Recurrent pelvic organ prolapse after hysterectomy; a 10-year national follow-up study.

PURPOSE: Hysterectomy may be a risk factor for pelvic organ prolapse (POP). We assessed the risk of recurrent POP (operations and visits) after hysterectomy among women with previous POP. We also studied patient and operation related risk factors for POP recurrence. METHODS: This retrospective cohort study included 1697 women having previous POP diagnosis or POP at the time of hysterectomy (FINHYST 2006 cohort). Follow-up was until the end of 2016. The data was derived from the Finnish National Care register linked to the cohort. Hysterectomy approaches and other demographics were compared to the risk of a prolapse diagnosis and/or surgery. Cox regression model was used to identify hazard ratios. RESULTS: Following hysterectomy, a total of 280 women (16.5%) had a POP reoperation and 359 (21.2%) had an outpatient visit due to POP. Vaginal vault prolapse repair was the most common POP reoperation (n = 181, 10.7%), followed by anterior wall repair (n = 120, 7.1%). Median time to POP reoperation was 3.7 years. Hysterectomy approach did not affect reoperations or visits. Previous cesarean section and anterior repair during hysterectomy were associated with decreased risk, whereas concomitant sacrospinous fixation and uterus prolapse as the main indication led to increased risk of anterior/vault prolapse reoperations. Concomitant posterior repair decreased posterior reoperations and visits, but uterus weight over 500 g caused a fivefold increased risk of posterior prolapse visit. Residential status was associated with elevated risk of any POP reoperations and visits. CONCLUSIONS: Approximately one out of five women suffering from POP ensue POP reoperation or visit after hysterectomy. These high rates are independent on hysterectomy approach, but probably indicate that hysterectomy may worsen previous pelvic floor dysfunction.

Pelvic organ prolapse after hysterectomy: A 10-year national follow-up study.

INTRODUCTION: Hysterectomy may have an effect on the pelvic floor. Here, we evaluated the rates and risks for pelvic organ prolapse (POP) surgeries and visits among women with a history of hysterectomy for benign indication excluding POP. MATERIAL AND METHODS: In this retrospective cohort study 3582 women who underwent hysterectomy in 2006 were followed until the end of 2016. The cohort was linked to the Finnish Care Register to catch any prolapse-related diagnoses and operation codes following the hysterectomy. Different hysterectomy approaches were compared according to the risk for a prolapse, including abdominal, laparoscopic, laparoscopic-assisted vaginal and vaginal. The main outcomes were POP surgery and outpatient visit for POP, and Cox regression was used to identify risk factors (hazard ratios [HR]). RESULTS: During the follow-up, 58 women (1.6%) underwent a POP operation, of which a posterior repair was the most common (n = 39, 1.1%). Outpatient visits for POP symptoms occurred in 92 (2.6%) women of which posterior wall prolapses (n = 58, 1.6%) were the most common. History of laparoscopic-assisted vaginal hysterectomy were associated with risk for POP operation (HR 3.0, p = 0.02), vaginal vault prolapse operation (HR 4.3, p = 0.01) and POP visits (HR 2.2, p < 0.01) as compared to the approach of abdominal hysterectomy. History of vaginal deliveries and concomitant stress urinary continence operation were associated with the risk for a POP operation (HR 4.4 and 11.9) and POP visits (HR 3.9 and 7.2). CONCLUSIONS: Risk for POP operations and outpatient visits for POP symptoms in hysterectomized women without a preceding POP seems to be small at least 10 years after hysterectomy. History of LAVH, vaginal deliveries and concomitant stress urinary incontinence operations increased the risk for POP operations after hysterectomy. These data can be utilized in counseling women considering hysterectomy for benign indication.

Parity associates with chromosomal damage in uterine leiomyomas.

Mechanical forces in a constrained cellular environment were recently established as a facilitator of chromosomal damage. Whether this could contribute to tumorigenesis is not known. Uterine leiomyomas are common neoplasms that display relatively few chromosomal aberrations. We hypothesized that if mechanical forces contribute to chromosomal damage, signs of this could be seen in uterine leiomyomas from parous women. We examined the karyotypes of 1946 tumors, and found a striking overrepresentation of chromosomal damage associated with parity. We then subjected myometrial cells to physiological forces similar to those encountered during pregnancy, and found this to cause DNA breaks and a DNA repair response. While mechanical forces acting in constrained cellular environments may thus contribute to neoplastic degeneration, and genesis of uterine leiomyoma, further studies are needed to prove possible causality of the observed association. No evidence for progression to malignancy was found.

