Gene mutation and surgical technique: Suggestion or more?

Advancements in chemotherapy and molecular targeted therapy have improved long-term outcomes for patients with resectable colorectal liver metastases (CLM). RAS mutation status was an original focus as a molecular biomarker as it predicted treatments response to anti-epidermal growth factor receptor agents. More recently, studies have incorporated somatic mutation data in analyses pertaining to surgical outcomes and prognosis. This evidenced-based review covers the implications of somatic mutations in patients undergoing resection of CLM.     

Does the difficulty grade of laparoscopic liver resection for colorectal liver metastases correlate with long-term outcomes?

IntroductionPrognosis of patients with colorectal liver metastases (CRLM) is strongly correlated with the oncological outcome after liver resection. The aim of this study was to analyze the impact of laparoscopic liver resection (LLR) difficulty score (IMM difficulty score) on the oncological results in patients treated for CRLM.MethodsAll patients who underwent LLRs for CRLM from 2000 to 2016 in our department, were retrospectively reviewed. Data regarding difficulty classification, -according to the Institute Mutualiste Montsouris score (IMM)-, recurrence rate, recurrence-free survival (RFS), overall survival (OS) and data regarding margin status were analyzed.ResultsA total of 520 patients were included. Patients were allocated into 3 groups based on IMM difficulty score of the LLR they underwent: there were 227 (43,6%), 84 (16,2%) and 209 (40,2%) patients in groups I, II and III, respectively. The R₁ resection rate in group I, II and III were 8,8% (20/227), 11,9% (10/84) and 12,4% (26/209) respectively (p = 0.841). Three- and 5-year RFS rates were 77% and 73% in group I, 58% and 51% in group II, 61% and 53% in group III, respectively (p = 0.038). Three and 5-year OS rates were 87% and 80% for group I, 77% and 66% for group II, 80% and 69% for group III respectively (p = 0.022).ConclusionThe higher LLR difficulty score correlates with significant morbidity and worse RFS and OS, although the more technically demanding and difficult cases are not associated with increased rates of positive resection margins and recurrence.     

Can transanal endoscopic microsurgery effectively treat T1 or T2 rectal cancer?A systematic review and meta-analysis

AimWe aimed to compare the safety and oncological outcomes of transanal endoscopic microsurgery (TEM) and radical surgery (RS) for patients with T1 or T2 rectal cancer.MethodWe searched Pubmed, Embase, Cochrane Library databases for relevant studies comparing TEM with RS in rectal cancer published until April 2020. We focused on safety and oncological outcomes.ResultsThis meta-analysis included 3526 patients from 12 studies. Compared with RS, TEM had a shorter operative time (weighted mean difference [WMD] −110.02, 95% confidence interval [CI]: 143.98, −76.06), less intraoperative blood loss (WMD -493.63, 95% CI: 772.66, −214.59), lower perioperative morality (risk ratio [RR] 0.25, 95% CI: 0.06, 0.99), and fewer postoperative surgical complications (RR 0.23, 95% CI: 0.11,0.45). TEM was associated with more patients with a positive margin or a doubtfully complete margin than RS (RR 7.36, 95% CI: 3.66, 14.78). TEM was associated with higher local recurrence (RR 2.63, 95% CI: 1.60, 4.31) and overall recurrence (RR 1.60, 95% CI: 1.09, 2.36). TEM had a negative effect on 5-year overall survival (hazard ratio [HR] 1.51, 95% CI: 1.16, 1.96), especially in the T2 without neoadjuvant therapy (NAT) subgroup (HR 2.02, 95% CI: 1.32, 3.09), but in the subgroups of T1 or T2 with NAT before TEM, TEM did not yield a significantly lower overall survival than RS.ConclusionTEM seems appropriate for T1 rectal cancer with favourable histopathology. For patients with T2 rectal cancer, NAT before TEM may contribute to achieving oncological outcomes equivalent to that achieved with RS.     

Prognostic factor analysis of irreversible electroporation for locally advanced pancreatic cancer – A multi-institutional clinical study in Asia

IntroductionIrreversible electroporation (IRE) is a modality that utilizes high electric voltage to cause cell apoptosis. IRE has been used to treat locally advanced pancreatic cancer (LAPC). However, studies of IRE via surgical approaches for LAPC are limited. This study aims to analyse the outcomes and related prognostic factors of IRE for Asian patients with LAPC.Materials and methodsFrom 2012 to 2017, this prospective trial for using IRE through surgical approaches for LAPC was conducted in 11 medical centres in Asia. All related and treatment outcomes were analysed from a prospective database.ResultsSeventy-four patients were enrolled. Thirty complications occurred in thirteen (17.6%) patients without mortality. The electrode placement direction (anteroposterior vs. craniocaudal, HR = 14.2, p < 0.01) and gastrointestinal invasion (HR = 15.7, p < 0.01) were significant factors for complications. The progression-free survival (PFS) rate in one year, three years, and five years were 69.1%, 48.7%, and 28.8%, and the overall survival (OS) rate in one year, three years, and five years were 97.2%, 53%, and 31.2%. In univariate analysis, the chemotherapy regimen, local tumour recurrence, axial tumour length, tumour volume, and serum carbohydrate antigen 19-9 levels were all significantly associated with PFS and OS. In multivariate analysis, the chemotherapy regimen was the only significant factor associated with PFS and OS. TS-1 (Tegafur, gimeracil, and oteracil) group has superior survival outcome than gemcitabine group.ConclusionThis study showed that combined induction chemotherapy and surgical IRE for LAPC is safe. For well-selected patients, IRE can achieve encouraging survival outcomes.