Treatment of DCIS--results from clinical trials

Association of the 12-Gene Breast DCIS Score® Assay With Local Recurrence in Patients With Ductal Carcinoma In Situ Treated on Accelerated Partial Breast Radiotherapy Protocols

Background

The following analysis explores clinicopathologic factors and the 12-gene Breast DCIS Score test result in order to better define an appropriate DCIS (ductal carcinoma in situ) population eligible for APBI (accelerated partial breast radiotherapy).

Methods

This exploratory analysis aimed to retrospectively measure the association between the 12-gene Oncotype DX Breast DCIS Score^® assay (Redwood City, CA) and relevant clinicopathologic factors with locoregional recurrence in a pooled cohort of women treated with local excision and APBI on prospective phase II (NCT01185145) and phase III (NCT01185132) clinical trials. Univariable Cox proportional hazards regression was used to determine whether there was an association between local recurrence and DCIS Score result risk group (≥ 39 vs < 39) and clinicopathologic factors.

Results

This analysis included 104 evaluable patients (n = 18 from NCT01185145 and n = 86 from NCT01185132). The median age was 60 years (range: 40-79). Seventy-nine percent of patients were postmenopausal. The median span of DCIS was 10 mm (range 2-45 mm). Two-thirds of the cohort presented with necrosis (71%). The distribution of DCIS Score^® results ranged from 0 to 82, with 69% of patients having a DCIS Score result < 39. The median follow-up time was 8.2 years in NCT01185145 versus 3.0 years in NCT01185132. There were 6 local ipsilateral breast recurrences. DCIS Score result was significantly associated with local recurrence in univariable modeling, hazard ratio = 10.3 (95% CI 1.7, 198.4); p = 0.010. None of the clinicopathologic characteristics resulted in any significant association with locoregional recurrence.

Conclusion

The Breast DCIS Score assay demonstrated risk stratification in this cohort of patients treated with local excision and APBI pooled from two clinical trials. These results are consistent with those recently published utilizing whole breast radiotherapy. Due to the small number of local recurrence events and limited follow-up time, further investigations are needed to confirm findings.

Expression of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and Ki-67 in ductal carcinoma in situ (DCIS) and DCIS with microinvasion

Ductal carcinoma in situ (DCIS) represents a heterogeneous disease in its histologic appearance and biological potential. Some women treated for DCIS subsequently develop invasive breast cancer. DCIS with microinvasion is considered as the interim stage in the progression from DCIS to invasive breast cancer. Analysis of the differences between DCIS and DCIS with microinvasion may aid in understanding the characteristic of DCIS with microinvasion and identifying biological factors determining progression of DCIS to invasive disease.Retrospective analysis of 219 cases between 2012 and 2018 was performed in our institution. The pathological results and axillary lymph nodes status were collected. Analysis of the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), and Ki-67 in pure DCIS (164 cases), and DCIS with microinvasion (55 cases) using immunohistochemistry.DCIS with microinvasion had a higher nuclear grade (P < .001) and was more likely to have sentinel lymph node biopsy (SLNB) positivity (P = .039) than DCIS. Expression of ER, PR were significantly higher in DCIS compared with DCIS with microinvasion (P < .001, P < .001). While the expression of HER-2 in DCIS with microinvasion (56.4%) was significantly higher than in DCIS (36.6%, P = .01). Furthermore, DCIS with microinvasion was significantly more likely to have aggressive subtype (Triple-negative and HER2-enriched tumors, P = .005).Our results indicated that DCIS with microinvasion was different from pure DCIS in clinicopathologic characteristics and molecular alterations. It displayed a more aggressive biological nature than pure DCIS. It may be a distinct entity.

Progression-specific genes identified in microdissected formalin-fixed and paraffin-embedded tissue containing matched ductal carcinoma in situ and invasive ductal breast cancers

BACKGROUND

The transition from ductal carcinoma in situ (DCIS) to invasive breast carcinoma (IBC) is an important step during breast carcinogenesis. Understanding its molecular changes may help to identify high-risk DCIS that progress to IBC. Here, we describe a transcriptomic profiling analysis of matched formalin-fixed and paraffin-embedded (FFPE) DCIS and IBC components of individual breast tumours, containing both tumour compartments. The study was performed to validate progression-associated transcripts detected in an earlier gene profiling project using fresh frozen breast cancer tissue. In addition, FFPE tissues from patients with pure DCIS (pDCIS) were analysed to identify candidate transcripts characterizing DCIS with a high or low risk of progressing to IBC.