Hysterectomy Provides Benefit in Health-Related Quality of Life: A 10-Year Follow-up Study.

STUDY OBJECTIVE: This study aims to evaluate short- and long-term effects of hysterectomy on health-related quality of life (HRQoL) and compare that with a representative age-standardized sample from the general population. DESIGN: A prospective survey as a part of FINHYST study. SETTING: Four Helsinki area hospitals. PATIENTS: Eight hundred thirty-six women with hysterectomy because of benign indications during 2006. INTERVENTIONS: A change in HRQoL assessed by the 15D instrument at baseline, and after 6 months and 10 years. The HRQoL of women was also compared with that of the age-standardized sample from the general female population. MEASUREMENTS AND MAIN RESULTS: Most hysterectomies were performed laparoscopically (41.8%), followed by vaginal (38.2%) and abdominal (20%) approaches. Indications were classified into 6 subgroups; myoma, abnormal uterine bleeding (AUB), endometriosis, pelvic organ prolapse (POP), adnexal mass, and precancerous lesions. The preoperative mean HRQoL in the patients was lower than that of the general population. In the whole study population, hysterectomy provided the greatest improvement in the dimensions of distress, vitality, discomfort and symptoms, and sexual activity, both short- and long-term. Those operated on for myoma, AUB, endometriosis, and POP showed an improved mean HRQoL after 6 months, whereas after 10 years in those operated on for myoma, AUB, and endometriosis, the HRQoL was still better than at baseline. Women with endometriosis never reached HRQoL of the general population. This is right, but the HRQoL of the general population remained lower than that of all other groups. CONCLUSION: Hysterectomy provided long-term improvement in HRQoL, especially in women with myoma, AUB, and endometriosis.

Genetic predisposition to uterine leiomyoma is determined by loci for genitourinary development and genome stability.

Uterine leiomyomas (ULs) are benign tumors that are a major burden to women's health. A genome-wide association study on 15,453 UL cases and 392,628 controls was performed, followed by replication of the genomic risk in six cohorts. Effects of the risk alleles were evaluated in view of molecular and clinical characteristics. 22 loci displayed a genome-wide significant association. The likely predisposition genes could be grouped to two biological processes. Genes involved in genome stability were represented by TERT, TERC, OBFC1 - highlighting the role of telomere maintenance - TP53 and ATM. Genes involved in genitourinary development, WNT4, WT1, SALL1, MED12, ESR1, GREB1, FOXO1, DMRT1 and uterine stem cell marker antigen CD44, formed another strong subgroup. The combined risk contributed by the 22 loci was associated with MED12 mutation-positive tumors. The findings link genes for uterine development and genetic stability to leiomyomagenesis, and in part explain the more frequent occurrence of UL in women of African origin.

Global metabolomic profiling of uterine leiomyomas.

BACKGROUND: Uterine leiomyomas can be classified into molecularly distinct subtypes according to their genetic triggers: MED12 mutations, HMGA2 upregulation, or inactivation of FH. The aim of this study was to identify metabolites and metabolic pathways that are dysregulated in different subtypes of leiomyomas. METHODS: We performed global metabolomic profiling of 25 uterine leiomyomas and 17 corresponding myometrium specimens using liquid chromatography-tandem mass spectroscopy. RESULTS: A total of 641 metabolites were detected. All leiomyomas displayed reduced homocarnosine and haeme metabolite levels. We identified a clearly distinct metabolomic profile for leiomyomas of the FH subtype, characterised by metabolic alterations in the tricarboxylic acid cycle and pentose phosphate pathways, and increased levels of multiple lipids and amino acids. Several metabolites were uniquely elevated in leiomyomas of the FH subtype, including N6-succinyladenosine and argininosuccinate, serving as potential biomarkers for FH deficiency. In contrast, leiomyomas of the MED12 subtype displayed reduced levels of vitamin A, multiple membrane lipids and amino acids, and dysregulation of vitamin C metabolism, a finding which was also compatible with gene expression data. CONCLUSIONS: The study reveals the metabolomic heterogeneity of leiomyomas and provides the requisite framework for strategies designed to target metabolic alterations promoting the growth of these prevalent tumours.

