HPV ctDNA detection of high-risk HPV types during chemoradiotherapy for locally advanced cervical cancer.

BACKGROUND: Chemoradiotherapy (CRT) is the standard of care for patients diagnosed with locally advanced cervical cancer (LACC), a human papillomavirus (HPV)-related cancer that relapses in 30%-60% of patients. This study aimed to (i) design HPV droplet digital PCR (ddPCR) assays for blood detection (including rare genotypes) and (ii) monitor blood HPV circulating tumor DNA (HPV ctDNA) levels during CRT in patients with LACC. METHODS: We analyzed blood and tumor samples from 55 patients with HPV-positive LACC treated by CRT in a retrospective cohort (n = 41) and a prospective cohort (n = 14). HPV-ctDNA detection was carried out by genotype-specific ddPCR. RESULTS: HPV ctDNA was successfully detected in 69% of patients (n = 38/55) before CRT for LACC, including nine patients with a rare genotype. HPV-ctDNA level was correlated with HPV copy number in the tumor (r = 0.41, P < 0.001). HPV-ctDNA positivity for HPV18 (20%, n = 2/10) was significantly lower than for HPV16 (77%, n = 27/35) or other types (90%, n = 9/10, P = 0.002). HPV-ctDNA detection (positive versus negative) before CRT was associated with tumor stage (P = 0.037) and lymph node status (P = 0.02). Taking into account all samples from the end of CRT and during follow-up in the prospective cohort, positive HPV-ctDNA detection was associated with lower disease-free survival (DFS) (P = 0.048) and overall survival (OS) (P = 0.0013). CONCLUSION: This is one of the largest studies to report HPV-ctDNA detection before CRT and showed clearance of HPV ctDNA at the end of treatment in most patients. Residual HPV ctDNA at the end of CRT or during follow-up could help to identify patients more likely to experience subsequent relapse.

Estrogen-Receptor, Progesterone-Receptor and HER2 Status Determination in Invasive Breast Cancer. Concordance between Immuno-Histochemistry and MapQuant™ Microarray Based Assay.

BACKGROUND: Hormone receptor status and HER2 status are of critical interest in determining the prognosis of breast cancer patients. Their status is routinely assessed by immunohistochemistry (IHC). However, it is subject to intra-laboratory and inter-laboratory variability. The aim of our study was to compare the estrogen receptor, progesterone receptor and HER2 status as determined by the MapQuant™ test to the routine immuno-histochemical tests in early stage invasive breast cancer in a large comprehensive cancer center. PATIENTS AND METHODS: We retrospectively studied 163 invasive early-stage breast carcinoma with standard IHC status. The genomic status was determined using the MapQuant™ test providing the genomic grade index. RESULTS: We found only 4 tumours out of 161 (2.5%) with discrepant IHC and genomic results concerning ER status. The concordance rate between the two methods was 97.5% and the Cohen's Kappa coefficient was 0.89. Comparison between the MapQuant™ PR status and the PR IHC status gave more discrepancies. The concordance rate between the two methods was 91.4% and the Cohen's Kappa coefficient was 0.74. The HER2 MapQuant™ test was classified as « undetermined ¼ in 2 out of 163 cases (1.2%). One HER2 IHC-negative tumour was found positive with a high HER2 MapQuant™ genomic score. The concordance rate between the two methods was 99.3% and the Cohen's Kappa coefficient was 0.86. CONCLUSION: Our results show that the MapQuant™ assay, based on mRNA expression assay, provides an objective and quantitative assessment of Estrogen receptor, Progesterone receptor and HER2 status in invasive breast cancer.

Merkel cell carcinoma: value of sentinel lymph-node status and adjuvant radiation therapy.

