Prognosis by breast cancer subtypes in patients treated with adjuvant chemotherapy in a clinical trial

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Background: Breast cancer can be classified into molecular subtypes that have distinct survival patterns. The purpose of this study was i) to evaluate the prognostic significance of breast cancer subtypes in a cohort of women taking part in the NEAT and BR9601 clinical trials comparing CMF with ECMF, and ii) to evaluate whether the subtypes were predictive of the added benefit of epirubicin in these trials.

Methods: Tumor tissue microarrays were stained and scored for ER, PR, HER2, EGFR and CK5/6. These were used to classify the tumors into six intrinsic subtypes (1). We used Cox regression to compare overall survival (OS), breast cancer specific survival (BSS) and relapse free survival (RFS) in the different subgroups. We also compared the effect of ECMF with CMF by subgroup.

Results: IHC data were available for 1725 cases of whom 805 were Luminal 1-basal negative, 153 were Luminal 1-basal positive, 174 were Luminal 2, 192 were HER2-like, 230 were core basal phenotype and 171 were 5-negative phenotype. Median follow-up time was 7 years. The prognostic effects of the subtypes were similar to those reported for unselected breast cancer cases irrespective of adjuvant therapy (Blows FM, et al. PLoS Med 2010;75:e1000279.). In particular, the luminal 1-basal negative tumors were associated with the best prognosis in five years after surgery and the HER2-like tumors were associated with the poorest prognosis. ECMF has previously shown to be associated with a 33% relative risk reduction for OS compared to CMF (Poole CJ et al. N Engl J Med 2006;35518:1851-62.). There was little evidence for significant heterogeneity of effect by tumor subtype for any end point (OS P= 0.40, BSS P=0.53 RFS P=0.50). However, there was an observed trend towards the largest additional benefit from ECMF being in women with tumors of the 5-negative phenotype (OS HR=0.39 95% CI 0.21-0.73) and the smallest being in Luminal 1-basal negative tumors (OS HR=0.86 95% CI 0.64-1.16).

Conclusions: In a clinical trial in which all patients received chemotherapy, we confirmed that breast cancer subtypes show distinct behaviour with differences in short and long term survival. The benefit of ECMF over CMF was statistically similar in all disease subtypes.

Low penetrance breast cancer susceptibility loci are associated with specific breast tumor subtypes: findings from the Breast Cancer Association Consortium

Breast cancers demonstrate substantial biological, clinical and etiological heterogeneity. We investigated breast cancer risk associations of eight susceptibility loci identified in GWAS and two putative susceptibility loci in candidate genes in relation to specific breast tumor subtypes. Subtypes were defined by five markers (ER, PR, HER2, CK5/6, EGFR) and other pathological and clinical features. Analyses included up to 30 040 invasive breast cancer cases and 53 692 controls from 31 studies within the Breast Cancer Association Consortium. We confirmed previous reports of stronger associations with ER+ than ER- tumors for six of the eight loci identified in GWAS: rs2981582 (10q26) (P-heterogeneity = 6.1 × 10(-18)), rs3803662 (16q12) (P = 3.7 × 10(-5)), rs13281615 (8q24) (P = 0.002), rs13387042 (2q35) (P = 0.006), rs4973768 (3p24) (P = 0.003) and rs6504950 (17q23) (P = 0.002). The two candidate loci, CASP8 (rs1045485, rs17468277) and TGFB1 (rs1982073), were most strongly related with the risk of PR negative tumors (P = 5.1 × 10(-6) and P = 4.1 × 10(-4), respectively), as previously suggested. Four of the eight loci identified in GWAS were associated with triple negative tumors (P ≤ 0.016): rs3803662 (16q12), rs889312 (5q11), rs3817198 (11p15) and rs13387042 (2q35); however, only two of them (16q12 and 2q35) were associated with tumors with the core basal phenotype (P ≤ 0.002). These analyses are consistent with different biological origins of breast cancers, and indicate that tumor stratification might help in the identification and characterization of novel risk factors for breast cancer subtypes. This may eventually result in further improvements in prevention, early detection and treatment.

