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Dive into the research topics where Jacob Korach is active.

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Featured researches published by Jacob Korach.


International Journal of Gynecological Cancer | 2009

Uterine leiomyosarcoma: does the primary surgical procedure matter?

Tamar Perri; Jacob Korach; Siegal Sadetzki; Bernice Oberman; Eddie Fridman; Gilad Ben-Baruch

Background: Uterine leiomyosarcoma (LMS) has a poor prognosis even after early-stage diagnosis. Because there are no accurate diagnostic tools for preoperatively distinguishing LMS from uterine leiomyoma, surgeons might opt for partial surgical procedures such as myomectomy or subtotal hysterectomy. We sought to determine whether a surgical procedure that cuts through the tumor influences prognosis. Materials and Methods: Demographic and clinical data of consecutive patients with stage I LMS treated between 1969 and 2005 were reviewed. The study population was divided into group A: patients whose first surgical intervention was total hysterectomy (n = 21); and group B: patients who underwent procedures involving tumor injury, for example, myomectomy, laparoscopic hysterectomy with a morcellator knife, or hysteroscopic myomectomy (n = 16). Survival rates were analyzed and compared. A Cox proportional hazards model was used to assess the association between variables of interest and prognosis. Results: The median age at diagnosis was 50 years (range, 30-74 years). Median follow-up duration was 44 months. The 2 groups did not differ significantly in age at diagnosis, menopausal status, gravidity, parity, postoperative radiotherapy, or time to last follow-up. Kaplan-Meier curves showed significantly better survival rates (P = 0.04) and a significant advantage in recurrence rate (P = 0.03) for group A compared with group B. Survival in group A was 2.8-fold better than that in group B (95% confidence interval, 1.02-7.67). These estimates remained stable after adjustment for age, menopausal status, and radiotherapy. Conclusions: In patients with stage I LMS, primary surgery involving tumor injury seems to be associated with a worse prognosis than total hysterectomy as a primary intervention.


Gynecologic Oncology | 2014

Exposure of fallopian tube epithelium to follicular fluid mimics carcinogenic changes in precursor lesions of serous papillary carcinoma

Hadar Brand; Stav Sapoznik; J. Jacob-Hirsch; Yuval Yung; Jacob Korach; Tamar Perri; Yoram Cohen; Ariel Hourvitz; Keren Levanon

OBJECTIVES Ovulation-related inflammation is suspected to have a causal role in ovarian carcinogenesis, but there are no human models to study the molecular pathways. Our aim is to develop such an ex-vivo model based on human fallopian tube (FT) epithelium exposed to human follicular fluid (FF). METHODS FT epithelium was dissociated from normal surgical specimens. FF was obtained from donors undergoing in-vitro fertilization. The cells were cultured on collagen-coated Transwells and incubated with FF for various periods of time. The transcriptomic changes resulting from FF treatment were profiled using Affymetrix expression arrays. Specific characteristics of the FT pre-cancerous lesions were studied using immunohistochemistry, immunofluorescence, RT-PCR and XTT assay. RESULTS We show that FF exposure causes up-regulation of inflammatory and DNA repair pathways. Double stranded DNA breaks are induced. There is a minor increase in cell proliferation. TP53, which is the hallmark of the precursor lesion in-vivo, is accumulated. Levels of expression and secretion of Interleukin-8 are significantly increased. CONCLUSIONS Our model addresses the main non-genetic risk factor for ovarian cancer, namely the impact of ovulation. This study demonstrates the biological implications of in-vitro exposure of human FT epithelial cells to FF. The model replicates elements characterizing the precursor lesions of ovarian cancer, and warrants further investigation of the linkage between repeated exposure to ovulation-related damage and accumulation of neoplastic changes.


Gynecologic Oncology | 2010

AKT1 pleckstrin homology domain E17K activating mutation in endometrial carcinoma.

