Surgical Resection Of Colon Cancer Research Articles

The dose-response effect of aerobic exercise on inflammation in colon cancer survivors.

Physical activity after surgical resection for colon cancer is associated with significantly longer disease-free survival. Inflammation is hypothesized to mediate the association between physical activity and disease-free survival in colon cancer. In this exploratory analysis of a randomized dose-response trial, 39 colon cancer survivors who completed standard therapy were stratified by cancer stage and randomized in a 1:1:1 ratio to one of three treatment groups for 24 weeks of usual-care control, 150 min/wk of moderate-intensity aerobic exercise (low-dose), or 300 min/wk of moderate-intensity aerobic exercise (high-dose). Inflammation outcomes included high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL6), and soluble tumor necrosis factor-alpha receptor 2 (sTNFαR2). Mixed models for repeated measures were used to test the hypothesis that exercise was associated with dose-response reductions in inflammation; exploratory analyses examined treatment effects by cancer stage. In the overall population, aerobic exercise was not associated with dose-response reductions in hs-CRP, IL6, or sTNFαR2. Cancer stage modified the association between randomized group and hs-CRP (P=0.022) and IL6 (P<0.001) but not sTNFαR2 (P=0.39). In stage I-II disease, compared to control, exercise was not associated with inflammation outcomes. In stage III disease, compared to control, low-dose exercise reduced hs-CRP: -35.4% (95% CI: -70.1, -0.7) and IL6: -29.6% (95% CI: -58.4, -0.8) but not sTNFαR2: 2.7% (95% CI: sTNFαR2: -15.7, 21.1); high-dose exercise was not associated with inflammation outcomes in stage III disease. This exploratory analysis offers preliminary data to support the hypothesis that inflammation may mediate the association between physical activity and disease-free survival in colon cancer. clinicaltrials.gov, identifier NCT02250053.

Deep learning to predict lymph node status on pre-operative staging CT in patients with colon cancer.

Lymph node (LN) metastases are an important determinant of survival in patients with colon cancer, but remain difficult to accurately diagnose on preoperative imaging. This study aimed to develop and evaluate a deep learning model to predict LN status on preoperative staging CT. In this ambispective diagnostic study, a deep learning model using a ResNet-50 framework was developed to predict LN status based on preoperative staging CT. Patients with a preoperative staging abdominopelvic CT whounderwent surgical resection for colon cancer were enrolled. Data were retrospectively collected from February 2007 to October 2019 and randomly separated into training, validation, and testing cohort 1. To prospectively test the deep learning model, data for testing cohort 2 was collected from October 2019 to July 2021. Diagnostic performance measures were assessed by the AUROC. A total of 1,201 patients (median [range] age, 72 [28-98 years]; 653 [54.4%] male) fulfilled the eligibility criteria and were included in the training (n = 401), validation (n = 100), testing cohort 1 (n = 500) and testing cohort 2 (n = 200). The deep learning model achieved an AUROC of 0.619 (95% CI 0.507-0.731) in the validation cohort. In testing cohort 1 and testing cohort 2, the AUROC was 0.542 (95% CI 0.489-0.595) and 0.486 (95% CI 0.403-0.568), respectively. A deep learning model based on a ResNet-50 framework does not predict LN status on preoperative staging CT in patients with colon cancer.

Importance of Arterial Vessel Length for Metastatic Lymph Node Retrieval and Survival in Standardized Left- and Right-Sided Colon Cancer Surgery.

We investigated the localization of lymph node metastases, and the role of arterial vessel and specimen lengths in left- and right-sided colon cancer surgery, for survival. This was a prospective cross-sectional population-based study of specimens from patients who underwent standardized surgical resection for colon cancer in 2012-2015. The mesocolon of the specimens was divided into four sections for pathological analysis of lymph nodes. Multiple linear regression analysis was used to explore the relationship between lymph node counts and patient- and surgery-related factors. For survival analysis, a multivariable Cox regression method was used. A total of 317 patients (160 females) were included. Median (range) age was 74 (30-95) years. Median number of lymph node retrieval was 32 (8-198) and was associated with increased specimen length but not to arterial vessel length. One hundred and thirty-three (42%) patients had lymph node metastases. All patients had these located < 5cm from the tumour. Ten, two, and three specimens had lymph node metastases around the central and peripheral ligation of the ileocolic artery and at the central ligation of the inferior mesenteric artery, respectively. The tumour stages in these specimens were T3-4N2M0-1. No statistically significant survival benefit was associated with longer arterial vessel length (p = 0.429). Neither retrieval of lymph nodes nor statistically significant survival was affected by vessel length in standardized left- and right-sided colon cancer surgery.

