Perineal wound healing after abdominoperineal resection for rectal cancer: a retrospective cohort study.

PURPOSE: Delayed perineal wound healing is a common complication after abdominoperineal resection (APR) in rectal cancer. The primary aim of this study was to evaluate the number of patients with delayed wound healing after APR. Secondary aims were to identify risk factors, and describe treatment. METHODS: Prospectively collected data from the Swedish Colorectal Cancer Registry (SCRCR) was used for retrospective analysis of APR performed at Skåne University Hospital Malmö between 2013 and 2018. Medical charts were retrospectively reviewed. Delayed healing was defined as non-healed perineal wound 30 days postoperatively. Patients undergoing extralevator APR requiring reconstruction were excluded. Statistical analysis was made using SPSS. Risk factors for impaired wound healing were analyzed using a multivariable model. RESULTS: A total of 162 patients were included, of which 114 underwent standard APR (sAPR) and 48 patients intersphincteric APR (isAPR). In the total population, 69% (111/162) were male, with median age 71 (26-87). The overall healing rate was 52% (85/162); 44% (50/114) in sAPR vs 73% (35/48) in isAPR (P < 0.001). Risk factors for impaired healing after multivariable analysis were BMI > 30 (OR 7.0; CI 95% 1.8-26.2, P = 0.004), reoperation (OR 7.9; CI 95% 1.6-39.8, P = 0.013), neoadjuvant radiotherapy (OR 5.2; CI 95% 1.02-25.1, P = 0.047) and sAPR (OR 2.598; CI 95% 1.05-6.41, P = 0.038). Eight percent (13/162) required an intervention (Clavien-Dindo ≥ 3). CONCLUSION: Delayed perineal wound healing is a frequent complication after APR but the majority could be treated conservatively. Several risk factors were identified. Further studies aiming at interventions reducing delayed perineal wound healing after APR are warranted.

CXCL2-CXCR2 axis mediates αV integrin-dependent peritoneal metastasis of colon cancer cells.

Peritoneal metastasis is an insidious aspect of colorectal cancer. The aim of the present study was to define mechanisms regulating colon cancer cell adhesion and spread to peritoneal wounds after abdominal surgery. Mice was laparotomized and injected intraperitoneally with CT-26 colon carcinoma cells and metastatic noduli in the peritoneal cavity was quantified after treatment with a CXCR2 antagonist or integrin-αV-antibody. CT-26 cells expressed cell surface chemokine receptors CXCR2, CXCR3, CXCR4 and CXCR5. Stimulation with the CXCR2 ligand, CXCL2, dose-dependently increased proliferation and migration of CT-26 cells in vitro. The CXCR2 antagonist, SB225002, dose-dependently decreased CXCL2-induced proliferation and migration of colon cancer cells in vitro. Intraperitoneal administration of CT-26 colon cancer cells resulted in wide-spread growth of metastatic nodules at the peritoneal surface of laparotomized animals. Laparotomy increased gene expression of CXCL2 at the incisional line. Pretreatment with CXCR2 antagonist reduced metastatic nodules by 70%. Moreover, stimulation with CXCL2 increased CT-26 cell adhesion to extracellular matrix (ECM) proteins in a CXCR2-dependent manner. CT-26 cells expressed the αV, ß1 and ß3 integrin subunits and immunoneutralization of αV abolished CXCL2-triggered adhesion of CT-26 to vitronectin, fibronectin and fibrinogen. Finally, inhibition of the αV integrin significantly attenuated the number of carcinomatosis nodules by 69% in laparotomized mice. These results were validated by use of the human colon cancer cell line HT-29 in vitro. Our data show that colon cancer cell adhesion and growth on peritoneal wound sites is mediated by a CXCL2-CXCR2 signaling axis and αV integrin-dependent adhesion to ECM proteins.

Retraction: Neutrophil extracellular traps promote peritoneal metastasis of colon cancer cells.

[This retracts the article DOI: 10.18632/oncotarget.26664.].

Neutrophil extracellular traps promote peritoneal metastasis of colon cancer cells.

Cytoreductive surgery is the only curative option for patients with peritoneal carcinomatosis, however, intraperitoneal recurrence rate is high making new ways to prevent cancer recurrence an urgent need. Recent evidence suggests that neutrophils are involved in cancer progression. The purpose of our study was to examine the role of neutrophils in the spread of colon cancer cells in the peritoneal cavity. The number of metastatic noduli in the peritoneal cavity was quantified in mice injected with murine colon cancer cells (CT-26) intraperitoneally after surgical laparotomy and treated with a neutrophil depleting antibody or DNase I. In addition, peritoneal metastases were harvested from patients with peritoneal carcinomatosis. Scanning and transmission electron microscopy showed extensive neutrophil extracellular trap (NET) formation in peritoneal colon cancer metastases in mice and patients. Neutrophil depletion markedly reduced the number of metastases in laparotomised animals. Administration of DNase I decreased the number of metastatic nodules by 88% in laparotomised animals as well as NET-induced chemokine-dependent colon cancer cell migration and adhesion in vitro. Finally, CT-26 cancer cells were found to express the αvß3 integrin and inhibition of αv integrin abolished NET-induced adhesion of colon cancer cells to vitronectin. Taken together, our data show that NETs play an important role in colon cancer cell metastasis in the peritoneal cavity and regulate colon cancer cell migration and adhesion to extracellular matrix proteins. These novel findings suggest that targeting NETs might be an effective strategy to antagonize intrabdominal recurrences of colon cancer after cytoreductive surgery in patients with peritoneal carcinomatosis.