REGISTRI: Regorafenib in first-line of KIT/PDGFRA wild type metastatic GIST: a collaborative Spanish (GEIS), Italian (ISG) and French Sarcoma Group (FSG) phase II trial.

BACKGROUND: Approximately 15% of adult GIST patients harbor tumors that are wild-type for KIT and PDGFRα genes (KP-wtGIST). These tumors usually have SDH deficiencies, exhibit a more indolent behavior and are resistant to imatinib. Underlying oncogenic mechanisms in KP-wtGIST include overexpression of HIF1α high IGFR signaling through the MAPK pathway or BRAF activating mutation, among others. As regorafenib inhibits these signaling pathways, it was hypothesized that it could be more active as upfront therapy in advanced KP-wtGIST. METHODS: Adult patients with advanced KP-wtGIST after central confirmation by NGS, naïve of systemic treatment for advanced disease, were included in this international phase II trial. Eligible patients received regorafenib 160 mg per day for 21 days every 28 days. The primary endpoint was disease control rate (DCR), according to RECIST 1.1 at 12 weeks by central radiological assessment. RESULTS: From May 2016 to October 2020, 30 patients were identified as KP-wtGIST by Sanger sequencing and 16 were confirmed by central molecular screening with NGS. Finally, 15 were enrolled and received regorafenib. The study was prematurely closed due to the low accrual worsened by COVID outbreak. The DCR at 12 weeks was 86.7% by central assessment. A subset of 60% experienced some tumor shrinkage, with partial responses and stabilization observed in 13% and 87% respectively, by central assessment. SDH-deficient GIST showed better clinical outcome than other KP-wtGIST. CONCLUSIONS: Regorafenib activity in KP-wtGIST compares favorably with other tyrosine kinase inhibitors, especially in the SDH-deficient GIST subset and it should be taken into consideration as upfront therapy of advanced KP-wtGIST. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02638766.

Perianal Paget's disease.

The incidence of extramammary Paget's disease (EMPD) is very low. It is very important to distinguish between primary Paget's disease and secondary to another process. An 85-year-old man consulted for the presence of an erythematous plaque located in the anal and gluteal area, confirming Paget cells in the biopsy.

Epithelioid Sarcoma in the Median Nerve of the Hand: A Case Report.

Epithelioid sarcoma of the peripheral nerves is extremely rare. We present a case concerning the median nerve of the right hand in a 35-year-old woman who was treated with radical resection, reconstructive surgery, and chemotherapy. After 2 years of follow-up, there is no evidence of local recurrence or metastatic dissemination.

Frequency of low-level and high-level mosaicism in sporadic retinoblastoma: genotype-phenotype relationships.

Somatic mutational mosaicism is a common feature of monogenic genetic disorders, particularly in diseases such as retinoblastoma, with high rates of de novo mutations. The detection and quantification of mosaicism is particularly relevant in these diseases, since it has important implications for genetic counseling, patient management, and probably also on disease onset and progression. In order to assess the rate of somatic mosaicism (high- and low-level mosaicism) in sporadic retinoblastoma patients, we analyzed a cohort of 153 patients with sporadic retinoblastoma using ultra deep next-generation sequencing. High-level mosaicism was detected in 14 out of 100 (14%) bilateral patients and in 11 out of 29 (38%) unilateral patients in whom conventional Sanger sequencing identified a pathogenic mutation in blood DNA. In addition, low-level mosaicism was detected in 3 out of 16 (19%) unilateral patients in whom conventional screening was negative in blood DNA. Our results also reveal that mosaicism was associated to delayed retinoblastoma onset particularly in unilateral patients. Finally we compared the level of mosaicism in different tissues to identify the best DNA source to identify mosaicism in retinoblastoma patients. In light of these results we recommended analyzing the mosaic status in all retinoblastoma patients using accurate techniques such as next-generation sequencing, even in those cases in which conventional Sanger sequencing identified a pathogenic mutation in blood DNA. Our results suggest that a significant proportion of those cases are truly mosaics that could have been overlooked. This information should be taking into consideration in the management and genetic counseling of retinoblastoma patients and families.