METHODS

Fifteen laser microdissected pairs of DCIS and IBC were profiled by Illumina DASL technology and used for expression validation by qPCR. Differential expression was independently validated using further 25 laser microdissected DCIS/IBC sample pairs. Additionally, laser microdissected epithelial cells from 31 pDCIS were investigated for expression of candidate transcripts using qPCR.

RESULTS

Multiple statistical calculation methods revealed 1784 mRNAs which are differentially expressed between DCIS and IBC (P < 0.05), of which 124 have also been identified in the gene profiling project using fresh frozen breast cancer tissue. Nine mRNAs that had been selected from the gene list obtained using fresh frozen tissues by applying pathway and network analysis (MMP11, GREM1, PLEKHC1, SULF1, THBS2, CSPG2, COL10A1, COL11A1, KRT14) were investigated in tissues from the same 15 microdissected specimens and the 25 independent tissue samples by qPCR. All selected transcripts were also detected in tumour cells from pDCIS. Expression of MMP11 and COL10A1 increased significantly from pDCIS to DCIS of DCIS/IBC mixed tumours.

CONCLUSION

We confirm differential expression of progression-associated transcripts in FFPE breast cancer samples which might mediate the transition from DCIS to IBC. MMP11 and COL10A1 may characterize pure DCIS with a high risk developing IDC.

PRSS3 is a prognostic marker in invasive ductal carcinoma of the breast

Objective

Serine protease 3 (PRSS3) is an isoform of trypsinogen, and plays an important role in the development of many malignancies. The objective of this study was to determine PRSS3 mRNA and protein expression levels in invasive ductal carcinoma of the breast and normal surrounding tissue samples.

Results

Both PRSS3 mRNA and protein levels were significantly higher in invasive ductal carcinoma of the breast tissues than in normal or benign tissues (all P < 0.05). High PRSS3 protein levels were associated with patients’ age, histological grade, Her-2 expression level, ki-67 expression, and the 5.0-year survival rate. These high protein levels are independent prognostic markers in invasive ductal carcinoma of the breast.

Materials and Methods

We used real-time quantitative polymerase chain reactions (N = 40) and tissue microarray immunohistochemistry analysis (N = 286) to determine PRSS3 mRNA and protein expression, respectively. PRSS3 protein levels in invasive ductal carcinoma of the breast tissues were correlated with the clinical characteristics of patients with invasive ductal carcinoma of the breast and their 5.0-year survival rate.

Conclusions

PRSS3 acts as an oncogene in invasive ductal carcinoma of the breast development and progression. This finding implies that detection of PRSS3 expression can be a useful prognosis marker and the targeting of PRSS3 can potentially represent a new strategy for invasive ductal carcinoma of the breast treatment.

Oestrogen-induced genes in ductal carcinoma in situ: their comparison with invasive ductal carcinoma

It is well known that oestrogens play important roles in both the pathogenesis and development of invasive ductal carcinoma (IDC) of human breast. However, molecular features of oestrogen actions have remained largely unclear in pure ductal carcinoma in situ (pDCIS), regarded as a precursor lesion of many IDCs. This is partly due to the fact that gene expression profiles of oestrogen-responsive genes have not been examined in pDCIS. Therefore, we first examined the profiles of oestrogen-induced genes in oestrogen receptor (ER)-positive pDCIS and DCIS (DCIS component (DCIS-c)) and IDC (IDC component (IDC-c)) components of IDC cases (n=4 respectively) by microarray analysis. Oestrogen-induced genes identified in this study were tentatively classified into three different groups in the hierarchical clustering analysis, and 33% of the genes were predominantly expressed in pDCIS rather than DCIS-c or IDC-c cases. Among these genes, the status of MYB (C-MYB), RBBP7 (RBAP46) and BIRC5 (survivin) expressions in carcinoma cells was significantly higher in ER-positive pDCIS (n=53) than that in ER-positive DCIS-c (n=27) or IDC-c (n=27) by subsequent immunohistochemical analysis of the corresponding genes (P<0.0001, P=0.03 and P=0.0003 respectively). In particular, the status of C-MYB immunoreactivity was inversely (P=0.006) correlated with Ki67 in the pDCIS cases. These results suggest that expression profiles of oestrogen-induced genes in pDCIS may be different from those in IDC; and C-MYB, RBAP46 and survivin may play important roles particularly among oestrogen-induced genes in ER-positive pDCIS.

