Potential histological discordance revealed by second review in the national rare gynecological cancer network (TMRG).

INTRODUCTION: Since 2010, the network of rare malignant tumors of the ovary (TMRG) was developed to optimize the management of patients, also allowing a histological second opinion of rare ovarian tumors. The aim of this work was to study the contribution of second opinion to improve histological diagnostic accuracy on ovarian rare malignant tumors included in the TMRG database. MATERIAL AND METHODS: Histological data of patients diagnosed with a rare ovarian tumor included in TMRG network over a one-year period (2018) were collected. Initial diagnoses were compared with second opinion from national gynecological pathologist experts. The modalities of histological second opinion requests were studied, as well as the histological characteristics of the tumors. The discordances were classified as minor (if the modification of histological diagnosis did not change patient management) and major (if the patient management can be modified). RESULTS: Of 1185 included patients, 937 matched the inclusion criteria. Full concordance between primary diagnosis and expert second opinion was reached in 611 cases (65,3%), minor discordance was seen in 114 (12,2%) and major discordance in 209 (22,3%) of cases. In systematic review requested by the network, 26% (n = 137) of cases were reported with a change in histological diagnosis, while the change concerned 44% (n = 186) of cases for a second opinion spontaneously requested by the initial pathologist. The discrepancies concerned all categories of ovarian tumors, with a majority of mucinous tumors (43% of major discordances), followed by stromal and sex-cord tumors (13.8% of major discordances) and clear cell tumors (12,4% of major discordances). CONCLUSION: This analysis confirms the diagnostic difficulty of ovarian tumors, due to their rarity and morphological heterogeneity. French pathologists are aware of these difficulties and spontaneously refer ovarian tumors with unusual histology for a second opinion and collaborate with rare tumor networks for systematic review.

Development of a noninvasive HIFU treatment for breast adenocarcinomas using a toroidal transducer based on preliminary attenuation measurements.

Breast cancer is the most commonly diagnosed type of cancer among women. For the last fifteen years, treatments that are less invasive than lumpectomy, such as high-intensity focused ultrasound (HIFU) therapy, have been developed, with encouraging results. In this study, a toroidal HIFU transducer was used to create lesions of at least 2 cm in diameter within less than one minute of treatment. The toroidal HIFU transducer created two focal zones that led to large, fast and homogeneous ablations (10.5 cc/min). The experiments were conducted in 30 human samples of normal breast tissues recovered from mastectomies to measure acoustic attenuation (N = 30), and then, HIFU lesions were created (N = 15). Eight HIFU ablations were performed to evaluate the reproducibility of the lesions. HIFU lesions were created in 45 s with a toroidal HIFU transducer working at 2.5 MHz. The longest and shortest axes of the HIFU lesions were 21.7 ± 3.1 mm and 23.5 ± 3.3 mm respectively, corresponding to an average volume of 7.3 ± 1.4 cm3. These HIFU lesions were performed at an average depth of 19.0 ± 1.5 mm, while the integrity of the skin was preserved. The HIFU-treated breast tissues had a higher level of attenuation (0.57 ± 0.11 Np.cm-1.MHz-1) when compared to the untreated tissues (0.21 ± 0.04 Np.cm-1.MHz-1). This study shows the feasibility of a fast and fully noninvasive treatment using a toroidal transducer for breast tumors measuring up to 15 mm in diameter.

Need for risk-adapted therapy for malignant ovarian germ cell tumors: A large multicenter analysis of germ cell tumors' patients from French TMRG network.