BACKGROUND: Sentinel lymph-node (LN) biopsy (SLNB) is a valuable tool to assess the regional LN status in Merkel cell carcinoma (MCC). However, its prognostic value is still debated. This study was undertaken to assess SLNB usefulness for MCC management and to determine the impact of SLNB status on disease-free survival (DFS) and overall survival (OS) by comparing SLNB-positive versus -negative patients according to demographic, clinical and treatment characteristics. PATIENTS AND METHODS: In this retrospective, multicenter observational study, SLNB was proposed to all patients referred for clinically N0 MCC. Treatment schedule consisted of wide-margin surgical resection of primary MCC followed by adjuvant radiation therapy (aRT) to the primary site and, for SLNB-positive patients, radical LN dissection followed by regional aRT. Univariate and multivariate analyses determined factors associated with DFS and OS. RESULTS: Among 87 patients with successful SLNB, 21 (24.1%) were SLNB-positive. Median follow-up for the entire series was 39 months; respective 3-year DFS and OS rates were 73% and 81.4%, respectively. Univariate analysis (all patients) identified SLNB-negativity as being associated with prolonged OS (P = 0.013) and aRT (all sites considered) was associated with longer DFS (P = 0.004) and OS (P = 0.018). Multivariate analysis (all patients) retained SLNB status and aRT (all sites considered) as being associated with improved DFS (P = 0.014 and 0.0008) and OS (P = 0.0020 and 0.0019). Moreover, for SLNB-negative patients, tumor-bed irradiation was also significantly associated with prolonged DFS (P = 0.006) and OS (P = 0.014). CONCLUSIONS: The present study demonstrates that SLNB-negativity is a strong predictor of longer DFS and OS in stage I and II MCC patients. The similar benefit for aRT on tumor bed observed in this study has to be confirmed by a prospective study. The results advocate for SLNB being considered to all MCC patients.

Extensive pure ductal carcinoma in situ of the breast: identification of predictors of associated infiltrating carcinoma and lymph node metastasis before immediate reconstructive surgery.

AIM: To identify predictors for infiltrating carcinoma and lymph node involvement, before immediate breast reconstructive surgery, in patients with an initial diagnosis of extensive pure ductal carcinoma in situ of the breast (DCIS). PATIENTS AND METHODS: Between January 2000 and December 2009, 241 patients with pure extensive DCIS in preoperative biopsy had underwent mastectomy. Axillary staging (sentinel node and/or axillary dissection) was performed in 92% (n = 221) of patients. Patients with micro-invasive lesions at initial diagnosis, recurrence or contralateral breast cancer were excluded. RESULTS: Respectively 14% and 21% of patients had a final diagnosis of micro-invasive carcinoma (MIC) and invasive ductal carcinoma (IDC). Univariate analysis showed that the following variables at diagnosis were significantly correlated with the presence of either MIC or IDC in the mastectomy specimen: palpable tumor (p = 0.002), high grade DCIS (p = 0.002) and detection of an opacity by mammography (p = 0.019). Axillary lymph node (ALN) involvement was reported in 9% of patients. Univariate analysis suggested that a body mass index higher than 25 (p = 0.007), a palpable tumor (p = 0.012) and the detection of an opacity by mammography (p = 0.044) were associated with an increased rate of ALN involvement. CONCLUSION: Skin-sparing mastectomy and immediate breast reconstruction (IBRS) has become increasingly popular, especially for patients with extended DCIS of the breast. This study confirmed that extended DCIS is associated with a substantial risk of finding MIC or IDC on the surgical specimen but also ALN involvement. Adjuvant systemic treatment and/or radiotherapy could be indicated for some of these patients after the surgery. Patients should be informed of the rate of 1) complications associated to IBRS that will potentially delay the introduction of systemic or local therapy 2) complications associated to radiotherapy after IBRS.

MiR-30a-5p connects EWS-FLI1 and CD99, two major therapeutic targets in Ewing tumor.

Ewing sarcoma is a pediatric bone tumor characterized in 85% of cases by the fusion between EWS and FLI1 genes that results in the expression of the EWS-FLI1 aberrant transcription factor. Histologically, the Ewing tumor expresses high levels of the CD99 membrane glycoprotein. It has been recently described that CD99 expression contributes to the Ewing tumor oncogenesis by modulating growth and differentiation of tumor cells. Different studies have also shown that overexpression of EWS-FLI1 induces CD99 expression in non-Ewing cells. At the opposite, the knockdown of EWS-FLI1 expression by siRNA approaches has no significant effect on CD99 mRNA level in Ewing cells. Here, by in vivo and in vitro studies, we show that while EWS-FLI1 inhibition has only slight effects on the amount of CD99 transcript, it induces a dramatic decrease of the CD99 protein expression level, hence suggesting post-transcriptional regulations, possibly mediated by microRNAs. To further investigate this issue, we identified a set of 91 miRNAs that demonstrate EWS-FLI1 modulation, three of them being predicted to bind CD99 3' untranslated region (30'UTR). Among these, we show that miR-30a-5p has the ability to interact with the 30'UTR region of CD99 and to regulate its expression. Moreover, the re-expression of miRNA-30a-5p in Ewing cell line induces decreased cell proliferation and invasion. In this study, we therefore show that miR-30a-5p constitutes a major functional link between EWS-FLI1 and CD99, two critical biomarkers and therapeutic targets in Ewing sarcoma.