Inflammatory mediators in breast cancer: coordinated expression of TNFα & IL-1β with CCL2 & CCL5 and effects on epithelial-to-mesenchymal transition

Background

The inflammatory chemokines CCL2 (MCP-1) & CCL5 (RANTES) and the inflammatory cytokines TNFα & IL-1β were shown to contribute to breast cancer development and metastasis. In this study, we wished to determine whether there are associations between these factors along stages of breast cancer progression, and to identify the possible implications of these factors to disease course.

Methods

The expression of CCL2, CCL5, TNFα and IL-1β was determined by immunohistochemistry in patients diagnosed with: (1) Benign breast disorders (=healthy individuals); (2) Ductal Carcinoma In Situ (DCIS); (3) Invasive Ducal Carcinoma without relapse (IDC-no-relapse); (4) IDC-with-relapse. Based on the results obtained, breast tumor cells were stimulated by the inflammatory cytokines, and epithelial-to-mesenchymal transition (EMT) was determined by flow cytometry, confocal analyses and adhesion, migration and invasion experiments.

Results

CCL2, CCL5, TNFα and IL-1β were expressed at very low incidence in normal breast epithelial cells, but their incidence was significantly elevated in tumor cells of the three groups of cancer patients. Significant associations were found between CCL2 & CCL5 and TNFα & IL-1β in the tumor cells in DCIS and IDC-no-relapse patients. In the IDC-with-relapse group, the expression of CCL2 & CCL5 was accompanied by further elevated incidence of TNFα & IL-1β expression. These results suggest progression-related roles for TNFα and IL-1β in breast cancer, as indeed indicated by the following: (1) Tumors of the IDC-with-relapse group had significantly higher persistence of TNFα and IL-1β compared to tumors of DCIS or IDC-no-relapse; (2) Continuous stimulation of the tumor cells by TNFα (and to some extent IL-1β) has led to EMT in the tumor cells; (3) Combined analyses with relevant clinical parameters suggested that IL-1β acts jointly with other pro-malignancy factors to promote disease relapse.

Conclusions

Our findings suggest that the coordinated expression of CCL2 & CCL5 and TNFα & IL-1β may be important for disease course, and that TNFα & IL-1β may promote disease relapse. Further in vitro and in vivo studies are needed for determination of the joint powers of the four factors in breast cancer, as well as analyses of their combined targeting in breast cancer.

Effect of tamoxifen and radiotherapy in women with locally excised ductal carcinoma in situ: long-term results from the UK/ANZ DCIS trial

BACKGROUND

Initial results of the UK/ANZ DCIS (UK, Australia, and New Zealand ductal carcinoma in situ) trial suggested that radiotherapy reduced new breast events of ipsilateral invasive and ductal carcinoma in situ (DCIS) compared with no radiotherapy, but no significant effects were noted with tamoxifen. Here, we report long-term results of this trial.

METHODS

Women with completely locally excised DCIS were recruited into a randomised 2×2 factorial trial of radiotherapy, tamoxifen, or both. Randomisation was independently done for each of the two treatments (radiotherapy and tamoxifen), stratified by screening assessment centre, and blocked in groups of four. The recommended dose for radiation was 50 Gy in 25 fractions over 5 weeks (2 Gy per day on weekdays), and tamoxifen was prescribed at a dose of 20 mg daily for 5 years. Elective decision to withhold or provide one of the treatments was permitted. The endpoints of primary interest were invasive ipsilateral new breast events for the radiotherapy comparison and any new breast event, including contralateral disease and DCIS, for tamoxifen. Analysis of each of the two treatment comparisons was restricted to patients who were randomly assigned to that treatment. Analyses were by intention to treat. All trial drugs have been completed and this study is in long-term follow-up. This study is registered, number ISRCTN99513870.