Expression of dog1 in low-grade fibromyxoid sarcoma: A study of 19 cases and review of the literature.

DOG1 is a highly-sensitive marker often included in the immunohistochemical panel for the diagnosis of gastrointestinal stromal tumors (GISTs). Recent research has shown that DOG1 may also be expressed by low-grade fibromyxoid sarcomas (LGFMSs); this may give rise to diagnostic error when the sarcoma is located in the abdominal cavity. This paper reports on immnohistochemical expression of DOG1 in 19 LGFMSs using two different monoclonal antibodies: K9 (Leica, Novocastra Laboratories, Newcastle upon Tyne, UK) and SP31 (Thermo Scientific, Freemont, USA). All LGFMSs displayed the standard histological pattern of alternating myxoid and fibrous areas, low cellularity and bland spindle-cell morphology. Positive staining for MUC4 was observed in 18/19 cases (94.7%), while there was rearrangement of the FUS gene in 14/19 (73.7%) cases and of the EWR1 gene in 2/19 (10.5%). The sarcoma staining negative for MUC4 displayed FUS gene rearrangement. Whole-section immunohistochemistry revealed positive staining for DOG1 in 8/19 cases (42.1%), though only with clone K9. Cytoplasmic as well as membrane staining was observed in all cases; staining was focal (10-30%) and of varying intensity (1+ to 2+). In conclusion, DOG1 clone K9 exhibited low sensitivity (42.1%) for the diagnosis of LGFMS, although higher than clone SP31. Since the two clones display similar sensitivity and specificity for GIST diagnosis, SP31 would appear to be more specific for this purpose, since no reaction was observed here with LGFMS, a GIST-mimicking lesion.

A study of the suitability of autoencoders for preprocessing data in breast cancer experimentation.

Breast cancer is the most common cause of cancer death in women. Today, post-transcriptional protein products of the genes involved in breast cancer can be identified by immunohistochemistry. However, this method has problems arising from the intra-observer and inter-observer variability in the assessment of pathologic variables, which may result in misleading conclusions. Using an optimal selection of preprocessing techniques may help to reduce observer variability. Deep learning has emerged as a powerful technique for any tasks related to machine learning such as classification and regression. The aim of this work is to use autoencoders (neural networks commonly used to feed deep learning architectures) to improve the quality of the data for developing immunohistochemistry signatures with prognostic value in breast cancer. Our testing on data from 222 patients with invasive non-special type breast carcinoma shows that an automatic binarization of experimental data after autoencoding could outperform other classical preprocessing techniques (such as human-dependent or automatic binarization only) when applied to the prognosis of breast cancer by immunohistochemical signatures.

Epidemiology of Barrett's esophagus and esophageal adenocarcinoma in Spain. A unicentric study.

INTRODUCTION: Barrett's esophagus (BE) is an acquired disease defined by the presence of intestinal metaplasia with goblet cells in the distal esophagus. The prevalence of BE has increased dramatically over the last years. AIMS: The primary aims of the study were to analyze the characteristics of BE and esophageal adenocarcinoma (EAC) in a Spanish health district during a follow-up period. METHODOLOGY: Sociodemographic factors, alcohol consumption and cigarette smoking were analyzed. We also studied the histological behavior and cause of death in each group. RESULTS: In the present study 430 patients were included, 338 with BE and 92 with EAC. Incidence rates have risen from 2.25 and 1.25 per 100,000 inhabitants in 1996 to 6.5 and 4.75 per 100,000 in 2011, respectively. In the EAC group, male gender, age and alcohol consumption were higher in comparison to the BE group, and the overall survival was 23 months. In the BE group, the main causes of death were non-esophageal cancer and cardiovascular disease. CONCLUSIONS: The incidence and prevalence rates of AEC and BE have risen over the past years. Risk factors for these conditions were male gender, age and alcohol consumption. Long BE (> 3 cm) is involved in dysplasia progression. AEC diagnosis mainly occurs after neoplasia is detected and, in a few cases, due to a previous BE. Cardiovascular diseases and non-esophageal cancers have been found to be the main cause of death in BE patients.

