Neoadjuvant letrozole for postmenopausal estrogen receptor-positive, HER2-negative breast cancer patients, a study from the Danish Breast Cancer Cooperative Group (DBCG).

INTRODUCTION: Neoadjuvant endocrine treatment (NET) is a low-toxicity approach to achieve operability in locally advanced breast cancer, and to facilitate breast conservation in early breast cancer, particular in patients with highly estrogen receptor (ER) positive and HER2-negative disease. Here, we report the results obtained by neoadjuvant letrozole in patients with early breast cancer in a phase-II design. MATERIAL AND METHODS: A total of 119 postmenopausal women with ER-positive, HER2-negative operable breast cancer were assigned to four months of neoadjuvant letrozole before definitive surgery. Sentinel node or diagnostic fine needle aspiration cytology procedure was performed prior to treatment and the women were assessed prior, at two months, and before surgery with clinical examination, mammography and ultrasonography. Surgical specimens were examined for pathological response. Primary outcome was pathological and clinical response. RESULTS: The per protocol population consisted of 112 patients. Clinical response was evaluated in 109 patients and pathological response in 108. Overall a mean decrease in tumor size was 15% (p ≤ .0001). One patient had complete pathological response and 55% of patients had partial pathological response. ER at 100%, ductal subtype, tumor size below 2 cm and lymph node-negative status was significantly associated with a better response to NET and malignancy grade 3 with a poorer response to NET. One patient progressed during treatment and received neoadjuvant chemotherapy. Eight patients received adjuvant chemotherapy due to lack of response. CONCLUSION: Neoadjuvant aromatase inhibitor therapy is an acceptable strategy in selected postmenopausal patients with ER-rich and HER2-negative early breast cancer with ductal histology and should be considered when chemotherapy either isn't indicated or feasible.

CYP19A1 polymorphisms and clinical outcomes in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1-98 trial.

To determine whether CYP19A1 polymorphisms are associated with abnormal activity of aromatase and with musculoskeletal and bone side effects of aromatase inhibitors. DNA was isolated from tumor specimens of 4861 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Tumors were genotyped for six CYP19A1 polymorphisms using PCR-based methods. Associations with breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI), musculoskeletal and bone adverse events (AEs) were assessed using Cox proportional hazards models. All statistical tests were two-sided. No association between the CYP19A1 genotypes and BCFI or DRFI was observed overall. A reduced risk of a breast cancer event for tamoxifen-treated patients with rs700518 variants was observed (BCFI CC/TC vs. TT: HR 0.53, 95 % CI 0.34-0.82, interaction P = 0.08), but not observed for letrozole-treated patients. There was an increased risk of musculoskeletal AEs for patients with rs700518 variants CC/TC versus TT (HR 1.22, 95 % CI 1.03-1.45, P = 0.02), regardless of treatment. Tamoxifen-treated patients with rs4646 variants had a reduced risk of bone AEs (AA/CA vs. CC: HR 0.76, 95 % CI 0.59-0.98), whereas an increase of minor allele (C) of rs10046 was associated with an increased risk of bone AEs (HR 1.28, 95 % CI 1.07-1.52). rs936308 variants were associated with a reduced risk of bone AEs in letrozole-treated patients (GG/GC vs. CC: HR 0.73, 95 % CI 0.54-0.99), different from in tamoxifen-treated patients (GG/GC vs. CC: HR 1.32, 95 % CI 0.92-1.90, interaction P = 0.01). CYP19A1 rs700518 variants showed associations with BCFI, DRFI, in tamoxifen treated patients and musculoskeletal AEs regardless of treatment. SNPs rs4646, rs10046, and rs936308 were associated with bone AEs.

Reevaluation of the proposed autocrine proliferative function of prolactin in breast cancer.

