Prevalence and clinical correlations of SF3B1 variants in lactotroph tumours

OBJECTIVE

A somatic mutational hotspot in the SF3B1 gene was reported in lactotroph tumours. The aim of our study was to examine the prevalence of driver SF3B1 variants in a multicentre independent cohort of patients with lactotroph tumours and correlate with clinical data.

DESIGN AND METHODS

This was a retrospective, multicentre study involving 282 patients with lactotroph tumours (including 6 metastatic lactotroph tumours) from 8 European centres. We screened SF3B1 exon 14 hotspot for somatic variants using Sanger sequencing and correlated with clinicopathological data.

RESULTS

We detected SF3B1 variants in seven patients with lactotroph tumours: c.1874G > A (p.Arg625His) (n = 4, 3 of which metastatic) and a previously undescribed in pituitary tumours variant c.1873C > T (p.Arg625Cys) (n = 3 aggressive pituitary tumours). In two metastatic lactotroph tumours with tissue available, the variant was detected in both primary tumour and metastasis. The overall prevalence of likely pathogenic SF3B1 variants in lactotroph tumours was 2.5%, but when we considered only metastatic cases, it reached the 50%. SF3B1 variants correlated with significantly larger tumour size; higher Ki67 proliferation index; multiple treatments, including radiotherapy and chemotherapy; increased disease-specific death; and shorter postoperative survival.

CONCLUSIONS

SF3B1 variants are uncommon in lactotroph tumours but may be frequent in metastatic lactotroph tumours. When present, they associate with aggressive tumour behaviour and worse clinical outcome.

Primary thyroid rhabdomyosarcoma in an adult: A challenging case with histomolecular diagnosis and literature review

INTRODUCTION AND IMPORTANCE

Primary thyroid sarcomas are very rare tumours, accounting for less than 1 % of all thyroid malignancies. We present the fifth case in the literature of primary thyroid rhabdomyosarcoma and the third in adults with, for the first time, an extensive molecular analysis.

CASE PRESENTATION

A 61-year-old woman presented with a rapidly progressive neck mass with extensive local invasion of the tumour.

CLINICAL DISCUSSION

Histologically, the neoplasm was composed of sheets of pleomorphic or spindle-shaped cells with eosinophilic cytoplasm and few large and very pleomorphic cells admixed with the spindle cell proliferation, without any thyroid epithelial component. Immunohistochemically, the tumour cells were positive for muscular markers and negative for epithelial and thyroid differentiation markers. Molecular tests revealed the presence of NF1, PTEN and TERT pathogenic mutations. Classifying undifferentiated neoplasm with muscular differentiation into the thyroid is challenging as many more common differential diagnoses could be favoured including anaplastic thyroid carcinoma with rhabdoid phenotype, leiomyosarcoma, and other rare sarcomas.

CONCLUSION

Primary thyroid rhabdomyosarcoma is extremely rare and can be diagnostically challenging. We emphasize the histological, immunohistochemical and molecular criteria in order to make an accurate diagnosis.

Photodynamic cystoscopy for bladder cancer diagnosis and for NMIBC follow-up: An overview of systematic reviews and meta-analyses

INTRODUCTION

Currently, bladder cancer detection is based on cytology and cystoscopy. White light cystoscopy (WLC) is an invasive procedure and may under-detect flat lesions. Blue light cystoscopy (BLC) and narrow band imaging (NBI) cystoscopy are new modalities that could improve the detection of non-muscle invasive bladder cancer (NMIBC) and its recurrence or progression to muscle invasive bladder cancer. We present a systematic review on BLC and NBI cystoscopy for bladder cancer diagnosis and NMIBC follow-up.

MATERIAL AND METHODS

All available systematic reviews and meta-analyses on cystoscopy published in PubMed® between May 2010 and March 2021 were identified and reviewed. The main endpoints were clinical performance for bladder cancer diagnosis and for recurrence or progression detection during NMIBC follow-up, and additional value compared with cytology and/or WLC.

RESULTS

Most of the meta-analyses and systematic reviews published suggest a better sensitivity of BLC and NBI cystoscopy compared to WLC, particularly for the detection of flat lesions (CIS). NBI- and BLC-guided TURBT could decrease the recurrence rates. However, their clinical utility to reduce progression rate and increase survival is still unclear.

