Omshree Shetty

Evidence for the presence of high risk human papillomavirus in retinoblastoma tissue from nonfamilial retinoblastoma in developing countries.

The prevalence of human papillomavirus (HPV) infection in India is high. HPV infection is known to cause cervical cancer and has also been implicated in the pathogenesis of retinoblastoma (RB), a common intraocular malignant tumor of childhood which can be familial or sporadic. Despite the high incidence of RB in India, its familial form is rare. Hence this study was undertaken to investigate whether high‐risk HPV types 16 and 18 are involved in the development of RB.

Pazopanib in metastatic multiply treated progressive gastrointestinal stromal tumors: feasible and efficacious

BACKGROUND A median progression free survival (PFS) of 18-20 months and median overall survival (OS) of 51-57 months can be achieved with the use of imatinib, in metastatic or advanced gastrointestinal stromal tumor (GIST). Sunitinib and regorafenib are approved options for patients progressing on imatinib, but with markedly decreased survival. pazopanib is a broad spectrum TKI targeting KIT, PDGFR and VEGFR receptors and has shown promising activity in phase 2 trials in GIST. METHODS All patients who received pazopanib for GIST between March 2014 and September 2015 in our institution were reviewed. Patients were assessed for response with CT or PET CT scans. Patients continued pazopanib until progression or unacceptable toxicity. Survival was evaluated by Kaplan Meier product method. RESULTS A total of 11 consecutive patients were included in our study. Median duration of follow up was seven months. The median lines of prior therapy was 2 [1-5]. Partial response (PR) was observed in seven patients and two had stable disease (SD). Two patients died within one month of start of pazopanib. Five of ten patients had progressed during the study with eight patients still alive. The median PFS was 11.9 months and the median OS was not reached. Common adverse events seen were hand-foot-syndrome (HFS) in four patients, anemia in four patients and fatigue in three patients. Grade 3/4 adverse events were uncommon. Three patients required dose modification of pazopanib. CONCLUSIONS Pazopanib is a reasonably efficacious well tolerated TKI and can be explored as a treatment option in advanced GIST that has progressed on imatinib.

Lymphoepithelioma-like carcinoma of breast—evaluation for Epstein-Barr virus–encoded RNA, human papillomavirus, and markers of basal cell differentiation

This is a largest series of 5 cases of lymphoepithelioma-like carcinoma (LEC) of the breast attempting to look at the expression of basal cytokeratins (CKs), human papillomavirus, and Epstein-Barr virus-encoded RNAs in these tumors. Five cases were selected after stringent evaluation of all breast carcinomas showing dense lymphoid infiltration. Histologically, all these tumors showed the typical histology except 1 tumor that showed an unusual granulomatous response. All tumors were negative for estrogen and progesterone receptors and HER2 (triple negative). Three tumors expressed CK5/6 and high-molecular-weight CK, whereas only the case with nodal metastasis expressed CK14. Analysis for in situ hybridization for Epstein-Barr virus-encoded RNAs and human papillomavirus DNA on paraffin-processed tissues was negative in all tumors. All of these patients received adjuvant therapy. One patient with tumor expressing basal marker, CK5/6, had contralateral breast malignancy after a duration of 53 months of treatment completion. The rest were disease free with the follow-up period in the range of 6 to 105 months. The lymphoepithelioma-like carcinoma of breast expressed basal CK profile that is more CK5/6 positive than CK14. Analysis of basal markers within these tumors may help in refining the definition of these tumors and in classifying them into prognostically relevant groups.

Outcomes and complications of surgery in patients with intermediate-risk neuroblastoma: experience from an Indian tertiary Cancer Centre

PurposeThe treatment of intermediate risk (IR) neuroblastoma has evolved with the focus now on reducing the drugs, dosage, and duration of chemotherapy. The aim of this study is to present the outcomes of treatment and the complications of surgery in patients with IR neuroblastoma treated at a tertiary cancer center in India.MethodsAll eligible patients with IR neuroblastoma treated between April 2005 and August 2016 were identified. The presence and number of image-defined risk factors (IDRF) before and after neoadjuvant chemotherapy were retrospectively analyzed as were the extent of surgery, complications, and outcomes.ResultsOf 282 neuroblastoma patients treated during the study period, 54 had IR neuroblastoma. Complete excision was achieved in 25 patients. There were 26 surgical complications in 22 patients with a similar incidence in patients with complete (n = 13) or incomplete (n = 13) resection (p = 0.78). After a median follow-up of 47 months, the 4-year overall and event-free survival was 91.5% and 75%, respectively. There was no difference in survival between patients who underwent complete resection versus those with incomplete resection (p = 0.9).ConclusionOutcomes of IR neuroblastoma are favorable. The extent of resection does not affect the survival and complications can occur even when the resection is incomplete.