Multiple clinical characteristics separate MED12-mutation-positive and -negative uterine leiomyomas.

Up to 86% of uterine leiomyomas harbour somatic mutations in mediator complex subunit 12 (MED12). These mutations have been associated with conventional histology, smaller tumour size, and larger number of tumours within the uterus. Prior studies, with limited sample sizes, have failed to detect associations between other clinical features and MED12 mutations. Here, we prospectively collected 763 uterine leiomyomas and the corresponding normal myometrial tissue from 244 hysterectomy patients, recorded tumour characteristics, collected clinical data from medical records, and screened the tissue samples for MED12 mutations to assess potential associations between clinical variables and mutation status. Out of 763 leiomyomas, 599 (79%) harboured a MED12 mutation. In the analysis of tumour characteristics, positive MED12-mutation status was significantly associated with smaller tumour size, conventional histology, and subserous location, relative to intramural. In the analysis of clinical variables, the number of MED12-mutation-positive tumours showed an inverse association with parity, and the number of mutation-negative tumours showed a positive association with a history of pelvic inflammatory disease. This study confirmed the previously reported differences and discovered novel differentiating features for MED12-mutation-positive and -negative leiomyomas. These findings emphasise the relevance of specific driver mutations in genesis and presentation of uterine leiomyomas.

MED12 mutations and FH inactivation are mutually exclusive in uterine leiomyomas.

BACKGROUND: Uterine leiomyomas from hereditary leiomyomatosis and renal cell cancer (HLRCC) patients are driven by fumarate hydratase (FH) inactivation or occasionally by mediator complex subunit 12 (MED12) mutations. The aim of this study was to analyse whether MED12 mutations and FH inactivation are mutually exclusive and to determine the contribution of MED12 mutations on HLRCC patients' myomagenesis. METHODS: MED12 exons 1 and 2 mutation screening and 2SC immunohistochemistry indicative for FH deficiency was performed on a comprehensive series of HLRCC patients' (122 specimens) and sporadic (66 specimens) tumours. Gene expression analysis was performed using Affymetrix GeneChip Human Exon Arrays (Affymetrix, Santa Clara, CA, USA). RESULTS: Nine tumours from HLRCC patients harboured a somatic MED12 mutation and were negative for 2SC immunohistochemistry. All remaining successfully analysed lesions (107/116) were deficient for FH. Of sporadic tumours, 35/64 were MED12 mutation positive and none displayed a FH defect. In global gene expression analysis FH-deficient tumours clustered together, whereas HLRCC patients' MED12 mutation-positive tumours clustered together with sporadic MED12 mutation-positive tumours. CONCLUSIONS: Somatic MED12 mutations and biallelic FH inactivation are mutually exclusive in both HLRCC syndrome-associated and sporadic uterine leiomyomas. The great majority of HLRCC patients' uterine leiomyomas are caused by FH inactivation, but incidental tumours driven by somatic MED12 mutations also occur. These MED12 mutation-positive tumours display similar expressional profiles with their sporadic counterparts and are clearly separate from FH-deficient tumours.

Integrated data analysis reveals uterine leiomyoma subtypes with distinct driver pathways and biomarkers.

Uterine leiomyomas are common benign smooth muscle tumors that impose a major burden on women's health. Recent sequencing studies have revealed recurrent and mutually exclusive mutations in leiomyomas, suggesting the involvement of molecularly distinct pathways. In this study, we explored transcriptional differences among leiomyomas harboring different genetic drivers, including high mobility group AT-hook 2 (HMGA2) rearrangements, mediator complex subunit 12 (MED12) mutations, biallelic inactivation of fumarate hydratase (FH), and collagen, type IV, alpha 5 and collagen, type IV, alpha 6 (COL4A5-COL4A6) deletions. We also explored the transcriptional consequences of 7q22, 22q, and 1p deletions, aiming to identify possible target genes. We investigated 94 leiomyomas and 60 corresponding myometrial tissues using exon arrays, whole genome sequencing, and SNP arrays. This integrative approach revealed subtype-specific expression changes in key driver pathways, including Wnt/ß-catenin, Prolactin, and insulin-like growth factor (IGF)1 signaling. Leiomyomas with HMGA2 aberrations displayed highly significant up-regulation of the proto-oncogene pleomorphic adenoma gene 1 (PLAG1), suggesting that HMGA2 promotes tumorigenesis through PLAG1 activation. This was supported by the identification of genetic PLAG1 alterations resulting in expression signatures as seen in leiomyomas with HMGA2 aberrations. RAD51 paralog B (RAD51B), the preferential translocation partner of HMGA2, was up-regulated in MED12 mutant lesions, suggesting a role for this gene in the genesis of leiomyomas. FH-deficient leiomyomas were uniquely characterized by activation of nuclear factor erythroid 2-related factor 2 (NRF2) target genes, supporting the hypothesis that accumulation of fumarate leads to activation of the oncogenic transcription factor NRF2. This study emphasizes the need for molecular stratification in leiomyoma research and possibly in clinical practice as well. Further research is needed to determine whether the candidate biomarkers presented herein can provide guidance for managing the millions of patients affected by these lesions.