CONCLUSIONS

BLC and NBI cystoscopy are efficient techniques for bladder cancer diagnosis and NMIBC follow-up. However, their clinical benefit remains to be confirmed.

Abstract 486: MicroRNA-30 family members inhibit breast cancer invasion, osteomimicry, and bone destruction by directly targeting multiple bone metastasis-associated genes

MicroRNAs (miRNAs), which are master regulators of gene expression, have emerged as key players in cancer metastasis. Here, we established miR-30 family members (miR-30a, miR-30b, miR-30c, miR-30d and miR-30e) as breast cancer bone metastasis suppressor genes. Low expression levels of miR-30s in primary tumors of breast cancer patients were associated with poor relapse-free survival. Additionally, miR-30s levels were significantly lower in estrogen receptor (ER)-negative/progesterone receptor (PR)-negative tumors than in their hormone-responsive counterparts. Overexpression of miR-30s in ER/PR-negative breast cancer cells resulted in the reduction of bone metastasis burden in vivo. MiR-30s overexpression also reduced tumor outgrowth, when tumor cells were implanted subcutaneously in animals. In vitro, miR-30s did not affect tumor cell proliferation, but inhibited tumor cell invasion. Furthermore, miR-30s restored bone homeostasis by reversing the in vitro effects of the tumor cell conditioned medium on stimulation of osteoclastogenesis and inhibition of osteoblastogenesis. We identified a number of genes associated with osteoclastogenesis stimulation (IL-8, IL-11), osteoblastogenesis inhibition (DKK-1), tumor cell osteomimicry (RUNX2, CDH11) and invasiveness (CTGF, ITGA5, ITGB3) that were direct and/or indirect targets for repression by miR-30s. Among these genes, integrin ITGA5 was a previously unknown miR-30 target. By silencing ITGA5 in ER-/PR-negative breast cancer cells, colonization of the bone marrow by tumor cells was drastically reduced in vivo. Overall, our data indicate that miR-30s employ multiple mechanisms to impede breast cancer bone metastasis. These findings may pave the way to a new field of therapeutic interventions in breast cancer patients with bone metastasis.

Citation Format: Martine Croset, Francesco Pantano, Casina Kan, Edith Bonnelye, Francoise Descotes, Catherine Alix-Panabières, Charles Lecellier, Richard Bachelier, Nathalie Allioli, Saw See Hong, Kai Bartkowiak, Klaus Pantel, Philippe Clézardin. MicroRNA-30 family members inhibit breast cancer invasion, osteomimicry, and bone destruction by directly targeting multiple bone metastasis-associated genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 486.

Molecular testing of BRAF, RAS and TERT on thyroid FNAs with indeterminate cytology improves diagnostic accuracy

OBJECTIVE

Liquid-based (LB)-FNA is widely recognized as a reliable diagnostic method to evaluate thyroid nodules. However, up to 30% of LB-FNA remain indeterminate according to the Bethesda system. Use of molecular biomarkers has been recommended to improve its pathological accuracy but implementation of these tests in clinical practice may be difficult. Here, we evaluated feasibility and performance of molecular profiling in routine practice by testing LB-FNA for BRAF, N/HRAS and TERT mutations.

METHODS

We studied a large prospective cohort of 326 cases, including 61 atypia of undetermined significance, 124 follicular neoplasms, 72 suspicious for malignancy and 69 malignant cases. Diagnosis of malignancy was confirmed by histology on paired surgical specimen.

RESULTS

Mutated LB-FNAs were significantly associated with malignancy regardless of the cytological classification. Overall sensitivity was 60% and specificity 89%. Importantly, in atypia of undetermined significance and follicular neoplasm patients undergoing surgery according to the Bethesda guidelines, negative predictive values were 85.4% and 90% respectively. TERT promoter mutation was rare but very specific for malignancy (5.5%) suggesting that it could be of interest in patients with indeterminate cytology.

CONCLUSIONS

Mutation profiling can be successfully performed on thyroid LB-FNA without any dedicated sample in a pathology laboratory. It is an easy way to improve diagnostic accuracy of routine LB-FNA and may help to better select patients for surgery and to avoid unnecessary thyroidectomies.

