Machine learning in liver surgery: Benefits and pitfalls

The application of machine learning (ML) algorithms in various fields of hepatology is an issue of interest. However, we must be cautious with the results. In this letter, based on a published ML prediction model for acute kidney injury after liver surgery, we discuss some limitations of ML models and how they may be addressed in the future. Although the future faces significant challenges, it also holds a great potential.

A comprehensive evaluation of 80 consecutive robotic low anterior resections: impact of not mobilizing the splenic flexure alongside low-tie vascular ligation as a standardized technique

Rectal cancer surgery represents challenges due to its location. To overcome them and minimize the risk of anastomosis-related complications, some technical maneuvers or even a diverting ileostomy may be required. One of these technical steps is the mobilization of the splenic flexure (SFM), especially in medium/low rectal cancer. High-tie vascular ligation may be another one. However, the need of these maneuvers may be controversial, as especially SFM may be time-consuming and increase the risk of iatrogenic. The objective is to present the short- and long-term outcomes of a low-tie ligation combined with no SFM in robotic low anterior resection (LAR) for mid- and low rectal cancer as a standardized technique. A retrospective observational single-cohort study was carried out at Reina Sofia University Hospital, Cordoba, Spain. 221 robotic rectal resections between Jul-18th-2018 and Jan-12th-2023 were initially considered. After case selection, 80 consecutive robotic LAR performed by a single surgeon were included. STROBE checklist assessed the methodological quality. Histopathological, morbidity and oncological outcomes were assessed. Anastomotic stricture occurrence and distance to anal verge were evaluated after LAR by rectosigmoidoscopy. Variables related to the ileostomy closure such as time to closure, post-operative complications or hospital stay were also considered. The majority of patients (81.2%) presented a mid-rectal cancer and the rest, lower location (18.8%). All patients had adequate perfusion of the anastomotic stump assessed by indocyanine green. Complete total mesorectal excision was performed in 98.8% of the patients with a lymph node ratio < 0.2 in 91.3%. The anastomotic leakage rate was 5%. One patient (1.5%) presented local recurrence. Anastomosis stricture occurred in 7.5% of the patients. The limitations were small cohort and retrospective design. The non-mobilization of the splenic flexure with a low-tie ligation in robotic LAR is a feasible and safe procedure that does not affect oncological outcomes.

Impact of the COVID-19 vaccination campaigns in Argentina during 2021: An observational quantification of the death probability for confirmed cases in Buenos Aires province

Background

A SARS-CoV-2 (COVID-19) vaccination campaign was launched in Argentina in January 2021. The vaccines then available were administered to the population in several different schemes. This observational study presents a quantification of the impact of the different schemes on the probability of death for confirmed COVID-19 cases in Argentina's Buenos Aires Province. The results provide a local measure of the schemes' effectiveness that heretofore has been lacking.

Methods

The study's main source of information is the Integrated Health Information System database, which contains 1,538,113 records of confirmed SARS-CoV-2 (COVID-19) cases reported in 2021 in the Province. To assess the real-world effectiveness of the vaccination campaign, two categorical variables representing vaccination status were defined. Probability of death was formulated as a generalized linear model with a logistic link and includes variables for geography, a socio-economic level index, symptom onset, sex, and vaccination status. The effectiveness level was derived from the death probability estimates.

Findings

The study's findings indicated that the most effective vaccine was rAd26-rAd5 (Sputnik), with ChAdOx1-S (AZ/Covishield) and BBIBP-CorV (Sinopharm) following in efficacy, for both single and multiple doses. The effectiveness of a single dose was consistently below 50%, while it ranged from 50% to 90% for two or more doses. Notably, the analysis of variables such as the municipality of residence of the infected persons and the season of symptom onset yielded particularly intriguing insights. The socioeconomic level of a municipality emerged as a moderately strong predictor of the probability of death, which was marginally higher in municipalities with lower-income populations. Additionally, the data revealed an increased probability of death during the winter season.

Interpretation

The vaccination campaigns carried out in Buenos Aires Province in 2021 significantly contributed to reducing the number of deaths due to SARS-CoV-2 (COVID-19) among its population. However, the extent of this impact varied considerably depending on individual characteristics such as age, health status, and vaccination schedule adherence.

Is unicentric familial papillary thyroid microcarcinoma different from multicentric?

BACKGROUND

Familial papillary thyroid microcarcinoma (FPTMC) appears to be more aggressive than sporadic papillary thyroid microcarcinoma (SPTMC). However, there are authors who indicate that unicentric FPTMC has a similar prognosis to SPTMC. The objective is to analyze whether unicentric FPTMC has a better prognosis than multicentric FPTMC.

DESIGN AND METHODS

Type of study: National multicenter longitudinal analytical observational study.

STUDY POPULATION

Patients with FPTMC.

STUDY GROUPS

Two groups were compared: Group A (unicentric FPTMC) vs. Group B (multicentric FPTMC).

STUDY VARIABLES

It is analyzed whether between the groups there are: a) differentiating characteristics; and b) prognostic differences.

STATISTICAL ANALYSIS

Cox regression analysis and survival analysis.

RESULTS

Ninety-four patients were included, 44% (n = 41) with unicentric FPTMC and 56% (n = 53) with multicentric FPTMC. No differences were observed between the groups according to socio-familial, clinical or histological variables. In the group B a more aggressive treatment was performed, with higher frequency of total thyroidectomy (99 vs. 78%; p = 0.003), lymph node dissection (41 vs. 15%; p = 0.005) and therapy with radioactive iodine (96 vs. 73%; p = 0.002). Tumor stage was similar in both groups (p = 0.237), with a higher number of T3 cases in the group B (24 vs. 5%; p = 0.009). After a mean follow-up of 90 ± 68.95 months, the oncological results were similar, with a similar disease persistence rate (9 vs. 5%; p = 0.337), disease recurrence rate (21 vs. 8%; p = 0.159) and disease-free survival (p = 0.075).

CONCLUSIONS

Unicentric FPTMC should not be considered as a SPTMC due to its prognosis is similar to multicentric FPTMC.