Distinct effects of TU-100 (daikenchuto) on long-lasting dysbiosis in the small intestine in patients with colorectal cancer and inflammatory bowel disease.

The profile of the human small intestinal microbiota remains to be uncovered primarily due to sampling difficulties. Ileostomy provides the intestinal luminal contents as ileostomy effluents (IE) that offer opportunity for performing extensive analyses of nutrients, gastrointestinal fluids, metabolites, and microbiome. In the present study, we evaluated changes in the microbiome, pH, and bacterial short-chain fatty acids (SCFAs) in IE obtained from patients who had undergone ileostomy following surgical resection of colon cancer and inflammatory bowel disease (IBD). We enrolled 11 patients who varied in the duration of ileostomy from 3 days to >5 years after surgery and had no inflammation in the small intestine. The analyses suggested that IE from patients previously having IBD had less diversity and greater intraday and interday fluctuations, and increased pH and decreased levels of propionic acid and acetic acid than those in IE from patients previously having cancer. Furthermore, correlation analysis suggested a possible effect of the intestinal microbiome on luminal pH, presumably via SCFA production. The present study suggested that inflammation in the colon may induce long-term dysbiosis in the small intestine even after removal of diseased parts of the colon. Moreover, pharmaceutical-grade Japanese traditional medicine daikenchuto (TU-100) was found to have beneficial effects on postoperative bowel dysfunction and the human small intestinal microbiota. Taken together, these results suggest the necessity of a direct remedy for dysbiosis and the treatment of gastrointestinal lesions to achieve favorable outcomes for chronic gastrointestinal disorders.

CARNOY'S SOLUTION INCREASES LYMPH NODES COUNT IN COLON CANCER SPECIMENS WHEN COMPARED TO FORMALIN FIXATION: A RANDOMIZED TRIAL.

ABSTRACT - BACKGROUND:At least 12 lymph nodes (LNs) should be examined following surgical resection of colon cancer. As it is difficult to find small LNs, fat clearing fixatives have been proposed, but there is no consensus about the best option.AIM: The objective of this study was to verify if Carnoy’s solution (CS) increases the LN count in left colon cancer specimens.METHODS: A prospective randomized trial (clinicaltrials.gov registration: NCT02629315) with 60 patients with left colon adenocarcinoma who underwent rectosigmoidectomy. Specimens were randomized for fixation with CS or 10% neutral buffered formalin (NBF). After dissection, the pericolic fat from the NBF group was immersed in CS and re-dissected (Revision). The primary endpoint was the total number of LNs retrieved.RESULTS: Mean LN count was 36.6 and 26.8 for CS and NBF groups, respectively (p=0.004). The number of cases with <12 LNs was 0 (CS) and 3 (NBF, p=0.237). The duration of dissection was similar. LNs were retrieved in all cases during the revision (mean: 19, range: 4-37), accounting for nearly 40% of the LNs of this arm of the study. After the revision, no case was found in the NBF arm with <12 LNs. Two patients had metastatic LNs during the revision (no upstaging occurred).CONCLUSION: Compared to NBF, CS increases LN count in colon cancer specimens. After conventional pathologic analysis, fixing the pericolic fat with CS and performing a second dissection substantially increased the number of LNs.

Effect of preoperative asymptomatic renal dysfunction on the clinical course after colectomy for colon cancer.