Expression of CD133 in differentiated thyroid cancer of young patients

AIMS

CD133 expression in cancer is frequently associated with poor outcome. Thyroid carcinomas are rare in childhood and adolescence and are associated with a higher risk of recurrence and more metastases than the adult tumours. The aim of the study was to assess whether the expression of CD133 in thyroid carcinomas of children, adolescents and young adults was correlated with clinical prognostic factors.

METHODS

Tissue microarrays were constructed with 235 tumours coming from 208 young adults with a median age of 28 years and 27 children with a median age of 13 years. An immunohistochemical study was performed with anti-CD133 antibody. CD133 expression was evaluated, using a semiquantitative score based on the percentage of positive cells. The mutation status of tumours was evaluated by reverse transcriptase PCR. Three cell lines were used to confirm CD133 expression by western blot.

RESULTS

CD133 expression was found in 43% of adult and 37% of child tumours and was confirmed by western blot in cell lines. In young adults, the expression of CD133 was significantly more frequent in patients with tumours >3 cm (p=0.04) and in patients with lymph node metastases (p=0.02). The expression of CD133 was more frequent in patients in whom the tumour presented a BRAF mutation (p=0.03).

CONCLUSIONS

CD133 expression is correlated with tumour size, lymph nodes metastases and BRAF mutations in young adults. The presence of these cancer stem cells could offer new therapeutic alternatives for aggressive thyroid cancers.

Keeping Data Continuous when Analyzing the Prognostic Impact of a Tumor Marker: An Example with Cathepsin D in Breast Cancer

The prognostic value of cathepsin D has been recently recognized, but as many quantitative tumor markers, its clinical use remains unclear partly because of methodological issues in defining cut-off values. Guidelines have been proposed for analyzing quantitative prognostic factors, underlining the need for keeping data continuous, instead of categorizing them. Flexible approaches, parametric and non-parametric, have been proposed in order to improve the knowledge of the functional form relating a continuous factor to the risk. We studied the prognostic value of cathepsin D in a retrospective hospital cohort of 771 patients with breast cancer, and focused our overall survival analysis, based on the Cox regression, on two flexible approaches: smoothing splines and fractional polynomials. We also determined a cut-off value from the maximum likelihood estimate of a threshold model. These different approaches complemented each other for (1) identifying the functional form relating cathepsin D to the risk, and obtaining a cut-off value and (2) optimizing the adjustment for complex covariate like age at diagnosis in the final multivariate Cox model. We found a significant increase in the death rate, reaching 70% with a doubling of the level of cathepsin D, after the threshold of 37.5 pmol mg(-1). The proper prognostic impact of this marker could be confirmed and a methodology providing appropriate ways to use markers in clinical practice was proposed.

S-phase fraction and DNA ploidy in 633 T1T2 breast cancers: a standardized flow cytometric study

The lack of a standardized methodology for quantifying DNA ploidy and S-phase fraction (SPF) by flow cytometry is hindering routine use of these markers in breast cancer management. In a retrospective clinical multicenter study, we validated a standardized flow cytometry protocol. We tested 633 frozen T(1)T(2), N(0)N(1), M(0) breast tumors obtained in four institutions. Cell preparation was standardized, and precise rules for data interpretation were followed. Three SPF classes were defined on the basis of tertiles after adjustment for ploidy. DNA aneuploidy was observed in 61.0% of cases. No significant difference was observed among centers. Aneuploidy and high SPF were associated with large tumor size, node involvement, high histological grade, and hormone receptor negativity. In the overall population (median follow-up, 69 months), patients with medium and high SPF values had shorter disease-free survival (DFS) than those with low SPF values (P < 0.0001). Ploidy had no significant influence. By Cox analysis, SPF, pN, and estrogen receptor status were independent predictors of DFS (P = 0.0002, P = 0.001, and P = 0.05). In node-negative patients, SPF was the only predictor of DFS (P = 0.01), whereas in node-positive patients, the risk of relapse increased with both high SPF (P = 0.003) and estrogen receptor negativity (P = 0.004). Low SPF values distinguished grade II tumors with a particularly good outcome. Our results strongly support the use of SPF in multicenter studies and clinical trials and suggest that node-negative patients with slowly proliferating tumors do not require systemic adjuvant therapy.