Transition from laparoscopic to robotic approach in rectal cancer: a single-center short-term analysis based on the learning curve

As a novel procedure becomes more and more used, knowledge about its learning curve and its impact on outcomes is useful for future implementations. Our aim is (i) to identify the phases of the robotic rectal surgery learning process and assess the safety and oncological outcomes during that period, (ii) to compare the robotic rectal surgery learning phases outcomes with laparoscopic rectal resections performed before the implementation of the robotic surgery program. We performed a retrospective study, based on a prospectively maintained database, with methodological quality assessment by STROBE checklist. All the procedures were performed by the same two surgeons. A total of 157 robotic rectal resections from June 2018 to January 2022 and 97 laparoscopic rectal resections from January 2018 to July 2019 were included. The learning phase was completed at case 26 for surgeon A, 36 for surgeon B, and 60 for the center (both A & B). There were no differences in histopathological results or postoperative complications between phases, achieving the same ratio of mesorectal quality, circumferential and distal resection margins as the laparoscopic approach. A transitory increase of major complications and anastomotic leakage could occur once overcoming the learning phase, secondary to the progressive complexity of cases. Robotic rectal cancer surgery learning curve phases in experienced laparoscopic surgeons was completed after 25-35 cases. Implementation of a robotic rectal surgery program is safe in oncologic terms, morbidity, mortality and length of stay.

Normothermic Regional Perfusion in Controlled Donation After Circulatory Determination of Death Simultaneous Pancreas - Kidney Transplantation

BACKGROUND

Simultaneous pancreas-kidney transplantation is the optimal treatment for patients with type 1 diabetes and renal failure. The use of pancreas grafts from donation after circulatory death (DCD), using normothermic regional perfusion (NRP), is still marginal worldwide, mainly due to possible additional risks of graft dysfunction and complications compared with grafts from donors after brain death.

METHODS

Case series of patients who underwent simultaneous pancreas-kidney transplantation after DCD-NRP between January 2018 and September 2022. This study evaluated early postoperative grafts and survival outcomes.

RESULTS

Four patients were included. One patient lost the pancreatic graft due to arterial thrombosis requiring transplantectomy. Another patient required a laparotomy due to hemoperitoneum. Overall, 1-year pancreas and kidney graft survival was 75% and 100%, respectively. One patient developed a lymphoma during the follow-up.

CONCLUSION

The use of pancreas grafts from DCD after NRP preservation is safe and feasible. Comparative studies with donors after brain death grafts and larger series are required to confirm the feasibility of DCD-NRP pancreas transplantation.

STAT3 phosphorylation at serine 727 activates specific genetic programs and promotes clear cell renal cell carcinoma (ccRCC) aggressiveness

The signal transducer and activator of transcription 3 (STAT3) is a transcription factor mainly activated by phosphorylation in either tyrosine 705 (Y705) or serine 727 (S727) residues that regulates essential processes such as cell differentiation, apoptosis inhibition, or cell survival. Aberrant activation of STAT3 has been related to development of nearly 50% of human cancers including clear cell renal cell carcinoma (ccRCC). In fact, phosho-S727 (pS727) levels correlate with overall survival of ccRCC patients. With the aim to elucidate the contribution of STAT3 phosphorylation in ccRCC development and progression, we have generated human-derived ccRCC cell lines carrying STAT3 Y705 and S727 phosphomutants. Our data show that the phosphomimetic substitution Ser727Asp facilitates a pro-tumoral phenotype in vitro, in a Y705-phosphorylation-independent manner. Moreover, we describe that STAT3 phosphorylation state determines the expression of different subsets of target genes associated with distinct biological processes, being pS727-dependent genes the most related to cellular hallmarks of cancer. In summary, the present study constitutes the first analysis on the role of overall STAT3 phosphorylation state in ccRCC and demonstrates that pS727 promotes the expression of a specific subset of target genes that might be clinically relevant as novel biomarkers and potential therapeutic targets for ccRCC.

Protocolization of multicenter clinical studies in the digital era. Is useful data centralization by a data-manager?

INTRODUCTION

In multicenter studies, the protocolization of data is a critical phase that can generate biases.The objective is to analyze the concordance and reliability of the data obtained in a clinical multicenter study between the protocolization in the center of origin and the centralized protocolization of the data by a data -manager.

METHODS

National multicenter clinical study about an infrequent carcinoma. A double protocolization of the data is carried out: (a) center of origin; and (b) centralized by a data manager: The concordance between the data is analyzed for the global data and for the two groups of the project: (a) study group (Familiar carcinoma, 30 researchers protocolize); (b) control group (Sporadic carcinoma, 4 people protocolize). Interobserver variability is evaluated using Cohen's kappa coefficient.

RESULTS

The study includes a total of 689 patients with carcinoma, 252 in the study group and 437 in the control group. Regarding the concordance analysis of the tumor stage, 2.5% of disagreements were observed and the concordance between people who protocolize was near perfect (Kappa = 0.931). Regarding the evaluation of the recurrence risk, disagreements occurred in 7% of the cases and the concordance was near perfect (Kappa = 0.819). Regarding the sonography evaluation (TIRADS), the disagreements were 6.9% and the concordance was near perfect (Kappa = 0.922). Also, 4.6% of transcription errors were detected.

CONCLUSIONS

In multicenter clinical studies, the centralized data protocolization o by a data-manager seems to present similar results to the direct protocolization in the database in the center of origin.

Machine perfusion and the prevention of ischemic type biliary lesions following liver transplant: What is the evidence?

The widespread uptake of different machine perfusion (MP) strategies for liver transplant has been driven by an effort to minimize graft injury. Damage to the cholangiocytes during the liver donation, preservation, or early posttransplant period may result in stricturing of the biliary tree and inadequate biliary drainage. This problem continues to trouble clinicians, and may have catastrophic consequences for the graft and patient. Ischemic injury, as a result of compromised hepatic artery flow, is a well-known cause of biliary strictures, sepsis, and graft failure. However, very similar lesions can appear with a patent hepatic artery and these are known as ischemic type biliary lesions (ITBL) that are attributed to microcirculatory dysfunction rather than main hepatic arterial compromise. Both the warm and cold ischemic period duration appear to influence the onset of ITBL. All of the commonly used MP techniques deliver oxygen to the graft cells, and therefore may minimize the cholangiocyte injury and subsequently reduce the incidence of ITBL. As clinical experience and published evidence grows for these modalities, the impact they have on ITBL rates is important to consider. In this review, the evidence for the three commonly used MP strategies (abdominal normothermic regional perfusion [A-NRP], hypothermic oxygenated perfusion [HOPE], and normothermic machine perfusion [NMP] for ITBL prevention has been critically reviewed. Inconsistencies with ITBL definitions used in trials, coupled with variations in techniques of MP, make interpretation challenging. Overall, the evidence suggests that both HOPE and A-NRP prevent ITBL in donated after circulatory death grafts compared to cold storage. The evidence for ITBL prevention in donor after brain death grafts with any MP technique is weak.