Comparison of methods for handling missing data on immunohistochemical markers in survival analysis of breast cancer

BACKGROUND

Tissue micro-arrays (TMAs) are increasingly used to generate data of the molecular phenotype of tumours in clinical epidemiology studies, such as studies of disease prognosis. However, TMA data are particularly prone to missingness. A variety of methods to deal with missing data are available. However, the validity of the various approaches is dependent on the structure of the missing data and there are few empirical studies dealing with missing data from molecular pathology. The purpose of this study was to investigate the results of four commonly used approaches to handling missing data from a large, multi-centre study of the molecular pathological determinants of prognosis in breast cancer.

PATIENTS AND METHODS

We pooled data from over 11,000 cases of invasive breast cancer from five studies that collected information on seven prognostic indicators together with survival time data. We compared the results of a multi-variate Cox regression using four approaches to handling missing data - complete case analysis (CCA), mean substitution (MS) and multiple imputation without inclusion of the outcome (MI-) and multiple imputation with inclusion of the outcome (MI+). We also performed an analysis in which missing data were simulated under different assumptions and the results of the four methods were compared.

RESULTS

Over half the cases had missing data on at least one of the seven variables and 11 percent had missing data on 4 or more. The multi-variate hazard ratio estimates based on multiple imputation models were very similar to those derived after using MS, with similar standard errors. Hazard ratio estimates based on the CCA were only slightly different, but the estimates were less precise as the standard errors were large. However, in data simulated to be missing completely at random (MCAR) or missing at random (MAR), estimates for MI+ were least biased and most accurate, whereas estimates for CCA were most biased and least accurate.

CONCLUSION

In this study, empirical results from analyses using CCA, MS, MI- and MI+ were similar, although results from CCA were less precise. The results from simulations suggest that in general MI+ is likely to be the best. Given the ease of implementing MI in standard statistical software, the results of MI+ and CCA should be compared in any multi-variate analysis where missing data are a problem.

BCL2 in breast cancer: a favourable prognostic marker across molecular subtypes and independent of adjuvant therapy received

BACKGROUND

Breast cancer is heterogeneous and the existing prognostic classifiers are limited in accuracy, leading to unnecessary treatment of numerous women. B-cell lymphoma 2 (BCL2), an antiapoptotic protein, has been proposed as a prognostic marker, but this effect is considered to relate to oestrogen receptor (ER) status. This study aimed to test the clinical validity of BCL2 as an independent prognostic marker.

METHODS

Five studies of 11 212 women with early-stage breast cancer were analysed. Individual patient data included tumour size, grade, lymph node status, endocrine therapy, chemotherapy and mortality. BCL2, ER, progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) levels were determined in all tumours. A Cox model incorporating the time-dependent effects of each variable was used to explore the prognostic significance of BCL2.

RESULTS

In univariate analysis, ER, PR and BCL2 positivity was associated with improved survival and HER2 positivity with inferior survival. For ER and PR this effect was time dependent, whereas for BCL2 and HER2 the effect persisted over time. In multivariate analysis, BCL2 positivity retained independent prognostic significance (hazard ratio (HR) 0.76, 95% confidence interval (CI) 0.66-0.88, P<0.001). BCL2 was a powerful prognostic marker in ER- (HR 0.63, 95% CI 0.54-0.74, P<0.001) and ER+ disease (HR 0.56, 95% CI 0.48-0.65, P<0.001), and in HER2- (HR 0.55, 95% CI 0.49-0.61, P<0.001) and HER2+ disease (HR 0.70, 95% CI 0.57-0.85, P<0.001), irrespective of the type of adjuvant therapy received. Addition of BCL2 to the Adjuvant! Online prognostic model, for a subset of cases with a 10-year follow-up, improved the survival prediction (P=0.0039).

CONCLUSIONS

BCL2 is an independent indicator of favourable prognosis for all types of early-stage breast cancer. This study establishes the rationale for introduction of BCL2 immunohistochemistry to improve prognostic stratification. Further work is now needed to ascertain the exact way to apply BCL2 testing for risk stratification and to standardise BCL2 immunohistochemistry for this application.