To evaluate the effect of mild renal dysfunction on the clinical course after colectomy in patients with colon cancer. The subjects of this retrospective study were 263 patients who underwent surgical resection for colon cancer at our hospital between 2011 and 2015. Renal function was assessed based on preoperative estimated glomerular filtration rate (eGFR) values. Patients were divided into groups based on their eGFR value of 55ml/min/1.73 m2. The Mann-Whitney U test, chi-square or Fisher exact test, and log-rank test were used in the data analysis. There were 59 patients (22.4%) in the low eGFR group and 204 patients in the normal eGFR group. There were differences between the groups in age, comorbidities, and the levels of hemoglobin, albumin, and serum creatinine. The overall postoperative complication rate, frequency of severe complications, and length of stay were significantly higher in the low eGFR group than in the normal eGFR group. Multivariate analysis revealed that low eGFR was the only independent risk factor for severe complications (Clavien-Dindo classification III/IV). There were no differences in survival between the groups. Preoperative asymptomatic renal dysfunction may be correlated with the development of postoperative complications and a possible significant risk factor for severe complications after colon cancer surgery.

A minimally invasive approach to colon cancer resection improves time to adjuvant chemotherapy

Background: Colorectal cancer is the second leading cause of cancer death in the United States each year. The use of adjuvant chemotherapy after surgical resection of colon cancer has been associated with survival benefit. Timely initiation of adjuvant chemotherapy has been shown to have an effect on overall survival (OS) and disease-free survival. This study examined the relationship between surgical subspecialty and postoperative complications, as well as operative approach on the effect of time to adjuvant chemotherapy (TTAC) at a single institution.

The Impact of Total Intravenous Propofol Anaesthesia versus Sevoflurane Anaesthesia on Perioperative Pain in Patients Undergoing Colonic Cancer Surgery

Background: Cancer colon is one of the most common malignancies. After colon cancer surgery patients may experience severe pain. Several studies have reported that a significant decrease in postoperative pain with propofol while other studies have showed this effect was not significant. Aim: Our goal was to assess the effect of combined epidural anaesthesia either with propofol or sevoflurane on intraoperative fentanyl consumption and postoperative pain in patients undergoing open surgical resection of colon cancer. Patients and Methods: 48 adult patients suffering from cancer colon scheduled for open surgical resection randomly allocated either to receive epidural-propofol by total intra venous anaesthesia (TIVA) (n = 24) or epidural-sevoflurane anaesthesia (n = 24), intraoperative heart rate and fentanyl consumption and postoperative pain score (verbal analogue scale, 0 - 10) were recorded. Results: In our study we found that the intensity of postoperative pain was low in all patients and the propofol based anaesthesia had relatively lower pain scores up to 24 hrs postoperatively in comparison to sevoflurane based anaesthesia, intraoperative fentanyl consumption was lower with sevoflurane and heart rate lower with propofol group. Conclusions: we recommend that use of multimodal analgesia decrease postoperative pain in all cancer colon patients undergoing open surgery who anaesthetized with either propofol or sevoflurane. Also use of propofol showed better analgesic outcomes postoperatively.

Early Elective Surgery After Colon Cancer Diagnosis has Higher Risk of Readmission and Death.

We hypothesized colon resection within 30 days of diagnosis of cancer would have higher rates of readmission and cancer specific mortality, unless there was demonstrated evidence of preoperative workup. Few studies have examined if negative consequences exist with expedited elective surgery after diagnosis of colon cancer. Surgery in a shorter time frame may result in a lack of appropriate preoperative care. Retrospective analysis of 25,407 patients in the Surveillance Epidemiology and End Results registry who underwent elective surgical resection for colon cancer from 2010 to 2015. Cohort stratified by age (66-75 vs >75 years). Primary outcomes of interest were 30-day readmission and 5-year colon cancer specific mortality. Relationships between timing of surgery and outcomes were assessed. On unadjusted analysis, surgery before 20 days of diagnosis was associated with higher risk of 30-day readmission and colon cancer specific mortality in both age groups. Among those age 66 to 75 years old, adjusting for patient factors and preoperative workup eliminated the risk of 30-day readmission (risk ratio 1.5-0.9 for 0-10 days, risk ratio 1.3-0.9 for 11-20 days). However, the risk for colon cancer specific mortality, although reduced, persisted (hazard ratio 2.2-1.3 for 0-10 days, hazard ratio 2.0-1.2 for 11-20 days). In the cohort older than 75 years, adjusting for patient level factors and preoperative workup eliminated risk of surgery 20 days postop or sooner. The risk associated with short time to surgery (within 30 days) may be mitigated if full oncologic workups are provided.