Multigene germline testing usefulness instead of BRCA1/2 single screening in triple negative breast cancer cases

Triple negative breast cancer is considered as the worst aggressive subtype with poor prognosis. Recent studies suggest a hereditary component is involved in TNBC development, especially in young patients. However, genetic spectrum remains unclear. Our purpose was to evaluate the usefulness of multigene panel testing in triple negative patients compared to overall breast cancer cases as well as contributing to elucidate which genes are most implicated in triple negative subtype development. Two breast cancer cohorts, comprising 100 triple negative breast cancer patients and 100 patients with other breast cancer subtypes, were analyzed by Next-Generation Sequencing using an On-Demand panel which included 35 predisposition cancer genes associated with inherited cancer susceptibility. The percentage of germline pathogenic variant carriers was higher in the triple negative cohort. ATM, PALB2, BRIP1 and TP53 were the most non-BRCA mutated genes. Moreover, triple negative breast cancer patients without family history related who were identified as carriers were diagnosed at significantly earlier age. As conclusion, our study reinforces the usefulness of multigene panel testing in breast cancer cases but specifically in those with triple negative subtype regardless family history.

Hospitalization Burden of Patients with Kidney Stones and Metabolic Comorbidities in Spain during the Period 2017-2020

Nephrolithiasis has become an increasing worldwide problem during the last decades. Metabolic syndrome, its components, and related dietary factors have been pointed out as responsible for the increasing incidence. The objective of this study was to evaluate the trends in the hospitalization rates of patients with nephrolithiasis, hospitalization features, costs, and how metabolic syndrome traits influence both the prevalence and complications of lithiasic patients. An observational retrospective study was conducted by analyzing hospitalization records from the minimum basic data set, including all patient hospitalizations in Spain in which nephrolithiasis has been coded as a main diagnosis or as a comorbidity during the period 2017-2020. A total of 106,407 patients were hospitalized and coded for kidney or ureteral lithiasis in this period. The mean age of the patients was 58.28 years (CI95%: 58.18-58.38); 56.8% were male, and the median length of stay was 5.23 days (CI95%: 5.06-5.39). In 56,884 (53.5%) patients, kidney or ureteral lithiasis were coded as the main diagnosis; the rest of the patients were coded mostly as direct complications of kidney or ureteral stones, such as "non-pecified renal colic", "acute pyelonephritis", or "tract urinary infection". The hospitalization rate was 56.7 (CI95%: 56.3-57.01) patients per 100,000 inhabitants, showing neither a significant increasing nor decreasing trend, although it was influenced by the COVID-19 pandemic. The mortality rate was 1.6% (CI95%: 1.5-1.7), which was higher, if lithiasis was coded as a comorbidity (3.4% CI95%: 3.2-3.6). Metabolic syndrome diagnosis component codes increased the association with kidney lithiasis when age was higher, reaching the highest in the eighth decade of life. Age, diabetes, and hypertension or lithiasis coded as a comorbidity were the most common causes associated with the mortality of lithiasic patients. In Spain, the hospitalization rate of kidney lithiasis has remained stable during the period of study. The mortality rate in lithiasic patients is higher in elderly patients, being associated with urinary tract infections. Comorbidity conditions such as diabetes mellitus and hypertension are mortality predictors.

Learning curve for performing laparoscopic common bile duct exploration in biliary surgery 2.0 era

BACKGROUND

Recent trials and metanalysis have demonstrated the favorable results of laparoscopic cholecystectomy (LC) and laparoscopic common bile duct exploration (LCBDE) for the treatment of cholecysto-choledocholithiasis. The aim of this study was to evaluate the LC + LCBDE learning curve including transcystic and transductal approaches and its effect on the outcomes.

METHODS

We identified all unselected patients who underwent LC + LCBDE by a single surgeon between May 2017 and July 2021. Pre-, intra-, and postoperative data were analyzed using the cumulative sum (CUSUM) analysis to evaluate the learning curve.

RESULTS

A total of 110 patients were included. Total postoperative complications rate was 12.7%, including bile leakage in six (5.5%) patients. Mean length of hospital stay was 2.7 (1-14) days. No patient had conversion to open surgery. The CUSUM graph divided the learning curve into three distinct phases: (1) Learning (1-38), (2) Competence (39-61) and (3) Proficiency (62-110). There was a significant increase in the transcystic approach rate with each phase (44.7% vs 73.9% vs 98%; P < .001). A significant decrease in the operative time (150.9 vs 117.6 vs 99.9 min; P < .001) and complication rate (21.1% vs 21.7% vs 2%; P = .01) were observed across the three phases.

CONCLUSION

Our data suggest that the learning curve for complete competence in LC + LCBDE is approximately 60 cases, provided that proper training is available. The initial learning phase can be carried out safely and efficiently with acceptable results.

Violacein and its antifungal activity: comments and potentialities

Violacein is an important natural antimicrobial pigment that is mainly produced by Chromobacterium violaceum and Janthinobacterium lividum. It presents a significant range of effects against phytopathogenic and human fungi, besides being featured as having low toxicity, and by its important ecological role in protecting amphibian species and applications in dyed medical fabric. The hypothesis about violacein's action mechanisms against mucormycosis (Rhizopus arrhizus) and candidiasis (Candida auris) is herein discussed based on data available in the scientific literature.

Short-term outcomes of robotic liver resection: An initial single-institution experience

BACKGROUND

Liver surgery has traditionally been characterized by the complexity of its procedures and potentially high rates of morbidity and mortality in inexperienced hands. The robotic approach has gradually been introduced in liver surgery and has increased notably in recent years. However, few centers currently perform robotic liver surgery and experiences in robot-assisted surgical procedures continue to be limited compared to the laparoscopic approach.

AIM

To analyze the outcomes and feasibility of an initial robotic liver program implemented in an experienced laparoscopic hepatobiliary center.

METHODS

A total of forty consecutive patients underwent robotic liver resection (da Vinci Xi, intuitive.com, United States) between June 2019 and January 2021. Patients were prospectively followed and retrospectively reviewed. Clinicopathological characteristics and perioperative and short-term outcomes were analyzed. Data are expressed as mean and standard deviation. The study was approved by the Institutional Review Board.

RESULTS

The mean age of patients was 59.55 years, of which 18 (45%) were female. The mean body mass index was 29.41 kg/m². Nine patients (22.5%) were cirrhotic. Patients were divided by type of resection as follows: Ten segmentectomies, three wedge resections, ten left lateral sectionectomies, six bisegmentectomies (two V-VI bisegmentectomies and four IVb-V bisegmentectomies), two right anterior sectionectomies, five left hepatectomies and two right hepatectomies. Malignant lesions occurred in twenty-nine (72.5%) of the patients. The mean operative time was 258.11 min and two patients were transfused intraoperatively (5%). Inflow occlusion was used in thirty cases (75%) and the mean total clamping time was 32.62 min. There was a single conversion due to uncontrollable hemorrhage. Major postoperative complications (Clavien–Dindo > IIIb) occurred in three patients (7.5%) and mortality in one (2.5%). No patient required readmission to the hospital. The mean hospital stay was 5.6 d.