Prediction of axillary lymph node status in male breast carcinoma.

BACKGROUND: To evaluate whether predictive factors of axillary lymph node metastasis in female breast cancer (BC) are similar in male BC. PATIENTS AND METHODS: From January 1994 to May 2011, we recorded 80 non-metastatic male BC treated at Institut Curie (IC). We analysed the calibration and discrimination performance of two nomograms [IC, Memorian Sloan-Kettering Cancer Center (MSKCC)] originally designed to predict axillary lymph node metastases in female BC. RESULTS: About 55% and 24% of the tumours were pT1 and pT4, respectively. Nearly 46% demonstrated axillary lymph node metastasis. About 99% were oestrogen receptor positive and 94% HER2 negative. Lymph node status was the only significant prognostic factor of overall survival (P = 0.012). The area under curve (AUC) of IC and MSKCC nomograms were 0.66 (95% CI 0.54-0.79) and 0.64 (95% CI 0.52-0.76), respectively. The calibration of these two models was inadequate. CONCLUSIONS: Multi-variate models designed to predict axillary lymph node metastases for female BC were not effective in our male BC series. Our results may be explained by (i) small sample size (ii) different biological determinants influencing axillary metastasis in male BC compared with female BC.

Genetic variability and integration of Merkel cell polyomavirus in Merkel cell carcinoma.

Merkel cell polyomavirus (MCPyV) is associated to Merkel cell carcinoma (MCC). We studied 113 MCC tumoral skin lesions originating from 97 patients. MCPyV detection was higher in fresh-frozen (FF) biopsies (94%) than in formalin-fixed paraffin-embedded biopsies (39-47%). Mean viral load in FF tumor was of 7.5 copies per cell with a very wide range (0.01-95.4). Nineteen complete sequences of LTAg were obtained, mainly from FF biopsies when the viral load was high. Seventeen showed stop codons, all localized downstream of the pRb protein binding domain. Sequence comparison and phylogenetic analysis showed that all sequences clustered in the large C clade of MCPyV strains. MCPyV integration was demonstrated in 19 out of 27 FF MCC DNA biopsies without evidence of specific host cellular genome integration site. In 13/19 cases, the viral junction was located within the second exon of the LTAg, after the pRB binding domain.

Identification of oncogenic microRNA-17-92/ZBTB4/specificity protein axis in breast cancer.

The human POK family members are transcription factors with a POZ domain and zinc-fingers that act primarily as transcriptional repressors. Several members of this family are involved in oncogenesis and this prompted us to assess whether expression levels of individual POK family members are associated with clinical outcomes in cancer. We have observed that ZBTB4 (zinc-finger and BTB domain containing 4) is downregulated in breast cancer patients, and that its expression is significantly correlated with relapse-free survival. Further integrative analysis of mRNA and microRNA (miR) expression data from the NCI-60 cell lines revealed an inverse correlation between ZBTB4 and oncogenic miRs derived from the miR-17-92 cluster and its paralogs. The experimental results using MDA-MB-231 and MCF-7 human breast cancer cells confirm that miRNAs derived from these clusters, containing miR-17-5p, miR-20a, miR-106a, miR-106b and miR-93, negatively regulate ZBTB4 expression. Overexpression of ZBTB4 or restoration of ZBTB4 by using an antagomir inhibit growth and invasion of breast cancer cells, and this effect is due, in part, to ZBTB4-dependent repression of the specificity protein 1 (Sp1), Sp3 and Sp4 genes, and subsequent downregulation of several Sp-dependent oncogenes, in part, through competition between ZBTB4 and Sp transcription factors for GC-rich promoter sequences. These results confirm that ZBTB4 functions as a novel tumor-suppressor gene with prognostic significance for breast cancer survival, and the oncogenic miR-17-92/ZBTB4/Sp axis may be a potential therapeutic target.