FINDINGS

Between May, 1990, and August, 1998, 1701 women were randomly assigned to radiotherapy and tamoxifen, radiotherapy alone, tamoxifen alone, or to no adjuvant treatment. Seven patients had protocol violations and thus 1694 patients were available for analysis. After a median follow-up of 12·7 years (IQR 10·9-14·7), 376 (163 invasive [122 ipsilateral vs 39 contralateral], 197 DCIS [174 ipsilateral vs 17 contralateral], and 16 of unknown invasiveness or laterality) breast cancers were diagnosed. Radiotherapy reduced the incidence of all new breast events (hazard ratio [HR] 0·41, 95% CI 0·30-0·56; p<0·0001), reducing the incidence of ipsilateral invasive disease (0·32, 0·19-0·56; p<0·0001) as well as ipsilateral DCIS (0·38, 0·22-0·63; p<0·0001), but having no effect on contralateral breast cancer (0·84, 0·45-1·58; p=0·6). Tamoxifen reduced the incidence of all new breast events (HR 0·71, 95% CI 0·58-0·88; p=0·002), reducing recurrent ipsilateral DCIS (0·70, 0·51-0·86; p=0·03) and contralateral tumours (0·44, 0·25-0·77; p=0·005), but having no effect on ipsilateral invasive disease (0·95, 0·66-1·38; p=0·8). No data on adverse events except cause of death were collected for this trial.

INTERPRETATION

This updated analysis confirms the long-term beneficial effect of radiotherapy and reports a benefit for tamoxifen in reducing local and contralateral new breast events for women with DCIS treated by complete local excision.

FUNDING

Cancer Research UK and the Australian National Health and Medical Research Council.

Molecular diversity in ductal carcinoma in situ (DCIS) and early invasive breast cancer

Ductal carcinoma in situ (DCIS) is a non-invasive form of breast cancer where cells restricted to the ducts exhibit an atypical phenotype. Some DCIS lesions are believed to rapidly transit to invasive ductal carcinomas (IDCs), while others remain unchanged. Existing classification systems for DCIS fail to identify those lesions that transit to IDC. We studied gene expression patterns of 31 pure DCIS, 36 pure invasive cancers and 42 cases of mixed diagnosis (invasive cancer with an in situ component) using Agilent Whole Human Genome Oligo Microarrays 44k. Six normal breast tissue samples were also included as controls. qRT-PCR was used for validation. All DCIS and invasive samples could be classified into the "intrinsic" molecular subtypes defined for invasive breast cancer. Hierarchical clustering establishes that samples group by intrinsic subtype, and not by diagnosis. We observed heterogeneity in the transcriptomes among DCIS of high histological grade and identified a distinct subgroup containing seven of the 31 DCIS samples with gene expression characteristics more similar to advanced tumours. A set of genes independent of grade, ER-status and HER2-status was identified by logistic regression that univariately classified a sample as belonging to this distinct DCIS subgroup. qRT-PCR of single markers clearly separated this DCIS subgroup from the other DCIS, and contains samples from several histopathological and intrinsic molecular subtypes. The genes that differentiate between these two types of DCIS suggest several processes related to the re-organisation of the microenvironment. This raises interesting possibilities for identification of DCIS lesions both with and without invasive characteristics, which potentially could be used in clinical assessment of a woman's risk of progression, and lead to improved management that would avoid the current over- and under-treatment of patients.

Aromatase and in situ estrogen production in DCIS (ductal carcinoma in situ) of human breast

Ductal carcinoma in situ or DCIS belongs to intraductal proliferative lesions, which are a group of cytologically and architecturally diverse ductal proliferations, typically originating from the terminal duct-lobular units. In these intraductal proliferative diseases, estrogens are considered to be involved in the progression of the disease especially from ductal non-neoplastic hyperplasia to DCIS and possibly development of invasive carcinoma from DCIS. Estrogen receptor (ER) alpha is abundantly expressed in atypical ductal hyperplasia and low grade DCIS. Suppression of estrogenic actions using tamoxifen resulted in inhibition of recurrence of DCIS and/or of progression into invasive carcinoma. Intratumoral estrogen concentration in DCIS determined by liquid chromatography/electrospray tandem mass spectrometry is significantly higher than that in non-neoplastic breast tissues with statistically not lower than that in invasive carcinoma. Aromatase mRNA expression in both stromal and parenchymal cells of DCIS determined by quantitative RT-PCR following laser capture microdissection was also much higher than that in non-neoplastic breast, although lower than that in invasive carcinoma. Immunohistochemistry of aromatase also revealed the similar patterns of immunolocalization as in invasive carcinoma. Aromatase is overexpressed in noninvasive breast malignancies including DCIS and results in elevated concentrations of intratumoral estradiol. These findings could provide the scientific rationale as to employing aromatase inhibitors in the management of ER positive DCIS patients.