Yoram Cohen; Bruria Shalmon; Jacob Korach; Iris Barshack; Eddie Fridman; Gideon Rechavi

OBJECTIVES The PI3K/AKT pathway is frequently activated in endometrial carcinoma (EC) mainly due to mutations in the PIK3CA and PTEN genes. These events are common and believed to be the key to endometrial carcinogenesis. Recently, a somatic activating mutation in the AKT1 gene (E17K) was identified in several cancer types. In this study we explored the frequency of this AKT1 mutation in endometrial carcinoma. METHODS Tumor DNA, extracted from 73 EC was analyzed for AKT1 E17K mutation (G49A) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In addition, the tumors were screened for coexisting common mutations in PTEN, PIK3CA and KRAS. RESULTS The AKT1 E17K mutation was detected in 4% of EC. One of the AKT1-mutated tumors showed coexisting PTEN loss-of-function mutation. CONCLUSION We identified the AKT1 E17K mutation in 4% of endometrial carcinomas. The presence of double AKT1/ PTEN mutants is in accord with the hypothesis that in EC more than one hit is required to completely activate the PI3K pathway. Furthermore, AKT1 mutations were limited to high grade, advanced stage tumors suggesting that this mutation confers a more aggressive tumor behavior.


International Journal of Gynecological Cancer | 2011

Prolonged conservative treatment of endometrial cancer patients: more than 1 pregnancy can be achieved.

Tamar Perri; Jacob Korach; Walter H. Gotlieb; Mario E. Beiner; Dror Meirow; Eddie Friedman; Alex Ferenczy; Gilad Ben-Baruch

Background: Preserving reproductive function in young patients with early endometrial cancer is an accepted concept today. The safety and feasibility of long-term conservative treatment, allowing more than 1 pregnancy, remain to be ascertained. Methods: This study was a retrospective chart review of a 27 women with endometrioid adenocarcinoma of the endometrium, who were treated conservatively at 2 tertiary-care institutions. Treatment comprised oral high-dose progestins with or without a levonorgestrel-releasing intrauterine device. Endometrial biopsy was repeated every 2 to 3 months. Results: Over 7.8 to 412 months (median, 57.4 months), tumors regressed completely in 24 (89%) of 27 patients and partially in 2 patients, with 79% responding within 1 to 17 months. Of the complete responders, 15 (62%) of 24 had a recurrence; 4 underwent hysterectomy, and 11 underwent subsequent progestational treatment. All 11 responded, and 3 subsequently conceived. After 2 to 4 years, 5 patients again had a recurrence, of whom 3 underwent hysterectomy. Overall, 2 patients developed ovarian adenocarcinoma. All patients are currently disease-free. Conception occurred in 14 (51.8%) of 27 patients, in 5 more than once. There were 17 live births, and 2 patients are pregnant. Conclusions: According to our data, prolonged progestational therapy for early-stage endometrial adenocarcinoma, allowing women to conceive, is feasible and apparently does not alter clinical outcome. Patients should be advised of the high recurrence rate and possible concomitant ovarian malignancy.


International Journal of Gynecological Cancer | 2009

Promising effect of aromatase inhibitors on recurrent granulosa cell tumors.

Jacob Korach; Tamar Perri; Mario E. Beiner; Tima Davidzon; Eddie Fridman; Gilad Ben-Baruch

Recurring adult-type granulosa cell tumors of the ovary are usually treated by surgical resection followed by chemotherapy or radiation. However, the results of such treatment are disappointing. We describe 4 patients in whom recurrent ovarian granulosa cell tumors were treated with an aromatase inhibitor, with promising results.


Cancer Epidemiology, Biomarkers & Prevention | 2008

Anti-Mesothelin Antibodies and Circulating Mesothelin Relate to the Clinical State in Ovarian Cancer Patients

Ingegerd Hellström; Eitan Friedman; Thorsten Verch; Yi Yang; Jacob Korach; Jade Jaffar; Elizabeth M. Swisher; Boxin Zhang; Gilad Ben-Baruch; Marcus C.B. Tan; Peter S. Goedegebuure; Karl Erik Hellström

Most human ovarian carcinomas express mesothelin, which is shed as a diagnostically useful biomarker. We applied an ELISA to measure antibodies to native mesothelin in serum from a series of patients with divergent clinical outcomes. The level of anti-mesothelin antibodies determined as OD450 nm and referred to as absorption units (AU) for 1:20 diluted serum was higher in patients who remained disease-free after therapy [no evidence of disease (NED); n = 14] than in patients whose disease recurred [clinical evidence of disease (CED); n = 21; P < 0.01]. Applying AU ≥ 0.5 at a serum dilution of 1:20 as cutoff, 10 of 14 (71%) ovarian carcinoma patients with NED and 9 of 21 (43%) patients with CED had antibodies to mesothelin compared with 6 of 23 (26%) healthy women (P < 0.008) and 5 of 24 (21%) women with other benign gynecologic diseases (P < 0.003), whereas 7 of 9 (78%) of women with pelvic inflammatory disease were positive. Three of the 14 (21%) NED patients had circulating mesothelin detected as an AU ≥ 0.2 at a serum dilution of 1:40 (P < 0.005) compared with 15 of 21 (71%) CED patients, and 9 of 14 (64%) NED patients (P < 0.0002) were positive for antibodies and negative for antigen compared with 1 of 21 (5%) CED patients. Although our data indicate that an antibody response to mesothelin is an important correlate of ovarian carcinoma, prospective studies are needed to show whether the measurement of such antibodies (alone or together with antigen) aids the diagnosis and monitoring of patients. (Cancer Epidemiol Biomarkers Prev 2008;17(6):1520–6)