BACKGROUND: Malignant ovarian germ cell tumors are rare tumors, affecting young women with a generally favorable prognosis. The French reference network for Rare Malignant Gynecological Tumors (TMRG) aims to improve their management. The purpose of this study is to report clinicopathological features and long-term outcomes, to explore prognostic parameters and to help in considering adjuvant strategy for stage I patients. PATIENTS AND METHODS: Data from patients with MOGCT registered among 13 of the largest centers of the TMRG network were analyzed. We report clinicopathological features, estimated 5-year event-free survival (5y-EFS) and 5-year overall survival (5y-OS) of MOGCT patients. RESULTS: We collected data from 147 patients including 101 (68.7%) FIGO stage I patients. Histology identifies 40 dysgerminomas, 52 immature teratomas, 32 yolk sac tumors, 2 choriocarcinomas and 21 mixed tumors. Surgery was performed in 140 (95.2%) patients and 106 (72.1%) received first line chemotherapy. Twenty-two stage I patients did not receive chemotherapy. Relapse occurred in 24 patients: 13 were exclusively treated with upfront surgery and 11 received surgery and chemotherapy. 5y-EFS was 82% and 5y-OS was 92.4%. Stage I patients who underwent surgery alone had an estimated 5y-EFS of 54.6% and patients receiving adjuvant chemotherapy 94.4% (P < .001). However, no impact on estimated 5y-OS was observed: 96.3% versus 97.8% respectively (P = .62). FIGO stage, complete primary surgery and post-operative alpha fetoprotein level significantly correlated with survival. CONCLUSION: Adjuvant chemotherapy does not seem to improve survival in stage I patients. Active surveillance can be proposed for selected patients with a complete surgical staging.

The French national network dedicated to rare gynecological cancers diagnosis and management could improve the quality of surgery in daily practice of granulosa cell tumors. A TMRG and GINECO group Study.

OBJECTIVE: The French national rare gynecological tumor network has been established to improve the quality of care through offering expertise in double reading histological diagnosis, reviewing cases and guiding management of these tumors through specialized multidisciplinary tumor boards and online clinical guidelines (www.ovaire-rare.com). The aim of this study is to evaluate the impact of the development and implementation of this network by assessing the conformity of medical practice with the guidelines concerning the granulosa cell tumors (GCTs). METHODS: This is a French nationwide study, including 463 patients (out of the 639 identified patients) with a definitive diagnosis of GCT between 2011 and 2016. Surgical practices were analyzed for conformity with the current guidelines (www.ovaire-rare.org). Medical records, surgical and pathological reports were systematically analyzed. Total conformity was defined by a conservative (unilateral salpingo-oophorectomy) or radical surgery (hysterectomy and bilateral salpingo-oophorectomy) including surgical staging (omentectomy, peritoneal biopsies and peritoneal cytology) according to the FIGO stage. Partial conformity referred to a conservative or radical surgery without surgical staging and non-conformity was defined as a non-optimal surgery as recommended by the guidelines. RESULTS: Median age at diagnosis was 49 years old (range 10-89). The median size of tumor was 94 mm (range 5-400). Radical surgery was performed in 240 patients (52%); while a fertility-sparing surgery was performed in 98 cases (21%). A surgical staging was performed in 76 cases (16%) and an evaluation of the endometrium in 289 cases (62%). Surgery was fully compliant with the guidelines in 65 patients (14%), partially compliant in 213 patients (46%), non-compliant in 137 patients (30%) and not assessable in 48 cases (10%). A statistically significant difference for compliance was observed in restaging surgery (p < 0,001), radical surgery (p = 0,017) and the period (before or after) of the implementation of the network (p < 0,001). Survival analyses did not allow us to demonstrate a significant difference in overall survival nor in PFS although there was a trend in favor of optimal surgery compared to incomplete/non optimal surgery. CONCLUSION: Surgical management's conformity to the guidelines increases over time from 2011 to 2016. According to this study, the implementation of a national network dedicated to rare gynecologic tumors seems to significantly improve the surgical management of the patients with ovarian granulosa cell tumors.

Networking for ovarian rare tumors: a significant breakthrough improving disease management.