CONCLUSION

Although robotic hepatectomy is a safe and feasible procedure with favorable short-term outcomes, it involves a demanding learning curve that requires a high level of training, skill and dexterity.

The Tokyo 2020 terminology of liver anatomy and resections: Updates of the Brisbane 2000 system

BACKGROUND

The Brisbane 2000 Terminology for Liver Anatomy and Resections, based on Couinaud's segments, did not address how to identify segmental borders and anatomic territories of less than one segment. Smaller anatomic resections including segmentectomies and subsegmentectomies, have not been well defined. The advent of minimally invasive liver resection has enhanced the possibilities of more precise resection due to a magnified view and reduced bleeding, and minimally invasive anatomic liver resection (MIALR) is becoming popular gradually. Therefore, there is a need for updating the Brisbane 2000 system, including anatomic segmentectomy or less. An online "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was hosted on February 23, 2021.

METHODS

The Steering Committee invited 34 international experts from around the world. The Expert Committee (EC) selected 12 questions and two future research topics in the terminology session. The EC created seven tentative definitions and five recommendations based on the experts' opinions and the literature review performed by the Research Committee. Two Delphi Rounds finalized those definitions and recommendations.

RESULTS

This paper presents seven definitions and five recommendations regarding anatomic segmentectomy or less. In addition, two future research topics are discussed.

CONCLUSIONS

The PAM-HBP Surgery Consensus has presented the Tokyo 2020 Terminology for Liver Anatomy and Resections. The terminology has added definitions of liver anatomy and resections that were not defined in the Brisbane 2000 system.

Minimally invasive anatomic liver resection: Results of a survey of world experts

BACKGROUND

Although the number of minimally invasive liver resections (MILRs) has been steadily increasing in many institutions, minimally invasive anatomic liver resection (MIALR) remains a complicated procedure that has not been standardized. We present the results of a survey among expert liver surgeons as a benchmark for standardizing MIALR.

METHOD

We administered this survey to 34 expert liver surgeons who routinely perform MIALR. The survey contained questions on personal experience with liver resection, inflow/outflow control methods, and identification techniques of intersegmental/sectional planes (IPs).

RESULTS

All 34 participants completed the survey; 24 experts (70%) had more than 11 years of experience with MILR, and over 80% of experts had performed over 100 open resections and MILRs each. Regarding the methods used for laparoscopic or robotic anatomic resection, the Glissonean approach (GA) was a more frequent procedure than the hilar approach (HA). Although hepatic veins were considered essential landmarks, the exposure methods varied. The top three techniques that the experts recommended for identifying IPs were creating a demarcation line, indocyanine green negative staining method, and intraoperative ultrasound.

CONCLUSION

Minimally invasive anatomic liver resection remains a challenging procedure; however, a certain degree of consensus exists among expert liver surgeons.

Expert Consensus Guidelines: How to safely perform minimally invasive anatomic liver resection

BACKGROUND

The concept of minimally invasive anatomic liver resection (MIALR) is gaining popularity. However, specific technical skills need to be acquired to safely perform MIALR. The "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was developed as a special program during the 32nd meeting of the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS).

METHODS

Thirty-four international experts gathered online for the consensus. A Research Committee performed a comprehensive literature review, classifying studies according to the Scottish Intercollegiate Guidelines Network method. Based on the literature review and experts' opinions, tentative recommendations were drafted and circulated among experts using online Delphi Rounds. Finally, formulated recommendations were presented online in the Expert Consensus Meeting of the JSHBPS on February 23rd, 2021. The final recommendations were validated and finalized by the 2nd Delphi Round in May 2021.

RESULTS

Seven clinical questions were selected, and 22 recommendations were formulated. All recommendations reached more than 85% consensus among experts at the final Delphi Round.

CONCLUSIONS

The Expert Consensus Meeting for safely performing MIALR has presented a set of clinical guidelines based on available literature and experts' opinions. We expect these guidelines to have a favorable effect on the safe implementation and development of MIALR.

[Construction of text resources for automatic identification of clinical information in unstructured narratives]

BACKGROUND

A significant proportion of the clinical record is in free text format, making it difficult to extract key information and make secondary use of patient data. Automatic detection of information within narratives initially requires humans, following specific protocols and rules, to identify medical entities of interest.

AIM

To build a linguistic resource of annotated medical entities on texts produced in Chilean hospitals.

MATERIAL AND METHODS

A clinical corpus was constructed using 150 referrals in public hospitals. Three annotators identified six medical entities: clinical findings, diagnoses, body parts, medications, abbreviations, and family members. An annotation scheme was designed, and an iterative approach to train the annotators was applied. The F1-Score metric was used to assess the progress of the annotator's agreement during their training.

RESULTS

An average F1-Score of 0.73 was observed at the beginning of the project. After the training period, it increased to 0.87. Annotation of clinical findings and body parts showed significant discrepancy, while abbreviations, medications, and family members showed high agreement.

CONCLUSIONS

A linguistic resource with annotated medical entities on texts produced in Chilean hospitals was built and made available, working with annotators related to medicine. The iterative annotation approach allowed us to improve performance metrics. The corpus and annotation protocols will be released to the research community.

M1 and M2 mAChRs activate PDK1 and regulate PKC βI and ε and the exocytotic apparatus at the NMJ

Neuromuscular junctions (NMJ) regulate cholinergic exocytosis through the M₁ and M₂ muscarinic acetylcholine autoreceptors (mAChR), involving the crosstalk between receptors and downstream pathways. Protein kinase C (PKC) regulates neurotransmission but how it associates with the mAChRs remains unknown. Here, we investigate whether mAChRs recruit the classical PKCβI and the novel PKCε isoforms and modulate their priming by PDK1, translocation and activity on neurosecretion targets. We show that each M₁ and M₂ mAChR activates the master kinase PDK1 and promotes a particular priming of the presynaptic PKCβI and ε isoforms. M₁ recruits both primed-PKCs to the membrane and promotes Munc18-1, SNAP-25, and MARCKS phosphorylation. In contrast, M₂ downregulates PKCε through a PKA-dependent pathway, which inhibits Munc18-1 synthesis and PKC phosphorylation. In summary, our results discover a co-dependent balance between muscarinic autoreceptors which orchestrates the presynaptic PKC and their action on ACh release SNARE-SM mechanism. Altogether, this molecular signaling explains previous functional studies at the NMJ and guide toward potential therapeutic targets.