MicroRNA deregulation in triple negative breast cancer reveals a role of miR-498 in regulating BRCA1 expression.

Emerging evidence suggests that BRCA1 pathway contributes to the behavior of sporadic triple negative breast cancer (TNBC), but little is known about the mechanisms underlying this association. Considering the central role that microRNAs (miRNAs) play in gene expression regulation, the aim of this study was to identify miRNAs specifically deregulated in TNBC and investigate their involvement in BRCA1 regulation. Using locked nucleic acid (LNA)-based microarrays, expression levels of 1919 miRNAs were measured in paraffin-embedded tissues from 122 breast tumors and 11 healthy breast tissue samples. Differential miRNA expression was explored among the main subtypes of breast cancer, and 105 miRNAs were identified as specific for triple negative tumors. In silico prediction revealed that miR-498 and miR-187-5p target BRCA1, and these results were confirmed by luciferase reporter assay. While miR-187-5p was found overexpressed in a luminal B cell line, miR-498 was highly expressed in a triple negative cell line, Hs578T, and its expression was negatively correlated with the levels of BRCA1. We functionally demonstrated that miR-498 inhibits BRCA1 in breast cancer cell lines, and showed that inhibition of miR-498 led to reduced proliferation in the triple negative cell line Hs578T. Our results indicate that miR-498 regulates BRCA1 expression in breast cancer and its overexpression could contribute to the pathogenesis of sporadic TNBC via BRCA1 downregulation.

Tumor microRNA expression profiling identifies circulating microRNAs for early breast cancer detection.

BACKGROUND: The identification of novel biomarkers for early breast cancer detection would be a great advance. Because of their role in tumorigenesis and stability in body fluids, microRNAs (miRNAs) are emerging as a promising diagnostic tool. Our aim was to identify miRNAs deregulated in breast tumors and evaluate the potential of circulating miRNAs in breast cancer detection. METHODS: We conducted miRNA expression profiling of 1919 human miRNAs in paraffin-embedded tissue from 122 breast tumors and 11 healthy breast tissue samples. Differential expression analysis was performed, and a microarray classifier was generated. The most relevant miRNAs were analyzed in plasma from 26 healthy individuals and 83 patients with breast cancer (36 before and 47 after treatment) and validated in 116 healthy individuals and 114 patients before treatment. RESULTS: We identified a large number of miRNAs deregulated in breast cancer and generated a 25-miRNA microarray classifier that discriminated breast tumors with high diagnostic sensitivity and specificity. Ten miRNAs were selected for further investigation, of which 4 (miR-505-5p, miR-125b-5p, miR-21-5p, and miR-96-5p) were significantly overexpressed in pretreated patients with breast cancer compared with healthy individuals in 2 different series of plasma. MiR-505-5p and miR-96-5p were the most valuable biomarkers (area under the curve 0.72). Moreover, the expression levels of miR-3656, miR-505-5p, and miR-21-5p were decreased in a group of treated patients. CONCLUSIONS: Circulating miRNAs reflect the presence of breast tumors. The identification of deregulated miRNAs in plasma of patients with breast cancer supports the use of circulating miRNAs as a method for early breast cancer detection.

Endobronchial lipoma: a rare cause of bronchial occlusion.

Endobronchial lipoma is a rare benign neoplasm of the tracheobronchial tree. Despite its benign nature, associated endoluminal polypoid growth can cause bronchial occlusion. In this paper, we present the consequences of a late diagnosis of this condition.

Gastrointestinal stromal tumors (GISTs): role of CD 117 and PDGFRA Golgi-like staining pattern in the recognition of mutational status.

