Conversion during laparoscopic LAR was found to be associated with an increased risk for the postoperative AL in RC patients. A nomogram model incorporating conversion, gender and patient's clinical N stage seems to offers a useful tool for predicting postoperative AL in these patients.

BackgroundThe impact of a patient’s gender on the development of anastomotic leak (AL) in rectal cancer patients following total mesorectal excision (TME) remains controversial. The aim of this study was to evaluate the association between patients’ gender and the risk of AL.MethodsAll rectal cancer patients following TME with a primary anastomosis during the study period from 2010 to 2014 were examined. Comparisons of the post-operative AL incidence rate between male and female patients were performed.ResultsOf all patients examined (n = 956), 587 (61.4%) were males and 369 (38.6%) were females. Male patients were more likely to have a history of smoking and drinking alcohol, but less likely to have a history of abdominal surgery compared to female patients. A higher incidence rate of pre-operative bowel obstruction and larger tumor volume in male patients was observed in our study. Of all the patients, 81 (8.5%) developed post-operative AL. More male patients (n = 62, 10.6%) suffered from AL than females (n = 19, 5.1%) (P = 0.003). Multivariate logistic regression analyses confirmed the association between male gender and AL [odds ratio (OR): 2.41, 95% confidence interval (CI): 1.37–4.23, P = 0.002]. Similar results were also obtained in patients who underwent laparoscopic TME (OR: 2.11, 95% CI: 1.15–3.89, P = 0.016).ConclusionsMale patents were found to have an increased risk for AL following TME with a primary anastomosis. A temporary protecting stoma may help to protect the anastomosis and lessen the risk for AL especially in male patients.

Patients with inflammatory bowel disease (IBD) are at a higher risk of developing colitis-associated colorectal cancer. The aim of the present study was to investigate the role of CD73 in IBD-associated tumorigenesis. A mouse model of colitis-associated tumorigenesis (CAT) induced by azoxymethane and dextran sulfate sodium was successfully constructed. Model mice were injected with CD73 inhibitor or adenosine receptor agonist. Colon length, body weight loss and tumor formation were assessed macroscopically. Inflammatory cytokine measurement and RNA sequencing on colon tissues were performed. Inhibition of CD73 by adenosine 5'-(α,β-methylene) diphosphate (APCP) suppressed the severity of CAT with attenuated weight loss, longer colons, lower tumor number and smaller tumor size compared with the model group. Activation of adenosine receptors using 1-(6-amino-9H-purin-9-yl)-1-deoxy-N-ethyl-β-D-ribofuranur onamide (NECA) exacerbated CAT. Histological assessment indicated that inhibition of CD73 reduced, while activation of adenosine receptors exacerbated, the histological damage of the colon. Increased expression of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-6) in colonic tissue was detected in the NECA group. According to RNA sequencing results, potential oncogenes such as arachidonate 15-lipoxygenase (ALOX15), Bcl-2-like protein 15 (Bcl2l15) and N-acetylaspartate synthetase (Nat8l) were downregulated in the APCP group and upregulated in the NECA group compared with the model group. Therefore, inhibition of CD73 attenuated IBD-associated tumorigenesis, while activation of adenosine receptors exacerbated tumorigenesis in a C57BL/6J mouse model. This effect may be associated with the expression of pro-inflammatory cytokines and the regulation of ALOX15, Bcl2l15 and Nat8l.

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Background and aim: Our previous study showed that high expression of CD73 (ecto-5’-nucleotidase) was a poor prognostic biomarker in patients with colorectal cancer (CRC). However, the underlying mechanism is unclear. Metastasis and chemo-resistance are among the main causes for the poor outcomes of CRC. The aim of this study is to evaluate the role of CD73 in the metastasis and chemo-resistance in CRC. Methods: The expression levels of CD73 were detected using quantitative RT-PCR and Western blot in 9 CRC cell lines and 3 5-FU-resistant cell lines (HCT8-FR, HCT116-FR, and RKO-FR). CD73 was overexpressed via lentiviral vector system and silenced using specific small interference RNA (si-CD73) in HCT8 and RKO. We then performed migration, invasion and MTS assays and wound healing assessment to evaluate the function of CD73 in cell progression and chemo-resistance. We conducted Cignal Finder Reporter Array to assess the main downstream signaling pathways of CD73. Results: Increased expression of CD73 was found in all 3 5-FU-resistant cell lines. Inhibition of CD73 expression in HCT8 and RKO by si-CD73 attenuated the capacity of cell migration and invasion but increased the sensitivity to 5-FU. On the other hand, overexpression of CD73 in HCT8 and RKO increased the capacity for cell migration but decreased the sensitivity to 5-FU. CD73-induced migration and chemo-resistance was found to be associated with the activation of MAPK/ERK pathway. Conclusions: High expression of CD73 was found to be associated with the metastasis and resistance to 5-FU via the activation of MAPK/ERK signaling pathway. This finding provides a molecular basis for the role of CD73 in the progression of CRC, suggesting a novel target for the treatment of CRC. Citation Format: Xuan-hui Liu, Xian-rui Wu, Yu-feng Chen, Feng-wei Wang, Xiao-bin Zheng, Dan Xie, Bo Shen, Jian-ping Wang, Xiao-jian Wu, Ping Lan. Role of CD73 in promoting metastasis and resistance to 5-fluorouracil of colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2938.