BACKGROUND: Rare ovarian tumors represent >20% of all ovarian cancers. Given the rarity of these tumors, natural history, prognostic factors are not clearly identified. The extreme variability of patients (age, histological subtypes, stage) induces multiple and complex therapeutic strategies. METHODS: Since 2011, a national network with a dedicated system for referral, up to 22 regional and three national reference centers (RC) has been supported by the French National Cancer Institute (INCa). The network aims to prospectively monitor the management of rare ovarian tumors and provide an equal access to medical expertise and innovative treatments to all French patients through a dedicated website, www.ovaire-rare.org. RESULTS: Over a 5-year activity, 4612 patients have been included. Patients' inclusions increased from 553 in 2011 to 1202 in 2015. Expert pathology review and patients' files discussion in dedicated multidisciplinary tumor boards increased from 166 cases in 2011 (25%) to 538 (45%) in 2015. Pathology review consistently modified the medical strategy in 5-9% every year. The rate of patients' files discussed in RC similarly increased from 294 (53%) to 789 (66%). An increasing number (357 in 5 years) of gynecologic (non-ovarian) rare tumors were also registered by physicians seeking for pathological or medical advice from expert tumor boards. CONCLUSION: Such a nation-wide organization for rare gynecological tumors has invaluable benefits, not only for patients, but also for epidemiological, clinical and biological research.

Phase II study of the PI3K inhibitor BKM120 in patients with advanced or recurrent endometrial carcinoma: a stratified type I-type II study from the GINECO group.

Backround:Patients with metastatic endometrial carcinoma have a poor prognosis and PIK3CA mutations and amplifications are common in these cancers. This study evaluated the efficacy and safety of the pure PI3K inhibitor BKM120 in advanced or recurrent endometrial carcinoma. METHODS: This phase II, multicentre, single-arm, double strata (histological low grade (LG) or high grade (HG)) open-label study enrolled patients with histologically confirmed advanced or recurrent endometrial carcinoma who had received not more than one prior chemotherapy regimen. Patients received initially BKM120 100 mg tablets once daily. Primary end points were proportion of patients free of progression at 2 months (HG strata) or at 3 months (LG strata), objective response rate (ORR), and safety. RESULTS: A total of 40 patients were enrolled, of whom 16 patients had received BKM120 at 100 mg. Because of high toxicities (cutaneous rash (54%), depressive events (47%), and anxiety (40%), the IDMC has proposed to stop recruitment at 100 mg and to continue the clinical trial with a lower dose of 60 mg per day. In addition, 24 patients (median age 67 years old) were newly enrolled (14 in the LG strata and 10 in the HG strata). Rate of nonprogression at 2 months in the HG strata was 70% and at 3 months was 60% in the LG strata. Median progression-free survival (PFS) for all patients is 4.5 months (CI 95% 2.8-6.1), and the median PFS for LG strata is 8.3 months compared with 3.8 months for the HG strata. No response was reported. At 60 mg per day, the most commonly reported treatment-related adverse events (AEs) were hyperglycaemia (58%), cognitive (31%), digestive (28%), hepatic liver functions (26%), and rash (23%). The most commonly reported treatment-related grade ⩾3 AEs were HTA (17%), hyperglycaemia (17%), and increased alanine aminotransferase (24%). Five patients (21%) stopped BKM120 for toxicity. CONCLUSIONS: The BKM120 was associated with an unfavourable safety profile and minimal antitumour activity in monotherapy in advanced or recurrent endometrial carcinoma. The clinical trial was stopped before end of recruitment for toxicity.

The molecular mechanisms underlying the ERα-36-mediated signaling in breast cancer.

Alterations in estrogen-mediated cellular signaling have largely been implicated in the pathogenesis of breast cancer. Here, we investigated the signaling regulation of a splice variant of the estrogen receptor, namely estrogen receptor (ERα-36), associated with a poor prognosis in breast cancers. Coupling in vitro and in vivo approaches we determined the precise sequential molecular events of a new estrogen signaling network in an ERα-negative cell line and in an original patient-derived xenograft. After estrogen treatment, ERα-36 rapidly associates with Src at the level of the plasma membrane, initiating downstream cascades, including MEK1/ERK activation and paxillin phosphorylation on S126, which in turn triggers a higher expression of cyclin D1. Of note, the direct binding of ERα-36 to ERK2 prevents its dephosphorylation by MKP3 and enhances the downstream signaling. These findings improve our understanding of the regulation of non-genomic estrogen signaling and open new avenues for personalized therapeutic approaches targeting Src or MEK in ERα-36-positive patients.