A rare case of a solitary fibrous tumour of bone showing NAB2-STAT6 exon 3-exon 19 fusion

a solitary fibrous tumour (SFT) is a mesenchymal tumour of fibroblastic origin that invariably displays a prominent hemangiopericytoma (HPC)-like vasculature. Currently, hemangiopericytoma (HPC) of soft tissues is a disregarded entity and is rather considered as a growth pattern, more often seen in tumours such as synovial sarcomas, malignant peripheral nerve sheath tumours, myopericytomas and SFTs. In most SFTs, tumour cells are CD34 immunopositive.1-2 Lately, signal transducer and activator of transcription (STAT)6 has been identified as a highly sensitive and specific immunohistochemical (IHC) marker for diagnosing a SFT, and a surrogate for a specific fusion gene, NAB2-STAT6, characterizing most SFTs. This article is protected by copyright. All rights reserved.

Unraveling the spectrum of KIT mutations in gastrointestinal stromal tumors: An Indian Tertiary Cancer Center Experience

Background: Primary mutations in the KIT gene are the driving force for gastrointestinal stromal tumors (GIST) tumorigenesis. Predictive role of KIT mutation status aids oncologists in patient management. There is a paucity of comprehensive data on the frequency of mutations in the KIT gene in GIST affecting Indian patients. The aims of this study were to determine the frequency and spectrum of molecular alterations affecting the KIT gene and assess their association with clinicopathologic features in a cohort of patients of GIST. Materials and Methods: Morphological and immunohistochemically confirmed GIST cases (n = 114) accessioned from August 2014-June 2015 were analyzed for mutations in KIT exons 9, 11, 13, and 17 and subjected to Sanger sequencing onto the ABI 3500 Genetic Analyzer. The sequences were analyzed using sequence analysis software: SeqScape® and Chromas Lite. Results: KIT mutations were seen in 70% of cases and the majority of KIT mutations involved exon 11 (57%), followed by exon 9 (10%), exon 13 (3%), and exon 17 (1%). Most common exon 11 mutations were in-frame deletions (61.4%) followed by substitution mutations (19.3%). Exon 9 mutations showed identical duplication of Ala-Tyr at codons 502–503. Simultaneous mutations affecting exon 11 and 13 were discovered. Novel variations, namely, p.Q556E (c.1666C>G), p.Q556dup (c.1666_1668dupCAG), p.K558_V559delinsS (c.1672_1677delAAGGTTinsAGT), p.Y503_F504insTY (c.1509_1510insACCTAT), and p.K642R (c.1925A>G) involving exons 11, 9, and 13, respectively, were observed. Interpretation and Conclusions: First study with complete analysis of all 4 exons of KIT (exons 9, 11, 13, and 17) in Indian GIST patients. Along with well-described KIT mutations, several rare double mutations as well as novel alterations were reported in this series.

Clinical practice and outcomes in advanced gastrointestinal stromal tumor: Experience from an Indian tertiary care center

Background: Management of advanced Gastrointestinal stromal tumors (GIST) has been revolutionized with the use of Imatinib guided by mutation analysis. Data from India remains scarce. Materials and Methods: Patients with metastatic GIST who were treated at Department of Gastro-intestinal & Hepaticopancreaticobiliary Oncology Unit at Tata Memorial Hospital, Mumbai between December, 2004 and December 2015 were included in the analysis. Clinical and radiological data was retrieved from stored medical records and charts. Results: A total of 83 patients with metastatic GIST were available for analysis. Median age was 54 years with a 3:1 male predominance. Stomach was the most common site of primary with liver being the most common site of metastasis. c-Kit mutation analysis results were available for 44 patients with exon 11 mutant being the most common mutation. With a median follow up of 33 months, the 10 years estimated progression free and overall survival (OS) was 18% and 51% respectively. Overall response rate to first line imatinib was 37.6% and estimated 3 years OS to first line therapy was significantly better for Exon 11 mutated patients (p=0.016). 34 patients received second line therapy in the form of either sunitinib, pazopanib or increased dose imatinib with a clinical benefit rate of 73.5%. C-Kit mutated patients had a better median OS compared to non mutated patients. Conclusions: GIST diagnosed and treated in the Indian subcontinent appears to show improved outcomes. The importance of c-Kit mutation analysis in determining the prognosis and outcomes of patients with advanced GIST is emphasized.

