Use of Darvadstrocel (Allogenic Stem Cell Therapy) for Crohn's Fistulas in Real Clinical Practice: The National Project to Implement Mesenchymal Stem Cell for the Treatment of Perianal Crohn's Fistula (the PRIME Study).

BACKGROUND: Perianal fistulas may affect 15% to 50% of patients with Crohn's disease. Treatment is complex, requiring a multidisciplinary approach. Darvadstrocel (allogenic mesenchymal cells obtained from lipoaspirates) was approved in 2018 by the European and Spanish Agencies of Medicines and Medical Products as a treatment for fistulas in Crohn's disease. Recent guidelines from the European Crohn's and Colitis Organisation and Spanish Working Group on Crohn's Disease and Ulcerative Colitis state that darvadstrocel is effective with a favorable safety profile and a strong level of evidence (n = 2). OBJECTIVE: Presenting real-world effectiveness data for darvadstrocel in a Spanish population. DESIGN: Observational retrospective cohort study with prospective data gathering. SETTINGS: The study was conducted at 14 institutions in Spain. PATIENTS: From November 2019 to April 2022, all patients (n = 73) treated with darvadstrocel in these institutions were included, fulfilling the following criteria: 1) complex fistula/s in a patient with Crohn's disease; 2) failure of conventional and antitumor necrosis factor treatment; and 3) the absence of collections of >2 cm confirmed by pelvic MRI at the time of surgery. INTERVENTIONS: Darvadstrocel treatment. MAIN OUTCOME MEASURES: Clinical response (closure of 50% or more of external openings), complete clinical closure (100% of external openings), and radiological closure (no fluid collection >2 cm, edema, or inflammation) evaluated 6 months after treatment. RESULTS: Clinical response was observed in 63 patients (86.3%), complete clinical closure in 50 patients (68.5%), and radiological closure in 45 patients (69.2%). Combined clinical and radiological response was observed in 41 patients (63.1%). Not all clinically healed patients had radiological closure, and vice versa. No serious adverse events were reported. LIMITATIONS: Retrospective nature of the study. CONCLUSIONS: Study results were consistent with those reported in previous clinical trials, real-world efficacy findings from the INSPIRE study (assessing darvadstrocel effectiveness in Europe, Israel, Switzerland, United Kingdom, and Japan), and previously published literature. Darvadstrocel was effective and demonstrated a favorable safety profile when used in normal clinical practice for the treatment of fistulas in Crohn's disease. See Video Abstract . USO DE DARVADSTROCEL TERAPIA CON CLULAS MADRE ALOGNICAS PARA FSTULA EN ENFERMEDAD DE CROHN EN LA PRCTICA CLNICA REAL EL PROYECTO NACIONAL PARA IMPLEMENTAR DE CLULAS MADRE MESENQUIMALES PARA EL TRATAMIENTO DE LA FSTULA DE CROHN PERIANAL EL ESTUDIO PRIME: ANTECEDENTES:Las fístulas perianales pueden afectar entre el 15 y el 50% de los pacientes con enfermedad de Crohn. El tratamiento es complejo y requiere un enfoque multidisciplinario. El darvadstrocel (células mesenquimales alogénicas obtenidas a partir de lipoaspirados) fue aprobado en 2018 por las Agencias Europea y Española de Medicamentos y Productos Sanitarios como tratamiento de las fístulas en la EC. Las recientes directrices de la Organización Europea de Crohn y Colitis y del Grupo de Trabajo Español sobre la Enfermedad de Crohn y Colitis Ulcerosa afirman que darvadstrocel es eficaz con un perfil de seguridad favorable y un sólido nivel de evidencia (2).OBJETIVO:Presentar datos de eficacia real de darvadstrocel en población española.DISEÑO:Estudio de cohorte retrospectivo observacional con recopilación prospectiva de datos.ESCENARIO:14 instituciones.PACIENTES:Desde noviembre de 2019 hasta abril de 2022, se incluyeron todos los pacientes (73) tratados con darvadstrocel en estas instituciones, que cumplieron los siguientes criterios: 1) fístula/s compleja/s en un paciente con enfermedad de Crohn; 2) fracaso del tratamiento convencional y anti factor de necrosis tumoral; 3) ausencia de colecciones > 2 cm confirmada por resonancia magnética pélvica en el momento de la cirugía.INTERVENCIONES:Tratamiento con Darvadstrocel.PRINCIPALES MEDIDAS DE RESULTADO:Respuesta clínica (cierre de ≥50% de las aberturas externas), cierre clínico completo (100% de las aberturas externas) y cierre radiológico (sin acumulación de líquido >2 cm, sin edema ni inflamación) evaluados 6 meses después del tratamiento.RESULTADOS:Se observó respuesta clínica en 63 pacientes (86.3%), cierre clínico completo en 50 pacientes (68.5%) y cierre radiológico en 45 pacientes (69.2%). Se observó respuesta clínica y radiológica combinada en 41 pacientes (63.1%). No todos los pacientes clínicamente curados tuvieron cierre radiológico y viceversa. No hubo eventos adversos graves reportados.LIMITACIONES:Estudio retrospectivoCONCLUSIONES:Los resultados del estudio fueron consistentes con los informados en ensayos clínicos anteriores, los hallazgos de eficacia en el mundo real del estudio INSPIRE (que evalúa la efectividad de darvadstrocel en Europa, Israel, Suiza, el Reino Unido y Japón) y la literatura publicada anteriormente. Darvadstrocel fue eficaz y demostró un perfil de seguridad favorable cuando se utiliza en la práctica clínica habitual para el tratamiento de fístulas en la enfermedad de Crohn. (Traducción-Dr. Jorge Silva Velazco ).