Detection and screening of chromosomal rearrangements in uterine leiomyomas by long-distance inverse PCR.

Genome instability is a hallmark of many tumors and recently, next-generation sequencing methods have enabled analyses of tumor genomes at an unprecedented level. Studying rearrangement-prone chromosomal regions (putative "breakpoint hotspots") in detail, however, necessitates molecular assays that can detect de novo DNA fusions arising from these hotspots. Here we demonstrate the utility of a long-distance inverse PCR-based method for the detection and screening of de novo DNA rearrangements in uterine leiomyomas, one of the most common types of human neoplasm. This assay allows in principle any genomic region suspected of instability to be queried for DNA rearrangements originating there. No prior knowledge of the identity of the fusion partner chromosome is needed. We used this method to screen uterine leiomyomas for rearrangements at genomic locations known to be rearrangement-prone in this tumor type: upstream HMGA2 and within RAD51B. We identified a novel DNA rearrangement upstream of HMGA2 that had gone undetected in an earlier whole-genome sequencing study. In more than 30 additional uterine leiomyoma samples, not analyzed by whole-genome sequencing previously, no rearrangements were observed within the 1,107 bp and 1,996 bp assayed in the RAD51B and HMGA2 rearrangement hotspots. Our findings show that long-distance inverse PCR is a robust, sensitive, and cost-effective method for the detection and screening of DNA rearrangements from solid tumors that should be useful for many diagnostic applications.

Clonally related uterine leiomyomas are common and display branched tumor evolution.

Uterine leiomyomas are extremely frequent benign smooth muscle tumors often presenting as multiple concurrent lesions and causing symptoms such as abnormal menstrual bleeding, abdominal pain and infertility. While most leiomyomas are believed to arise independently, a few studies have encountered separate lesions harboring identical genetic changes, suggesting a common clonal origin. To investigate the frequency of clonally related leiomyomas, genome-wide tools need to be utilized, and thus little is known about this phenomenon. Using MED12 sequencing and SNP arrays, we searched for clonally related uterine leiomyomas in a set of 103 tumors from 14 consecutive patients who entered hysterectomy owing to symptomatic lesions. Whole-genome sequencing was also utilized to study the genomic architecture of clonally related tumors. This revealed four patients to have two or more tumors that were clonally related, all of which lacked MED12 mutations. Furthermore, some tumors were composed of genetically distinct subclones, indicating a nonlinear, branched model of tumor evolution. DEPDC5 was discovered as a novel tumor suppressor gene playing a role in the progression of uterine leiomyomas. Perhaps counterintuitively­considering Knudson's two-hit hypothesis­a large shared deletion was followed by different truncating DEPDC5 mutations in four clonally related leiomyomas. This study provides insight into the intratumor heterogeneity of these tumors and suggests that a shared clonal origin is a common feature of leiomyomas that do not carry an MED12 mutation. These observations also offer one explanation to the common occurrence of multiple concurrent lesions.

Hysterectomies in Finland in 1990-2012: comparison of outcomes between trainees and specialists.