[Axillary lymph node metastases with an occult breast: About 16 cases from a cohort of 7770 patients]. / Envahissement ganglionnaire axillaire sans tumeur primitive mammaire retrouvée : à propos de 16cas issus d'une cohorte de 7770patientes.

OBJECTIVES: Isolated axillary lymph node metastases is an unusual clinical presentation of breast carcinoma. We studied its different issues. METHODS: This study is a follow-up study of 16patients, treated between 1996 and 2012, presenting with axillary metastases with an occult breast carcinoma, which could not be identified by physical examination nor by a conventional imaging or a breast MRI. Clinical characteristics, histological analysis, treatment, monitoring and five-year survival rate were studied. RESULTS: The incidence of this kind of breast cancer was 0.20%. A breast MRI was performed in 75% of the patients. The histology of these tumors showed a rate of hormono-sensibility of 50% and an HER2 overexpression of 44%. Sixty-nine percent of the patients had no breast surgery or radiotherapy; global five-year survival rate for these women was 77.4%±11.5. CONCLUSION: The survival rates of this study should lead the practitioner to choose a less aggressive breast therapy. Moreover, the histological characteristics explain the high metastatic potential of these tumors, and relate them to the HER2+ subclass of gene expression patterns of breast carcinomas.

[Postoperative morbidities after modified posterior pelvic exenteration for ovarian cancer]. / Complications après exentération pelvienne postérieure modifiée selon Hudson dans le cadre de tumeurs malignes ovariennes.

OBJECTIVE: Complication and survival analysis of cytoreduction surgery with modified posterior pelvic exenteration in the surgical treatment of the ovarian malignant tumor. METHODS: A retrospective monocentric study between 2000 and 2013 in Rhone-Alpes cancer treatment center. One hundred and fifty-two patients with ovarian cancer and treated by surgery with modified posterior pelvic exenteration were included. Complication in the 30 days after surgery was analysed by the Clavien-Dindo classification. RESULTS: In our study, rate of global complication was 62.5% with a morbidity rate of grave complication of 7.9%. Our rate of complete resection was 82.2%. Three fistulas (2.2%) were found. On average, there was 6.6±1.8 (2-11) surgery gesture associated with Hudson resection during surgery. In univariate analysis, there was a statistic significant association between complication from the rank II of Clavien-Dindo classification and supraradical surgery, post-chemotherapy surgery, recurrent surgery, the resection of a diaphragmatic dome, and the partial gastric resection. This association was also observed with the number of surgical gesture associated with Hudson resection. CONCLUSIONS: The main prognostic surgical factor in ovarian cancer is to obtain a no macroscopic residual disease. The modified posterior pelvic exenteration allowed to obtain it. Our study demonstrates a low rate of grave complication further to this type of surgery.

Translational studies within the TAMRAD randomized GINECO trial: evidence for mTORC1 activation marker as a predictive factor for everolimus efficacy in advanced breast cancer.

BACKGROUND: Everolimus is an agent frequently associated with specific toxicities. Predictive markers of efficacy are needed to help define which patients could benefit from it. The goal of this exploratory study was to identify potential predictive biomarkers in the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) activation pathway using primary tumor samples collected during the phase II tamoxifen plus everolimus (TAMRAD) trial. PATIENTS AND METHODS: Tumor tissues were collected retrospectively from the TAMRAD trial. Immunohistochemistry was carried out using specific antibodies directed toward proteins that result in mTORC1 activation [canonical phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mTOR or alternative pathways]. DNA was extracted from the tumor tissue; mutation screening in the PIK3CA gene (exons 9 and 20) and the KRAS gene (exons 2 and 3) was first carried out using Sanger direct sequencing, and then completed by next-generation sequencing for PIK3CA. An exploratory analysis of everolimus efficacy in terms of a time-to-progression (TTP) increase was carried out in each biomarker subgroup (high versus low expression referring to the median percentage of marked cells). RESULTS: A total of 55 primary tumor samples from the TAMRAD trial­25 from the tamoxifen-alone group and 30 from the tamoxifen/everolimus group­were evaluated for biomarkers. The subgroups most likely to have an improvement in TTP with tamoxifen/everolimus therapy, compared with tamoxifen alone, were patients with high p4EBP1, low 4EBP1, low liver kinase B1, low pAkt, and low PI3K. Among the 45 samples screened for mutation status, nine samples (20%; 95% CI 9.6-34.6) had a PIK3CA mutation. KRAS mutation was observed in one patient. CONCLUSIONS: A positive correlation between late effectors of mTORC1 activation, a positive correlation between Akt-independent mTORC1 activation, and an inverse correlation between canonical PI3K/Akt/mTOR pathway and everolimus efficacy were observed in this exploratory analysis. However, these correlations need to be validated in larger studies before applying the findings to routine clinical practice.