The pituitary hormone prolactin (PRL) has been implicated in tumourigenesis. Expression of PRL and its receptor (PRLR) was reported in human breast epithelium and breast cancer cells. It was suggested that PRL may act as an autocrine/paracrine growth factor. Here, we addressed the role of locally synthesised PRL in breast cancer. We analysed the expression of PRL in human breast cancer tumours using qPCR analysis and in situ hybridization (ISH). PRL mRNA expression was very low or undetectable in the majority of samples in three cDNA arrays representing samples from 144 breast cancer patients and in 13 of 14 breast cancer cell lines when analysed by qPCR. In accordance, PRL expression did not reach detectable levels in any of the 19 human breast carcinomas or 5 cell lines, which were analysed using a validated ISH protocol. Two T47D-derived breast cancer cell lines were stably transfected with PRL-expressing constructs. Conditioned medium from the T47D/PRL clones promoted proliferation of lactogen-dependent Nb2 cells and control T47D cells. Surprisingly, the PRL-producing clones themselves displayed a lower proliferation rate as compared to the control cells. Their PRLR protein level was reduced and the cells were no longer responsive to exogenous recombinant PRL. Taken together, these data strongly indicate that autocrine PRL signalling is unlikely to be a general mechanism promoting tumour growth in breast cancer patients.

Prognostic effect of estrogen receptor status across age in primary breast cancer.

Estrogen receptor (ER) status is considered as an important prognostic factor as well as a predictive factor for endocrine responsiveness in breast cancer. We analyzed the distribution of ER status across age and estimated variations in the prognostic impact of ER status related to patients' age and time since diagnosis. Overall, 26,944 patients with primary breast cancer diagnosed from 1989 to 2004 were included. The proportion of ER positive tumors increased over age from 51 to 82%. In multivariate analysis of overall survival, ER positive status was found to be a significantly positive prognostic factor over all age groups. This effect was limited to the first 5 years after diagnosis, RR: 2.08 (95% CI: 1.95-2.22, p < 0.0001). Overall survival during the following 5 years was slightly superior for women with ER negative tumors, RR of death: 0.89 (95% CI: 0.79-1.00, p = 0.049). Results were unchanged in patients who did not receive adjuvant systemic therapy (n = 6,272). Thus, positive ER status does not confer a negative impact on survival in young women as has been previously reported. The inferior prognosis for ER negative patients during the first 5 years after diagnosis changes into a slightly superior residual prognosis compared to ER positive patients independent of use of adjuvant systemic therapy. This may have an impact on future designing of guidelines for adjuvant endocrine therapy beyond 5 years.

Evaluation of and quality assurance in HER2 analysis in breast carcinomas from patients registered in Danish Breast Cancer Group (DBCG) in the period of 2002-2006. A nationwide study including correlation between HER-2 status and other prognostic variables.

INTRODUCTION: In Denmark, analysis for HER2 is situated in the pathology laboratories dealing with breast pathology. The analysis was introduced during the late 1990's, and was gradually intensified in the following years up to now. The present study deals with the experience with the analysis during the last 5 years, from 2002 - 2006. PATIENTS AND METHODS: All patients, registered in DBCG (Danish Breast Cancer Group) and with a HER2-test were included. The analysis followed international recommendations, with an initial immunohistochemical (IHC) analysis with a semiquantitative grading of the reaction in four grades, 0 and 1+, defined as HER2-negative, 2+, equivocal and 3+, HER2-positive. In the 2+ group, a FISH-test was applied to identify the presence of gene amplification, defined as a ratio >/=2. We investigated the number of analyses performed, the number of positive cases and the relation between the result of IHC and the result of FISH. Furthermore we looked at the relation to other prognostic factors. RESULTS: The number of analyses gradually increased during the years of investigation, from 30% of patients in 2002 to 71% in 2006. The increase was seen in all laboratories resulting in all laboratories but one having a substantial number of analyses. Sixty-two percent of all cases were HER2-negative, 18% were equivocal and 21% positive in the IHC-analysis. Of the 2+, equivocal cases, 23% had gene-amplification. Thus, 23% of patients were defined as HER2-positive and eligible for treatment with trastuzumab. There was a significant correlation to other prognostic factors. The results are in accordance with what is found elsewhere. The quality of the test is further assured by all laboratories participating in external quality assurance schemes.

Breast conserving treatment in Denmark, 1989-1998. A nationwide population-based study of the Danish Breast Cancer Co-operative Group.