OBJECTIVE: To assess trends for hysterectomy methods in the Nordic countries and to compare outcomes of hysterectomies in Finland done by trainees with those done by specialists. DESIGN: Register-based study. SETTING: NOMESCO database for the Nordic countries and the Finnish Hospital Discharge Register. POPULATION: National prospective cohort of 5279 hysterectomies in Finland. METHODS: Numbers of hysterectomies in the Nordic countries were collected in 1995-2011 and in Finland in 1990-2012. The Finhyst study to collect data on hysterectomies for benign indications was carried out in Finland in 2006. Information concerning patients, surgeons, and hysterectomy outcome was analysed. MAIN OUTCOME MEASURES: Hysterectomy numbers and methods. Operating time, blood loss, and complications in hysterectomies done by trainees and specialists. RESULTS: In Finland, the rate of hysterectomies has been reduced by approximately 50% since the 1990s and is now similar to that in the other Nordic countries. The laparoscopic method is twice as common in Finland as in other Nordic countries, constituting 35-40% of all hysterectomies. The operating time for all hysterectomy methods was 16-25% longer among trainees than specialists. For the abdominal or laparoscopic methods there were no significant differences in the complication rates between the groups. In the vaginal approach, blood loss of ≥1000 mL was slightly more common in operations done by trainees (1.3% vs. 2.6%, p = 0.037). CONCLUSIONS: Laparoscopic hysterectomy is more common in Finland than in the other Nordic countries. Although trainees need more time to operate, there were no differences between the trainees and the specialists with regard to major complication rates.

MED12 mutation frequency in unselected sporadic uterine leiomyomas.

OBJECTIVE: To determine the frequency of mediator complex subunit 12 (MED12) mutations in well-documented, prospectively collected, unselected series of sporadic uterine leiomyomas to better understand the contribution of MED12 mutations in leiomyoma genesis. DESIGN: Mutation analysis of two prospectively collected sample series. SETTING: Department of gynecology in university hospital and medical genetics research laboratory. PATIENT(S): 164 uterine leiomyomas from 28 patients (13 consecutive and 15 unselected patients) undergoing hysterectomy. INTERVENTION(S): MED12 mutation screening by direct sequencing, and clinical data collection. MAIN OUTCOME MEASURE(S): MED12 mutation status and various clinical variables. RESULT(S): MED12 mutations were found in 73 (83.0%) of 88 and 65 (85.5%) of 76 of uterine leiomyomas from the consecutive and unselected patient series, respectively. Smaller tumor size and a larger number of tumors correlated with positive MED12 mutation status. CONCLUSION(S): The frequency of MED12 mutations in our prospectively collected uterine leiomyoma sets was higher than in previous works. This is in keeping with the concept that MED12 mutation-positive tumors tend to be smaller in size than MED12 mutation-negative tumors. The results highlight the central role of MED12 mutations in uterine leiomyoma genesis.

Mutations in Exon 1 highlight the role of MED12 in uterine leiomyomas.

Mediator regulates transcription by connecting gene-specific transcription factors to the RNA polymerase II initiation complex. We recently discovered by exome sequencing that specific exon 2 mutations in mediator complex subunit 12 (MED12) are extremely common in uterine leiomyomas. Subsequent screening studies have focused on this mutational hot spot, and mutations have been detected in uterine leiomyosarcomas, extrauterine leiomyomas and leiomyosarcomas, endometrial polyps, and colorectal cancers. All mutations have been missense changes or in-frame insertions/deletions. Here, we have analyzed 611 samples representing all above-mentioned tumor types for possible exon 1 mutations. Five mutations were observed, all of which were in-frame insertion/deletions in uterine leiomyomas. Transcriptome-wide expression data revealed that MED12 exon 1 and exon 2 mutations lead to the same unique global gene expression pattern with RAD51B being the most upregulated gene. Immunoprecipitation and kinase activity assays showed that both exon 1 and exon 2 mutations disrupt the interaction between MED12 and Cyclin C and CDK8/19 and abolish the mediator-associated CDK kinase activity. These results further emphasize the role of MED12 in uterine leiomyomas, show that exon 1 and exon 2 exert their tumorigenic effect in similar manner, and stress that exon 1 should be included in subsequent MED12 screenings.

The effectiveness of urinary incontinence treatments measured using the 15D Health-Related Quality of Life instrument.