[Spontaneous regression of breast cancer after biopsy. About two cases]. / Régression spontanée de cancers mammaires après biopsie : à propos de deux cas.

We report two cases of spontaneous regression of breast cancer occurred in our institution. It was about a 34- and an 82-year-old patient. The examination revealed a palpable nodule. In both cases, biopsy revealed a negative immunohistochemical staining for estrogen and progesterone receptors, and HER-2 negative. Histological analysis of the surgical specimen found fibrous tissue rearrangement without carcinoma. In the first case, a sarcoidosis was diagnosed at the same time, the mediastinal nodes mimicked a metastatic cancer. These cases illustrate a rare phenomenon. The main hypothesis is a carcinoma- directed immune response triggered by the biopsy.

Lysyl oxidase activity regulates oncogenic stress response and tumorigenesis.

Cellular senescence, a stable proliferation arrest, is induced in response to various stresses. Oncogenic stress-induced senescence (OIS) results in blocked proliferation and constitutes a fail-safe program counteracting tumorigenesis. The events that enable a tumor in a benign senescent state to escape from OIS and become malignant are largely unknown. We show that lysyl oxidase activity contributes to the decision to maintain senescence. Indeed, in human epithelial cell the constitutive expression of the LOX or LOXL2 protein favored OIS escape, whereas inhibition of lysyl oxidase activity was found to stabilize OIS. The relevance of these in vitro observations is supported by in vivo findings: in a transgenic mouse model of aggressive pancreatic ductal adenocarcinoma (PDAC), increasing lysyl oxidase activity accelerates senescence escape, whereas inhibition of lysyl oxidase activity was found to stabilize senescence, delay tumorigenesis, and increase survival. Mechanistically, we show that lysyl oxidase activity favors the escape of senescence by regulating the focal-adhesion kinase. Altogether, our results demonstrate that lysyl oxidase activity participates in primary tumor growth by directly impacting the senescence stability.

Hyperthermic intraperitoneal chemotherapy with oxaliplatin and without adjuvant chemotherapy in stage IIIC ovarian cancer.

OBJECTIVE: To assess the feasibility and efficacy of cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) without adjuvant chemotherapy for relapsed or persistent advanced ovarian cancer. METHODS: This observational study included stage IIIC ovarian cancer patients due to undergo CRS (interval debulking or recurrent surgery) followed by HIPEC with oxaliplatin (460 mg/m2) for 30 min. RESULTS: Twenty-two patients (12 interval debulking procedures and 10 recurrence procedures) were enrolled between September 2003 and September 2007. HIPEC was not performed in four patients because of operative findings. No patient received adjuvant chemotherapy after HIPEC. Patients were followed up routinely until recurrence or death. Median peritoneal cancer index at surgery was 6 (range: 1-18). Before HIPEC, all patients had completeness of cytoreduction scores of 0 or 1. Median length of hospital stay was 21 days (range 13-65). Ten patients (55.6%) had CTCAE grade 3-4 toxicity, including three patients (16.7%) requiring reoperation. No postoperative mortality was observed. With a median follow-up of 38 months (CI 95% 23.8-39.2), median overall survival was not reached. The 3-year overall survival rate was 83% (CI 95% 54-95). Median disease-free survival was, respectively, 16.9 months (CI 95% 10.2-23.2) and 10 months (CI 95% 4.5-11.3) for patients undergoing interval debulking or recurrence surgery. CONCLUSION: HIPEC without adjuvant chemotherapy is both feasible and safe, but with a high rate of grade 3-5 toxicity. Survival results are encouraging but should be confirmed in a randomized trial.