Molecular characterization of a series of solitary fibrous tumors, including immunohistochemical expression of STAT6 and NATB2-STAT6 fusion transcripts, using Reverse Transcriptase(RT)–Polymerase chain reaction(PCR) technique: An Indian experience

A solitary fibrous tumor (SFT) is characterized by a diverse clinicopathologic spectrum. Recent studies have unraveled STAT6 as a useful diagnostic immunohistochemical (IHC) marker for a SFT and NAB2-STAT6 as its specific gene fusion transcript. Thirty-three SFTs were tested for STAT6 immunostaining by polymer detection technique. STAT6 immunoexpression was further graded, based on intensity (mild, moderate and strong) and percentage of immunopositive tumor cells, ranging from 1 to 25%(1+); 26-50%(2+); 51-75%(3+) and in more than 75%(4+) tumor nuclei. These cases along with 17 other tumors were tested for 8 variants of NAB2-STAT6, using qualitative endpoint reverse-transcriptase (RT)-PCR technique. RNA extraction was performed using Recover All Total nucleic acid extraction kit. The selected cases were screened for all the 8 fusion variants, using 8 primer pairs for NAB2 and STAT6 genes. Thirty-three SFTs occurred in 18 men and 15 women (M: F=1.2:1), with age varying from 13 to 74 years(average=49.6); across various body sites. Immunohistochemically, most SFTs (30/33) (90.9%) displayed moderate to strong immunostaining for STAT6, including 3+ and 4+ immunostaining patterns in 27/33 (81.8%) tumors. By RT-PCR, 30/33(90.9%) cases of SFT were positive for NAB2-STAT6 fusions, including NAB2ex4/STAT6ex2 (7cases), NAB2ex7/STAT6ex2 (7cases), NAB2ex6/STAT6ex3 (6cases), NAB2ex6/SAT6ex16 (4cases), NAB2ex3/STAT6ex19 (4cases), NAB2ex6/STAT6ex17 (single case), NAB2ex4/STAT6ex4 (single case) and NAB2ex6/STAT6ex18 (none). NAB2-STAT6 fusions were not observed in 9 cases of synovial sarcoma, 4 of Ewing sarcoma, 2 of MPNST and 2 cases of dedifferentiated liposarcomas (100% specificity). On comparing with clinical outcomes, more cases (7/11)(63.6%) of classic SFT were associated with favorable outcomes, while more cases(5/8)(62%) of atypical and malignant SFTs were associated with aggressive outcomes. This study reinforces high sensitivity and specificity of NAB2-STAT6 fusion and its correlation with strong and diffuse IHC expression of STAT6 in a SFT, irrespective of its occurrence in various body sites and its histopathologic types. NAB2ex4-STAT6ex2 and NAB2ex7-STAT6ex2 fusions were relatively more frequently observed in our patients. Atypical and malignant SFTs, together, were more frequently associated with relatively aggressive clinical outcomes.

Diffuse glioma – Rare homozygous IDH point mutation, is it an oncogenetic mechanism?

Isocitrate dehydrogenase (IDH1/IDH2) mutations in gliomas of WHO grade II/III and secondary glioblastoma are almost always heterozygous missense mutations. Here, we report an extremely rare case of homozygous IDH1R132H mutation in a recurrent WHO grade III anaplastic astrocytoma. The authors here also review the relevant literature for the possible metabolic impact of homozygous IDH1/2 mutations in the gliomagenesis.

A Rare Case of a Vaginal Solitary Fibrous Tumor, Presenting as a Cystic Mass, Showing NAB2ex4-STAT6ex2 Fusion and STAT6 Immunostaining

Solitary fibrous tumor (SFT) has been rarely documented in the female genital tract. Until now, only 5 such cases have been reported in the vagina. A 40-yr-old woman was referred to us with a history of antitubercular treatment and intra-abdominal adhesions; for which she previously underwent laparoscopic lysis of adhesions. Subsequently, she developed a vaginal mass, which appeared as a complex cyst on ultrasonogram. Histopathologic examination of the excised mass revealed a cellular spindle cell tumor with collagenous deposition in the stroma. The tumor cells were composed of oval to spindle shaped nuclei and were arranged in a diffuse, as well as in a focally, hemangiopercytomatous pattern. There were no significant mitotic figures or tumor necrosis. By immunohistochemistry, the tumor cells showed patchy positivity for CD34 and diffuse intranuclear positivity for STAT6, along with cytoplasmic positivity for MIC2 and BCL2. Few cells were estrogen receptor positive. MIB1/Ki67 highlighted 2% to 3% tumor nuclei (low). Diagnosis of a SFT was rendered. Subsequently, the tumor was subjected to molecular analysis, by reverse transcriptase-polymerase chain reaction and sequencing, which revealed presence of NAB2ex4-STAT6ex2 fusion transcript. This case constitutes the first case of a vaginal SFT confirmed by STAT6 immunostaining and NAB2-STAT6 fusion. It exemplifies the role of specific immunohistochemical markers, such as STAT6 in differentiating a SFT from various other spindle cell tumors occurring in this location. Literature review of similar reported cases and treatment implications in such cases are discussed herein.