INTRODUCTION AND HYPOTHESIS: The health-related quality of life (HRQoL) is significantly impaired among urinary incontinent women and the effectiveness of urinary incontinence (UI) treatment should be measured using an HRQoL instrument. METHODS: A prospective, observational study evaluating the HRQoL of 178 non-selected UI patients referred for routine treatment at the Helsinki University Central Hospital between the years 2004 and 2010. HRQoL was assessed using the generic 15D questionnaire on four occasions: before treatment, 6 and 18 months after treatment, and after a median follow-up of 5 years. The HRQoL of the patients was compared with that of an age-standardized Finnish female population. RESULTS: Compared with the general population, the baseline total HRQoL score of the patients was significantly impaired (p < 0.001). It was worse among the urge or mixed (UUI (±SUI)) incontinence patients than among the stress incontinence (SUI) patients (p = 0.035). During follow-up, HRQoL improved and the improvement was more substantial among the operatively than among the conservatively treated patients (p = 0.027). Statistically significant improvement was only seen in the SUI group (Δ + 0.021, 95 % CI 0.005-0.036), but clinically relevant improvement was also found in the operatively treated UUI (±SUI) group. The maximum benefit of treatment was reached between at 2 and 3 years. CONCLUSIONS: 15D is a sensitive tool for monitoring the change in HRQoL and could be implemented into clinical practice. Operative treatment of UI is effective when measured by improved HRQoL. Not only SUI patients, but also selected patients with an urgency component may benefit from surgery.

Exomic landscape of MED12 mutation-negative and -positive uterine leiomyomas.

Uterine leiomyomas are extremely common tumors originating from the smooth muscle cells of myometrium. We recently reported recurrent somatic mutations in mediator complex subunit 12 (MED12) in the majority of these lesions, and analyzed chromosomal abnormalities in leiomyomas by whole-genome sequencing. The aim of our study was to examine in detail uterine leiomyoma exomes, to search for driver mutations in MED12 mutation-negative leiomyomas and to scrutinize MED12 mutation-positive leimyomas for additional contributing mutations. We analyzed whole exome sequencing data of 27 uterine leiomyomas (12 MED12 mutation-negative and 15 MED12 mutation-positive) and their paired normal myometrium. We searched for genes, which would be recurrently mutated. No such genes were identified in MED12 mutation-negative uterine leiomyomas. Similarly, MED12 mutation-positive leiomyomas displayed no additional recurrent changes. The complete lack of novel driver point mutations in the examined series highlights the unique role of MED12 mutations in genesis of uterine leiomyomas, and suggests that these mutations alone may be sufficient for tumor development. Additional factors that cannot be detected by exome sequencing, such as somatic structural rearrangements, epigenetic events and intronic variants, are likely to have a particular impact to the development of MED12 wild-type lesions.

Ten years of progress--improved hysterectomy outcomes in Finland 1996-2006: a longitudinal observation study.

OBJECTIVES: To study the outcome of various hysterectomies in 2 years 1996 (N =10110) and 2006 (N=5279). The hypothesis was that the change in operative practices in 10 years has resulted in improvements. DESIGN: 2 prospective nationwide cohort evaluations with the same questionnaire. SETTING: All national operative hospitals in Finland. PARTICIPANTS: Patients scheduled to either abdominal hysterectomy (AH), vaginal hysterectomy (VH) or laparoscopic hysterectomy (LH) for benign disease. OUTCOME MEASURES: Patients' characteristics, surgery-related details and complications (organ injury, infection, venous thromboembolism and haemorrhage). RESULTS: The overall complication rates fell in LH and markedly in VH (from 22.2% to 11.7%, p<0.001). The overall surgery-related infectious morbidity decreased in all groups and significantly in VH (from 12.3% to 5.2%, p<0.001) and AH (from 9.9% to 7.7%, p<0.05). The incidence of bowel lesions in VH sank from 0.5% to 0.1% and of ureter lesions in LH from 1.1% to 0.3%. In 2006 there were no deaths compared with three in 1996. CONCLUSIONS: The rate of postoperative complications fell markedly in the decade from 1996 to 2006. This parallels with the recommendation of the recent meta-analyses by Cochrane collaboration; the order of preference of hysterectomies was for the first time precisely followed in this nationwide study. TRIAL REGISTRATION: The 2006 study was registered in the Clinical Trials of Protocol Registration System Data (NCT00744172).

Characterization of uterine leiomyomas by whole-genome sequencing.