Subtyping of breast cancer by immunohistochemistry to investigate a relationship between subtype and short and long term survival: a collaborative analysis of data for 10,159 cases from 12 studies

BACKGROUND

Immunohistochemical markers are often used to classify breast cancer into subtypes that are biologically distinct and behave differently. The aim of this study was to estimate mortality for patients with the major subtypes of breast cancer as classified using five immunohistochemical markers, to investigate patterns of mortality over time, and to test for heterogeneity by subtype.

METHODS AND FINDINGS

We pooled data from more than 10,000 cases of invasive breast cancer from 12 studies that had collected information on hormone receptor status, human epidermal growth factor receptor-2 (HER2) status, and at least one basal marker (cytokeratin [CK]5/6 or epidermal growth factor receptor [EGFR]) together with survival time data. Tumours were classified as luminal and nonluminal tumours according to hormone receptor expression. These two groups were further subdivided according to expression of HER2, and finally, the luminal and nonluminal HER2-negative tumours were categorised according to expression of basal markers. Changes in mortality rates over time differed by subtype. In women with luminal HER2-negative subtypes, mortality rates were constant over time, whereas mortality rates associated with the luminal HER2-positive and nonluminal subtypes tended to peak within 5 y of diagnosis and then decline over time. In the first 5 y after diagnosis the nonluminal tumours were associated with a poorer prognosis, but over longer follow-up times the prognosis was poorer in the luminal subtypes, with the worst prognosis at 15 y being in the luminal HER2-positive tumours. Basal marker expression distinguished the HER2-negative luminal and nonluminal tumours into different subtypes. These patterns were independent of any systemic adjuvant therapy.

CONCLUSIONS

The six subtypes of breast cancer defined by expression of five markers show distinct behaviours with important differences in short term and long term prognosis. Application of these markers in the clinical setting could have the potential to improve the targeting of adjuvant chemotherapy to those most likely to benefit. The different patterns of mortality over time also suggest important biological differences between the subtypes that may result in differences in response to specific therapies, and that stratification of breast cancers by clinically relevant subtypes in clinical trials is urgently required.

Predictive markers of anthracycline benefit: a prospectively planned analysis of the UK National Epirubicin Adjuvant Trial (NEAT/BR9601)

BACKGROUND

The NEAT/BR9601 trial showed benefit for addition of anthracyclines to cyclophosphamide, methotrexate, and fluorouracil (CMF) as adjuvant treatment for early breast cancer. We investigated prospectively predictive biomarkers of anthracycline benefit including HER2 and TOP2A.

METHODS

1941 tumours from 2391 women recruited to NEAT/BR9601 were analysed on tissue microarrays for HER2 and TOP2A amplification and deletion, HER1-3 and Ki67 expression, and duplication of chromosome 17 centromere enumeration probe (Ch17CEP). Log-rank analyses identified factors affecting relapse-free and overall survival, and regression models tested independent prognostic effect of markers, with adjustment for known prognostic factors (age, nodal status, oestrogen-receptor status, grade, and tumour size). The predictive value of markers was tested by treatment interactions for relapse-free and overall survival.

FINDINGS

1762 patients were analysed. 21% of tumours (n=367) were HER2 amplified, 10% were TOP2A amplified (n=169), 11% showed TOP2A deleted (n=191), 23% showed Ch17CEP duplication (n=406), and 61% had high (>13.0%) Ki67 (n=1136). In univariate analyses, only HER2 amplification and TOP2A deletion were significant prognostic factors for relapse-free (hazard ratio [HR] 1.59, 95% CI 1.32-1.92, p<0.0001; and 1.52, 1.20-1.92, p=0.0006, respectively) and overall survival (1.79, 1.47-2.19, p<0.0001; and 1.62, 1.26-2.08, p=0.0002 respectively). We detected no significant interaction with anthracycline benefit for Ki67, HER2, HER1-3, or TOP2A. By contrast, in multivariate analyses, Ch17CEP duplication was associated with significant improvements in both relapse-free (HR 0.92, 95% CI 0.72-1.18 for tumours with normal Ch17CEP vs 0.52, 0.34-0.81 for tumours with abnormal Ch17CEP; p for interaction=0.004) and overall survival (0.94, 0.72-1.24 vs 0.57, 0.36-0.92; p for interaction=0.02) with anthracycline use.