BACKGROUND: Randomised studies have shown that breast conserving surgery followed by radiotherapy is associated with a prognosis similar to mastectomy alone. This formed the basis for recommending breast conserving surgery combined with radiotherapy as a standard treatment for suited breast cancer patients in Denmark. PATIENTS AND METHODS: To evaluate the results of this treatment, we performed a nationwide population-based follow-up study of patients aged less than 75 years treated in Denmark from 1989 to 1998 based on the database of Danish Breast Cancer Cooperative Group. RESULTS: At 15 years of follow-up, the Kaplan-Meier estimate of overall survival was 69% among 3 758 patients who received the recommended treatment. Within the first 10 years of follow-up, the cumulative incidences of loco-regional recurrences, distant metastases or other malignant disease, or death as a first event were 9.0, 19.9, and 6.0% respectively, when analysed in a competing risk setting. The risk of loco-regional recurrences was significantly decreased in patients aged 50 years or more and increased with increasing tumour size. There was a pronounced beneficial effect of adjuvant radiotherapy with those not receiving radiotherapy having a hazard ratio of 3.52 (95% CI 2.21-5.61). The effect of resection margins was significant for loco-regional recurrences only in node negative patients. CONCLUSION: In conclusion, the present study shows that results similar to those from randomised clinical trials can be obtained when breast conserving treatment is applied as a standard treatment in an entire population.

Diagnostic challenges in clinical, radiological and histopathological tests regarding papillomatous lesions of the breast.

Papillomas of the female breast is a relatively frequent lesion, and the majority are benign when excised. However, some may host malignant or premalignant areas. Consequently, it is a worldwide accepted principle to excise the lesion whenever diagnosed. However, this leads to a large number of patients having an unnecessary operation. The present study was designed to investigate whether we could find clinical, radiological and pathological factors in the preoperative, diagnostic setting that could identify patients hosting a benign papilloma in order to avoid operation. The patient material consisted of 260 patients, all with a preoperative diagnosis of a papillomatous process in core biopsy. The lesion was excised, and 71% had a benign lesion. The rest had lesions ranging from premalignant to malignant. In the clinical, radiological and histopathological investigations conducted, we were not able to identify factors that statistically significant could predict whether the lesion was benign or malignant. However, our data showed a higher prevalence of malignant and premalignant lesions for older patient, larger lesions, and lesions found at a longer distance from the papilla. We conclude that, since almost 30% of the patients in our study ended up with a premalignant or malignant diagnosis, where no statistically significant preoperative factors could indicate a benign outcome, operation is warranted in all patients with a preoperative diagnosis of a papillomatous lesion.

PAM50 Risk of Recurrence Score Predicts 10-Year Distant Recurrence in a Comprehensive Danish Cohort of Postmenopausal Women Allocated to 5 Years of Endocrine Therapy for Hormone Receptor-Positive Early Breast Cancer.

Purpose The PAM50-based Prosigna risk of recurrence (ROR) score has been validated in randomized clinical trials to predict 10-year distant recurrence (DR). The value of Prosigna for predicting DR was examined in a comprehensive nationwide Danish cohort consisting of postmenopausal women with hormone receptor-positive early breast cancer treated with 5 years of endocrine therapy alone. Patients and Methods Using the population-based Danish Breast Cancer Cooperative Group database, follow-up data were collected on all patients diagnosed from 2000 through 2003 who, by nationwide guidelines, were treated with endocrine therapy for 5 years. Primary tumor blocks from 2,740 patients were tested with Prosigna and, after determination of human epidermal growth factor receptor 2 (HER2) status, data from 2,558 hormone receptor-positive/HER2-negative samples were analyzed, including 1,395 node-positive patients. Fine and Gray models were applied to determine the prognostic value of ROR for DR. Results Median follow-up for recurrence was 9.2 years. Twenty-six percent of the node-positive patients were classified as low ROR (n = 359) with a DR risk of 3.5% (95% confidence interval [CI], 1.9% to 6.1%) versus a DR risk of 22.1% (95% CI, 18.6% to 25.8%) at 10 years for patients classified as high ROR (n = 648). Node-negative patients classified as low and high ROR had a risk of DR of 5.0% (95% CI, 2.9% to 8.0%) and 17.8% (95% CI, 14.0% to 22.0%), respectively. Luminal B tumors (n = 947; DR risk, 18.4% [95% CI: 15.7% to 21.3%]) had a significantly worse outcome than luminal A tumors (n = 1,474,;DR risk, 7.6% [95% CI: 6.1% to 9.2%]; P < .001). Conclusion Prosigna ROR score improved the prediction of outcome in this nationwide Danish population. In a real-world setting, Prosigna can reliably identify node-negative patients and a significant proportion of patients with one to three positive nodes who can be spared treatment with adjuvant chemotherapy.