BACKGROUND: Uterine leiomyomas are benign but affect the health of millions of women. A better understanding of the molecular mechanisms involved may provide clues to the prevention and treatment of these lesions. METHODS: We performed whole-genome sequencing and gene-expression profiling of 38 uterine leiomyomas and the corresponding myometrium from 30 women. RESULTS: Identical variants observed in some separate tumor nodules suggested that these nodules have a common origin. Complex chromosomal rearrangements resembling chromothripsis were a common feature of leiomyomas. These rearrangements are best explained by a single event of multiple chromosomal breaks and random reassembly. The rearrangements created tissue-specific changes consistent with a role in the initiation of leiomyoma, such as translocations of the HMGA2 and RAD51B loci and aberrations at the COL4A5-COL4A6 locus, and occurred in the presence of normal TP53 alleles. In some cases, separate events had occurred more than once in single tumor-cell lineages. CONCLUSIONS: Chromosome shattering and reassembly resembling chromothripsis (a single genomic event that results in focal losses and rearrangements in multiple genomic regions) is a major cause of chromosomal abnormalities in uterine leiomyomas; we propose that tumorigenesis occurs when tissue-specific tumor-promoting changes are formed through these events. Chromothripsis has previously been associated with aggressive cancer; its common occurrence in leiomyomas suggests that it also has a role in the genesis and progression of benign tumors. We observed that multiple separate tumors could be seeded from a single lineage of uterine leiomyoma cells. (Funded by the Academy of Finland Center of Excellence program and others.).

MED12, the mediator complex subunit 12 gene, is mutated at high frequency in uterine leiomyomas.

Uterine leiomyomas, or fibroids, are benign tumors that affect millions of women worldwide and that can cause considerable morbidity. To study the genetic basis of this tumor type, we examined 18 uterine leiomyomas derived from 17 different patients by exome sequencing and identified tumor-specific mutations in the mediator complex subunit 12 (MED12) gene in 10. Through analysis of 207 additional tumors, we determined that MED12 is altered in 70% (159 of 225) of tumors from a total of 80 patients. The Mediator complex is a 26-subunit transcriptional regulator that bridges DNA regulatory sequences to the RNA polymerase II initiation complex. All mutations resided in exon 2, suggesting that aberrant function of this region of MED12 contributes to tumorigenesis.

FINHYST, a prospective study of 5279 hysterectomies: complications and their risk factors.

BACKGROUND: Hysterectomy guidelines highlight an increase in urinary tract injuries with laparoscopic hysterectomy (LH). This national survey analyses complications of LH, abdominal hysterectomy (AH) and vaginal hysterectomy (VH). METHODS: A prospective cohort undergoing hysterectomy for benign indications during 2006 was drawn from 53 hospitals in Finland; all communal hospitals participated. Detailed questionnaires covered surgical data and intra- and post-operative major and minor complications, for which risk factors were analysed by a multivariate logistic regression model adjusted for surgical data and patient characteristics. RESULTS: Major complications rates in AH (n= 1255, 24%), LH (1679, 32%) and VH (2345, 44%) were 4.0, 4.3 and 2.6%, and total complications rates were 19.2, 15.4 and 11.7%, respectively. Logistic regression showed no statistically significant differences between approaches for any organ injuries or other major complications. Most bladder and bowel injuries (88 and 83%), but not ureter injuries (10%), were recognized intra-operatively. The ureter injury rate was low after LH (0.3%), as it was after other types of hysterectomy. Compared with LH, AH increased the odds of wound infection, and was an independent risk factor for urinary infections and febrile events. Compared with AH, LH and VH both presented a higher risk for pelvic infection; surgically treated equally often regardless of the type of hysterectomy. No differences in complications emerged between LH and VH. Obesity was a risk factor for many infections. Surgical adhesiolysis [odds ratio (OR) 2.41, 95% confidence interval (CI) 1.38-4.21] was the strongest single risk factor for major complications as a whole. Bladder injury was associated with a history of caesarean section (OR 4.01, 95% CI 2.06-7.83) and with a large uterus ≥500 g (OR 2.88, 95% CI 1.05-7.90), while bowel injury was associated with adhesiolysis (OR 29.07, 95% CI 7.17-117.88). CONCLUSIONS: FINHYST is a large prospective hysterectomy study illustrating actual complications. Whenever possible, hysterectomy should be minimally invasive.