Changes in the management of IBD patients since the onset of COVID-19 pandemic. A path toward the implementation of telemedicine in Spain?

BACKGROUND: COVID-19 pandemic increased medical services demand aside from interrupting daily clinical practice for other diseases such as inflammatory bowel disease (IBD). Here we present the results of a survey to gain the perception of IBD specialists in their patient-management using telemedicine in their daily practice. METHODS: This was an observational survey study among physicians focused on IBD (gastroenterologist, surgeons, and pediatricians) members of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU), the Spanish Association of Gastroenterology (AEG), and the Spanish Association of Coloproctology (AECP), regarding changes of management of IBD patients. RESULTS: We received a total of 269 responses to the survey (from May to June 2020). Before the pandemic, nearly all the respondents reported performing very frequently their visits face-to-face (n=251, 93.3%) while, during the pandemic, the telephone visits were the most frequent visits performed (n=138, 51.3%). Regarding communication difficulties, 157 (58.4%) respondents reported the impossibility of performing a proper examination as the most relevant issue. Also, 114 (42.4%) respondents considered remote visits more time-consuming than face-to-face visits. Most gastroenterologists (n=188, 83.2%) considered patients with active perianal disease in special need of face-to-face consultation and more than half of the surgeons (n=35, 50.7%) reported having performed an immediate postoperative follow-up remotely. CONCLUSIONS: Most IBD units have implemented remote visits during the pandemic, but most professionals found them more time-consuming and unsuitable for some disease profiles. Therefore, there is a need for the development of better telemedicine systems that can meet professionals' and patients' requirements.

Validation of a Novel Fecal Incontinence Scale: The Rapid Assessment Fecal Incontinence Score (RAFIS).