Evaluation of the short-term outcomes of minimally invasive surgery in colon cancer: an initial experience in a Middle Eastern oncology center using a randomized comparative design

Background The surgical approach to treat colon cancer has remained a matter of debate for many years. The assessment of short-term outcomes of the most common available modalities for surgical resection of colon cancer, which are the laparoscopic and open techniques, is considered a tool by which the best approach for colon cancer resection can be judged and documented. The aim of this work was to report on the initial experience in laparoscopic resection of colon cancer in a Middle Eastern oncology center. Patients and methods A total of 88 patients were involved in the current study who were proved to have colon cancer by a confirmed biopsy. They were subjected randomly to open or laparoscopic colectomy (LAC) and followed up for short-term outcomes (operative time, blood loss, and postoperative sequelae) to determine the most beneficial strategy based on its advantages. Data were collected and analyzed using Statistical Package for the Social Sciences version 20. Results The results showed that LAC was significantly different compared with open colectomy (OC) regarding the postoperative pain score, which was 3.14 and 6.85 for LAC and OC, respectively (P=0.02). Time to bowel sounds return was faster in LAC at 3.48 vs 7.5 h in OC (P Conclusion LAC showed multiple advantages over OC in many aspects related to short-term outcomes. The results of this study support the view that minimally invasive LAC is an effective and safe procedure for resection of colon cancer.

Exosomal markers (CD63 and CD9) expression and their prognostic significance using immunohistochemistry in right-sided and left-sided colon cancer.

182 Background: Exosomes play pivotal roles in cancer progression, metastasis and chemoresistance. CD63 and CD9 are widely accepted exosomal markers. Their pattern of expression and prognostic significance in patients with RSCC and LSCC is unknown. This study explored CD63 and CD9 expression and prognostic significance in patients with RSCC and LSCC using immunohistochemistry (IHC). Methods: Between 2015 and 2018, 63 patients underwent surgical resection of colon cancer for whom we had available tissues for CD63 and CD9 IHC staining. Two pathologists independently scored the CD63 and CD9 expression in the tumor and adjacent normal mucosa (ANM). Staining intensity was graded 1-3 and staining percentage was estimated in 10% increments. Mean Quick-score (Q-score) (intensity X percentage of staining) was calculated. Results: RSCC and LSCC represented 52% and 48% of the patients respectively. The ANM and Tumor CD63 Q-scores were 225 vs 191 (p = 0.009) in RSCC and 224 vs 154 (p = 0.0001) in LSCC, respectively. The ANM and Tumor CD9 Q-scores were 134 vs 152 (p = 0.142) in RSCC and 135 vs 154 (p = 0.137) in LSCC, respectively. In patients with RSCC and LSCC, the mean Tumor CD63 Q-score was 191 vs 154 (p = 0.024), while the mean ANM CD63 Q-score was 225 vs 224 (p = 0.920). The mean Tumor CD9 Q-score was 152 and 154 (p = 0.883), and the mean ANM CD9 Q-score was 134 vs 135 (p = 0.926). In our cohort, there was no difference in progression free survival (PFS) between patients with RSCC and LSCC (p = 0.2349). In all patients, there was no difference in PFS in patients with CD63 expression &lt; 100 and ≥100 (p = 0.8284). Among patients with RSCC, there was a significantly lower PFS in patients with CD63 expression &lt; 100 vs. ≥100 (p = 0.0259). However, among patients with LSCC, there was no difference in PFS in patients with CD63 expression &lt; 100 vs. ≥100 (p = 0.3494). Conclusions: To our knowledge, this is the first study to show a difference in exosomal marker (CD63) expression pattern and its prognostic significance in patients with RSCC and LSCC. There was a significant positive correlation between progression free survival in patients with RSCC and higher exosomal expression.

Lymph node evaluation for colon cancer in routine clinical practice: a population-based study.