INTERPRETATION

In women with early breast cancer receiving adjuvant chemotherapy, the most powerful predictor of benefit from anthracyclines is Ch17CEP duplication. In view of the location of HER2/TOP2A on chromosome 17, Ch17CEP duplication might explain the inconsistencies in previous studies of factors predicting benefit from anthracyclines.

FUNDING

Cancer Research UK and the Scottish Breast Cancer Clinical Trials Group.

Familial relative risks for breast cancer by pathological subtype: a population-based cohort study

INTRODUCTION

The risk of breast cancer to first degree relatives of breast cancer patients is approximately twice that of the general population. Breast cancer, however, is a heterogeneous disease and it is plausible that the familial relative risk (FRR) for breast cancer may differ by the pathological subtype of the tumour. The contribution of genetic variants associated with breast cancer susceptibility to the subtype-specific FRR is still unclear.

METHODS

We computed breast cancer FRR for subtypes of breast cancer by comparing breast cancer incidence in relatives of breast cancer cases from a population-based series with known estrogen receptor (ER), progesterone receptor (PR) or human epidermal growth factor receptor 2 (HER2) status with that expected from the general population. We estimated the contribution to the FRR of genetic variants associated with breast cancer susceptibility using subtype-specific genotypic relative risks and allele frequencies for each variant.

RESULTS

At least one marker was measured for 4,590 breast cancer cases, who reported 9,014 affected and unaffected first-degree female relatives. There was no difference between the breast cancer FRR for relatives of patients with ER-negative (FRR = 1.78, 95% confidence intervals (CI): 1.44 to 2.11) and ER-positive disease (1.82, 95% CI: 1.67 to 1.98), P = 0.99. There was some suggestion that the breast cancer FRR for relatives of patients with ER-negative disease was higher than that for ER-positive disease for ages of the relative less than 50 years old (FRR = 2.96, 95% CI: 2.04 to 3.87; and 2.05, 95% CI: 1.70 to 2.40 respectively; P = 0.07), and that the breast cancer FRR for relatives of patients with ER-positive disease was higher than for ER-negative disease when the age of the relative was greater than 50 years (FRR = 1.76, 95% CI: 1.59 to 1.93; and 1.41, 95% CI: 1.08 to 1.74 respectively, P = 0.06). We estimated that mutations in BRCA1 and BRCA2 explain 32% of breast cancer FRR for relatives of patients with ER-negative and 9.4% of the breast cancer FRR for relatives of patients with ER-positive disease. Twelve recently identified common breast cancer susceptibility variants were estimated to explain 1.9% and 9.6% of the FRR to relatives of patients with ER-negative and ER-positive disease respectively.

CONCLUSIONS

FRR for breast cancer was significantly increased for both ER-negative and ER-positive disease. Including receptor status in conjunction with genetic status may aid risk prediction in women with a family history.

Triple negative breast cancers: clinical and prognostic implications

Triple negative breast cancers are defined by the absence of oestrogen, progesterone and HER2 expression. Most triple negative cancers display distinct clinical and pathological characteristics with a high proportion of these tumours occurring at a younger age of onset and in African-American women. Triple negative tumours typically demonstrate high histological grade and are the most common breast cancer subtype in BRCA1 carriers. In addition, many of the features of triple negative cancers are similar to those identified in the basal-like molecular subtype which has recently been characterised by gene expression profiling. Although the two groups overlap, they are not synonymous. Triple negative breast cancers are of pivotal clinical importance given the lack of therapeutic options. The prognostic significance of triple negative tumours remains unclear since the group is heterogeneous and worst prognosis seems to be mostly confined to those that express basal cytokeratins or epidermal growth factor receptor (EGFR). This review focuses on outlining the pathological, molecular, and clinical features of triple negative breast cancers, discusses its prognostic value and summarises current therapeutic approaches and future directions of research.

