Surgical safety margin of gastroenterological cancer surgery: A truth or a dream?

The extent of distal intramural spread of colorectal cancer cell study of it's relationship with histological grading, stage of disease and CEA level

BACKGROUND

The free margin of distal resection is an attempt to prevent local recurrence of the tumor and prolong survival. The recommended length of distal resection margin are varied among the researchers. This study was done to know the correlation between extents of distal intramural spread (DIS) and histology grading, stage and CEA levels of colorectal cancer.

METHODS

The design of the study was a cross sectional. Sample was patients diagnosed with colon or rectal adenocarcinoma in the period of September 2017-March 2018 and underwent resection at Dr.Kariadi Hospital. Resected fresh tissue tumors were directly measured for the distal resection margin and histopathologic examination done by anatomical pathologists. This study has been approved by the ethics committee of Dr.Kariadi Hospital/Faculty of Medicine Diponegoro University. The relationship between DIS length to histology grading, tumor stage and CEA level were analyzed using Spearman's correlation test.

RESULTS

The subjects of this study were 26 patients with colorectal cancer consisted of 15 men and 11 women. The average age of the patients was 53,04 years. The locations of the tumor were 17 in the rectum and 9 in the colon. The length DIS were between 1,07 and 11,49 mm. The longer DIS were occurred when the grading histology worsens, the tumor stage increases and the higher CEA levels with correlation coefficient were r = 0,77 (p < 0,001); r = 0,66 (p < 0,001) and r = 0,44 (p = 0,024) respectively. For the rectal location, the DIS length range were 0,28-10,36 mm. The longer DIS when grading histology worsens r = 0,59 (p = 0,012) and an increased tumor stage r = 0,73 (p = 0,001). The DIS length of the rectum was not proven to correlate with elevated CEA levels r = 0,14 (p = 0,588).

CONCLUSION

Histological grading, tumor stage and CEA levels can be predictors of distal intramural spread (DIS) colorectal cancer. The strongest correlation were between DIS and histologic grading. Thus, in mid and lower third of the rectal cancer, the histologic grade examination is strongly recommended. Based on this study, it is recommended that in rectal cancer undergoing sphincter preserving surgery distal resection sould be more than 2 cm from the tumor margin.

Novel reference genes in colorectal cancer identify a distinct subset of high stage tumors and their associated histologically normal colonic tissues

Background

Reference genes are often interchangeably called housekeeping genes due to 1) the essential cellular functions their proteins provide and 2) their constitutive expression across a range of normal and pathophysiological conditions. However, given the proliferative drive of malignant cells, many reference genes such as beta-actin (ACTB) and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) which play critical roles in cell membrane organization and glycolysis, may be dysregulated in tumors versus their corresponding normal controls

Methods

Because Next Generation Sequencing (NGS) technology has several advantages over hybridization-based technologies, such as independent detection and quantitation of transcription levels, greater sensitivity, and increased dynamic range, we evaluated colorectal cancers (CRC) and their histologically normal tissue counterparts by NGS to evaluate the expression of 21 “classical” reference genes used as normalization standards for PCR based methods. Seventy-nine paired tissue samples of CRC and their patient matched healthy colonic tissues were subjected to NGS analysis of their mRNAs.

Results

We affirmed that 17 out of 21 classical reference genes had upregulated expression in tumors compared to normal colonic epithelial tissue and dramatically so in some cases. Indeed, tumors were distinguished from normal controls in both unsupervised hierarchical clustering analyses (HCA) and principal component analyses (PCA). We then identified 42 novel potential reference genes with minimal coefficients of variation (CV) across 79 CRC tumor pairs. Though largely consistently expressed across tumors and normal control tissues, a subset of high stage tumors (HSTs) as well as some normal tissue samples (HSNs) located adjacent to these HSTs demonstrated dysregulated expression, thus identifying a subset of tumors with a potentially distinct and aggressive biological profile.

