Clinicopathological factors associated with positive circumferential margins in rectal cancers

Development of a Predictive Nomogram for Circumferential Resection Margin in Rectal Cancer Surgery

INTRODUCTION

Circumferential resection margin (CRM) is a key quality metric and predictor of oncologic outcomes and overall survival following surgery for rectal cancer. We aimed to develop a nomogram to identify patients at risk for a positive CRM in the preoperative setting.

METHODS

We performed a retrospective evaluation of the National Cancer Database from 2010 to 2014 for patients with clinical stage I-III rectal cancer who underwent total mesorectal excision. Patients were excluded for emergency operation, resection for cancer recurrence, palliative resection, transanal resection, and missing CRM status. The primary outcome was positive CRM. Secondary outcomes included overall survival.

RESULTS

There were 28,790 patients included. 2245 (7.8%) had a positive CRM. Higher tumor grade, lack of neoadjuvant chemotherapy, mucinous/signet tumor histology, open approach, abdominoperineal resection, higher T stage, lymphovascular invasion, and perineural invasion were all significantly associated with positive CRM (P < 0.05) and were included in the nomogram. The C-statistic was 0.703, suggesting a good predictive model.

CONCLUSIONS

Positive CRM is associated with specific patient demographics and tumor characteristics. These factors can be used along with preoperative MRI to predict CRM positivity in the preoperative period and plan accordingly.

Effect of rurality and socioeconomic deprivation on presentation stage and long-term outcomes in patients undergoing surgery for colorectal cancer

BACKGROUND

Geographical remoteness and socioeconomic status (SES) are important factors affecting presentation stage and survival for colorectal cancer. A series of patients from a single institution in northern New South Wales was studied to determine if rural isolation or SES affected presentation and survival in patients undergoing resection.

METHODS

Consecutive colorectal cancer resections performed at Lismore Base Hospital from 2011 to 2019 were identified. Patient residential addresses were categorized by the Modified Monash Model (MMM), an Australian Government definition of rural isolation, and Socioeconomic Index for Areas (SEIFA) quintiles, an Australian Bureau of Statistics index of socioeconomic deprivation. Univariate and Cox regression survival analysis was performed on data from histopathology and clinical notes matched with survival data.

RESULTS

A total of 405 patients were included in MMM categories 3 (n = 207, 51.1%), 4 (n = 69, 17%) and 5 (n = 129, 31.9) corresponding to large, medium and small rural towns. MMM 3 was associated with emergency cases (25.6% versus 18.7%, P < 0.001), nodal disease (44.4% versus 38.4%, P = 0.018) and T3/4 tumours (82.1% versus 73.7%, P < 0.001) compared with isolated patients without difference in 5-year survival (P = 0.370). Disadvantaged SEIFA quintiles 1/2 demonstrated increased poor differentiation (23.0% versus 15.4%, P < 0.001) and vascular invasion (15.8% versus 9.1%, P < 0.001) with reduced 5-year survival (57.0% versus 70.4%, P = 0.039). Independent predictors of survival included age, emergency cases, group stage, lymphatic invasion and low lymph node yield.

CONCLUSION

A 'rural reversal' may be present for patients in northern New South Wales; however, SES and established clinicopathological factors are the strongest predictors of survival in our population.