Terahertz pulsed spectroscopy of freshly excised human breast cancer

The complex refractive indices of freshly excised healthy breast tissue and breast cancers collected from 20 patients were measured in the range of 0.15 - 2.0 THz using a portable terahertz pulsed transmission spectrometer. Histology was performed to classify the tissue samples as healthy adipose tissue, healthy fibrous breast tissue, or breast cancers. The average complex refractive index was determined for each group and it was found that samples containing cancer had a higher refractive index and absorption coefficient. The terahertz properties of the tissues were also used to simulate the impulse response functions expected when imaging breast tissue in a reflection geometry as in terahertz pulsed imaging (TPI). Our results indicate that both TPS and TPI can be used to distinguish between healthy adipose breast tissue, healthy fibrous breast tissue and breast cancer due to the differences in the fundamental optical properties.

Neo-tAnGo: A neoadjuvant randomized phase III trial of epirubicin/cyclophosphamide and paclitaxel ± gemcitabine in the treatment of women with high-risk early breast cancer (EBC): First report of the primary endpoint, pathological complete response (pCR)

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Background: Neo-tAnGo used a 2-by-2 factorial design, addressing: (i) gemcitabine (G) in a sequential neoadjuvant chemotherapy (CT) regimen of epirubicin/cyclophosphamide (EC) and paclitaxel (T); and (ii) the sequencing of these treatment components (EC then T ± G versus T ± G then EC). Methods: Patients (Pts) with early breast cancer (T2 tumours or above) were randomised to EC then T, T then EC, EC then TG or TG then EC. All components were given x 4 cycles. (E= 90 mg/m2 day (d)1 every (q) 21d; C = 600 mg/m2 d1 q21d; T = 175 mg/m2 d1 q14d; G = 2,000 mg/m2 d1 q14d.) The primary endpoint was pCR, defined as absence of invasive disease in the breast and axillary lymph nodes. 800 pts were required to detect 10% differences in the primary endpoint pCR rates, at the 5% (2-sided) significance level with 85% power. Stratification was by age, inflammatory/locally advanced disease, tumour size, clinical involvement of axillary nodes and oestrogen receptor (ER) status. Results: Between January 2005 and September 2007, 831 pts were randomised by 88 consultants from 57 UK centres. Characteristics were balanced across groups: 63% <50 years old, 25% had inflammatory and/or locally advanced disease, 79% of tumours <50 mm, 50% node positive and 34% ER negative. Two-reader review of 813 (98%) eligible pts'. pathology reports, blinded to treatment arm, were carried out. pCR rates were 17% (95% CI 14–21) for EC&T pts and 17% (95% CI 14–21) for EC&TG pts (p = 0.98). However the sequence T±G then EC, showed pCR of 20% (95% CI 16–24) compared with 15% (95% CI 11–18) for EC then T±G pts (p = 0.03). Adjustment by stratification did not alter results. Conclusions: The Neo-tAnGo results confirm those of the adjuvant tAnGo trial in terms of gemcitabine effect (ASCO 2008). The sequence of T±G-first has demonstrated a significant advantage in pCR compared with the more conventional anthracycline-first sequencing.

[Table: see text]

Sentinel lymph node biopsy (SLNB) prior to primary chemotherapy (PC) in breast cancer patients