Conclusion

While classical CRC reference genes were found to be differentially expressed between tumors and normal controls, novel reference genes, identified via NGS, were more consistently expressed across malignant and normal colonic tissues. Nonetheless, a subset of HST had profound dysregulation of such genes as did many of the histologically normal tissues adjacent to such HSTs, indicating that the HSTs so distinguished may have unique biological properties and that their histologically normal tissues likely harbor a small population of microscopically undetected but metabolically active tumors.

Electronic supplementary material

The online version of this article (10.1186/s12881-019-0867-y) contains supplementary material, which is available to authorized users.

Management of cavernous abdominal wall defects post radical cystectomy in adult exstrophy complex

The exstrophy-epispadias complex represents a spectrum of genitourinary malformations ranging from simple glanular epispadias to an overwhelming multisystem defect, cloacal exstrophy. Neonatal total reconstruction of bladder exstrophy-epispadias complex is the treatment of choice. An adult patient presenting with untreated exstrophy is very rare. Malignant transformation, commonly adenocarcinoma, in such cases is a known complication due to mucosal metaplasia of urothelium. Management in such cases necessitates a radical surgical procedure that often results in a massive defect in the anterior abdominal wall. Providing a cover for such defects is a challenging task for the reconstructive surgeon. Local skin flaps and wide mobilisation of the rectus muscle are the usually employed techniques for closure of such defects. However, these may be inadequate in extremely large defects such as those encountered in our patients. We, hereby, describe our technique of closure of the abdominal wall defect using a pedicled anterolateral thigh flap.

Transcriptome analysis of human colorectal cancer biopsies reveals extensive expression correlations among genes related to cell proliferation, lipid metabolism, immune response and collagen catabolism

Precise characterization of biological processes critical to proliferation and metastasis of colorectal cancer should facilitate the development of diagnostic and prognostic biomarkers as well as novel treatments. Using mRNA-Seq, we examined the protein coding messenger RNA (mRNA) expression profiles across different histologically defined stages of primary colon cancers and compared them to their patient matched normal tissue controls. In comparing 79 colorectal cancers to their matched normal mucosa, tumors were distinguished from normal non-malignant tissues not only in the upregulation of biological processes pertaining to cell proliferation, inflammation, and tissue remodeling, but even more strikingly, in downregulated biological processes including fatty acid beta oxidization for ATP production and epithelial cell differentiation and function. A network analysis of deregulated genes revealed newly described cancer networks and putative hub genes.

Taken together, our findings suggest that, within an inflammatory microenvironment, invasive, dedifferentiated and rapidly dividing tumor cells divert the oxidation of fatty acids and lipids from energy production into lipid components of cell membranes and organelles to support tumor proliferation. A gene co-expression network analysis provides a clear and broad picture of biological pathways in tumors that may significantly enhance or supplant current histopathologic studies.

Wide versus narrow margins after partial hepatectomy for hepatocellular carcinoma: Balancing recurrence risk and liver function

BACKGROUND

The goal of this study was to compare the outcome after partial hepatectomy for hepatocellular carcinoma (HCC) in which a margin less than or equal to 5 mm or greater than 5 mm was achieved.

METHODS

A review of our 3300-patient prospective HPB database was performed from 12/2002 to 4/2015. Patients were stratified into two groups: resection margins ≤5 ("narrow") and >5 mm ("wide") as measured on final pathologic assessment.

RESULTS

One-hundred thirty patients were included in the analysis (margin ≤5 mm, n = 41 and margin >5 mm, n = 89). At the time of analysis 54 patients had developed 56 recurrences, 15 (37%) in the narrow margin group and 41 (46%) in the wide margin group, p = 0.45. The pattern of recurrence was similar in the two groups: intrahepatic 11 (79%) versus 30 (75%), p = 1, and extra-hepatic 6 (43%) versus 17 (43%), p = 1. Median disease-free survival was similar in both groups, 18.1 versus 19.5 months (p = 0.85).

CONCLUSIONS

A narrow resection margin (5 mm or less) does not detract from oncologic outcomes after partial hepatectomy for HCC. Tailoring resection margins may lead to greater preservation of hepatic parenchyma. Factors other than margin status represent the driving forces for local and systemic recurrence.