Aim Studies have demonstrated a relationship between lymph node (LN) yield and survival after colectomy for cancer. The impact of surgical technique on lymph node yield has not been well explored. Method This is a retrospective study of right colectomies (RC) for cancer at a single institution from 2012–2014. Exclusion criteria were previous colectomy, emergent and palliative operations. All data were collected by chart review. Primary outcomes were LN yield and the lymph node to length of surgical specimen (LN-LSS) ratio. Multivariable mixed models were created with surgeon and pathologist as random effects. Sensitivity analyses were performed to exclude stage IV cancers and to analyze groups on an “as-treated” basis. Results We identified 181 open (O-RC), 163 laparoscopic (L-RC) and 119 robotic (R-RC) cases. Open RC was more commonly performed in females with metastatic disease. Mean LN yield was 28, 29, and 34 in O-RC, L-RC, and R-RC, respectively; mean LN-LSS ratios were 0.83, 0.91 and 1.0. The R-RC approach produced a higher LN yield compared to other approaches (p < 0.01), and a higher LN-LSS ratio compared to O-RC (p < 0.01). These findings were unchanged in sensitivity analyses. Conclusion Robotic RC improves LN yield and LN-LSS ratio, which may reflect a better mesocolic excision. The effect of these findings on survival requires further investigation.

Purpose Incisional hernia (IH) is a common complication after colectomy, with impacts on both healthcare utilization and quality of life. The true incidence of IH after minimally invasive colectomy is not well described. The purpose of this study was to examine the IH incidence after minimally invasive right colectomies (RC), and to compare the IH rate after laparoscopic (L-RC) and robotic (R-RC) colectomies. Methods This is a retrospective review of patients undergoing minimally invasive RC at a single institution from 2009–2014. Only patients undergoing RC for colonic neoplasia were included. Patients with previous colectomy or intraperitoneal chemotherapy were excluded. Three L-RC patients were included for each R-RC patient. The primary outcome was incisional hernia (IH) rate based on clinical examination or computed tomography (CT). Univariate and multivariate time-to-event analyses were used to assess predictors of IH. Results 276 patients where included, of which 69 had undergone R-RHC and 207 L-RHC. Patient and tumor characteristics were similar between the groups, except for higher tumor stage in L-RC patients. Both the median time to diagnosis (9.2 months) and the overall IH rate were similar between the groups (17.4% for R-RHC and 22.2% for L-RHC), as were all other postoperative complications. In multivariable analyses, the only significant predictor of IH was former or current tobacco use (HR 3.0, p=0.03). Conclusions This study suggests that the incidence of IH is high after minimally invasive colectomy, and that this rate is equivalent after R-RC and L-RC. Reducing the IH rate is an important opportunity for improving quality of life and reducing health care utilization after minimally invasive colectomy.

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INTRODUCTION: IGF-I receptor (IGF-1R) blockade has been shown to slow prostate cancer xenograft growth. Caloric restriction inhibits xenograft growth through modulation of the insulin-IGF axis. We hypothesized that caloric restriction combined with IGF-I receptor blockade would result in additive suppression of prostate cancer growth. METHODS: Sixty SCID mice were subcutaneously injected with 22RV1 cells (suppressible with IGF-1R blockade in vitro) and randomized to four groups: 1) ad libitum feeding with intraperitoneal saline (ad lib), 2) ad libitum with 20 mg/kg twice weekly intraperitoneal AMG479 IGF-I receptor blocking antibody (Amgen), (ad lib/Ab), 3) 40% calorie restriction with intraperitoneal saline (CR), 4) 40% calorie restriction with intraperitoneal AMG479, (CR/Ab). Diet and treatment with either antibody or saline were initiated one week after tumor injection. The animals were euthanized after 19 days of treatment and tumors were weighed. Fasting plasma levels of insulin, IGF-I, IGFBP-3, and IGFBP-1 were measured and tumors were stained for Ki67, TUNEL, and CD31. Cleaved caspase 3 and AKT activation in tumors were assessed by western blot. RESULTS: Mean tumor weight at sacrifice in the CR/Ab group was significantly lower (p&lt;0.05) than the other three groups (166 mg ± 23 vs. Ad lib: 467 mg ± 58, Ad lib/Ab: 502 mg ± 52 and CR: 295 mg ± 56). Mean tumor weight was also lower in the CR group as compared to the ad lib groups (p&lt; 0.05). Cleaved Caspase 3/Total Caspase 3 ratios were increased by 2 to 3 fold in the CR groups compared to the ad lib groups irrespectively of antibody therapy. Ki67 expression was significantly decreased in the CR/Ab group compared to the ad lib group (77 ± 1.2 vs. 81± 1.4 p&lt;0.05). Plasma IGF-1 and IGFBP-3 levels were significantly reduced in the CR groups compared to the Ad lib groups irrespectively of treatment. AKT activation correlated to plasma IGF-1 levels. Mice in the Ad lib/Ab group had increased plasma insulin levels compared to the Ad lib group. The CR and CR/AB groups had significantly lower plasma insulin (80 and 60% reduction respectively) relative to the ad lib group. Angiogenesis was not affected by these interventions. CONCLUSION: Combining caloric restriction with antibody therapy targeting the IGF-1 receptor had additive anticancer effects on 22RV1 tumor growth. This additive anticancer effect may be due to suppression of the insulin elevation observed with AMG479 resulting in increased apoptosis and decreased proliferation in the CR/Ab combination arm. Further pre-clinical and clinical trials are warranted to evaluate the role of dietary interventions in combination with anti IGF1R antibody therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-458. doi:10.1158/1538-7445.AM2011-LB-458

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