OBJECTIVE: The development and validation of a new version of the fecal incontinence (FI) scale "Rapid Assessment Fecal Incontinence Score" (RAFIS) incorporating domains for severity, type of stool loss, and global perception of the effect of incontinence on quality of life (QoL). BACKGROUND: FI negatively impacts on QoL. Currently used incontinence questionnaires have outstanding limitations on the global assessment of the impact of the disease on QoL that patients perceive. We developed a new version of RAFIS with a more complete questionnaire. MATERIALS AND METHODS: A 3-phase study was performed to evaluate the applicability and reliability of our questionnaire as a tool for assessing FI. Our score was completed by 98 patients (78 women; mean age: 57±13 y) who presented with FI and who were referred from 4 colorectal surgery centers. The RAFIS was assessed for internal consistency, test-retest reliability, and sensitivity to change. A multivariate analysis was performed. Comparisons were made with the Wexner Cleveland Clinic Incontinence Score and the Fecal Incontinence Quality of Life Scale. RESULTS: The RAFIS showed good internal consistency and test-retest reliability, differentiating the severity of incontinence but not the etiology. There was a moderate-high correlation between the new scale and the reference scales. Sensitivity to change, compared with the Wexner Score, was moderate. Comparison with established QoL instruments showed a moderate negative correlation. Logistic regression of the RAFIS discriminated between mild and moderate-severe impact on QoL. No correlation was detected with the new score to the presence of an anal sphincter defect or sphincter hypotonia. CONCLUSION: The RAFIS scale is easy to administer and compares well with other validated incontinence instruments.

Feasibility and safety of calcium alginate hydrogel sealant for the treatment of cryptoglandular fistula-in-ano: phase I/IIa clinical trial.

AIM: Complex perianal fistulas pose a challenge to the surgeon since the fistulous tract must be eliminated without impairing continence. Although without strong scientific evidence, some bibliography has demonstrated the efficacy of some sealants in the treatment of anal fistulas. We aimed to assess the feasibility and safety of calcium alginate hydrogel injections into the fistulous tract as treatment for trans-sphincteric cryptoglandular fistulas. METHODS: A prospective, single-centre, case series of this novel technique was conducted in a level 3 Spanish hospital, including patients diagnosed with trans-sphincteric perianal fistulas and treated with a calcium alginate hydrogel sealant. A strict follow-up was performed by an independent surgeon at 1, 3, 6 and 12 months. The main outcome measures were feasibility, safety (number of adverse events) and efficacy of the treatment. RESULTS: Twenty patients were treated. The treatment was performed for all patients. Seven adverse events related to the injection product or the surgical procedure were identified. After a 12-month follow-up, 12 patients were completely cured and eight were not cured, with a greater response in the first 6 months. These findings were confirmed by endoanal ultrasound, with a Cohen's kappa concordance rate of 0.89. No statistically significant differences were observed in pain measured using the visual analogue scale, faecal incontinence measured using the Wexner scoring system, and quality of life analysed by the SF-36 Health Survey. CONCLUSION: The treatment was feasible, safe and with discrete satisfactory healing results. It also demonstrated an acceptable safety profile, without worsening of faecal incontinence, quality of life and pain following treatment.

Treatment of faecal incontinence with autologous expanded mesenchymal stem cells: results of a pilot study.

AIM: Management of faecal incontinence (FI) remains challenging because no definitive optimal treatment for this condition has yet been determined. Regenerative medicine could be an attractive therapeutic alternative for treating FI. Here, we aimed to determine the safety and feasibility of autologous expanded mesenchymal stem cells derived from adipose tissue (AdMSCs) in the treatment of patients diagnosed with structural FI. METHOD: This was a randomized, multicentre, triple-blinded, placebo-controlled pilot study conducted at four sites in Spain with 16 adults with FI and a sphincter defect. Autologous AdMSCs were obtained from patients from surgically excised adipose tissue. These patients were intralesionally infused with a single dose of 4 × 107 AdMSCs or a placebo while under anaesthesia. We assessed the safety and feasibility of the treatment as the cumulative incidence of adverse events and the treatment efficacy using the Cleveland Clinic Faecal Incontinence Score, Faecal Incontinence Quality of Life score and Starck criteria to classify sphincter defects and anorectal physiology outcomes. RESULTS: Adipose tissue extraction, cell isolation and intralesional infusion procedures were successful in all the patients. There was only one adverse event connected to adipose tissue extraction (a haematoma), and none was associated with the injection procedure. There were no significant differences in any of the assessed clinical, manometric or ultrasonographic parameters. CONCLUSION: This study indicates that this infusion procedure in the anal sphincter is feasible and safe. However, it failed to demonstrate efficacy to treat patients with structural FI.