AIMS: to determine whether potential correlations between CD117 and PDGFRA might serve as an indication for targeted therapies. MATERIAL AND METHODS: immunohistochemical expression of CD117 and PDGFRA was evaluated in 99 paraffin-embedded GISTs in conjunction with KIT and PDGFRA mutational status. RESULTS: CD117-positive staining was noted in 93 out of 99 cases. The predominant staining pattern was cytoplasmic, either with or without membrane accentuation; in 44.5% of cases, a clear Golgi-like pattern was evident. Correlations were found between KIT mutation and both CD117 expression (p = 0.006) and Golgi-like pattern (p = 0.026). Cytoplasmic PDGFRA-positive staining was detected in 87% of cases, both with and without membrane accentuation; in 8% cases an evident Golgi-like staining pattern was observed. A significant correlation was noted between PDGFRA mutations and Golgi-like staining pattern (p = 0.001). Moreover, 95% of PDGFRA-positive GISTs were also CD117-positive, suggesting that expression of the two markers is not mutually exclusive; most of these had mutations in KIT exon 11. PDGFRA-positive/CD117-negative tumors had mutations in PDGFRA, mainly in exon 18. PDGFRA-negative/CD117-negative staining was observed in 15% of cases, all of which displayed mutations in KIT exon 11. CD117-positive/PDGFRA-negative cases were characterized by mutations in KIT, mainly in exon 11. CONCLUSIONS: CD117 and PDGFRA staining are not exclusive, and the presence of a Golgi-like staining pattern for either, whilst not pathognomonic, is highly suggestive of KIT and PDGFRA mutated GISTs, respectively, and may be used with some reservations as an alternative indication for prescribing targeted therapies.

Old and new immunohistochemical markers for the diagnosis of gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are generally CD117-positive and KIT or PDGFRA mutation-driven mesenchymal tumors of the gastrointestinal tract, probably originating in interstitial cells of Cajal or related precursors. CD117 is the best diagnostic marker for GISTs, but 5-10% are negative. Staining pattern may be cytoplasmic, membrane, and paranuclear (Golgi pattern). PDGFRA expression can be located in the cytoplasm, membrane, and paranuclear region (Golgi pattern), but the lack of specificity, ubiquity of the staining, and technical problems have pushed it a second plane. In GISTs, the staining pattern of PKCO is cytoplasmic, diffuse, and granular, although a Golgi pattern may be seen. Global expression varies. The staining pattern of DOG1 varies from cytoplasmic to membranous, with usually strong, diffuse intensity. The positivity rate is almost identical in some series to CD117 positivity. Currently, it is considered the most specific and sensitive marker for GIST. The current panel for GIST includes CD117, smooth muscle actin, CD34, desmin, and S-100. Some authors also include PDGFRA, PKC0, and DOG1. The last two can be of value in a subset of GISTs, mainly in CD117-negative cases.

Human papillomavirus detection by PCR assay in a large series of high-grade squamous intraepithelial lesions with cytohistological correlation and follow-up.

