Genome-wide analysis of 944 133 individuals provides insights into the etiology of haemorrhoidal disease

OBJECTIVE

Haemorrhoidal disease (HEM) affects a large and silently suffering fraction of the population but its aetiology, including suspected genetic predisposition, is poorly understood. We report the first genome-wide association study (GWAS) meta-analysis to identify genetic risk factors for HEM to date.

DESIGN

We conducted a GWAS meta-analysis of 218 920 patients with HEM and 725 213 controls of European ancestry. Using GWAS summary statistics, we performed multiple genetic correlation analyses between HEM and other traits as well as calculated HEM polygenic risk scores (PRS) and evaluated their translational potential in independent datasets. Using functional annotation of GWAS results, we identified HEM candidate genes, which differential expression and coexpression in HEM tissues were evaluated employing RNA-seq analyses. The localisation of expressed proteins at selected loci was investigated by immunohistochemistry.

RESULTS

We demonstrate modest heritability and genetic correlation of HEM with several other diseases from the GI, neuroaffective and cardiovascular domains. HEM PRS validated in 180 435 individuals from independent datasets allowed the identification of those at risk and correlated with younger age of onset and recurrent surgery. We identified 102 independent HEM risk loci harbouring genes whose expression is enriched in blood vessels and GI tissues, and in pathways associated with smooth muscles, epithelial and endothelial development and morphogenesis. Network transcriptomic analyses highlighted HEM gene coexpression modules that are relevant to the development and integrity of the musculoskeletal and epidermal systems, and the organisation of the extracellular matrix.

CONCLUSION

HEM has a genetic component that predisposes to smooth muscle, epithelial and connective tissue dysfunction.

Feasibility and Early Results of Interstitial Intensity-Modulated HDR/PDR Brachytherapy (IMBT) with/without Complementary External-Beam Radiotherapy and Extended Surgery in Recurrent Pelvic Colorectal Cancer

BACKGROUND

A new multimodality treatment concept consisting of extended resection and postoperative fractionated intensity-modulated interstitial brachytherapy (IMBT) was introduced for pelvic recurrence of colorectal carcinoma.

PATIENTS AND METHODS

46 patients received extended resection and single plastic tubes were sutured directly onto the tumor bed. IMBT was started within 2 weeks postoperatively with a median dose of 24.5 Gy (5-35 Gy). Patients were treated either with high-dose-rate brachytherapy (HDR; n = 23) or with pulsed-dose-rate brachytherapy (PDR; n = 23). 25 patients received complementary 45-Gy external-beam irradiation (EBRT) to the pelvic region after explanting the plastic tubes.

RESULTS

Median follow-up was 20.6 months (7-107 months) and mean patient survival 25.7 +/- 25.8 months (median 17, range 1-107 months). After 5 years overall survival, disease-free survival and local control rate were 23%, 20% and 33%, significantly influenced by the resectional state. There was a trend in favor of PDR compared to HDR, which reached statistical significance in patients who had not received additional EBRT.

CONCLUSION

The combination of extended surgery and postoperative interstitial IMBT is feasible and offers effective interdisciplinary treatment of recurrent colorectal cancer. In this small and inhomogeneous cohort of patients PDR seems to be more effective than HDR, particularly when application of complementary EBRT is not possible. None of the patients who required resection of distant metastasis survived > 2 years in this study.

Endoscopic removal of large colorectal polyps: prevention of unnecessary surgery?

PURPOSE

Because of the potential risk of malignancy and technical difficulties in achieving complete removal, large colorectal polyps represent a special problem for the endoscopist. The aim of this study was to evaluate the capabilities and risks of endoscopy in complete removal of large colorectal polyps.

METHODS

Endoscopic polypectomy of 186 colorectal polyps larger than 3 cm in diameter (range, 3-13 cm) was performed; 141 were sessile and 45 pedunculated. Most of the polyps were located in the rectum (n = 88), sigmoid (n = 63), and cecum (n = 9). The remaining adenomas were situated in other parts of the colon. Sessile polyps were removed using the piecemeal technique.

RESULTS

Histology results showed an adenoma in 167 cases, and invasive carcinoma was present in the adenoma in 19 patients. Of the adenomas, 29 were tubulous, 118 tubulovillous, and 20 villous; adenoma with severe dysplasia was found in 49 cases. Complete endoscopic removal was achieved in all sessile and pedunculated polyps. None of the patients with invasive carcinoma who underwent surgical resection (n = 10) had any evidence of tumor in the resected specimen. Bleeding occurred in 4 patients after polypectomy (2 percent). Perforation occurred in 1 patient (0.5 percent), who had an invasive carcinoma of the cecum. There was no procedure-related mortality. During a mean follow-up period of 40 (range, 3-87) months, 6 patients presented with recurrence of a benign adenoma (3 percent), which was treated endoscopically, and 1 patient presented with a recurrent invasive carcinoma, which was treated surgically.

CONCLUSIONS

Endoscopic polypectomy is a safe and effective method of treating large colorectal polyps.

A genomic polymorphism within the tumor necrosis factor locus influences plasma tumor necrosis factor-alpha concentrations and outcome of patients with severe sepsis

OBJECTIVES

To determine the allele frequency and genotype distribution of a bi-allelic tumor necrosis factor (TNF) gene polymorphism and plasma TNF-alpha concentrations in postoperative intensive care unit (ICU) patients suffering from severe sepsis.

DESIGN

Prospective, consecutive entry study of patients with severe sepsis in a postoperative ICU.

SETTING

University hospital.

PATIENTS

Forty patients with diagnosis of severe sepsis, admitted to the ICU between June 1993 and December 1994.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A 782 basepairs fragment of genomic DNA, including the polymorphic site of the restriction enzyme Ncol within the TNF locus, was amplified by means of polymerase chain reaction. The genotype of each patient was determined after Ncol digestion of the amplified product and subsequent agarose gel electrophoresis. Reading the size of the resulting DNA bands from the agarose gel demonstrated the genotype, as defined by the two alleles TNFB1 and TNFB2. Serial blood samples were drawn every sixth hour during the first 48 hrs and every 12th hour thereafter, for < or = 96 hrs after diagnosis. TNF-alpha plasma concentrations were detected by an enzyme-linked immunosorbent assay. Assessment of organ dysfunction was performed by calculating a Multiple Organ Failure score. The overall allele frequency (TNFB1 0.35; TNFB2 0.65) and genotype distribution (TNFB1 homozygotes 10%; TNFB1/TNFB2 heterozygotes 48%; TNFB2 homozygotes 42%) in 40 patients with severe sepsis were comparable with those values found in normal individuals. Development of multiple organ failure occurred in 33 (82.5%) of 40 patients, whereas 23 (57.5%) of 40 patients did not survive. In contrast to the overall allele frequency, nonsurvivors showed a significantly higher prevalence of the allele TNFB2(p < .005). Patients homozygous for the allele TNFB2 demonstrated a higher mortality rate than heterozygous (TNFB1/TNFB2) patients (p = .0022). In addition, patients with TNFB2 homozygotes displayed higher circulating TNF-alpha concentrations as well as higher Multiple Organ Failure scores compared with heterozygous (TNFB1/TNFB2) patients.

CONCLUSIONS

The bi-allelic Ncol polymorphism within the TNF locus is a genomic marker for patients with increased TNF-alpha response and poor prognosis in severe sepsis. The amount of TNF released in situations of severe infection and sepsis appears to be influenced genetically. TNFB2 homozygous individuals displaying increased circulating TNF plasma concentrations combined with high mortality rate may be included in future studies testing anti-TNF strategies in severe sepsis.