good architectural and cellular preservation. Estrogen treatment of the xenograft-bearing mice had no effect on the high level of cell proliferation observed in estrogen receptor-negative, comedo DCIS specimens (two-sided P = .89). In contrast, increased levels of cell proliferation in response to estrogen supplementation were measured in three estrogen receptor-positive, noncomedo DCIS specimens (two-sided P < .001). However, even with estrogen treatment, cell proliferation levels in estrogen receptor-positive DCIS specimens did not reach those seen in estrogen receptor-negative DCIS specimens.

CONCLUSION AND IMPLICATION

Estrogen receptor-negative, comedo DCIS lesions appear to be estrogen independent; therefore, antiestrogen (e.g., tamoxifen) therapy may not benefit patients with comedo DCIS.

p53 protein expression, cell proliferation and steroid hormone receptors in ductal and lobular in situ carcinomas of the breast

p53 and c-erbB-2 expression, and their correlation with cell proliferation and steroid hormone receptors, were investigated in 121 carcinomas, 23 lobular in situ carcinomas (LCIS), 74 intraductal carcinomas (DCIS) and 24 minimal invasive carcinomas. DCIS were classified according to the EORTC classification. All markers were measured immunohistochemically on paraffin sections. None of the LCIS, 9 DCIS and 9 minimal invasive cancers showed nuclear positivity for p53. A strong association between histological type and p53 expression was found. Proliferation rates correlated with p53 expression. c-erbB-2 positivity was found in 1 LCIS, 27 DCIS and 12 minimal invasive cancers. There was a significant correlation between p53 expression and c-erbB-2. Both parameters were associated with high proliferation rate and negativity for steroid hormone receptor status. Nuclear pleomorphism could become a comparable prognostic marker in DCIS as it is for infiltrating carcinomas.

Recent Progress in Breast Conserving Therapy: From Experiences in Japan

Breast conserving therapy (BCT) was conducted in 22.1% of breast cancer patients in 1994 in Japan and is being performed with increasing frequency. According to the data already published, 10-27% of patients treated with BCT had a positive surgical margin. The recurrence rate in the breast is 1-2% annually, The 5-year overall survival in patients mostly consisting of stage I is 90% or higher at the present time. A case-control analysis of a multicenter study revealed that significant risk factors for breast recurrence were a positive surgical margin and absence of radiation therapy. Progress in basic research and diagnosis has also been instrumental in improving treatment results.

Immunohistochemical detection of oestrogen receptors in ductal carcinoma in situ of the breast

The expression of oestrogen receptor (ER) protein in invasive carcinoma of the breast and its clinical significance has been extensively evaluated. Little information is available regarding ER expression in ductal carcinoma in situ (DCIS). In this study, 46 formalin-fixed, paraffin-embedded tissue specimens of mammographically detected DCIS were evaluated immunohistochemically for the presence of ER using specific monoclonal antibodies against ER (ER-ICA Abbott Lab). The associations between ER expression and histological type, degree of differentiation and patient menopausal status were evaluated. Positive ER staining was present in 72% of cases. Non-comedo types of DCIS were more frequently ER-positive than comedocarcinoma. ER-positive tumours were inversely correlated with the presence of nuclear pleomorphism. The incidence of ER in pre-menopausal and post-menopausal women was similar. In conclusion, ER expression is present in a considerable percentage of DCIS, and ER-positivity is associated with the degree of differentiation and non-comedo carcinoma variants.

Immunohistochemical evaluation of multiple biological markers in ductal carcinoma in situ of the breast

In order to obtain prognostic clinicopathological information, 49 cases of pure ductal carcinoma in situ of the breast (DCIS), were evaluated for the immunohistochemical expression of potential predictor markers including c-erbB-2 oncogene product, p53 protein, oestrogen (ER) and progesterone (PR) receptors, oestrogen-regulated proteins pS2 and cathepsin-D (cath-D), CD44 protein and 67-kDa laminin receptor (MLuC5). Immunohistochemical findings were compared with conventional pathological parameters, clinical findings, and the clinical outcome of the patients. When markers were matched to each other, statistical analyses provided a significant positive correlation between c-erbB-2 overexpression and p53 positivity (P < 0.01) and between ER and PR (P < 0.01), ER, PR and pS2 (P < 0.01), pS2 and MLuC5 (P < 0.05). Significant negative correlations between c-erbB-2 overexpression and ER (P < 0.05), PR (P < 0.01) and pS2 (P < 0.01) positivity was also observed. Data on the relationship between marker status and pathological findings revealed a significant positive trend between c-erbB-2, p53, and increased grade values (P < 0.05) and opposite results with PR receptor expression (P < 0.01). c-erbB-2 overexpression was further significantly associated with comedotype carcinoma (P < 0.05) and distribution of disease in confluent neoplastic ducts (P < 0.01). Although no statistically significant correlation among biological markers expression, clinical findings and outcome was demonstrated, overall this study indicates that tumour cells from a subset of DCIS, which includes comedotype carcinoma, express significantly unfavourable prognostic factors.

