Single-cell and bulk transcriptome sequencing identifies two epithelial tumor cell states and refines the consensus molecular classification of colorectal cancer.

The consensus molecular subtype (CMS) classification of colorectal cancer is based on bulk transcriptomics. The underlying epithelial cell diversity remains unclear. We analyzed 373,058 single-cell transcriptomes from 63 patients, focusing on 49,155 epithelial cells. We identified a pervasive genetic and transcriptomic dichotomy of malignant cells, based on distinct gene expression, DNA copy number and gene regulatory network. We recapitulated these subtypes in bulk transcriptomes from 3,614 patients. The two intrinsic subtypes, iCMS2 and iCMS3, refine CMS. iCMS3 comprises microsatellite unstable (MSI-H) cancers and one-third of microsatellite-stable (MSS) tumors. iCMS3 MSS cancers are transcriptomically more similar to MSI-H cancers than to other MSS cancers. CMS4 cancers had either iCMS2 or iCMS3 epithelium; the latter had the worst prognosis. We defined the intrinsic epithelial axis of colorectal cancer and propose a refined 'IMF' classification with five subtypes, combining intrinsic epithelial subtype (I), microsatellite instability status (M) and fibrosis (F).

Conventional laparoscopic versus single-incision laparoscopic right hemicolectomy: a case cohort comparison of short-term outcomes in 144 consecutive cases.

BACKGROUND: Single-incision laparoscopic surgery (SILS) is a recent development of minimally invasive surgery for colorectal disease. The literature comparing it against conventional laparoscopic colectomy remains limited. METHODS: A retrospective case-cohort study compared the benefits and outcomes of SILS right hemicolectomy (SRH) with those of conventional laparoscopic right hemicolectomy (LRH). The medical records of consecutive patients from a prospectively collected database were reviewed. Demographic data, operative details, recovery parameters, and details of resected specimens were obtained and analyzed in an intention-to-treat manner. RESULTS: From January 2006 to March 2011, 104 elective LRHs (72 %) and 40 elective SRHs (28 %) were performed. The demographics for these two groups were comparable in terms of gender, age, ethnicity, body mass index (BMI), comorbidities and American Society of Anesthesiology score. As the records showed, 62 % of the LRHs and 57 % of the SRHs were performed for malignancies (p = 0.536). Seven of the LRH cases (7 %) were converted to open procedure, whereas two of the SILS cases (5 %) were converted. Three SILS cases (7 %) were completed with additional laparoscopic ports. The two groups did not differ significantly in terms of wound length, mean operative time, lymph node clearance, or margins of resected specimen. The recovery parameters (pain score, hospital length of stay, and complications rate) also were equivalent between the two groups. CONCLUSION: As a feasible and safe procedure with early postoperative outcomes equivalent to those for LRH, SRH is a suitable alternative. The possible advantages of SILS over conventional laparoscopic surgery may be validated only with randomized controlled trials in the future.