Abstract #5111

Background: Lymph node status is the single most important determinant of prognosis and is used for planning adjuvant therapy. Patient selection and timing of SLNB for PC continue to evolve; SLNB prior to PC may allow more accurate initial staging and prognostication and guide decisions about adjuvant treatment.&#x2028; Methods: 78 patients (pts) who were treated in the Cambridge Breast Unit as part of Neo-tAnGo (a multicentre PC trial). 57 were identified as potentially suitable for SLNB pre-PC (clinically node negative, non-inflammatory tumours 2–5cm in size). 38 had axillary ultrasound, and of these, 18 had sonographically suspicious nodes. 12/18 had confirmed nodal metastasis on core biopsy (CB) and had direct ALND post-PC. The remaining 20 patients had innocent nodes or were CB negative, of whom 19 underwent SLNB. A total of 19 patients in this subgroup did not undergo axillary ultrasound; 16 of these proceeded to ALND post-PC and 3 to SLN biopsy pre-PC according to unit policy at the time. A total of 22 (19 + 3) pts were available for analysis of SLN biopsy pre-PC in terms of time to treatment compared to the remainder of the centre's cohort in the Neo-tAnGo study. 42, (22 SLNB + 20 node positive on CB), were analysed as having axillary pathological staging before PC and compared to the other patient cohort on study.&#x2028; Results: The SLN was successfully identified in all 22 pts using dual localisation techniques with a mean SLN harvest of 2.8 nodes per patient (range 1–10). 6/22 pts (27%) were node positive, and 5 had single SLN involvement (4 macro-; 1 micro-) and one had a macro- and a micrometastasis in 2 different nodes. The mean time from diagnosis to start of PC in the SLN group was 23 days (range 8–43) compared 18 days (range 7–36) for the comparator cohort on study (p=0.02). When all 42 pts with pathological axillary assessment were analysed (including clinically node positive pts with tumours &gt;5cm), there was no significant difference in time from diagnosis to start of PC for pts undergoing CB and/or SLNB (21 days) compared with no axillary assessment (17 days) (wilcoxon test p=0.10). The mean number of nodes removed on completion ALND was 9 (range 4–16). There was no evidence of any viable tumour or fibrosis in any of the non-SLN's (NSLN) examined. Amongst the group of 18 ultrasound/CB positive pts who underwent ALND without SLNB, nodal disease was found in 9 (50%) with evidence of pathological downstaging in 4 (22%).&#x2028; Conclusion: There is potential loss of staging information when SLNB is performed after PC and the clinical significance of a negative SLNB result in this setting is uncertain. A combination of axillary ultrasound (with CB) and SLNB can more accurately stage the axilla without significant overall delays in commencement of PC for clinically node positive and negative pts. Downstaging of disease in NLSN may occur in response to PC with a lower NSLN rate (0%) when compared to primary surgical treatment in smaller tumours (15–25%).

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5111.

A model for predicting non-sentinel lymph node metastatic disease when the sentinel lymph node is positive

BACKGROUND

Women with axillary sentinel lymph node (SLN)-positive breast cancer usually undergo completion axillary lymph node dissection (ALND). However, not all patients with positive SLNs have further axillary nodal disease. Therefore, in the patients with low risk of further disease, completion ALND could be avoided. The Memorial Sloan-Kettering Cancer Center (MSKCC) developed a nomogram to estimate the risk of non-SLN disease. This study critically appraised the nomogram and refined the model to improve predictive accuracy.

METHODS

The MSKCC nomogram was applied to 118 patients with a positive axillary SLN biopsy who subsequently had completion ALND. Predictive accuracy was assessed by calculating the area under the receiver-operator characteristic (ROC) curve. A further predictive model was developed using more detailed pathological information. Backward stepwise multiple logistic regression was used to develop the predictive model for further axillary lymph node disease. This was then converted to a probability score. After k-fold cross-validation within the data, an inverse variance weighted mean ROC curve and area below the ROC curve was calculated.

RESULTS

The MSKCC nomogram had an area under the ROC curve of 68 per cent. The revised predictive model showed the weighted mean area under the ROC curve to be 84 per cent.

CONCLUSION

The modified predictive model, which incorporated size of SLN metastasis, improved predictive accuracy, although further testing on an independent data set is desirable.

Regulation of p53 tetramerization and nuclear export by ARC

Inactivation of the transcription factor p53 is central to carcinogenesis. Yet only approximately one-half of cancers have p53 loss-of-function mutations. Here, we demonstrate a mechanism for p53 inactivation by apoptosis repressor with caspase recruitment domain (ARC), a protein induced in multiple cancer cells. The direct binding in the nucleus of ARC to the p53 tetramerization domain inhibits p53 tetramerization. This exposes a nuclear export signal in p53, triggering Crm1-dependent relocation of p53 to the cytoplasm. Knockdown of endogenous ARC in breast cancer cells results in spontaneous tetramerization of endogenous p53, accumulation of p53 in the nucleus, and activation of endogenous p53 target genes. In primary human breast cancers with nuclear ARC, p53 is almost always WT. Conversely, nearly all breast cancers with mutant p53 lack nuclear ARC. We conclude that nuclear ARC is induced in cancer cells and negatively regulates p53.