Influence of robotics in surgical complication rate in elderly population with rectal cancer.

BACKGROUND: Rectal cancer surgery is a technically complex procedure. Moreover, short-term outcomes show high rate of complications especially in elderly and laparoscopic surgery has not demonstrated to be able to reduce this complication rate. Robotics has several advantages in pelvic surgical procedures, which could have an impact in complication rates in elderly patients. AIMS: The aim of our study is to demonstrate whether robotic surgery has any influence on the reduction of complications in the aged population undergoing rectal cancer. METHODS: We performed a retrospective analysis of a prospective database of 151 patients who underwent robotic surgery for rectal cancer. We divided our population into three groups: under 65-year-old, between 65- and 80-year-old and above 80-year-old. We recorded complications in each group intra and post procedure. RESULTS: The present study included 151 patients (94 males). Of them, 77 patients were under 66 year old, 63 patients were between 66 and 79 year old and 11 patients were 80 year old and above. The analysis showed conversion rates of 10.38%, 13.69%, 27.27%, and the complication rate of 23.4%, 23.8%, and 27.3% in each group. Univariate analysis showed no differences between the three groups. Nevertheless, there were statistical differences from BMI, ASA and neoadjuvant therapy. In multivariant analysis only neoadjuvant therapy was significant. CONCLUSIONS: Robotic approach does not decrease complications in elderly population and conversion is similar in these age groups. So we should not rule out robotic surgery in elderly patients, although we must select each case with a multidisciplinary approach.

Electrical Modeling of the Growth and Differentiation of Skeletal Myoblasts Cell Cultures for Tissue Engineering.

In tissue engineering, of utmost importance is the control of tissue formation, in order to form tissue constructs of clinical relevance. In this work, we present the use of an impedance spectroscopy technique for the real-time measurement of the dielectric properties of skeletal myoblast cell cultures. The processes involved in the growth and differentiation of these cell cultures in skeletal muscle are studied. A circuit based on the oscillation-based test technique was used, avoiding the use of high-performance circuitry or external input signals. The effect of electrical pulse stimulation applied to cell cultures was also studied. The technique proved useful for monitoring in real-time the processes of cell growth and estimating the fill factor of muscular stem cells. Impedance spectroscopy was also useful to study the real-time monitoring of cell differentiation, obtaining different oscillation amplitude levels for differentiated and undifferentiated cell cultures. Finally, an electrical model was implemented to better understand the physical properties of the cell culture and control the tissue formation process.

Long-term Efficacy and Safety of Stem Cell Therapy (Cx601) for Complex Perianal Fistulas in Patients With Crohn's Disease.