Fishers' perception of the interaction between the South American sea lions and the Chinook salmon fishery in southern Chile

We studied how the South American sea lion (SASL, Otaria flavescens) interacts with the operation of an artisanal fishery of Chinook salmon, a non-native species in Chile, using a combination of biological and social approaches, including a valuation by fishers about this interaction. During austral summer of 2019, an observer onboard artisanal fishing boats characterized the attack behavior of SASLs to gillnet-captured Chinook salmon during 33 hauls and analyzed which factors may affect the intensity of attacks. To analyze the relationship between fishers and SASLs, a Likert scale about the perception and views about nature was applied. A total of 23 interviews—including 35 open and 16 closed questions—with fishers were conducted to describe how they perceived the interactions with SASLs. Interactions with SASLs were recorded in 35% of the fishing events and varied depending on both operational factors, such as the number of boats, as well as environmental factors, such as moon’s luminosity. Even though SASL interactions resulted in seven fish (~ 70 kg) damaged of a total catch of 2815 kg (2.5%) during the survey, boats with a damaged catch by SASL lost up to 11% of their revenue. This is consistent with 87% of the interviewed fishers who considered that the conflict with the SASL negatively impacts their activity and results in economic losses. A negative perception towards SASLs likely results from personal experience and revenue loss, even though impacts of SASL interactions at the scale of the entire fishery may be less important. While older fishers with less formal education have a productivist and instrumental focus, younger fishers with a more sustainable and conservationist view of fishing offer an opportunity to lead an improved local understanding of the relationship between salmon, SASLs, and humans.

Effects of negative-pressure therapy with and without ropivacaine instillation in the early evolution of severe peritonitis in pigs

PURPOSE

The abdomen is the second most common source of sepsis and secondary peritonitis, which likely lead to death. In the present study, we hypothesized that instillation of local anesthetics into the peritoneum might mitigate the systemic inflammatory response syndrome (SIRS) in the open abdomen when combined with negative-pressure therapy (NPT) to treat severe peritonitis.

METHODS

We performed a study in 21 pigs applying a model of sepsis based on ischemia/reperfusion and fecal spread into the peritoneum. The pigs were randomized into three groups, and treated for 6 h as follows: Group A: temporary abdominal closure with ABTHERA™ Open Abdomen Negative-Pressure Therapy; Group B: temporary abdominal closure with ABTHERA™ Open Abdomen Negative-Pressure Therapy plus abdominal instillation with physiological saline solution (PSS); and Group C: temporary abdominal closure with ABTHERA™ Open Abdomen Negative-Pressure Therapy plus peritoneal instillation with a solution of ropivacaine in PPS.

RESULTS

A comparison between the three groups revealed no statistically significant difference for any of the parameters registered (p > 0.05), i.e., intra-abdominal pressure, blood pressure, heart rate, O2 saturation, diuresis, body temperature, and blood levels of interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), and c-reactive protein (CRP). In addition, histological studies of the liver, ileum, kidney and lung showed no difference between groups.

CONCLUSIONS

The use of abdominal instillation (with or without ropivacaine) did not change the effect of 6 h of NPT after sepsis in animals with open abdomen. The absence of adverse effects suggests that longer treatments should be tested.

Landmarks to identify segmental borders of the liver: A review prepared for PAM-HBP expert consensus meeting 2021

BACKGROUND

In preparation for the upcoming consensus meeting in Tokyo in 2021, this systematic review aimed to analyze the current available evidence regarding surgical anatomy of the liver, focusing on useful landmarks, strategies and technical tools to perform precise anatomic liver resection (ALR).

METHODS

A systematic review was conducted on MEDLINE/PubMed for English articles and on Ichushi database for Japanese articles until September 2020. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN).

RESULTS

A total of 3169 manuscripts were obtained, 1993 in English and 1176 in Japanese literature. Subsequently, 63 English and 20 Japanese articles were selected and reviewed. The quality assessment of comparative series and case series was revealed to be usually low; only six articles were qualified as high quality. Forty-two articles focused on analyzing intersegmental/sectional planes and their relationship with specific hepatic landmark veins. In 12 articles, the authors aimed to investigate liver surface anatomic structures, while 36 articles aimed to study technological tools and contrast agents for surgical segmentation during ALR. Although Couinaud's classification has remained the cornerstone in daily diagnostic/surgical practices, it does not always portray the realistic liver segmentation and there has been no standardization on which a single strategy should be followed to perform precise ALR.

CONCLUSIONS

A global consensus should be pursued in order to establish clear guidelines and proper recommendations to perform ALR in the era of minimally invasive surgery.

Timing of Ablation and Prognosis of Patients With Electrical Storm and Scar-Related Left Ventricular Dysfunction

Although radiofrequency catheter ablation (RFCA) is indicated in electrical storm (ES) refractory to antiarrhythmic drugs, its most appropriate timing has not been determined. Our objective is to analyse the impact of the timing of RFCA on 30-day mortality in patients with ES and previous scar-related systolic dysfunction. In this multi-centre study, we analysed 104 patients (age: 72 ± 10, left ventricular ejection fraction: 30 ± 6%) attended consecutively due to an ES caused by monomorphic ventricular tachycardia. Sixty-four subjects were treated with RFCA (mean time from admission = 83 ± 67 hours) and 40 were not. Upon admission 25 (24%) individuals had severe heart failure. Mortality rate at 30 days was 24 (23%) patients. RFCA was associated with a reduction of 30-day mortality (hazard ratio = 0.2; p = 0.008). After showing a positive correlation between the time of the RFCA (hours) and survival at 30 days (C-statistic = 0.77; p <0.001), we found that only subjects ablated >48 hours after admission had lower mortality at 30 days than those treated conservatively: 38% (no RFCA) versus 30% (RFCA ≤48 hours) versus 7% (RFCA >48 hours) (adjusted hazard ratio for RFCA >48 hours vs others = 0.2; p = 0.007). Among the patients ablated, those who were non-inducible had lower 30-day mortality: 8% versus 29% (p = 0.03). Extracorporeal membrane oxygenation was associated with a higher rate of non-inducibility in RFCA >48 hours (100% vs 76%; p = 0.03), but not in RFCA ≤48 hours (60% vs 60%; p = 1). In conclusion, among high-risk patients with ES, RFCA performed >48 hours after admission is associated with a reduction in 30-day mortality. In such subjects, the probability of successful RFCA increases when performed under extracorporeal membrane oxygenation support.