Gynecologic Oncology | 2011

FOXL2 C402G mutation detection using MALDI-TOF-MS in DNA extracted from Israeli granulosa cell tumors

Rotem Gershon; Sarit Aviel-Ronen; Jacob Korach; Vered Daniel-Carmi; Camila Avivi; Dalia Bar-Ilan; Iris Barshack; Dror Meirow; Gilad Ben-Baruch; Yoram Cohen

OBJECTIVE To develop a rapid, sensitive and reliable method to detect FOXL2 C402G mutation in granulosa cell tumor (GCT) and to investigate the prevalence of FOXL2 mutation in granulose cell tumors among Israeli patients. METHODS We designed and optimized a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) genotyping assay to detect FOXL2 C402G mutation in DNA isolated from formalin-fixed paraffin-embedded tissue samples. We examined 20 tumor samples obtained from Israeli patients diagnosed with granulose cell tumor. RESULTS Eighteen out of 20 samples were found to harbor FOXL2 C402G mutation. Pathological review of the two tumors harboring wild type FOXL2 (C402) concluded that they were adenocarcinomas and has been misclassified at initial diagnosis. We found that the prevalence of FOXL2 mutations among Israeli patients with GCT (100%) is similar to previous reports. CONCLUSIONS Our results indicate that the FOXL2 mutations can be reliably detected by MALDI-TOF-MS genotyping. MALDI-TOF-MS genotyping is a simple, robust and highly sensitive method to detect FOXL2 C402G mutation. Our results confirm previous studies reporting over 95% prevalence of FOXL2 mutation in GCT. Furthermore, we suggest that testing for the presence of the FOXL2 C402G mutation may improve diagnostic accuracy.


The Journal of Urology | 1993

Conservative Treatment of a Vesicocervical Fistula Resulting from Shirodkar Cervical Cerclage

Jacob Golomb; Jacob Ben-Chaim; Benad Goldwasser; Jacob Korach; Shlomo Mashiach

A case of a vesicocervical fistula caused by Shirodkar cervical cerclage and presenting as total urinary incontinence is reported. The patient was managed conservatively by bladder drainage alone with complete resolution of the fistulous tract. This rare complication is avoidable if the bladder is adequately dissected from the cervix during placement of the cerclage suture.


Abdominal Imaging | 2006

Importance of accurate preoperative diagnosis in the management of aggressive angiomyxoma: report of three cases and review of the literature

A. Wiser; Jacob Korach; Walter H. Gotlieb; Eduard Fridman; Sara Apter; Gilad Ben-Baruch

Background:Aggressive angiomyxoma is a benign but locally aggressive tumor that occurs mostly in young women. Because excision is often incomplete, the risk of local recurrence is high. This report describes differences in presentation and the importance of accurate preoperative diagnosis of this rare neoplasm.Methods and results:We describe three cases with different presentations. Two were initially misdiagnosed, and local recurrence necessitated reoperation. Accurate diagnosis in the third case was followed by complete excision, with no recurrence.Conclusion:Aggressive angiomyxoma should be considered in the differential diagnosis of young women who present with a well-defined mass in the pelvic tissue. Accurate preoperative diagnosis should alert the surgeon to the need for wide excision, which is essential for prevention of local recurrence.


Acta Obstetricia et Gynecologica Scandinavica | 1996

A prospective study of high‐ versus low‐dose oxytocin for induction of labor

Ariel Hourvitz; M. Alcalay; Jacob Korach; Gad Barkai; Daniel S. Seidman

Background. To assess the efficacy and safety of a high‐dosage oxytocin induction regimen.

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Nicoletta Colombo

European Institute of Oncology

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Amit M. Oza

Princess Margaret Cancer Centre

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