BACKGROUND & AIMS: Therapies for perianal fistulas in patients with Crohn's disease are often ineffective in producing long-term healing. We performed a randomized placebo-controlled trial to determine the long-term efficacy and safety of a single local administration of allogeneic expanded adipose-derived stem cells (Cx601) in patients with Crohn's disease and perianal fistulas. METHODS: We performed a double-blind study at 49 hospitals in Europe and Israel, comprising 212 patients with Crohn's disease and treatment-refractory, draining, complex perianal fistulas. Patients were randomly assigned (1:1) to groups given a single local injection of 120 million Cx601 cells or placebo (control), in addition to the standard of care. Efficacy endpoints evaluated in the modified intention-to-treat population (randomly assigned, treated, and with 1 or more post-baseline efficacy assessment) at week 52 included combined remission (closure of all treated external openings draining at baseline with absence of collections >2 cm, confirmed by magnetic resonance imaging) and clinical remission (absence of draining fistulas). RESULTS: The study's primary endpoint, at week 24, was previously reported (combined remission in 51.5% of patients given Cx601 vs 35.6% of controls, for a difference of 15.8 percentage points; 97.5% confidence interval [CI] 0.5-31.2; P = .021). At week 52, a significantly greater proportion of patients given Cx601 achieved combined remission (56.3%) vs controls (38.6%) (a difference of 17.7 percentage points; 95% CI 4.2-31.2; P = .010), and clinical remission (59.2% vs 41.6% of controls, for a difference of 17.6 percentage points; 95% CI 4.1-31.1; P = .013). Safety was maintained throughout week 52; adverse events occurred in 76.7% of patients in the Cx601 group and 72.5% of patients in the control group. CONCLUSION: In a phase 3 trial of patients with Crohn's disease and treatment-refractory complex perianal fistulas, we found Cx601 to be safe and effective in closing external openings, compared with placebo, after 1 year. ClinicalTrials.gov no: NCT01541579.

Platelet-rich plasma (PRP) versus fibrin glue in cryptogenic fistula-in-ano: a phase III single-center, randomized, double-blind trial.

PURPOSE: To compare the clinical outcome of autologous platelet-rich growth factor (PRP) with commercial fibrin glue in the management of high cryptogenic fistulae-in-ano. METHOD: The study was conducted at a single center between July 2012 and July 2015 and performed as a phase III, randomized, double-blind comparison of autologously prepared PRP versus fibrin glue for cryptoglandular anal fistulae without active sepsis. Patients were assessed with clinical and endosonographic follow-up. Patients were followed up at 1 week and then at 3, 6, and 12 postoperative months. The primary outcome measure was the fistula healing rate (complete, partial, and non-healing) with secondary outcome measures assessing fistula recurrence, continence status, quality of life, and visual analog pain scores. RESULTS: Of the 56 enrolled patients, 32 were PRP-treated and 24 were fibrin-treated. The groups were well matched for fistula type with an improved overall healing rate for PRP-treated over fibrin-treated cases (71% vs. 58.3%, respectively; P = 0.608); a complete healing rate of 48.4% vs. 41.7%, respectively; and a partial healing rate of 22.6% vs. 16.7%, respectively. The median pain scores of PRP-treated patients were lower at the first visit with a greater initial pain decrease early during follow-up. Improvements in pain reduction impacted the quality of life measures (P = 0.035). All adverse events were minor and no patient experienced a negative impact on continence. CONCLUSION: Treatment of complex cryptoglandular anal fistula with autologous PRP is as effective as fibrin glue with less cost and no adverse effect on continence.

A New Perspective on Vacuum-Assisted Closure for the Treatment of Anastomotic Leak Following Low Anterior Resection for Rectal Cancer, Is It Worthy?

BACKGROUND: Anastomotic dehiscence is a common complication of anterior resection. In this work, we evaluate the management of the pelvic cavity after low rectal resection using vacuum closure (VAC) with a gastroscope, and we establish factors that determine the success of closure and analyzed the rate of ileostomy closure after leakage was resolved. PATIENTS AND METHODS: This is a descriptive case series analysis conducted at a tertiary hospital. Twenty-two patients with low colorectal anastomosis leakage or opening of the rectal stump after anterior resection for rectal cancer were included. They were treated with VAC therapy. RESULTS: The total number of endoscopic sessions was 3.1 ± 1.9 in the anterior resection with anastomosis group and 3.2 ± 1.8 in the Hartmann group. In 11 patients the therapy was administered in an ambulatory setting. The mean time to healing was 22.3 ± 14.7 days. Full resolution was achieved in 19 patients (followed-up 1 year). Ileostomy closure was carried out in 5 patients (38.46%) during follow-up. None of these patients showed leakage signs. Statistically significant differences were obtained depending on the onset of therapy, with better results in patients who underwent earlier vacuum-assisted therapy (before the sixth week after initial surgery), P = .041. CONCLUSIONS: VAC therapy is an alternative to surgery that can be safely administered in an ambulatory setting. Early administration in the 6 weeks following surgery is an independent predictive factor for successful closure; however, colonic transit was only recovered in a small percentage of patients.