OBJECTIVE: High-grade squamous intraepithelial lesions (HSIL) are the precursors of invasive cervical carcinomas and are generally associated with the integration of mucosotropic human papillomavirus (HPV) DNA into the host cell genome. Detection of HPV is easy to perform nowadays, even in laboratories with limited technological capacity, and follow-up procedures for patients with HSIL are well established. STUDY DESIGN: HPV detection was performed in a large group of patients with HSIL, and results were correlated with cytological, histological, and colposcopic findings. Discrepancies were examined and discussed. RESULTS: Conventional Papanicolaou (Pap) screening detected 446 HSIL (0.20%) in 218,906 cervical smears. HPV detection by PCR was positive in 339/358 (94.7%) patients. The strains involved were: HPV 16 in 180 patients (53.1%), HPV 18 in 35 (10.3%), HPV 31/33 in 27 (8%), HPV 6/11 in 10 (2.96%), and an unidentified type in 73 (30%). For the last 97 patients (2006-2007), HPV typing was expanded with the following results: HPV 52 was detected in 9 patients (9.2%), HPV 58 in 6 (6.1%), HPV 51 in 4 (4.1%), HPV 68 in 2 (2.0%), and HPV 39 in 1 (1.0%). The number of nonidentified patients dropped to 9 (9.4%); in addition, 14/97 (14.4%) patients were infected with 2 or more viral types. Finally, 19 (5.3%) patients were HPV negative. Colposcopy revealed minor changes in 59 patients (17.3%), major changes in 264 (77.6%), and normal findings in 17 (5.1%). A biopsy was taken in 331/446 patients, and the diagnosis of HSIL or overt malignancy was histologically confirmed in 281 (84.9%) patients: CIN II in 46, CIN III in 224, and histologically upgraded in 11 (6 microinvasive squamous carcinomas, 1 squamous carcinoma, 2 in situ endocervical adenocarcinomas, and 2 microinvasive endocervical adenocarcinomas). Thirty-five patients (10.6%) were downgraded to CIN I and 15 (4.5%) patients had a negative biopsy. Follow-up in the negative-biopsy patients confirmed the existence of SIL in 11 patients [1 HSIL and 10 low-grade squamous intraepithelial lesions (LSIL)] while 4 were considered false positives (atrophic changes, 2; reactive changes, 2). After treatment, 31/331 (9.36%) patients displayed recurrence (HSIL in 29 and LSIL in 2). The viral strains involved in patients with recurrence were HPV 16 in 16 patients (51.6%); HPV 18 in 4 (12.9%); HPV 16 and 18 in 1 (3.2%); HPV 31 in 1 (3.2%); HPV 52 in 1 (3.2%); HPV 18, 31, and 58 in 1 (3.2%); HPV 68 in 1 (3.2%); HPV 51 and 73 in 1 (3.2%), and an unidentified type in 5 (16.1%). Follow-up in 14/19 HSIL and HPV-negative patients confirmed the existence of cervical pathology. CONCLUSIONS: HPV detection improves diagnostic sensitivity and provides an ideal tool for monitoring the response to treatment in HSIL patients. The pathogenic relevance of HPV strain 18 may be greater than previously assumed.

Gastrointestinal stromal tumors: morphological, immunohistochemical and molecular changes associated with kinase inhibitor therapy.

Recurrent or metastatic GISTs are currently treated with kinase inhibitors since they achieves disease control in 70-85% of patients but this response depend on KIT and PDGFRA gene mutation status. We review the morfological and molecular findings associated to kinase inhibitors administration in GISTs based on the literature on Medline and authors' own experience. The initial response to kinase inhibitors (imatinib mesylate, Gleevec, Novartis) usually is partial and depend on the mutational KIT or PDGFRA state. Amongst patients wih KIT mutations, the best results are achived in those harboring exon 11 (85%) and exon 9 (45%) mutations. GISTs harboring PDGFRA gene mutations generally respond favorably except those involving the Asp842Val mutation. In the absence of KIT/PDGFRA gene mutations, partial response or disease stabilization is reported in 23% and 50% of patients, respectively, and disease progression in 19%. Histological examination of tumors displaying an initial response to imatinib reveals a highly-variable reduction in the number of tumor cells, a decline in the proliferative index, myxohyaline or sclerohyaline stroma, and a varying degree of bleeding and edema, necrosis and cystification. 72% of patients with initial good response to imatinib, display metastases or new nodule growth within an existing clinically-quiescent tumor after 12-36 months of treatment. This secondary resistance is characterized by a number of well-defined morphological and molecular changes. Histologically, the new growths display increased mitotic activity, pleomorphism, an epithelioid or mixed phenotype and persistent KIT expression although more rarely, dedifferentiation and loss of KIT expression (Fig. 4), as well as trans-differentiation into a rhabdomyosarcoma or epithelial phenotype has been reported. Molecularly, 46-67% of patients present additional KIT mutations, generally in the kinase domain (exons 13, 14 and 17) but also in the ATP-binding domain (exons 15,16) of the same allele. Secondary PDGFRA mutations are very rare. Secondary mutations have not been observed in GISTs not harboring KIT/PDGFRA mutations, or in tumors displaying an unusual morphology or loss of CD117 expression. A number of studies highlight the presence of different resistance mutations within different new tumor nodules, as well as the simultaneous development of distinct resistant tumor subclones within a single lesion (acquired polyclonal resistance). Secondary mutation in genes other than KIT/PDGFRA has only been reported in BRAF (Val600Glu).