Mesotrypsin promotes malignant growth of breast cancer cells through shedding of CD109

Serine proteases have been implicated in many stages of cancer development, facilitating tumor cell growth, invasion, and metastasis, and naturally occurring serine protease inhibitors have shown promise as potential anticancer therapeutics. Optimal design of inhibitors as potential therapeutics requires the identification of the specific serine proteases involved in disease progression and the functional targets responsible for the tumor-promoting properties. Here, we use the HMT-3522 breast cancer progression series grown in 3D organotypic culture conditions to find that serine protease inhibitors cause morphological reversion of the malignant T4-2 cells, assessed by inhibition of proliferation and formation of acinar structures with polarization of basal markers, implicating serine protease activity in their malignant growth behavior. We identify PRSS3/mesotrypsin upregulation in T4-2 cells as compared to their nonmalignant progenitors, and show that knockdown of PRSS3 attenuates, and treatment with recombinant purified mesotrypsin enhances, the malignant growth phenotype. Using proteomic methods, we identify CD109 as the functional proteolytic target of mesotrypsin. Our study identifies a new mediator and effector of breast cancer growth and progression.

Current status of treatment for early-stage invasive breast cancer

Az emlőrák a nők leggyakoribb rákos megbetegedése. Évente több mint egymillió nő betegszik meg emlőrákban. Az emlőrákos morbiditás meredeken emelkedett a fejlett ipari országokban az utóbbi pár évtizedben, de a mortalitási ráta mostanában csökken. Az utóbbi a szervezett lakossági szűréseknek, a korszerű sebészi és sugárterápiás beavatkozásoknak és a hatékonyabb szisztémás kezeléseknek köszönhető. A fejlődés egyik legizgalmasabb területe az új terápiás szerek bevezetése a klinikai gyakorlatba. A célzott terápia (tirozinkinázok gátlása) rohamosan fejlődik. Korai (0./I./II. stádium) emlőrákban a daganatot műtéttel eltávolítják, és ezt követi az adjuváns kezelés. Az adjuváns kezelés célja a lokoregionális és távoli mikroszkopikus daganatdepozitok elpusztítása. A daganatos kiújulás kockázatának megbecsülésére prognosztikai faktorokat használunk. Az optimális individualizált kezelés meghatározását a prediktív faktorok segítik. A dolgozatban a korai emlőrák kezelésének jelenlegi helyzetét tárgyaljuk, beleértve az emlőmegtartó kezelést, a mastectomia utáni sugárkezelést, a hormon- és kemoterápiát, valamint a humán epidermális növekedési faktor receptor-2- (HER-2-) pozitív daganatok trastuzumabkezelését.

Quality aspects of the tissue microarray technique in a population-based cohort with ductal carcinoma in situ of the breast

AIMS

Tissue microarray (TMA) is an efficient technique for analysis of molecular markers. Prospectively collected samples have been reported to give excellent concordance between TMA data and corresponding whole-sections. The aim was to evaluate the usefulness of TMA in a population-based cohort of 213 women with ductal carcinoma in situ of the breast (DCIS).

METHODS AND RESULTS

We studied immunohistochemical HER2, oestrogen (ER) and progesterone (PR) receptor status. The prognostic impact was similar for all markers comparing whole sections and TMAs. The proportion of positive tumours was similar regarding HER2 and ER, whereas PR tumours were more frequently positive in the TMAs (P = 0.007). The concordance was 80% (kappa value 0.63) between original sections and TMAs. The proportion of successfully analysed tumours was 70%. Smaller tumours had a lower ratio (P < 0.0001) and a larger proportion of mismatched results (P = 0.05).

CONCLUSIONS

Retrospective analyses of tumours from cohorts with long-term follow-up are indispensable. We have shown that the TMA technique is a useful tool for high-throughput analysis of DCIS. However, our study has pinpointed some technical hazards within a population-based cohort, including many small lesions and the poor condition of some donor blocks. Mismatched results may be due to tumour heterogeneity.