[Merkel cell carcinoma revisited: a new example of viro-induced human tumour]. / Le carcinome à cellules de Merkel revisité : un nouvel exemple de tumeur humaine viro-induite.

Merkel cell carcinoma (MCC) is a neuroendocrine carcinoma of the skin of poor outcome. A new type of virus, isolated in 2008, was found to be strongly associated with CCM. This virus, belonging to the family of polyomavirus, was called MCPyV for Merkel Carcinoma Polyomavirus. Recent data favour a causative role of MCPyV in oncogenesis. MCC represents thus a new model for the understanding of the mechanisms of oncogenesis. The distinct molecular viral signature in every case of MCC represents an original tool for the follow-up of the disease. New therapeutic perspectives are to be drawn using this model.

Milk fat globule--epidermal growth factor--factor VIII (MFGE8)/lactadherin promotes bladder tumor development.

Milk fat globule-epidermal growth factor-factor VIII (MFGE8), also called lactadherin or SED1, is a secreted integrin-binding protein that promotes elimination of apoptotic cells by phagocytes leading to tolerogenic immune responses, and vascular endothelial growth factor (VEGF)-induced angiogenesis: two important processes for cancer development. Here, by transcriptomic analysis of 228 biopsies of bladder carcinomas, we observed overexpression of MFGE8 during tumor development, correlated with expression of genes involved in cell adhesion or migration and in immune responses, but not in VEGF-mediated angiogenesis. To test whether MFGE8 expression was instrumental in bladder tumor development, or a simple consequence of this development, we used genetic ablation in a mouse model of carcinogen-induced bladder carcinoma. We showed that Mfge8 was also upregulated in mouse carcinoma, and that in its absence, Mfge8-deficient animals developed less advanced tumors. Angiogenesis was similar in carcinogen-treated Mfge8-expressing or -deficient bladders, thus ruling out a major role of the proangiogenic function of Mfge8 for its protumoral role. By contrast, the tumor-promoting role of Mfge8 was not observed anymore in mice devoid of adaptive immune system, and human tumors overexpressing MFGE8 where invaded with macrophages and regulatory T cells, thus suggesting that MFGE8/lactadherin favors development of bladder tumors at least partly by an immune system-dependent mechanism. Our observations suggest future use of MFGE8-inhibiting molecules as therapies of bladder carcinomas, and of a limited number of other human cancers, in which our analysis of public databases also revealed overexpression of MFGE8.

[Preoperative concomitant radiochemotherapy in bulky carcinoma of the cervix: Institut Curie experience]. / Chimioradiothérapie concomitante préopératoire dans les carcinomes du col utérin de stades IB2 à IIB : expérience de l'institut Curie.

PURPOSE: To evaluate the treatment results of patients (pts) with Figo stage IB2, IIA, IIB cervical carcinoma (CC) treated with preoperative radiochemotherapy, followed by extended radical hysterectomy. PATIENTS AND METHODS: Retrospective study of 148 women treated at the Institut Curie for operable Figo Stage IB2 to IIB, biopsy proved CC. Among them, 70 pts, median age 46 years, were treated using the same regimen associating primary radiocisplatinum based chemotherapy, intracavitary LDR brachytherapy, followed by extended radical hysterectomy. Kaplan-Meier estimates were used to draw survival curves. Comparisons of survival distribution were assessed by the log-rank test. RESULTS: Complete histological local-regional response was obtained in 56% of the pts (n=39). Residual macroscopic or microscopic disease in the cervix was observed in 28 pts (40%). All but one had in situ microscopic residual CC. Lateral residual disease in the parametria was also present in nine pts, all with residual CC. Pelvic lymph nodes were free from microscopic disease in 56 pts (80%). Eight of 55 (11%) radiological N0 patients had microscopic nodal involvement, as compared to 6/15 (40%) radiological N1 (p=0.03). Seventeen pts (25%) had residual cervix disease but negative nodes. After median follow-up of 40 months (range, 8-141), 38/70 patients (54.1%) are still alive and free of disease, six (8.6%) alive with disease, and 11 (15.8%) patients were lost for follow-up but free of disease. CONCLUSION: The treatment of locally advanced CC needs a new multidisciplinary diagnostic and treatment approach using new therapeutic arms to improve the survival and treatment tolerance among women presenting this disease.