Guidelines recommend that 12 or more lymph nodes (lns) be evaluated during surgical resection of colon cancer. Here, we report ln yield and its association with survival in routine practice. Electronic records of treatment were linked to the population-based Ontario Cancer Registry to identify all patients with colon cancer treated during 2002-2008. The study population (n = 5508) included a 25% random sample of patients with stage ii or iii disease. Modified Poisson regression was used to identify factors associated with ln yield; Cox models were used to explore the association between ln yield and overall (os) and cancer-specific survival (css). During 2002-2008, median ln yield increased to 17 from 11 nodes (p < 0.001), and the proportion of patients with 12 or more nodes evaluated increased to 86% from 45% (p < 0.001). Lymph node positivity did not change over time (to 53% from 54%, p = 0.357). Greater ln yield was associated with younger age (p < 0.001), less comorbidity (p = 0.004), higher socioeconomic status (p = 0.001), right-sided tumours (p < 0.001), and higher hospital volume (p < 0.001). In adjusted analyses, a ln yield of less than 12 nodes was associated with inferior os and css for stages ii and iii disease [stage ii os hazard ratio (hr): 1.36; 95% confidence interval (ci): 1.19 to 1.56; stage ii css hr: 1.52; 95% ci: 1.26 to 1.83; and stage iii os hr: 1.45; 95% ci: 1.30 to 1.61; stage iii css hr: 1.54; 95% ci: 1.36 to 1.75]. Despite a temporal increase in ln yield, the proportion of cases with ln positivity has not changed. Lymph node yield is associated with survival in patients with stages ii and iii colon cancer. The association between ln yield and survival is unlikely to be a result of stage migration.

Integrated post-surgical colon cancer care planning at the Rutgers Cancer Institute of New Jersey and Robert Wood Johnson University Hospital.

75 Background: Colorectal cancer is the second leading cause of cancer death in the United States each year. The use of adjuvant chemotherapy after surgical resection of colon cancer has been associated with a survival benefit. Timely initiation of adjuvant chemotherapy has been shown to have an effect on overall and disease-free survival. There is no integrated post-surgical colon cancer care planning for patients who have surgery at our institution. Poor understanding on the part of patients and ancillary providers regarding appropriate follow up may cause delay in time to adjuvant chemotherapy initiation. Methods: Baseline data was obtained for the ASCO Quality Training Program. Chart review was conducted on patients with stage III colorectal cancer that were treated at the Cancer Institute of New Jersey and Robert Wood Johnson University Hospital to identify average time to adjuvant chemotherapy initiation and factors which were thought to have a strong influence on chemotherapy initiation. Time to initiation of adjuvant chemotherapy, pathology report resulting, central access obtainment, and outpatient medical oncology appointment was abstracted from patient charts. Other factors including the presence of intraoperative or postoperative complications, type of surgeon, academic versus private medical oncologist, and the presence of an inpatient medical oncology consult were also identified and reviewed. Results: 128 patient charts were reviewed. Mean number of days from surgery to adjuvant chemotherapy (n = 79) was 49.6, to pathology report resulting (n = 70) was 4.92, to central access obtainment (n = 49) was 40, and to outpatient medical oncology appointment (n = 38) was 30. The presence of intraoperative (p &lt; 0.059) and postoperative complications (p &lt; 0.0155) was found to have a statistically significant effect on time to initiation of adjuvant chemotherapy. Conclusions: While there are some uncontrollable factors like operative complications that delay time to initiation of chemotherapy, engaging the patient may help decrease the time to adjuvant chemotherapy by increasing patient awareness of the importance of seeking aggressive postoperative care.

Mesocolic Lymph Node Number, Size, and Density: An Anatomical Study.

Lymph nodes play a critical role in the staging, treatment, and prognosis of colon cancer. However, the normal number and morphology of lymph nodes in the normal mesocolon is unknown. This study aimed to investigate the number and size of lymph nodes in the ascending and sigmoid mesocolons. This is a descriptive anatomical cadaver study of 10 sigmoid mesocolons and 5 ascending mesocolons, resected in a standardized manner and examined systematically after serial histological sectioning. The number, maximum length, and appearance of lymph nodes were analyzed, and the 2 mesocolons were compared by using the Mann-Whitney U test, the Wilcoxon signed rank test, and the χ test. Ten cadavers (mean age, 82.9 years; 5 male) with no evidence of colorectal disease were examined. The number, maximum length, and appearance of lymph nodes and fat-associated lymphoid clusters were the primary outcomes measured. The median number of lymph nodes in the sigmoid and ascending mesocolons was 71 (range, 24-116) and 61 (range, 33-71). More than 90% of lymph nodes were less than 5 mm in maximum length. Sigmoid mesocolic nodes were significantly smaller than ascending mesocolic nodes (median maximum lymph nodes length, 1.6 mm vs 2.1 mm; p < 0.001), but there was no statistically significant difference in the density of lymph nodes between the sigmoid and ascending mesocolon. Fatty replacement was seen in almost 30% of lymph nodes. A few fat-associated lymphoid clusters were observed in both mesocolons. Only 15 mesocolic specimens could be examined because of the detailed labor-intensive methodology, and younger cadavers were not available for analysis. In this descriptive anatomical study, the median number of lymph nodes in the sigmoid and ascending mesocolon was 71 and 61. Ascending mesocolic nodes were significantly larger than sigmoid mesocolic nodes. These anatomical findings are relevant to the interpretation of lymph node yields after the surgical resection of colon cancer.