Laboratory handling and histology reporting of breast specimens from patients who have received neoadjuvant chemotherapy

Neoadjuvant chemotherapy is increasingly being offered to patients with invasive breast carcinoma but surgical excision specimens following such therapy may be difficult to interpret in the pathology laboratory, both macroscopically and histologically. We provide here some guidelines for handling such postneoadjuvant chemotherapy samples and describe the histopathological features which may be encountered in both the breast and lymph nodes received. We also present a brief review of the literature and suggest a simple method for quantifying the degree of response to neoadjuvant chemotherapy in both the primary breast carcinoma and the lymph nodes.

Lobular in situ neoplasia and columnar cell lesions: diagnosis in breast core biopsies and implications for management

Histopathologists are encountering intra-lobular epithelial proliferations more frequently in core biopsies taken from lesions identified in mammographic breast screening programmes. In particular, columnar cell lesions are increasingly being seen in core biopsies taken for the histological assessment of mammographically detected microcalcifications. The morphological features of lobular neoplasia are relatively well known, but columnar cell lesions, particularly forms with atypical features, are less widely recognised. The biological and clinical significance of both of these intra-lobular processes is controversial, (1) as indicators of adjacent malignancy when encountered in core biopsy, (2) the relative risk conferred of development of subsequent malignancy, and (3) their precursor behaviour. For this reason, the optimal clinical management of these lesions, particularly when encountered on core biopsy, is unclear. This review provides an update on the histological diagnosis of lobular neoplasia and columnar cell lesions and outlines recent clinico-pathological and molecular findings with discussion on clinical management.

Phenotype-directed analysis of genotype in early-onset, familial breast cancers

Considerable heterogeneity of morphology and disease outcome exists within breast cancers (BC), which likely reflects variable molecular pathogeneses within this broad clinical group.

AIM

To evaluate the underlying genomic alterations associated with familial, early-onset BC (EOBC) phenotypes, in order to improve the management of this disease.

METHODS

Using hierarchical clustering of morphological and immunophenotypical parameters, 116 EOBC were stratified into six groups. Conventional and array-based comparative genomic hybridisation was used to analyse the genomic alterations.

RESULTS

Specific areas of genomic imbalance were associated with individual phenotypes. The largest phenotypical group was high grade, oestrogen receptor and HER-2 negative. This group contained the majority of BRCA1 germline mutation-associated tumours and commonly showed loss of chromosomal regions 5cent-5q13, 5q14-22 and 4q28-32. High mitotic rate, an important indicator of tumour cell proliferation and poor prognosis, was associated with gain of 19p, mapped within 7 Mb of the telomere. This region contains the candidate oncogene CDC34, the protein product of which is involved in ubiquitin-mediated degradation of the cyclin-dependent kinase inhibitor, p27Kip1.

CONCLUSION

Phenotype-based analysis can be used to determine the genetic changes important in subtypes of BC. Further, the different morphological phenotypes could act as a cost-effective surrogate for genotypical stratification to facilitate optimal management of this disease.

The natural history of ductal carcinoma in situ of the breast: a review

BACKGROUND

Ductal carcinoma in situ represents about 20% of all tumours diagnosed within mammographic screening programs. The natural history of DCIS is poorly understood, as it cannot be observed directly. Estimates of the proportion of DCIS that progress to invasive cancer, as well as factors that may influence progression, are important for clinical management. Here we review various sources of evidence regarding the natural history of DCIS.

METHODS

We identified relevant publications of studies on: follow-up studies of DCIS initially misdiagnosed as benign, studies of recurrence of DCIS as invasive cancer, autopsy studies, studies of risk factors for DCIS, animal studies and studies that used mathematical models to study growth of DCIS and invasive cancer. Data sources included the MEDLINE data base, searches of articles cited in key reviews and editorials.

RESULTS

The most direct evidence regarding the progression of DCIS to invasive cancer comes from studies where DCIS was initially misdiagnosed as benign and treated by biopsy alone. These studies suggest that between 14-53% of DCIS may progress to invasive cancer over a period of 10 or more years. The reported prevalence of undiagnosed DCIS in autopsy studies, of approximately 9%, has been used to suggest a larger reservoir of DCIS may exist in the population. All types of study designs reviewed had limitations that may bias the estimate of progression in either direction.

CONCLUSION

The available evidence suggests not all DCIS will progress to invasive cancer in the medium term but precise estimates of progression are not possible given the limitations of the data. Mathematical modelling of various scenarios of progression and studies of genetic factors involved in progression may shed further light on the natural history of DCIS.