ESR1 gene status correlates with estrogen receptor protein levels measured by ligand binding assay and immunohistochemistry.

The Estrogen Receptor (ER) is an established predictive marker for the selection of adjuvant endocrine treatment in early breast cancer. During the 1990s Immunohistochemistry (IHC) replaced cytosol based assays for determination of ER status. This study examined the association between ER protein level determined by two different methods and ESR1 gene copy number. From 289 primary high-risk breast cancer patients, randomized in the Danish Breast Cancer Cooperative Group (DBCG) 77C trial, results from cytosolic ER levels were available from ligand binding assays. Archival tumor tissue was retrieved from 257 patients. ESR1/CEN-6 ratio was analyzed successfully by Fluorescence In Situ Hybridization (FISH) in 220 (86%) patients. ESR1 amplification (ESR1/CEN-6 ≥ 2.00) was observed in 23% of the patients and ESR1 deletion (ESR1/CEN-6 < 0.80) was observed in 32%. Further, we identified ESR1 gain (ratio ESR1/CEN-6 from 1.30 to 1.99) in 19% of the patients. A positive correlation of ESR1 FISH with both ER-cytosol and ER IHC was found (p < 0.0001). Amplification and gain of the ESR1 gene are associated with higher ER protein content measured by ligand binding assay and a more intense nuclear staining by IHC compared to tumors with normal ESR1 gene status. Major variations in ER measured by ligand binding assay and IHC are observed within all ESR1 copy number subgroups and other mechanisms than gene copy number seem to contribute to the ER protein content in the tumors.

The correlation between dual-color chromogenic in situ hybridization and fluorescence in situ hybridization in assessing HER2 gene amplification in breast cancer.

Fluorescence in situ hybridization (FISH) is regarded as the gold standard method for detecting HER2 gene amplification. Chromogenic in situ hybridization (CISH) is a promising alternative to FISH because CISH has the advantages of being a method evaluated by bright-field microscopy and the generated chromogenic signals are also stable. This study presents a dual color CISH for simultaneous detection of the HER2 gene and chromosome 17. The CISH method performs a chromogenic detection "on top" of the Food and Drug Administration (FDA)-approved HER2 FISH pharmDx method, where the fluorochrome-labeled probes are detected using enzyme-labeled antibodies and visualized by chromogenic enzymatic reactions. The HER2 status (amplified/not amplified and HER2 ratios) was evaluated by the CISH method and compared with results obtained by the FDA-approved FISH method. Of the 72 successfully investigated invasive breast carcinomas, both FISH and CISH detected HER2 amplification in 24 cases and nonamplification was detected in 47 cases. One case showed a discrepancy between FISH and CISH. The concordance between CISH and FISH was found to be almost perfect (98.6%). The correlation between the HER2 ratios obtained by the 2 methods showed excellent correlation (correlation coefficient 0.95). In conclusion, it is possible by dual-color CISH method to demonstrate HER2 genes and chromosome 17 genes, in the same tissue section and reliably assess HER2 status. The CISH method is a very promising alternative to the FISH method.

Re-evaluation of the prolactin receptor expression in human breast cancer.