Methylation, a key step for nongenomic estrogen signaling in breast tumors.

Estrogen receptor alpha (ERalpha) is a member of a large conserved superfamily of steroid hormone nuclear receptors which regulates many physiological pathways by acting as a ligand-dependent transcription factor. Evidence is emerging that estrogens also induce rapid signaling to the downstream kinase cascades; however the mechanisms underlying this nongenomic function remain poorly understood. We have recently shown that ERalpha is methylated specifically by the arginine methyltransferase PRMT1 at arginine 260 in the DNA-binding domain of the receptor. This methylation event is required for mediating the extra-nuclear function of the receptor which would thereby interact with Src/FAK and p85 and propagate the signal to downstream transduction cascades that orchestrate cell proliferation and survival. Of particular interest, a possible role of methylated ERalpha in mammary tumorigenesis is also evident by the fact that, as demonstrated by immunohistochemical studies on a cohort of breast cancer patients, ERalpha is methylated in normal epithelial breast cells and is hypermethylated in a subset of breast cancers. Hypermethylation of ERalpha in breast cancer might cause hyperactivation of cellular kinase signaling, notably of Akt, described as a selective survival advantage for primary tumor cells even in the presence of anti-estrogens. A detailed understanding of the molecular mechanisms that control estrogen signaling in breast cancer is a crucial step in identifying new effective therapies.

[Rare ovarian tumours: therapeutic strategies in 2010, national website observatory for rare ovarian cancers and delineation of referent centers in France]. / Les tumeurs rares de l'ovaire: stratégies thérapeutiques en 2010, Observatoire francophone des tumeurs rares de l'ovaire et émergence des centres de références.

Majorities of the rare ovarian cancers were represented by germ cell tumours and sex cords ovarian tumours with borderline tumours, clear cell carcinoma and mucinous carcinoma and are extremely rare malignant diseases of the ovaries. Tumors of the stromal (Leydig cells) and/or sex cords (Sertoli cells) represent approximately 7% of ovarian cancers and develop from the conjunctive tissue (respectively, interstitial and nurse cells) of the ovaries. All together, they represented less than 5% of the adult malignant and non malignant ovarian tumours. Treatment of rare ovarian tumors is currently as follows. Surgery is the same as that for ovarian adenocarcinoma, with one major difference: conservation of reproductive function in women of reproductive age is usual case for this type of tumor. Chemotherapy for germ cell and sex cords tumors, based on data reported in the literature is the same as that prescribed for testicular germ-cell tumors. For rare epithelial carcinoma, carboplatin plus paclitaxel remains the standard attitude with a well-known less efficiency than for other epithelial subtypes. Surgery, chemotherapy and possible surgical intervention for residual lesions are highly complex. Too rare to be included in randomized studies, treatment of these tumors has benefited from the therapeutic advancements made against testicular germ-cell tumors or with publications using retrospective data. Effectively, some prognostic factors such stage, histology, number of managed patients seems to be prognostic for survival. Because of the rarity of these tumours a specialized website (www.ovaire-rare.org) was developed in France in 2002. Objectives were: to delineate prognostic factors of these very rare diseases, to favour patient inclusion in a clinical trial available online, to provide access to online medical expert forum (disease-related) for complex cases, and finally to demonstrate the impact of these tools on improving medical practice. The website provides very interesting data for a better knowledge of these rare tumors and will possibly help improve medical practice. Since 2008, referent centers were delineated to promote optimal management of these tumors, organization of clinical and molecular research at a national or international level and to elaborate guidelines. The other new scientific data concern surgical procedures for sex cords tumors, evidence for presence of FOXL2 mutation in adult granulosa cell tumors, the use of paclitaxel plus carboplatin for sex cords tumors.

Prognostic value of Dicer expression in human breast cancers and association with the mesenchymal phenotype.