Disseminated tumor cells and the risk of locoregional recurrence in nonmetastatic breast cancer.

BACKGROUND: In early breast cancer patients, bone marrow (BM)-disseminated tumor cells (DTCs) were associated with distant metastasis and locoregional recurrence. Our aim was to determine whether BM DTC detection could be related to specific locoregional dissemination of cancer cells, according to radiotherapy volumes. PATIENTS AND METHODS: The relationship between locoregional recurrence-free survival (LRFS) and DTC detection was evaluated according to the various locoregional volumes irradiated after surgery. RESULTS: BM DTCs were detected in 94 of 621 stage I-III breast cancer patients (15%) and were not associated with axillary node status. Eighteen patients (2.9%) experienced locoregional recurrence (median follow-up 56 months), of whom eight (44%) were initially BM DTC positive. BM DTC detection was the only prognostic factor for LRFS [P = 0.0005, odds ratio = 5.2 (2.0-13.1), multivariate analysis]. In BM DTC-positive patients, a longer LRFS was observed in those who were given adjuvant hormone therapy (P = 0.03) and radiotherapy to supraclavicular nodes (SCNs)/internal mammary nodes (IMNs) (P = 0.055) (multivariate analysis; interaction test: P = 0.028). CONCLUSIONS: The presence of DTC in BM may be associated with a different pattern of locoregional cancer cell dissemination and influences LRFS. The possible reseeding of the primary cancer area by DTC could be prevented by systemic hormone therapy but also by SCN/IMN irradiation.

The human protein kinase HIPK2 phosphorylates and downregulates the methyl-binding transcription factor ZBTB4.

HIPK2 is a eukaryotic Serine-Threonine kinase that controls cellular proliferation and survival in response to exogenous signals. Here, we show that the human transcription factor ZBTB4 is a new target of HIPK2. The two proteins interact in vitro, colocalize and associate in vivo, and HIPK2 phosphorylates several conserved residues of ZBTB4. Overexpressing HIPK2 causes the degradation of ZBTB4, whereas overexpressing a kinase-deficient mutant of HIPK2 has no effect. The chemical activation of HIPK2 also decreases the amount of ZBTB4 in cells. Conversely, the inhibition of HIPK2 by drugs or by RNA interference causes a large increase in ZBTB4 levels. This negative regulation of ZBTB4 by HIPK2 occurs under normal conditions of cell growth. In addition, the degradation is increased by DNA damage. These findings have two consequences. First, we have recently shown that ZBTB4 inhibits the transcription of p21. Therefore, the activation of p21 by HIPK2 is two-pronged: stimulation of the activator p53, and simultaneous repression of the inhibitor ZBTB4. Second, ZBTB4 is also known to bind methylated DNA and repress methylated sequences. Consequently, our findings raise the possibility that HIPK2 might influence the epigenetic regulation of gene expression at loci that remain to be identified.

Prognosis of women with stage IV breast cancer depends on detection of circulating tumor cells rather than disseminated tumor cells.

BACKGROUND: At metastatic relapse, detection of circulating tumor cells (CTC) in peripheral blood is predictive of poor survival of breast cancer patients. Detection of disseminated tumor cells (DTC) in bone marrow (BM) is an independent prognostic factor in early breast cancer. We evaluated the prognostic value of DTC detection in the BM of metastatic breast cancer patients. MATERIALS AND METHODS: BM aspirates from 138 patients were screened for DTC with the pancytokeratin mAb A45-B/B3, according to the ISHAGE classification. One hundred and ten patients (80%) were enrolled before first-line treatment. Thirty-seven patients were simultaneously screened for CTC in the blood. RESULTS: DTC detection rate in the BM was 59%. DTC were associated with bone metastasis (P = 0.0001), but not with a poorer overall survival. Adverse significant prognostic factors were hormone receptor negativity (P = 0.0004) and more than one line of chemotherapy (P = 0.002). CTC detection in the subgroup of 37 metastatic patients was associated with shorter survival (P = 0.01). CONCLUSIONS: Detection of CTC but not BM DTC had a prognostic significance in stage IV breast cancer patients. CTC in blood are a more reliable and a less invasive tool to evaluate prognostic and monitor tumor response in this metastatic setting.