Analysis of minimally invasive sacrocolpopexy with 24-hour hospital stay for the treatment of pelvic organ prolapse

OBJECTIVES

The objective of this study is to analyze the impact (in terms of safety and saving of hospital costs) of the implementation of a new protocol for the correction of pelvic organ prolapse (POP) by minimally invasive sacrocolpopexy (MISC) with 24-hour hospital stay.

MATERIAL AND METHODS

Prospective observational study of the first 78 MISC procedures performed consecutively. 46 procedures (59%) were performed with 24-hour hospital stay, and 32 (41%) required more than 24hours. The postoperative complications were determined for each group: visits to the Emergency Department, reoperations, and the average cost per procedure regarding hospital stay and ER visits. The cost model was established according to the data of the Analytical Accounting System of the Jiménez Díaz Foundation Hospital and of the Official State Gazette of Madrid.

RESULTS

There were no differences regarding intraoperative or postoperative complications between both groups. The number of visits to the Emergency Department, reinterventions or hospital re-admissions was lower in the 24-hour hospital stay group, without reaching statistical significance. The implementation of the MISC protocol with 24-hour hospital stay represented a saving of 607.91€ per procedure in hospital costs.

CONCLUSIONS

Correction of the POP with MISC with a 24-hour hospital discharge policy was feasible and safe in at least 59% of the patients, with similar complications, visits to the Emergency Department or hospital readmission rates.

Hemoperitoneum secondary to an spontaneous rupture of the spleen mimmicking a duodenal perforated ulcera: A case report

Spontaneous rupture of the spleen without traumatic cause is an unfrequent entity, usually related with pathologic spleens. We present a case of spontaneous rupture of an histologically normal spleen with splenomegalia secondary to smoking habit. The hemoperitoneum caused by the spontaneous rupture of the spleen mimmicked a hollow viscera perforation.

Completeness of T, N, M and stage grouping for all cancers in the Mallorca Cancer Registry

BACKGROUND

TNM staging of cancer is used to establish the treatment and prognosis for cancer patients, and also allows the assessment of screening programmes and hospital performance. Collection of staging data is becoming a cornerstone for cancer registries. The objective of the study was to assess the completeness of T, N, M and stage grouping registration for all cancers in the Mallorca Cancer Registry in 2006-2008 and to explore differences in T, N, M and stage grouping completeness by site, gender, age and type of hospital.

METHODS

All invasive cancer cases during the period 2006-2008 were selected. DCO, as well as children's cancers, CNS, unknown primary tumours and some haematological cases were excluded. T, N, M and stage grouping were collected separately and followed UICC (International Union Against Cancer) 7th edition guidelines. For T and N, we registered whether they were pathological or clinical.

RESULTS

Ten thousand two hundred fifty-seven cases were registered. After exclusions, the study was performed with 9283 cases; 39.4 % of whom were women and 60.6 % were men. T was obtained in 48.6 % cases, N in 36.5 %, M in 40 % and stage in 37.9 %. T and N were pathological in 71 % of cases. Stage completeness exceeded 50 % in lung, colon, ovary and oesophagus, although T also exceeded 50 % at other sites, including rectum, larynx, colon, breast, bladder and melanoma. No differences were found in TNM or stage completeness by gender. Completeness was lower in younger and older patients, and in cases diagnosed in private clinics.

CONCLUSIONS

T, N, M and stage grouping data collection in population-based cancer registries is feasible and desirable.

Development and psychometric validation of a brief comprehensive health status assessment scale in older patients with hematological malignancies: The GAH Scale

OBJECTIVES

The purpose of this study was to develop a new brief, comprehensive geriatric assessment scale for older patients diagnosed with different hematological malignancies, the Geriatric Assessment in Hematology (GAH scale), and to determine its psychometric properties.

MATERIALS AND METHODS

The 30-item GAH scale was designed through a multi-step process to cover 8 relevant dimensions. This is an observational study conducted in 363 patients aged≥65years, newly diagnosed with different hematological malignancies (myelodysplasic syndrome/acute myeloblastic leukemia, multiple myeloma, or chronic lymphocytic leukemia), and treatment-naïve. The scale psychometric validation process included the analyses of feasibility, floor and ceiling effect, validity and reliability criteria.

RESULTS

Mean time taken to complete the GAH scale was 11.9±4.7min that improved through a learning-curve effect. Almost 90% of patients completed all items, and no floor or ceiling effects were identified. Criterion validity was supported by reasonable correlations between the GAH scale dimensions and three contrast variables (global health visual analogue scale, ECOG and Karnofsky), except for comorbidities. Factor analysis (supported by the scree plot) revealed nine factors that explained almost 60% of the total variance. Moderate internal consistency reliability was found (Cronbach's α: 0.610), and test-retest was excellent (ICC coefficients, 0.695-0.928).

CONCLUSION

Our study suggests that the GAH scale is a valid, internally reliable and a consistent tool to assess health status in older patients with different hematological malignancies. Future large studies should confirm whether the GAH scale may be a tool to improve clinical decision-making in older patients with hematological malignancies.

Advances in thyroid cancer treatment: latest evidence and clinical potential

Advanced thyroid carcinoma is an infrequent tumor entity with limited treatment possibilities until recently. The extraordinary improvement in the comprehension of genetic and molecular alterations involving the RAS/RAF/mitogen-activated protein kinase and phosphatidylinositide 3-kinase/Akt/mammalian target of rapamycin signaling and interacting pathways that are involved in tumor survival, proliferation, differentiation, motility and angiogenesis have been the rationale for the development of new effective targeted therapies. Data coming from phase II clinical trials have confirmed the efficacy of those targeted agents against receptors in cell membrane and cytoplasmic molecules. Moreover, four of those investigational drugs, vandetanib, cabozantinib, sorafenib and lenvatinib, have reached a phase III clinical trial with favorable results in progression-free survival and overall survival in medullary thyroid carcinoma and differentiated thyroid carcinoma. Further analysis for an optimal approach has been conducted according to mutational profile and tumor subtypes. However, consistent results are still awaited and the research for adequate prognostic and predictive biomarkers is ongoing. The following report offers a comprehensive review from the rationale to the basis of targeted agents in the treatment of thyroid carcinoma. In addition, current and future therapeutic developments by the inhibition of further molecular targets are discussed in this setting.

[Final results of an initiative aiming to improve the referrals from primary care to a Department of Urology]

OBJECTIVES

To test two interventions aiming at improving the compliance of primary health care physicians with an agreed-on protocol of referrals to a urology department.