Expanded allogeneic adipose-derived mesenchymal stem cells (Cx601) for complex perianal fistulas in Crohn's disease: a phase 3 randomised, double-blind controlled trial.

BACKGROUND: Complex perianal fistulas in Crohn's disease are challenging to treat. Allogeneic, expanded, adipose-derived stem cells (Cx601) are a promising new therapeutic approach. We aimed to assess the safety and efficacy of Cx601 for treatment-refractory complex perianal fistulas in patients with Crohn's disease. METHODS: We did this randomised, double-blind, parallel-group, placebo-controlled study at 49 hospitals in seven European countries and Israel from July 6, 2012, to July 27, 2015. Adult patients (≥18 years) with Crohn's disease and treatment-refractory, draining complex perianal fistulas were randomly assigned (1:1) using a pre-established randomisation list to a single intralesional injection of 120 million Cx601 cells or 24 mL saline solution (placebo), with stratification according to concomitant baseline treatment. Treatment was administered by an unmasked surgeon, with a masked gastroenterologist and radiologist assessing the therapeutic effect. The primary endpoint was combined remission at week 24 (ie, clinical assessment of closure of all treated external openings that were draining at baseline, and absence of collections >2 cm of the treated perianal fistulas confirmed by masked central MRI). Efficacy was assessed in the intention-to-treat (ITT) and modified ITT populations; safety was assessed in the safety population. This study is registered with ClinicalTrials.gov, number NCT01541579. FINDINGS: 212 patients were randomly assigned: 107 to Cx601 and 105 to placebo. A significantly greater proportion of patients treated with Cx601 versus placebo achieved combined remission in the ITT (53 of 107 [50%] vs 36 of 105 [34%]; difference 15·2%, 97·5% CI 0·2-30·3; p=0·024) and modified ITT populations (53 of 103 [51%] vs 36 of 101 [36%]; 15·8%, 0·5-31·2; p=0·021). 18 (17%) of 103 patients in the Cx601 group versus 30 (29%) of 103 in the placebo group experienced treatment-related adverse events, the most common of which were anal abscess (six in the Cx601 group vs nine in the placebo group) and proctalgia (five vs nine). INTERPRETATION: Cx601 is an effective and safe treatment for complex perianal fistulas in patients with Crohn's disease who did not respond to conventional or biological treatments, or both. FUNDING: TiGenix.

The impact of body mass index and nuclear ß-catenin on survival in locally advanced rectal cancer treated with preoperative radiochemotherapy.

BACKGROUND AND OBJECTIVE: We examined the prognostic value of obesity and nuclear ß-catenin in patients with locally advanced rectal cancer. METHODS: We prospectively recruited a total of 98 eligible patients with locally advanced cancer for preoperative radiochemotherapy followed by total mesorectal excision. Patients' height and weight were reaorded before radiochemotherapy, and the immunohistochemical expression of nuclear ß-catenin was analyzed. Disease-free survival (DFS) was analyzed using the Kaplan-Meier method and a Cox regression model was employed for the multivariate analysis. RESULTS: Obese patients were associated with a lower number of recurrences (3.6% vs. 34.3%, P = 0.001), and a higher DFS (95% vs. 53%; HR, 0.09; 95%CI, 0.01-0.64; P = 0.005) than non-obese patients. In the multivariate analysis, body mass index, nuclear ß-catenin expression, and the absence of lymph node metastases showed a significant increase in DFS. CONCLUSIONS: Obesity and nuclear ß-catenin are independent favorable prognostic factors for DFS in locally advanced cancer treated with preoperative radiochemotherapy. J. Surg. Oncol. 2017;115:301-306. © 2017 Wiley Periodicals, Inc.