BACKGROUND: Dicer, a ribonuclease, is the key enzyme required for the biogenesis of microRNAs and small interfering RNAs and is essential for both mammalian development and cell differentiation. Recent evidence indicates that Dicer may also be involved in tumourigenesis. However, no studies have examined the clinical significance of Dicer at both the RNA and the protein levels in breast cancer. METHODS: In this study, the biological and prognostic value of Dicer expression was assessed in breast cancer cell lines, breast cancer progression cellular models, and in two well-characterised sets of breast carcinoma samples obtained from patients with long-term follow-up using tissue microarrays and quantitative reverse transcription-PCR. RESULTS: We have found that Dicer protein expression is significantly associated with hormone receptor status and cancer subtype in breast tumours (ER P=0.008; PR P=0.019; cancer subtype P=0.023, luminal A P=0.0174). Dicer mRNA expression appeared to have an independent prognostic impact in metastatic disease (hazard ratio=3.36, P=0.0032). In the breast cancer cell lines, lower Dicer expression was found in cells harbouring a mesenchymal phenotype and in metastatic bone derivatives of a breast cancer cell line. These findings suggest that the downregulation of Dicer expression may be related to the metastatic spread of tumours. CONCLUSION: Assessment of Dicer expression may facilitate prediction of distant metastases for patients suffering from breast cancer.

Lobular and ductal carcinomas of the breast have distinct genomic and expression profiles.

Invasive ductal carcinomas (IDCs) and invasive lobular carcinomas (ILCs) are the two major pathological types of breast cancer. Epidemiological and histoclinical data suggest biological differences, but little is known about the molecular alterations involved in ILCs. We undertook a comparative large-scale study by both array-compared genomic hybridization and cDNA microarray of a set of 50 breast tumors (21 classic ILCs and 29 IDCs) selected on homogeneous histoclinical criteria. Results were validated on independent tumor sets, as well as by quantitative RT-PCR. ILCs and IDCs presented differences at both the genomic and expression levels with ILCs being less rearranged and heterogeneous than IDCs. Supervised analysis defined a 75-BACs signature discriminating accurately ILCs from IDCs. Expression profiles identified two subgroups of ILCs: typical ILCs ( approximately 50%), which were homogeneous and displayed a normal-like molecular pattern, and atypical ILCs, more heterogeneous with features intermediate between ILCs and IDCs. Supervised analysis identified a 75-gene expression signature that discriminated ILCs from IDCs, with many genes involved in cell adhesion, motility, apoptosis, protein folding, extracellular matrix and protein phosphorylation. Although ILCs and IDCs share common alterations, our data show that ILCs and IDCs could be distinguished on the basis of their genomic and expression profiles suggesting that they evolve along distinct genetic pathways.

The molecular causes of low ATM protein expression in breast carcinoma; promoter methylation and levels of the catalytic subunit of DNA-dependent protein kinase.

AIMS: To investigate whether aberrant methylation of the ATM promoter or loss of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) may be the underlying causes of reduced ATM protein levels often seen in breast tumours. METHODS AND RESULTS: Methylation-specific polymerase chain reaction was used to determine the ATM promoter status and DNA-PKcs levels were measured by immunohistochemistry. None of the 74 invasive carcinomas (ICs) studied showed ATM promoter hypermethylation, whereas promoter methylation of CDKN2A/p16 (1.8%) and GSTP1 (15.8%) was detected. Of 92 ICs examined, 68 had reduced DNA-PKcs levels, supporting previous findings that alterations in double-strand break repair are associated with breast cancer pathogenesis. Although no association was found between the DNA-PKcs and ATM scores for the series of 92 tissues and 22/24 tissues with normal DNA-PKcs had reduced ATM, 29 tumours showed low expression of both DNA-PKcs and ATM compared with normal tissues. CONCLUSIONS: No evidence was found that the reduction in ATM protein levels seen in breast carcinoma is the result of epigenetic silencing. However, cross-regulation between DNA-PKcs and ATM may be a possible cause in a subset of tumours and warrants further investigation.