Prognostic of DNA-synthesizing enzyme activities (thymidine kinase and thymidylate synthase) in 908 T1-T2, N0-N1, M0 breast cancers: a retrospective multicenter study

Among the methodological approaches of tumor proliferation, thymidine kinase (TK) and thymidylate synthase (TS) assays take into account the specific pathways of pyrimidine synthesis. Studies pointing to a prognostic value of TK and TS in breast cancer involved small numbers of patients. We investigated the prognostic value of these enzymes and their combination in a large retrospective multicenter study. Nine hundred eight T1T2, N0N1, M0 primary breast cancer samples (median follow-up 68 months) were tested. TK and TS were measured in cytosols by using standardized radioenzymatic methods. Although a positive correlation was obtained between TK and TS (p<10(-5)), major discrepancies were observed in some tumors. High levels of both enzymes were associated with large tumor size, histological grade III and steroid receptor-negative tumors. Univariate analysis showed that TK, TS and their combination were predictive of poor metastasis-free (MFS) (p < 10(-4); p=0.004; p < 10(-4)) and disease-free survival (DFS) (p < 10(-4); p=0.007; p=0.0001). TK was selected as an independent factor for MFS in Cox analysis. It was the only variable selected in node-negative patients. Subgroups with specific outcomes, with possible therapeutic implications, were identified: a) in node-negative patients not receiving adjuvant treatment, TK values in the 4th quartile were associated with poor MFS (p=0.0002) and DFS (p=0.0005) as compared to the other quartiles; b) in node-positive patients receiving adjuvant chemotherapy, low levels of both TK and TS were associated with the highest survival rates (MFS: p=0.04; DFS: p=0. 03).

[Standardization and quality control in the evaluation of proliferation parameters in T1T2, N0N1, M0 breast cancer : multicentric retrospective study I. DNA synthesis enzyme activities]

As part of a clinical research project co-ordinated in Grenoble, six French institutions (CRLCC Angers, CHU Grenoble, Hospices civils Lyon, AP Marseille, CRLCC St-Cloud, CHU Tours) grouped together in order to study the following proliferative parameters in primary breast cancer: DNA synthesis enzymes [thymidine kinase (TK), thymidylate synthase (TS)], signal transduction enzyme [protein tyrosine kinase (PTK)] and S-phase fraction (%S). TK, TS and PTK were measured in cytosols using radio-enzymatic biochemical methods. S-phase was estimated using flow cytometry. The first step consisted in standardization and technical validation of the measurements. The second step consisted in the clinical validation by using a retrospective series of 1,003 breast cancers T1T2, N0N1, M0. We report the results of the first step, together with the distributions of the variables and their relationship with classical clinical variables: 1) Using standardized methods and a cytosolic control, a good reproducibility of measurements was obtained, whether assays were performed in one (TS, PTK) or in several laboratories (TK). 2) Significantly different distributions of TK and TS were observed between the different centres mainly due to different conditions of storage of tumours and cytosols. 3) A highly significant correlation was observed between TK, TS and PTK. Highest TK, TS and PTK levels were observed in tumours with high histological grade or receptor negative tumors. This study clearly illustrates the importance of quality assurance of multicentre studies.

Tissue extraction procedures for investigation of urokinase plasminogen activator (uPA) and its inhibitors PAI-1 and PAI-2 in human breast carcinomas

Urokinase type plasminogen activator (uPA) and its inhibitors, plasminogen activator inhibitor type I (PAI-1) and type II (PAI-2), are supposed to be involved in the expression of the invasive and metastatic phenotype of cancer cells. However, clinical investigations on the prognostic significance of their levels in tumor tissue are difficult to realize because of the absence of a convenient method of measurement of these parameters. The aim of the present investigation was to set up a method allowing the measurement of these enzymes and of sex steroid receptor status in appropriate subcellular fraction(s) in conditions easily reproducible in routine. We found that a tissue homogenate prepared according to the method recommended [5] for current measurement of sex steroid receptors is appropriate for further distinct preparations. One aliquot is used for cytosol preparation; another can be treated by 2% Triton X-100 (vol/vol) and provide an extract containing the totality of uPA and PAI-1. The advantage of this procedure is that appropriate subcellular fractions can be derived from a unique homogenization step. Total uPA and PAI-1 are measured in a Triton extract with good performance as compared to previous investigations [4]. PAI-2 is measured in the same cytosol fraction used for sex steroid receptors and other parameters. Because of its simplicity and its high reliability, this method could be a useful tool in the investigation of uPA family proteases and analysis of their prognostic significance in early breast tumors.