Factibility and security study of the PICS-AF™ plug for the treatment of cryptoglandular anal fistula. / Estudio de factibilidad y seguridad del plug de colágeno (PICS-AF™) en el tratamiento de la fístula anal criptoglandular.

INTRODUCTION: The PICS-AF™ (Curaseal Inc.) device is a new plug made of collagen that has a retention system in the internal orifice. This pilot study was designed to assess both the feasibility and safety of this plug in the treatment of trans-sphincteric anal fístulas. METHODS: A total of 44 patients (34 men), with a mean age of 54.68±7.3, with trans-sphincteric anal fístulas were included in the study; 34 of them were analyzed. All patients were examined according to a strict preoperative protocol and until 6 months after surgery. The feasibility of the procedure and the adverse events were analyzed. RESULTS: Finally, 34 patients were operated on, and in 30 of them the plug was used. Therefore, the feasibility was calculated at 88%. There was a total of 16 adverse events, 4recorded as not related (3 mild and one moderate) and 12 related to the procedure or to the device implanted. Of these, 5were mild, 5moderate and 2severe. The majority of the events reported were related to proctalgia (4 patients) or infection at the implant site (4 patients). CONCLUSIONS: The present study indicates that the new collagen plug can be placed effectively and with an acceptable complication rate.

Learning curve in robotic rectal cancer surgery: current state of affairs.

INTRODUCTION: Robotic-assisted rectal cancer surgery offers multiple advantages for surgeons, and it seems to yield the same clinical outcomes as regards the short-time follow-up of patients compared to conventional laparoscopy. This surgical approach emerges as a technique aiming at overcoming the limitations posed by rectal cancer and other surgical fields of difficult access, in order to obtain better outcomes and a shorter learning curve. MATERIAL AND METHODS: A systematic review of the literature of robot-assisted rectal surgery was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The search was conducted in October 2015 in PubMed, MEDLINE and the Cochrane Central Register of Controlled Trials, for articles published in the last 10 years and pertaining the learning curve of robotic surgery for colorectal cancer. It consisted of the following key words: "rectal cancer/learning curve/robotic-assisted laparoscopic surgery". RESULTS: A total of 34 references were identified, but only 9 full texts specifically addressed the analysis of the learning curve in robot-assisted rectal cancer surgery, 7 were case series and 2 were non-randomised case-comparison series. Eight papers used the cumulative sum (CUSUM) method, and only one author divided the series into two groups to compare both. The mean number of cases for phase I of the learning curve was calculated to be 29.7 patients; phase II corresponds to a mean number 37.4 patients. The mean number of cases required for the surgeon to be classed as an expert in robotic surgery was calculated to be 39 patients. CONCLUSION: Robotic advantages could have an impact on learning curve for rectal cancer and lower the number of cases that are necessary for rectal resections.

Screening of KRAS Mutation in Pre- and Post-Surgery Serum of Patients Suffering from Colon Cancer by COLD-PCR HRM.

Genomic characterization of cell-free circulating tumour DNA (ctDNA) may offer an opportunity to assess clonal dynamics throughout the course of a patient's illness. The existence of KRAS driver mutations in colon cancer patients is determinant to decide their treatment and to predict their outcome. DNA is extracted automatically from 400 µL of serum using the MagNa Pure Compact with the Nucleic Acid Isolation Kit I. DNA amplification, COLD-PCR and HRM were performed in the same run in the Light Cycler 480.We found three different situations: pre- and post-surgical samples grouped with the negative control, pre-surgical samples appear to group with the positive control and the post-surgical samples appear to group with the negative control and finally both samples, pre- and post-surgical ones, appear to be grouped with the positive control. COLD-PCR HRM is a cost-effective way for screening one of the most common driver mutations to predict the worst prognosis in colorectal cancer.