METHODS

Joint formative meetings (every six months) were celebrated throughout a 24-month period. Also a counseling telephone line was implemented. 18.088 referrals were analyzed. The effect of both expositions was tested comparing basal data (T0) with the performance at 6, 12, 18 and 24 months later (T1, T2, T3 and T4, respectively). An additional comparison was conducted to approach the results 1 year after the study ended (T5).

RESULTS

61.7% of the referrals at baseline complied with the protocol. A significant improvement was detected at T1 (compliance 73.4%, RR with respect to T0 1.19, 95% CI 1.14- 1.23). At T2, 73.7% of referrals were adequate (RR with respect to T0 1.19, 95% CI 1.15-1.24). The percent of adequate referrals at T3 remained stable (73.4%, RR with respect to T0 1.18, 95% CI 1.15-1.23). Nevertheless, adequacy of referrals by the end of the second year (T4) significantly decreased (67.3%, RR with respect to T0, 1.09, 95% CI 1.05-1.12). Adequacy at T5 was almost identical to the basal (64.4%, RR with respect to T0, 1.04 95% CI 1.04-1.07).

CONCLUSIONS

Learning activities can be effective in improving the quality of referrals from primary care to one urology department. Stopping the activities entails an immediate return to the basal standards.

Incidence of -93 MLH1 promoter polymorphism in familial and sporadic colorectal cancer

AIM

The MLH1 promoter contains a common single nucleotide polymorphism (-93 guanine > adenine) located in an essential region for maximum transcriptional activity. This has been associated with an increased risk of microsatellite instability (MSI) colorectal cancer. The aim of the study was to compare the distribution of MLH1 -93G>A genotypes between patients with familial colon cancer, sporadic colon cancer and healthy subjects.

METHOD

We genotyped 200 familial colon samples, 183 cases of sporadic colon cancer and 236 control subjects. MSI was analysed.

RESULTS

The GA genotype was under-represented in patients with familial colon cancer, whereas the AA genotype was over-represented in cases of sporadic colon cancer. A greater frequency of the MLH1 GA genotype was found in the cancer cases with MLH1 focal immunohistochemistry (IHC) for anti-MLH1 antibody. When we compared genotype distribution in the familial colorectal cancer cases with and without MSI, we failed to detect any correlation, although the GA genotype is more frequent in cases with MSI.

CONCLUSION

There is a relationship between the MLH1 -93G>A polymorphism in the homozygous state and the risk of sporadic colorectal cancer. The variant MLH1 -93G>A appears to be related to cases with focal IHC activity more than to complete absence of the MLH1 protein in the tumour tissue.

Concordance analysis of ultrasonographic diagnoses by urology nurses

OBJECTIVES

To check the degree of concordance in renal ultrasound examination between two nurses and one experienced urologist with the aim of testing nurses' competence performing renal ultrasound.

METHODS

The echographic aspect of both kidneys (normal or abnormal) was evaluated. Every abnormal finding resulted in the automatic classification of the kidney as 'abnormal'. The agreement between observers was tested using the Kappa concordance index.

RESULTS

Eventually, 75 and 45 consecutive examinations performed by the urologist and nurse MM, and the urologist and nurse NJ, respectively, were evaluable. Overall, the study tested 120 patients. Prevalence of 'abnormal' kidneys was intermediate (28-36%). The overall agreement percentage exceeded 88% (88,8-92%). Kappa coefficient was always 0.7.

CONCLUSIONS

Urological ultrasound examination by qualified well-trained nurses provides records very similar to those delivered by an experienced urologist.

Quality perception in the outpatient area of an Urology department. Can we improve it?

OBJECTIVES

To test patient's satisfaction after consultation in the outpatient area of the Urology Department in a public hospital using a structured interview.

METHODS

We used the Comunidad Autónoma de Madrid (CAM) standard interview form modified to include three questions related to the implementation of a 'one-visit'policy and nurses' empowerment. Patients' opinions were gathered with respect to waiting times in the waiting room, facilities, and staff kindness and professionalism. Sample size was estimated in 386 patients. The effect of every predictive factor on the overall satisfaction was tested using the chi square test. To define the effect of every variable in presence of the rest of covariates a logistic regression model was used.

RESULTS

Participation reached 65.5%. Overall, 86.4% of the patients were satisfied. Irrespectively of the professional and personal style, the quality perception was homogeneous (p=ns). Multivariate analysis couldn't disclose any independent predictive variable. Only the perception in the item 'overall time available for the consultation' approached statistical significance (p=0.08), with patients scoring high in this variable getting the highest overall satisfaction scores.

CONCLUSIONS

There was no personal or professional style particularly related with patient satisfaction. Nevertheless, there is a slight trend towards a higher satisfaction when patients feel enough time has been spent in their consultation. The new organizational resources (one-visit clinic and nurses' empowerment) are both welcome but are not clearly related to patient satisfaction.

Lynch syndrome diagnostics: decision-making process for germ-line testing

Cancer risks and medical management of Lynch syndrome (LS) differ from other hereditary or familial clustering of colorectal cancer. Differential diagnosis has improved as a result of the growing clinical and molecular knowledge about LS. Appropriate application of these advances in several scenarios constitutes a decision-making process to further decide germ-line testing with accuracy and efficiency. However, an only molecular-screening algorithm, with a limited number of steps and choices, may be difficult to devise. How, when, where and at what expense to use the different diagnostic tools remain dynamic and changeable under different circumstances. From a clinical point of view, it is advisable to discuss conflicting aspects to guide LS diagnosis.

[Obesity as risk factor for lithiasic recurrence]

OBJECTIVES

Obese patients may have special characteristics in the urinary stones formed, as the body mass index (BMI) may also be a predictive factor in lithiasic recurrence. We aim to evaluate and compare the lithiasic characteristics according to the different BMI categories, also considering the likelihood of lithiasic recurrence in presence of age and gender covariables.

MATERIAL AND METHODS

Retrospective, cross-sectional analysis on 346 lithiasic patients, 96 (27.7%) had low-normal weight, 151 (43.6%) overweight, and 99 (28.6%) obesity. The Chi-square and ANOVA tests were used. Survival analysis for the calculation of likelihood of lithiasic recurrence (yes/no) was made based on time on 158 patients in whom complete resolution of the initial stone was achieved by the Kaplan Meier method. Comparisons between the different categories of BMI were made using the log-Rank, Breslow and Tarone-Ware tests. Multivariate analysis was also made with the Cox regression model, introducing the covariables of age and gender.