Concomitant expression of the chemokines RANTES and MCP-1 in human breast cancer: a basis for tumor-promoting interactions

The chemokines RANTES (CCL5) and MCP-1 (CCL2) were suggested to contribute, independently, to breast malignancy. In the present study, we asked if the two chemokines are jointly expressed in clinical samples of breast cancer patients, and do they interact in breast tumor cells. We found that RANTES and MCP-1 were expressed by breast tumor cells in primary tumors of Ductal Carcinoma In Situ and of Invasive Ductal Carcinoma, but minimally in normal breast epithelial duct cells. The chemokines were also detected in metastases and pleural effusions. Novel findings showed that co-expression of RANTES and MCP-1 in the same tumor was associated with more advanced stages of disease, suggesting that breast tumors "benefit" from interactions between the two chemokines. Accordingly, MCP-1 significantly promoted the release of RANTES from endogenous pre-made vesicles, in an active process that depended on calcium from intracellular and extracellular sources, and on intracellular transport of RANTES towards exocytosis. Our findings show a chemokine-triggered release of stored pro-malignancy chemokine from breast tumor cells. These observations support a major tumor-promoting role for co-expression of the chemokines in breast malignancy, and agree with the significant association of joint RANTES and MCP-1 expression with advanced stages of breast cancer.

[Combined surgery and radiotherapy in the treatment of ductal carcinoma in situ of the breast: preliminary results of the Hungarian multicenter prospective randomised study]

The aim of this work is to report the preliminary results of the Hungarian multicentric randomised DCIS study. Between 2000 and 2007, 278 patients with ductal carcinoma in situ (DCIS) treated by breast-conserving surgery were randomised according to predetermined risk groups. Low/intermediate-risk patients (n=29) were randomised to 50 Gy whole-breast irradiation (WBI) or observation. High-risk cases (n=235) were allocated to receive 50 Gy WBI vs. 50 Gy WBI plus 16 Gy tumour bed boost. Very high-risk patients (patients with involved surgical margins; n=14) were randomised to 50 Gy WBI plus 16 Gy tumour bed boost or reoperation (reexcision plus radiotherapy or mastectomy alone). Immunohistochemistry (IHC) was performed to detect the expression of potential molecular prognostic markers (ER, PR, Her2, p53, Bcl-2 and Ki-67). At a median follow-up of 36 months no recurrence was observed in the low/intermediate- and very high-risk patient groups. In the high-risk group, 4 (1.7%) local recurrences and 1 (0.4%) distant metastasis occurred. No patient died of breast cancer. In the high-risk group of patients, the 3- and 5-year probability of local recurrence was 1.1% and 3.1%, respectively. The positive immunostaining for Her2 (38%), p53 (37%) and Ki-67 (44%) correlated with a high nuclear grade. Significant inverse correlation was found between the expression of ER (77%), PR (67%), Bcl-2 (64%) and grade. Preliminary results suggest that breast-conserving surgery followed by radiotherapy yields an annual local recurrence rate of less than 1% in patients with DCIS. IHC of molecular prognostic markers can assist to gain insight into the biologic heterogeneity of DCIS.

In situ production of sex steroids in human breast carcinoma

It is well known that sex steroids are closely involved in the growth of human breast carcinomas, and the great majority of breast carcinomas express sex steroid receptors. In particular, recent studies have demonstrated that estrogens and androgens are locally produced and act in breast carcinoma tissues without release into plasma. Blockade of intratumoral estrogen production potentially leads to an improvement in the prognosis of invasive breast carcinoma patients, and, therefore, it is important to obtain a better understanding of sex steroid-producing enzymes in breast carcinoma. In this review, we summarize recent studies on tissue concentration of sex steroids and expression of enzymes related to intratumoral production of estrogens [aromatase, steroid sulfatase (STS), and 17beta-hydroxysteroid dehydrogenase type 1 (17betaHSD1)], and androgens (17betaHSD5 and 5alpha-reductase) in invasive and in situ (noninvasive) breast carcinomas, and discuss the significance of intratumoral production of sex steroids in breast carcinoma.