Comparison of a new microplate oestrogen receptor (ER) enzyme immunoassay with other ER detection methods

In a study involving 50 breast cancer tumours, we compared two oestrogen receptor (ER) detection methods developed by us--a microplate immunoenzymometric assay (EIA96) and an immunohistochemistry kit (HistoCIS-ER)--with the radioligand assay (RLA), the Abbott immunoenzymometric assay ER-EIA and the reverse transcriptase polymerase chain reaction technique (RT-PCR). Among the three ER protein cytosolic assays (EIA96, ER-EIA and RLA), the two EIAs showed the best agreement (y = 1.086x - 7.840; r2 = 0.876). At the calculated optimal cut-off values (8 and 14 fmol mg(-1) protein for EIA96 and RLA respectively), EIA96 was more sensitive than RLA (0.94 for EIA96, 0.88 for RLA), but slightly less specific (0.82 for EIA96, 0.94 for RLA). The Cox logistical regression model applied to EIA96, RLA and RT-PCR showed that EIA96 discriminated the best between ER-EIA+ and ER-EIA- samples. The RT-PCR technique and HistoCIS-ER both had a positivity-negativity concordance of 86% with EIA96.

Microtiter plate immunoenzymometric assay for estrogen receptor

The estrogen receptor (ER) status of breast cancer is used both as a prognostic factor and as a predictor of response to endocrine therapy. An immunoenzymometric assay for ER was developed on 96-well microtiter plates (EIA96). This technique involves two monoclonal antibodies directed against different epitopes in the B domain of ER. The two-step protocol (16-18 h and 3 h at 4 degrees C) requires 100 microL of cytosol. This assay showed a detection limit of 0.58 pmol/L. Intra- and interassay CVs of clinical specimens were < or = 5% except for the least concentrated sample (6.5 pmol/L, CV = 6.7%). In a comparison study involving cytosols of breast adenocarcinoma tissue biopsies, we compared the EIA96 with the radioligand assay (RLA) and the Abbott ER-EIA, widely used techniques for determining ER concentration in cytosols of breast cancer tumors. The two EIAs showed excellent agreement; however, two samples showed discrepant results by EIA96 and RLA.

Microtiter plate immunoenzymometric assay for estrogen receptor

The estrogen receptor (ER) status of breast cancer is used both as a prognostic factor and as a predictor of response to endocrine therapy. An immunoenzymometric assay for ER was developed on 96-well microtiter plates (EIA96). This technique involves two monoclonal antibodies directed against different epitopes in the B domain of ER. The two-step protocol (16-18 h and 3 h at 4 degrees C) requires 100 microL of cytosol. This assay showed a detection limit of 0.58 pmol/L. Intra- and interassay CVs of clinical specimens were &lt; or = 5% except for the least concentrated sample (6.5 pmol/L, CV = 6.7%). In a comparison study involving cytosols of breast adenocarcinoma tissue biopsies, we compared the EIA96 with the radioligand assay (RLA) and the Abbott ER-EIA, widely used techniques for determining ER concentration in cytosols of breast cancer tumors. The two EIAs showed excellent agreement; however, two samples showed discrepant results by EIA96 and RLA.

A genotype study of the c-Ha-ras-1 locus in human bladder tumors

PURPOSE

To clarify the role of the c-Ha-ras-1 gene in bladder cancer predisposition and prognosis.

MATERIALS AND METHODS

The c-Ha-ras-1 locus was studied by Southern blotting in white blood cells and tumor samples obtained from 126 patients with bladder cancer (74 Ta-T1 and 52 T2-T4). A comparison with 84 unaffected patients and a survival analysis were performed.