Transmission of Burkholderia cepacia complex: evidence for new epidemic clones infecting cystic fibrosis patients in Italy

To analyze national prevalence, genomovar distribution, and epidemiology of the Burkholderia cepacia complex in Italy, 225 putative B. cepacia complex isolates were obtained from 225 cystic fibrosis (CF) patients attending 18 CF centers. The genomovar status of these isolates was determined by a polyphasic approach, which included whole-cell protein electrophoresis and recA restriction fragment length polymorphism (RFLP) analysis. Two approaches were used to genotype B. cepacia complex isolates: BOX-PCR fingerprinting and pulsed-field gel electrophoresis (PFGE) of genomic macrorestriction fragments. A total of 208 (92%) of 225 isolates belonged to the B. cepacia complex, with Burkholderia cenocepacia as the most prevalent species (61.1%). Clones delineated by PFGE were predominantly linked to a single center; in contrast, BOX-PCR clones were composed of isolates collected either from the same center or from different CF centers and comprised multiple PFGE clusters. Three BOX-PCR clones appeared of special interest. One clone was composed of 17 B. cenocepacia isolates belonging to recA RFLP type H. These isolates were collected from six centers and represented three PFGE clusters. The presence of insertion sequence IS 1363 in all isolates and the comparison with PHDC reference isolates identified this clone as PHDC, an epidemic clone prominent in North American CF patients. The second clone included 22 isolates from eight centers and belonged to recA RFLP type AT. The genomovar status of strains with the latter RFLP type is not known. Most of these isolates belonged to four different PFGE clusters. Finally, a third clone comprised nine B. pyrrocinia isolates belonging to recA RFLP type Se 13. They represented three PFGE clusters and were collected in three CF centers.

Histological markers that predict clinical recurrence in ductal carcinoma in situ of the breast: an Australian population-based study

AIMS

The incidence of ductal carcinoma in situ (DCIS) has increased substantially since the advent of widespread screening mammography. Identification of histological markers that predict recurrent disease is essential for optimal treatment management. To assist the clinico-pathological stratification of DCIS, we sought to determine histological markers of recurrence in DCIS in an Australian population-based series.

METHODS

In a study of all DCIS reported in Victoria between 1988 and 1992, managed by breast conserving therapy (wide local excision or subtotal mastectomy) with or without adjuvant radiotherapy and/or hormonal therapy, the histological features of DCIS lesions with subsequent ipsilateral recurrence as in situ or invasive breast cancer were compared with a similarly managed control group of DCIS without recurrence.

RESULTS

Large lesion size, presence of nuclear pleomorphism, absence of cellular polarisation and extensive necrosis were all significant predictors of recurrence (P<0.05). Primary and recurrent DCIS lesions had similar morphological features, and invasive recurrence was characterised by ductal type with high nuclear grade.

CONCLUSION

This study identifies histological markers in DCIS associated with recurrence in an Australian population, and demonstrates similar histological appearances between primary and secondary lesions. These histological characteristics may be used to stratify DCIS subtypes and facilitate the future optimisation of disease management.

Biological markers that predict clinical recurrence in ductal carcinoma in situ of the breast

The optimal management of ductal carcinoma in situ (DCIS) is controversial, due in part to our poor understanding of its natural history. We undertook to identify subgroups of DCIS based on the expression of biomarkers, which were related to the likelihood of clinical recurrence. Biomarker expression of a total of 95 DCIS lesions in a nested case-control study within a population-based cohort with up to 135 months follow-up data (median 101 months) was analysed using immunohistochemistry. ERBB2-positivity and bcl-2-, oestrogen receptor (ER)- and progesterone receptor (PR)-negativity were individually associated with the risk of clinical recurrence. The predictive value of these biomarkers was independent of cytonuclear grade. ERBB2, bcl-2, ER and PR expression were conserved in the recurrent lesions, including subsequent invasive cancers. p21-positive DCIS was also associated with clinical recurrence, independently of the associations with ERBB2/bcl-2/ER/PR expression. These data identify clinically and biologically relevant subcategories of DCIS lesions, an essential basis for improving management.