RESULTS

A significant growing linear tendency has been demonstrated between multiplicity and BMI (p=0.03). The variables size and composition did not show significant differences between the groups. Median follow-up of 158 patients included in the survival analysis was 1866 days (95% CI 1602.5-2129.5). Eighteen (11.4%) of them recurred, without finding significant differences between groups: 4 low-normal weight (9.8%), 10 overweight (14.1%) and 4 obese (8.7%). The multivariate analysis also did not show a significant influence of the BMI on lithiasic recurrence (p=0.86; HR =1.06; 95% CI: 0.56-2.03).

CONCLUSION

A significant influence of BMI was shown on lithiasic multiplicity on diagnosis, although not on lithiasic recurrence based on time. It seems to be necessary to carry out studies in larger samples to calculate the true influence of BMI on lithiasic recurrence.

The one-stop clinic as the standard of out-patient care in a hospital urology department

PURPOSE

To evaluate the performance of a 'one-stop' clinic in terms of proportion of discharges or inclusion in surgical waiting lists.

MATERIALS AND METHODS

All patients were referred from primary care facilities (population 220,646) and from different departments in the hospital. Eight senior urologists, two registered nurses and two nurse attendants participated in the experience. Prior to the start of the project, referral protocols had been agreed with the primary care physicians involved. Compliance with the protocols was periodically tested. Eventually 5537 first visits (January-December 2009) where evaluable.

RESULTS

Overall, the 'one-stop' format proved feasible in 74.2% of the patients (4108/5537). Patients, who successfully used the 'one-stop' format, were significantly younger than those who required additional consultations (43 vs 50 years old, respectively, Student 's t test < 0.001). For obvious reasons the 'one-stop' format was universally possible in male sterilization and penile phimosis patients. Similarly, the 'one-stop' policy was applied in most consultations due to male sexual dysfunction (75%) and urinary tract infection (73%). Other health problems, such as haematuria (62%) and renal colic (46%), required more than one visit so that care of the patient reverted to the traditional, outpatient care model.

CONCLUSION

A 'one-stop' philosophy is feasible for a number of procedures in a urological outpatient clinic. The costs to implement such an approach would be limited to managerial expenditure.

Analysis of pharmacodynamic interaction of sevoflurane and propofol on Bispectral Index during general anaesthesia using a response surface model

BACKGROUND

Propofol and sevoflurane act on the GABA(A) receptor, modulating the function of this receptor in an additive manner. The pharmacodynamic interaction of both drugs considering their effect on EEG activity analysed by the bispectral index (BIS) was identified as additive, but this has not been studied in a clinical setting. The objective of this study was to analyse the pharmacodynamic interaction of propofol and sevoflurane on BIS using a surface response model in patients undergoing general anaesthesia with i.v. induction and inhalation maintenance.

METHODS

We performed a prospective study in 24 patients undergoing general anaesthesia with propofol induction and sevoflurane maintenance. Anaesthetic depth was measured with a BIS VISTA Bilateral monitor. Propofol biophase concentration was determined using a three-compartment pharmacokinetic model, and sevoflurane end-tidal concentration was measured continuously. The response surface model described by Minto and colleagues was used to analyse the interaction. Statistical analysis was performed with Excel 2002 and SPSS v11.0.

RESULTS

The mean value of U(50)(theta) was 0.956 (sd 0.029) in the overall estimated data, and remained within the predefined range for all ratios of the drugs, fulfilling the criterion of additivity. The median of the weighted residuals between the actual BIS value and the BIS value predicted by the model was -5.926%.

CONCLUSIONS

Under the study conditions, it was confirmed that sevoflurane and propofol have an additive effect on BIS, with no evidence suggesting the existence of a synergistic effect for the concentrations of both drugs typically used in clinical practice.

BRCA1 5272-1G>A and BRCA2 5374delTATG are founder mutations of high relevance for genetic counselling in breast/ovarian cancer families of Spanish origin

The distribution of BRCA1 and BRCA2 germ line mutations in breast/ovarian cancer families varies among different populations, which typically present a wide spectrum of unique mutations. Splicing mutation 5272-1G>A of BRCA1 and frameshift mutation 5374delTATG of BRCA2 are highly prevalent mutations in Castilla-León (Spain), accounting for 18.4% and 13.6% of BRCA1 and BRCA2 positive families, respectively. To test the presence of founder effects, 9 Spanish 5272-1G>A and 13 5374delTATG families were genotyped with polymorphic markers linked to BRCA1 or BRCA2. All the 5272-1G>A families shared a common haplotype in eight markers (1.1 Mb region) and the mutation age was estimated in 15 generations (approximately 380 years). A conserved haplotype associated to 5374delTATG was observed in four markers (0.82 Mb). The mutation occurred approximately 48 generations ago (approximately 1200 years). Each mutation likely arose from a common ancestor that could be traced to a small area of Castilla-León and expanded to other Spanish regions. They can have a significant impact on the clinical management of asymptomatic carriers as well as on the genetic screening strategy to be followed in populations with Spanish ancestries.

The TP53 Arg72Pro and MDM2 309G>T polymorphisms are not associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers

Background:

The TP53 pathway, in which TP53 and its negative regulator MDM2 are the central elements, has an important role in carcinogenesis, particularly in BRCA1- and BRCA2-mediated carcinogenesis. A single nucleotide polymorphism (SNP) in the promoter region of MDM2 (309T>G, rs2279744) and a coding SNP of TP53 (Arg72Pro, rs1042522) have been shown to be of functional significance.

Methods:

To investigate whether these SNPs modify breast cancer risk for BRCA1 and BRCA2 mutation carriers, we pooled genotype data on the TP53 Arg72Pro SNP in 7011 mutation carriers and on the MDM2 309T>G SNP in 2222 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Data were analysed using a Cox proportional hazards model within a retrospective likelihood framework.

Results:

No association was found between these SNPs and breast cancer risk for BRCA1 (TP53: per-allele hazard ratio (HR)=1.01, 95% confidence interval (CI): 0.93–1.10, P_trend=0.77; MDM2: HR=0.96, 95%CI: 0.84–1.09, P_trend=0.54) or for BRCA2 mutation carriers (TP53: HR=0.99, 95%CI: 0.87–1.12, P_trend=0.83; MDM2: HR=0.98, 95%CI: 0.80–1.21, P_trend=0.88). We also evaluated the potential combined effects of both SNPs on breast cancer risk, however, none of their combined genotypes showed any evidence of association.

Conclusion:

There was no evidence that TP53 Arg72Pro or MDM2 309T>G, either singly or in combination, influence breast cancer risk in BRCA1 or BRCA2 mutation carriers.