Are ipsilateral breast tumour invasive recurrences in young (< or =40 years) women more aggressive than their primary tumours?

The characteristics of ipsilateral breast tumour recurrences (IBTRs) relative to those of their primary tumours (PTs) remain scarcely studied. Of 70 young (< or =40 years) premenopausal women with IBTRs, we studied a series of 63 with paired histological data. Median follow-up since IBTR was 10 years. Rates of histological types, grades or hormonal receptors were not significantly different in PTs and in IBTRs. The concordance between IBTRs and their PTs was good for histological types. IBTRs with conserved histological types tended to occur more locally, but not significantly sooner than others. These IBTRs had good concordance for hormone receptors. In discordant cases there were as many losses as appearances of the receptors. The concordance was weak for grades, with equivalent numbers of IBTRs graded lower as higher than their PTs. The 10-year overall survival rate was 70%. Neither the conservation of histological type, location, nor of the two combined were associated with deaths. Early (<2 years) IBTRs, tended to be associated with poorer survival (HR=2.24 (0.92-5.41); P=0.08). IBTRs did not display features of higher aggressiveness than PTs. Neither clinical nor histological definition of a true recurrence could be established other than the conservation of the histological type.

RB1 and TP53 pathways in radiation-induced sarcomas.

The tumour suppressor genes, TP53 and RB1, and four genes involved in their regulation, INK4a, ARF, MDM2 and MDMX, were analysed in a series of 36 post-radiotherapy radiation-induced sarcomas. One-third of the tumours developed in patients carrying a germline mutation of RB1 that predisposed them to retinoblastoma and radiation-induced sarcomas. The genetic inactivation of RB1 and/or TP53 genes was frequently observed in these sarcomas. These inactivations were owing to an interplay between point mutations and losses of large chromosome segments. Radiation-induced somatic mutations were observed in TP53, but not in RB1 or in the four other genes, indicating an early role of TP53 in the radio-sarcomagenesis. RB1 and TP53 genes were biallelically coinactivated in all sarcomas developing in the context of the predisposition, indicating that both genes played a major role in the formation of these sarcomas. In the absence of predisposition, TP53 was biallelically inactivated in one-third of the sarcomas, whereas at least one allele of RB1 was wild type. In both genetic contexts, the TP53 pathway was inactivated by genetic lesions and not by the activation of the ARF/MDM2/MDMX pathway, as recently shown in retinoblastomas. Together, these findings highlight the intricate tissue- and aetiology-specific relationships between TP53 and RB1 pathways in tumorigenesis.

HER2 status of bone marrow micrometastasis and their corresponding primary tumours in a pilot study of 27 cases: a possible tool for anti-HER2 therapy management?

Discrepancies have been reported between HER2 status in primary breast cancer and micrometastatic cells in bone marrow. The aim of this study was to assess HER2 gene status in micrometastatic cells in bone marrow and corresponding primary tumour. Micrometastatic cells were detected in bone marrow aspirations in a prospective series of 27 breast cancer patients by immunocytochemistry (pancytokeratin antibody). HER2 status of micrometastatic cells was assessed by fluorescence in situ hybridisation (FISH), respectively in 24 out of 27. Primary tumour HER2 status was assessed by immunohistochemistry (CB11 antibody) and by FISH in 20 out of 27 of the cases. HER2 was amplified or overexpressed in five out of 27 (18.5%) primary tumours and in four out of 27 (15%) micrometastatic cells. In two cases, HER2 was overexpressed and amplified in primary tumour, but not in micrometastatic cells, whereas, in one case, HER2 presented a low amplification rate (six copies) in micrometastatic cells not found in the primary tumour. We demonstrated that negative and positive HER2 status remained, in the majority of the cases, stable between the bone marrow micrometastasis and the primary tumour. Therefore, the efficiency of anti-HER2 adjuvant therapy could be evaluated, in a clinical trial, by sequential detection of HER2-positive micrometastatic cells within the bone marrow, before and after treatment.

hSNF5/INI1-deficient tumours and rhabdoid tumours are convergent but not fully overlapping entities.