The pituitary hormone PRL is involved in tumorigenesis in rodents and humans. PRL promotes proliferation, survival and migration of cancer cells acting via the PRL receptor (PRLR). Aiming to perform a large-scale immunohistochemical (IHC) screening of human mammary carcinomas for PRLR expression, we evaluated the specificity of commercially available anti-human PRLR antibodies (B6.2, U5, PRLRi pAb, 1A2B1, 250448 and H-300). The latter three antibodies were found to specifically recognise PRLR. The relative PRLR expression level detected with these antibodies closely reflected the level of (125)I-PRL binding to the cell surface. The monoclonal antibody (mAb) 250448 was specific for the N-()glycosylated form of PRLR and blocked PRL binding and signalling. The PRLRi polyclonal antibody recognised cytokeratin-18. The mAb B6.2, previously used in a number of studies, was found to lack specificity for PRLR and to rather recognise a PRLR-associated protein. The mAb U5 raised against the rat PRLR did not cross-react with the human receptor. Only one mAb, 1A2B1, was found useful for detection of PRLR in IHC applications. This antibody recognised PRLR expressed in human breast cancer cell lines and decidual cells in tissue sections of human placenta. Screening of 160 mammary adenocarcinomas demonstrated significant immunoreactivity in only four tumours, indicating that PRLR is generally not strongly upregulated in human breast cancer. However, even a very low level of PRLR expression was found to be sufficient to mediate PRL responsiveness in breast cancer cell lines.

[Prognostic and predictive factors for endocrine treatment in breast carcinoma]. / Status over klinisk anvendte prognostiske og praediktive faktorer ved allokering til systemisk behandling efter primaer cancer mammae.

There is a long tradition for defining prognostic factors in breast carcinoma; the classic ones being lymphnode status, tumor size, malignancy grade, and hormone receptor status. More important are the detection of predictive factors, defined as factors in the tumor which predict the effect of a certain treatment. The hormone receptors are a classic example of predictive factors for determining whether patients should be offered endocrine treatment. New predictive factors are HER2 for predicting the effect of trastuzumab and TOP2A for predicting the effect of certain chemotherapies.

[Preoperative biopsy diagnosis in suspicion of breast cancer]. / Praeoperativ biopsidiagnostik ved mistanke om brystkraeft.

The golden standard in non-operative breast cancer diagnosis is the triple test, a combination of clinical evaluation, mammography/ultrasound and needle biopsy, either fine needle aspiration cytology (FNAC) or histological core biopsy. FNAC and core biopsy both have advantages and disadvantages but neither of them can act as a decisive diagnostic procedure on its own. The final diagnosis should always be a consensus between the three diagnostic modalities in the triple test. Quality assurance of the pathological diagnosis is a must. The number of uncertain diagnoses i.e. atypia or suspicion of malignancy should be kept at a minimum. These diagnostic categories call for additional diagnostic procedures and thereby cause a delay in reaching the final diagnosis leading to definitive treatment.

Prognostic and predictive value of centrally reviewed expression of estrogen and progesterone receptors in a randomized trial comparing letrozole and tamoxifen adjuvant therapy for postmenopausal early breast cancer: BIG 1-98.

PURPOSE: To evaluate locally versus centrally assessed estrogen (ER) and progesterone (PgR) receptor status and the impact of PgR on letrozole adjuvant therapy compared with tamoxifen in postmenopausal women with early breast cancer. PATIENTS AND METHODS: Breast International Group (BIG) 1-98 randomly assigned 8,010 patients to four arms comparing letrozole and tamoxifen with sequences of each agent. The Central Pathology Office received material for 6,549 patients (82%), of which 79% were assessable (6,291 patients). Prognostic and predictive value of both local and central hormone receptor expression on disease-free survival (DFS) were evaluated among 3,650 assessable patients assigned to the monotherapy arms. Prognostic value and the treatment effect were estimated for centrally assessed ER and PgR expression levels using the Subpopulation Treatment Effect Pattern Plot. RESULTS: Central review confirmed 97% of tumors as hormone receptor-positive (ER and/or PgR > or =10%). Of 105 tumors locally ER-negative, 73 were found to have more than 10% positive cells, and eight had 1% to 9%. Of 6,100 tumors locally ER positive, 66 were found to have no staining, and 54 had only 1% to 9%. Discordance was more marked for PgR than ER. Patients with tumors reclassified centrally as ER-negative, or as hormone receptor-negative, had poor DFS. Centrally assessed ER and PgR showed prognostic value. Among patients with centrally assessed ER-expressing tumors, letrozole showed better DFS than tamoxifen, irrespective of PgR expression level. CONCLUSION: Central review changed the assessment of receptor status in a substantial proportion of patients, and should be performed whenever possible in similar trials. PgR expression did not affect the relative efficacy of letrozole over tamoxifen.