RESULTS

The patients with bladder cancer presented 7 different c-Ha-ras-1 alleles, 12 different genotypes, heterozygosity in 49% of cases and a loss of heterozygosity (in the tumor) in 13 cases. The most frequent allele (a1, 6.6 kb) was present in 83% of patients. Heterozygosity correlated with vascular invasion in the tumor (p < 0.0001). In the small subgroup of 11 patients with rare alleles and genotypes, these alleles and genotypes occurred more often in patients with T2-T4 tumors (p < 0.01 for alleles and genotypes), aneuploid tumors (p < 0.001, p < 0.005) and tumors with vascular invasion (p < 0.01, p < 0.005). However, in this study, the majority of patients with high risk tumors possessed common alleles and genotypes. Survival analysis showed that neither the c-Ha-ras-1 genotype nor allelomorphism was an independent prognostic factor. Elsewhere, no rare allele occurred more frequently in bladder cancer affected patients than in unaffected patients.

CONCLUSION

This study confirms c-Ha-ras-1 gene polymorphism in a bladder cancer affected population and, in some cases, a loss of genetic material in the vicinity of this locus. No specific genotype can be implicated in the predisposition to bladder carcinoma, and c-Ha-ras-1 genotyping appears of limited value in the clinical management of these patients.

[Restriction polymorphism of C-HA-ras-1 locus in bladder tumors]

The c-Ha-ras-1 polymorphism was studied in 92 bladder tumor samples (newly diagnosed and/or recurrent) obtained from 73 patients and in the paired white blood cells (WBC). A heterozygous state was detected in WBC DNA of 38 patients (52%). The statistical analysis (univariate and multivariate) demonstrated an association between the heterozygous state of the patients and a lymphatic invasion. In patients with a pTa tumor, there was a relation between the heterozygous state and a younger age at diagnosis. A loss of heterozygosity for c-Ha-ras-1 locus was detected in seven out of the 38 informative tumors (18.4%). No significant correlation was observed with the prognostic factors. These results address the relation between the heterozygous genomic state and the risk of lymphatic invasion in the patients with a bladder tumor.

Human breast cancer: correlation study between HER-2/neu amplification and prognostic factors in an unselected population

In 199 breast cancers, HER-2/neu amplification was analyzed by Southern blotting (149 cases) and by slot blotting (149 cases), with 99 cases studied using both techniques. There were 18.8% amplified tumors (> or = 2 copies) by Southern blotting and 15.4% by slot blotting. The difference in the percentages of amplified tumors was not statistically significant (p = 0.44). There was a correlation between HER-2/neu amplification and the SBR grade (p = 0.046): this correlation relied on the absence of amplification in the GI tumors. In a subset study, the negativity of the progesterone receptor content was correlated with HER-2/neu amplification in the node positive (p = 0.02), the pre-menopausal (p = 0.04) and the pre-menopausal node positive (p = 0.002) patients. In the literature as in our results, amplification appears to be correlated with poor prognostic factors. However, in a subgroup with most of the favorable prognostic factors: positive estrogen and progesterone receptor contents and node negativity, the frequency of amplified tumors (19.4%, n = 67) was the same as that observed in the whole group (16.6%, n = 199). This result may suggest that the HER-2/neu amplification could act as an independent prognostic factor.

A sulfone group-labeled TEM-DNA probe: comparison with a 32P-labeled probe in dot-hybridization

A non-radioactive DNA probe for the TEM-type beta-lactamase gene was obtained by using the 'Chemiprobe' system. It was used along with a 32P-labeled TEM probe to screen for TEM beta-lactamase gene in 107 bacterial isolates representing 7 Gram-negative genera and previously classified as TEM-positive or negative. The DNA to be tested was extracted from these bacterial isolates by the Birnboim-Doly method and, after blotting into charged nylon membranes, it was submitted to hybridization with either the TEM 'Chemiprobe' or the 32P-TEM probe. The TEM 'Chemiprobe' could detect as few as 25 pg specific DNA if it was used at a concentration of 5 ng per cm2 of membrane. The results obtained by both probes were concordant in 93.5% of the entire sample. The TEM 'Chemiprobe' was specific since only one false positive was observed. Furthermore, it appeared at least as sensitive as the 32P-labeled TEM probe. As the dot-hybridization with the sulfone-labeled probe was sensitive, simple and easy to perform, it will be useful for large-scale screening in clinical laboratory.