Rhabdoid tumours (RTs) are rare but highly aggressive tumours of childhood. Their rarity and their miscellaneous locations make the diagnosis particularly challenging for pathologists. Central nervous system and peripheral RTs have been associated with biallelic inactivation of the hSNF5/INI1/SMARCB1 (hSNF5/INI1) tumour suppressor gene. Immunohistochemistry (IHC) with a monoclonal anti-hSNF5/INI1 antibody has recently been proposed as an efficient diagnostic tool for RTs. We have conducted a retrospective study of 55 tumours referred to our institution with a suspicion of RT. This analysis included pathological review, IHC with anti-hSNF5/INI1 antibody, and molecular investigation using quantitative DNA fluorescent analysis and sequencing of the nine exons of hSNF5/INI1. The molecular lesion could be detected in 37 of the 39 cases exhibiting negative staining for hSNF5/INI1. In the two discrepant cases, the lack of detection of genetic abnormality was probably owing to the presence of a high number of non-tumour cells in the samples. This indicates that hSNF5/INI1 IHC is very sensitive and highly specific for the detection of hSNF5/INI1 loss-of-function. Among the 38 cases with typical RT histological features, six failed to exhibit hSNF5/INI1 mutation and stained positive for hSNF5/INI1. This strongly supports the evidence of a second genetic locus, distinct from hSNF5/INI1, associated with RT. Conversely, seven tumours with histological features poorly compatible with RT stained negative for hSNF5/INI1; they nevertheless exhibited an age of onset and a clinical behaviour similar to RT. This suggests that hSNF5/INI1 inactivation is not strictly limited to typical RT but characterizes a wider family of hSNF5/INI1-deficient tumours. Consequently, we believe that anti-hSNF5/INI1 IHC should be performed widely, even when the pathological characteristics are not typical. The molecular investigation should be performed in infants when a rhabdoid predisposition syndrome is suspected.

Challenges in the stratification of breast tumors for tailored therapies.

Studying the molecular stratification of breast carcinoma is a real challenge considering the extreme heterogeneity of these tumors. Many patients are now treated following recommendation established at several NIH and St Gallen consensus conferences. However a significant fraction of these breast cancer patients do not need adjuvant chemotherapies while other patients receive inefficacious therapies. High density gene expression arrays have been designed to attempt to establish expression profiles that could be used as prognostic indicators or as predictive markers for response to treatment. This review is intended to discuss the potential value of these new indicators, but also the current weaknesses of these new genomic and bioinformatic approaches. The combined analysis of transcriptomic and genomic alteration data from relatively large numbers of well annotated tumor specimens may offer an opportunity to overcome the current difficulties in validating recently published non overlapping gene lists as prognostic or therapeutic indicators. There is also hope for identifying and deciphering signal transduction pathways driving tumor progression with newly developed algorithms and semi quantitative parameters obtained in simplified in vitro or in vivo models for specific transduction pathways.

MYC activation associated with the integration of HPV DNA at the MYC locus in genital tumors.

To determine whether integration of human papillomavirus (HPV) DNA sequences could lead to the deregulation of genes implied in oncogenesis, we analysed the HPV integration sites in a series of nine cell lines derived from invasive genital carcinomas. Using in situ hybridization, HPV16 or 18 sequences were found at chromosome band 8q24, the localization of MYC, in IC1, IC2, IC3, IC6 and CAC-1 cells and at other sites in IC4, IC5, IC7 and IC8 cells. We then localized viral sequences at the molecular level and searched for alterations of MYC structure and expression in these cells. MYC genomic status and viral integration sites were also analysed in primary tumors from which IC1, IC2, IC3 and IC6 cells were derived. In IC1, IC2 and CAC-1 cells, HPV DNA was located within 58 kb of MYC, downstream, upstream, or within MYC. In IC3 and IC6 cells, HPV DNA was located 400-500 kb upstream of MYC. Amplification studies showed that, in IC1, IC2 and IC3, viral and MYC sequences were co-amplified in an amplicon between less than 50 and 800 kb in size. MYC amplification was also observed in primary tumors, indicating that this genetic alteration, together with viral insertion at the MYC locus, had already taken place in vivo. MYC was not amplified in the other cell lines. MYC mRNA and protein overexpression was observed in the five cell lines in which the HPV DNA was inserted close to the MYC locus, but in none of the lines where the insertion had occurred at other sites. MYC activation, triggered by the insertion of HPV DNA sequences, can be an important genetic event in cervical oncogenesis.