Controversies in the treatment of ductal carcinoma in situ

In summary, certain subgroups of DCIS appear not to require radiation. Corroboration of these results from retrospective reviews and prospective trials is necessary to confirm the safety and efficacy of individualized treatment strategies. Even though the current standard of treatment is (1) lumpectomy with radiation therapy, (2) mastectomy, or (3) mastectomy with reconstruction, it is possible in the future to say that patients with low-grade DCIS (the exact criteria to be defined) may be eligible for breast conservation without radiation, and all patients with high-grade DCIS or perhaps low-grade DCIS with necrosis would be treated best by lumpectomy plus radiation. It is possible that a small subgroup of patients may be best treated by mastectomy, or perhaps, as the results of B-24 become available, by radiation therapy plus tamoxifen. The use of tumor markers such as c-erbB-2, cathepsin D, and NM 23 may help us to better define these subgroups, but much study is necessary before a definite treatment strategy is reached.

Oestrogen receptor: a stable phenotype in breast cancer

Oestrogen receptor (ER) expression in breast cancer is regarded as a phenotype that may change during the natural history of the disease or during endocrine therapy. It has been suggested that in up to 70% of tumours that show acquired resistance the mechanism may be changed in ER status from positive to negative. This paper proposes an alternative hypothesis that ER expression in a stable phenotype in breast cancer. The paper reviews the literature on ER expression during the natural history of breast cancer in patients and also presents data on the effect of endocrine therapy on ER expression. If the alternative hypothesis is true it has important implications for treatment from chemoprevention to acquired endocrine resistance in advanced disease. Equally, if the hypothesis is true, attempts to develop laboratory models of endocrine resistance where ER-positive tumours become ER negative need to be re-evaluated.

Ductal carcinoma in situ: assessment of necrosis and nuclear morphology and their association with biological markers

One hundred and five cases of pure ductal carcinoma in situ (DCIS) seen in the Guy's Hospital breast unit between 1975 and 1991 were reviewed. The presence and extent of necrosis and the degree of cytonuclear differentiation were assessed and the expression of p53 protein, cerbB2 protein, progesterone receptor, and a proliferation antigen KiS1, all factors reported to be of prognostic significance in invasive ductal carcinoma, was evaluated using immunohistochemical methods. A strong correlation was seen between the presence and extent of necrosis and the degree of cytonuclear differentiation and between both these morphological criteria and the biological markers as well as between the individual markers. The presence of extensive necrosis was associated with lack of cytonuclear differentiation and both were associated with a high proliferation rate, the presence of cerbB2 and p53 protein, and the absence of progesterone receptors. In cases with little or no necrosis, there was good nuclear differentiation and a strong correlation with the presence of progesterone receptor, absence of cerbB2 and p53 protein, and a low rate of proliferation.

Prognostic classification of breast ductal carcinoma-in-situ

We present a new prognostic classification designated the Van Nuys classification for ductal carcinoma-in-situ (DCIS). The classification combines high nuclear grade and comedo-type necrosis to predict clinical recurrence. Three groups of DCIS patients were defined by the presence or absence of high nuclear grade and comedo-type necrosis: 1--non-high-grade DCIS without comedo-type necrosis, 2--non-high-grade DCIS with comedo-type necrosis, 3--high-grade DCIS with or without comedo-type necrosis. There were 31 local recurrences in 238 patients after breast-conservation surgery 3.8% (3/80) in group 1, 11.1% (10/90) in group 2, and 26.5% (18/68) in group 3. The 8-year actuarial disease-free survivals were 93%, 84%, and 61%, respectively (all p < or = 0.05). The Van Nuys classification defines three distinct and easily recognisable groups, each of which has a different likelihood of local recurrence if treated with breast conservation.

Ductal carcinoma in situ of the breast. Histologic categorization and its relationship to ploidy and immunohistochemical expression of hormone receptors, p53, and c-erbB-2 protein

BACKGROUND

Ductal carcinoma in situ (DCIS) of the breast has been diagnosed increasingly since the advent of mammography. However, the natural history of these lesions remains uncertain. Ductal carcinoma in situ of the breast does not represent a single entity but a heterogeneous group with histologic and clinical differences. The histologic subtype of DCIS seems to have an influence on its biologic behavior, but there are few studies correlating subtype with biologic markers.

METHODS

The authors studied a consecutive series of 40 cases of DCIS and after its histologic categorization verified its relationship with ploidy using image analysis and analyzing estrogen receptor (ER), progesterone receptor (PR), p53 and c-erbB-2 expression using immunohistochemistry.

RESULTS

The three groups proposed according to the grade of malignancy were correlated significantly with some of the additional parameters studied, including aneuploidy and c-erbB-2 expression. Aneuploidy was detected in 77.5% of cases of DCIS mainly in high and intermediate grade subtypes (100% and 80% vs. 35.7% in low grade) whereas immunoreactivity for c-erbB-2 was detected in 45% of cases of DCIS mainly in the high grade group. Expression of ER and PR were observed frequently in this study (63.9% and 65.7% respectively), but without correlation with the histologic subtype of DCIS, although we found a somewhat significant association between high grade DCIS and lack of ER, p53 protein expression was detected in 36.8% of these cases, but no relationship between this expression and histologic subtype or grading of DCIS was found.

CONCLUSIONS

These results provide further evidence for the morphologic and biologic heterogeneity of DCIS. Besides histologic classification and nuclear grading, some biologic markers such as aneuploidy and c-erbB-2 expression constitute additional criteria of high grade of malignancy.