Surgical management of breast cancer

Breast cancer treatment outcomes have improved as a result of early detection and multidisciplinary treatment approaches. Treatment options continue to expand as understanding increases regarding the relationship between disease burden, biology, and outcome. In this article we present the current principles and challenges that face the clinician who is treating breast disease. Better understanding of the biology of high-risk lesions and the significance of minimal metastatic disease permits better treatment. Advances in reconstructive surgery, continued refinement of resection techniques, and the management of less common presentations of breast cancer are presented.

National Breast Cancer Audit: ductal carcinoma in situ management in Australia and New Zealand

BACKGROUND

Ductal carcinoma in situ (DCIS) is a significant issue in Australia and New Zealand with rising incidence because of the implementation of mammographic screening. Current information on its natural history is unable to accurately predict progression to invasive cancer. In 2003, the National Breast Cancer Centre in Australia published recommendations for DCIS. In Australia and New Zealand, the National Breast Cancer Audit collects information on DCIS cases. This article will examine these recommendations and provide information from the audit on current DCIS management.

METHODS

Three thousand six hundred and twenty-nine cases of DCIS were entered by 274 breast surgeons between January 1998 and December 2004. Data items in the National Breast Cancer Audit database that were covered in the National Breast Cancer Centre recommendations were reviewed. Information was available on the following: diagnostic biopsy rates for all cases and mammographically positive cases and rates of breast conserving surgery (BCS), clear margins following BCS, postoperative radiotherapy following BCS for groups at high risk of recurrence as well as axillary procedures and tamoxifen prescription.

RESULTS

Close adherence was found in diagnostic biopsy, BCS and clear margin rates. Some high-risk groups received radiotherapy, although women with 'close' margins did not in 33% of cases. Axillary procedures were conducted in 23% of cases and most (81%) patients were not prescribed tamoxifen.

CONCLUSION

There was predominantly close adherence to recommendations with three possible areas of improvement: fewer axillary procedures, an appraisal of radiotherapy practice following BCS and more investigation into tamoxifen prescription practices for DCIS.

Selective estrogen receptor modulators inhibit growth and progression of premalignant lesions in a mouse model of ductal carcinoma in situ

Introduction

Ductal carcinoma in situ (DCIS) is a noninvasive premalignant lesion and is considered a precursor to invasive carcinoma. DCIS accounts for nearly 20% of newly diagnosed breast cancer, but the lack of experimentally amenable in vivo DCIS models hinders the development of treatment strategies. Here, we demonstrate the utility of a mouse transplantation model of DCIS for chemoprevention studies using selective estrogen receptor modulators (SERMs). This model consists of a set of serially transplanted lines of genetically engineered mouse mammary intraepithelial neoplasia (MIN) outgrowth (MIN-O) tissue that have stable characteristics. We studied the ovarian-hormone-responsiveness of one of the lines with a particular focus on the effects of two related SERMs, tamoxifen and ospemifene.

Methods

The estrogen receptor (ER) status and ovarian-hormone-dependence of the mouse MIN outgrowth tissue were determined by immunohistochemistry and ovarian ablation. The effects of tamoxifen and ospemifene on the growth and tumorigenesis of MIN outgrowth were assessed at 3 and 10 weeks after transplantation. The effects on ER status, cell proliferation, and apoptosis were studied with immunohistochemistry.

Results

The MIN-O was ER-positive and ovarian ablation resulted in reduced MIN-O growth and tumor development. Likewise, tamoxifen and ospemifene treatments decreased the MIN growth and tumor incidence in comparison with the control (P < 0.01). Both SERMs significantly decreased cell proliferation. Between the two SERM treatment groups, there were no statistically significant differences in MIN-O size, tumor latency, or proliferation rate. In contrast, the ospemifene treatment significantly increased ER levels while tamoxifen significantly decreased them.

Conclusion

Tamoxifen and ospemifene inhibit the growth of premalignant mammary lesions and the progression to invasive carcinoma in a transplantable mouse model of DCIS. The inhibitory effects of these two SERMs are similar except for their effects on ER modulation. These differences in ER modulation may suggest different mechanisms of action between the two related SERMs and may portend different long-term outcomes. These data demonstrate the value of this model system for preclinical testing of antiestrogen or other therapies designed to prevent or delay the malignant transformation of premalignant mammary lesions in chemoprevention.