Variation in positron emission tomography use after colon cancer resection.

Colon cancer surveillance guidelines do not routinely include positron emission tomography (PET) imaging; however, its use after surgical resection has been increasing. We evaluated the secular patterns of PET use after surgical resection of colon cancer among elderly patients and identified factors associated with its increasing use. We used the SEER-linked Medicare database (July 2001 through December 2009) to establish a retrospective cohort of patients age ≥ 66 years who had undergone surgical resection for colon cancer. Postoperative PET use was assessed with the test for trends. Patient, tumor, and treatment characteristics were analyzed using univariable and multivariable logistic regression analyses. Of the 39,221 patients with colon cancer, 6,326 (16.1%) had undergone a PET scan within 2 years after surgery. The use rate steadily increased over time. The majority of PET scans had been performed within 2 months after surgery. Among patients who had undergone a PET scan, 3,644 (57.6%) had also undergone preoperative imaging, and 1,977 (54.3%) of these patients had undergone reimaging with PET within 2 months after surgery. Marriage, year of diagnosis, tumor stage, preoperative imaging, postoperative visit to a medical oncologist, and adjuvant chemotherapy were significantly associated with increased PET use. PET use after colon cancer resection is steadily increasing, and further study is needed to understand the clinical value and effectiveness of PET scans and the reasons for this departure from guideline-concordant care.

PIK3CA mutations predict recurrence in localized microsatellite stable colon cancer.

PIK3CA, which encodes the p110α catalytic subunit of PI3Kα, is one of the most frequently altered oncogenes in colon cancer (CC), but its prognostic value is still a matter of debate. Few reports have addressed the association between PIK3CA mutations and survival and their results are controversial. In the present study, we aimed to clarify the prognostic impact of PIK3CA mutations in stage I–III CC according to mismatch repair status. Fresh frozen tissue samples from two independent cohorts with a total of 826 patients who underwent curative surgical resection of CC were analyzed for microsatellite instability and screened for activating point mutations in exon 9 and 20 of PIK3CA by direct sequencing. Overall, 693 tumors (84%) exhibited microsatellite stability (MSS) and 113 samples (14%) harbored PIK3CA mutation. In the retrospective training cohort (n = 433), patients with PIK3CA-mutated MSS tumors (n = 47) experienced a significant increased 5-year relapse-free interval compared with PIK3CA wild-type MSS tumors (n = 319) in univariate analysis (94% vs. 68%, Log-rank P = 0. 0003) and in multivariate analysis (HR = 0.12; 95% confidence interval, 0.029–0.48; P = 0.0027). In the prospective validation cohort (n = 393), the favorable prognostic impact of PIK3CA mutations in MSS tumors (n = 327) was confirmed (83% vs. 67%, Log-rank P = 0.04). Our study showed that PIK3CA mutations are associated with a good prognosis in patients with MSS stage I–III CC.

