Robotic rectal cancer surgery: comparative study of the impact of obesity on early outcomes.

The aim of this study was to compare the outcomes of robotic total mesorectal excision (TME) in obese versus non-obese patients. A total of 533 patients, of whom 161 were obese (30·2 per cent) underwent robotic proctectomy during the study interval. Patient obesity was not associated with adverse short-term clinical outcomes after robotic rectal cancer surgery. Indicated in the obese perhaps?

Robotic lateral pelvic lymph node dissection after chemoradiation for rectal cancer: a Western perspective.

AIM: There are limited outcome data for lateral pelvic lymph node dissection (LPLND) following neoadjuvant chemoradiotherapy (nCRT), particularly in the West. Our aim was to evaluate the short-term perioperative and oncological outcomes of robotic LPLND at a single cancer centre. METHOD: A retrospective analysis of a prospective database of consecutive patients undergoing robotic LPLND for rectal cancer between November 2012 and February 2020 was performed. The main outcomes were short-term perioperative and oncological outcomes. Major morbidity was defined as Clavien-Dindo grade 3 or above. RESULTS: Forty patients underwent robotic LPLND during the study period. The mean age was 54 years (SD ± 15 years) and 13 (31.0%) were female. The median body mass index was 28.6 kg/m2 (IQR 25.5-32.6 kg/m2 ). Neoadjuvant CRT was performed in all patients. Resection of the primary rectal cancer and concurrent LPLND occurred in 36 (90.0%) patients, whilst the remaining 4 (10.0%) patients had subsequent LPLND after prior rectal resection. The median operating time was 420 min (IQR 313-540 min), estimated blood loss was 150 ml (IQR 55-200 ml) and length of hospital stay was 4 days (IQR 3-6 days). The major morbidity rate was 10.0% (n = 4). The median lymph node harvest from the LPLND was 6 (IQR 3-9) and 13 (32.5%) patients had one or more positive LPLNs. The median follow-up was 16 months (IQR 5-33 months), with 1 (2.5%) local central recurrence and 7 (17.5%) patients developing distant disease, resulting in 3 (7.5%) deaths. CONCLUSION: Robotic LPLND for rectal cancer can be performed in Western patients to completely resect extra-mesorectal LPLNs and is associated with acceptable perioperative morbidity.

Colorectal premalignancy is associated with consensus molecular subtypes 1 and 2.

Background: Gene expression-based profiling of colorectal cancer (CRC) can be used to identify four molecularly homogeneous consensus molecular subtype (CMS) groups with unique biologic features. However, its applicability to colorectal premalignant lesions remains unknown. Patients and methods: We assembled the largest transcriptomic premalignancy dataset by integrating different public and proprietary cohorts of adenomatous and serrated polyps from sporadic (N = 311) and hereditary (N = 78) patient populations and carried out a comprehensive analysis of carcinogenesis pathways using the CMS random forest (RF) classifier. Results: Overall, transcriptomic subtyping of sporadic and hereditary polyps revealed CMS2 and CMS1 subgroups as the predominant molecular subtypes in premalignancy. Pathway enrichment analysis showed that adenomatous polyps from sporadic or hereditary cases (including Lynch syndrome) displayed a CMS2-like phenotype with WNT and MYC activation, whereas hyperplastic and serrated polyps with CMS1-like phenotype harbored prominent immune activation. Rare adenomas with CMS4-like phenotype showed significant enrichment for stromal signatures along with transforming growth factor-ß activation. There was a strong association of CMS1-like polyps with serrated pathology, right-sided anatomic location and BRAF mutations. Conclusions: Based on our observations made in premalignancy, we propose a model of pathway activation associated with CMS classification in colorectal carcinogenesis. Specifically, while adenomatous polyps are largely CMS2, most hyperplastic and serrated polyps are CMS1 and may transition into other CMS groups during evolution into carcinomas. Our findings shed light on the transcriptional landscape of premalignant colonic polyps and may help guide the development of future biomarkers or preventive treatments for CRC.