Mo1072 Optimizing the Utilization of Adjuvant Chemotherapy Following Surgical Resection of Colon Cancer: A Comparison of Laparoscopic Versus Open Approach

Purpose Previous research has demonstrated that laparoscopic approach to colon cancer resection is a safe and potentially beneficial alternative to open surgery. Open colon cancer surgery has higher complication rates than laparoscopic surgery, whichmay delay chemotherapy for stage-specific tumors. Omission or delay in chemotherapy is known to significantly impact overall survival. In this study, we examine the use of appropriate adjuvant chemotherapy following open and laparoscopic surgery for colon cancer in a large national cancer registry. Methods The National Cancer Data Base (NCDB) captures over 70% of cancer cases in the United States and provides detailed information on patient, tumor, and treatment characteristics. Cases of colon cancer undergoing segmental or hemicolectomy with node positive disease in the NCDB from 2010-2011 were included in the analysis. Primary outcomes were use of any adjuvant chemotherapy and use of adjuvant chemotherapy within 90 days of surgery. To adjust for non-random treatment selection, propensity adjustment with inverse probability weighting (IPW) was performed. Patient and tumor characteristics before and after IPW adjustment were compared. Weighted logistic regression after IPW was used to compare the association of laparoscopic and open surgery with the use of adjuvant chemotherapy. Results From 2010-2011, 19,531 patients with colon cancer and positive lymph nodes undergoing surgery were identified in the NCDB, with 12,088 patients (61.9%) undergoing open surgery and 7,443 (38.1%) treated laparoscopically. Patients undergoing open surgery tended to have more comorbidities, larger tumors, higher clinical T and N staging, and were more likely to be treated at community cancer programs (as opposed to comprehensive cancer centers or academic research programs); however, these differences were minimized after IPW adjustment (Table). Before IPW, rates of adjuvant chemotherapy use were 62.3% for patients after open surgical resection, compared to 70.6% after laparoscopic surgery (p<0.001). After IPW, odds ratio (OR) for adjuvant chemotherapy use was 1.27 (95% CI: 1.19-1.36) for laparoscopic versus open surgery, indicating that patients undergoing laparoscopic surgery were more likely to receive adjuvant therapy. For adjuvant chemotherapy within 90 days of surgery, OR was 1.28 (1.20-1.36), again favoring a laparoscopic approach (Figure). Conclusion Patients undergoing laparoscopic surgery for pathologic stage III colon cancer had higher rates of adjuvant chemotherapy use and lower rates of delay in chemotherapy initiation compared to those treated with open procedures, likely due to reduced complications from laparoscopic surgery. Further research will need to examine long-term outcomes in this population in order to understand the impact on disease recurrence and long-term survival. Table. Preoperative patient characteristics by surgical approach before and after IPW adjustment

The use of extended perioperative low molecular weight heparin (tinzaparin) to improve disease-free survival following surgical resection of colon cancer

Auer, Rebeccaa; Scheer, Adenaa; Wells, Philip S.b,c; Boushey, Robina; Asmis, Timd; Jonker, Derekd; Carrier, Marcb,c Author Information

Does delay of adjuvant chemotherapy impact survival in patients with resected stage II and III colon adenocarcinoma?

It is unclear whether delays in commencing adjuvant chemotherapy after surgical resection of colon adenocarcinoma adversely impact survival. Patients with stage II-III colon adenocarcinoma who received adjuvant chemotherapy at 2 centers were identified through the institutional tumor registry. Time to adjuvant chemotherapy, overall survival (OS), and relapse-free survival (RFS) were calculated from the day of surgery. Patients were dichotomized into early (time to adjuvant chemotherapy ≤ 60 days) and late treatment (time to adjuvant chemotherapy >60 days) groups. OS and RFS were compared using log-rank test and multivariate analysis by the Cox proportional hazards model. Of 186 patients included in the study, 49 (26%) had received adjuvant chemotherapy >60 days after surgical resection. Thirty percent of the delays were system related (eg, late referrals, insurance authorizations). Time to adjuvant chemotherapy >60 days was associated with significantly worse OS in both univariate analysis and a Cox proportional hazards model (hazard ratio, 2.17; 95% confidence interval, 1.08-4.36). Although difference in RFS between the 2 groups favored time to adjuvant chemotherapy <60, this did not reach statistical significance. Adjuvant chemotherapy delay >60 days after surgical resection of colon cancer is associated with worse OS.

PO-66 The use of extended peri-operative low molecular weight heparin to improve disease-free survival following surgical resection of colon cancer: a pilot randomized controlled trial

PO-66 The use of extended peri-operative low molecular weight heparin to improve disease-free survival following surgical resection of colon cancer: a pilot randomized controlled trial