High ligation of inferior mesenteric artery: a standard procedure for colorectal cancer?

Construction of a nomogram based on clinicopathologic features to predict the likelihood of No. 253 lymph node metastasis in rectal cancer patients

PURPOSE

To explore the high-risk factors for rectal cancer No.253 lymph node metastasis (LNM) and to construct a risk nomogram for the individualized prediction of No.253 LNM.

METHODS

This was a retrospective analysis of 425 patients with rectal cancer who underwent laparoscopic-assisted radical surgery. Independent risk factors for rectal cancer No.253 LNM was identified using multivariate logistic regression analysis, and a risk prediction nomogram was constructed based on the independent risk factors. In addition, the performance of the model was evaluated by discrimination, calibration, and clinical benefit.

RESULTS

Multivariate logistic regression analysis showed that No.253 lymphadenectasis on CT (OR 10.697, P < 0.001), preoperative T4-stage (OR 4.431, P = 0.001), undifferentiation (OR 3.753, P = 0.004), and preoperative Ca199 level > 27 U/ml (OR 2.628, P = 0.037) were independent risk factors for No.253 LNM. A nomogram was constructed based on the above four factors. The calibration curve of the nomogram was closer to the ideal diagonal, indicating that the nomogram had a better fitting ability. The area under the ROC curve (AUC) was 0.865, which indicated that the nomogram had high discriminative ability. In addition, decision curve analysis (DCA) showed that the model could show better clinical benefit when the threshold probability was between 1% and 50%.

CONCLUSION

Preoperative No.253 lymphadenectasis on CT, preoperative T4-stage, undifferentiation, and elevated preoperative Ca199 level were found to be independent risk factors for the No.253 LNM. A predictive model based on these risk factors can help surgeons make rational clinical decisions.

No.253 Lymph Nodes Metastasis in Left-Sided Colorectal Cancer Liver Metastasis (CRLM) Patients: Incidence and Prognosis

Background:

No.253 lymph node is the gateway to systemic metastasis for left-sided colorectal cancer. However, the value of D3 resection is still controversial. This study aimed to identify the incidence rate and prognostic value of 253LN metastasis in patients with left-sided colorectal cancer liver metastasis (CRLM) mainly through blood vessels and thus to provide theoretical basis for 253LN resection.

Methods:

From February 2012 to February 2019, a total of 281 patients who underwent curative resection for both primary and metastatic tumors were collected retrospectively. The clinicopathological and genetic characteristics were compared between 58 patients with positive 253LN and 223 patients with negative. Relapse-free survival (RFS) and overall survival (OS) were compared with Kaplan–Meier method. Cox regression analysis and a forest plot were conducted for RFS.

Results:

The incidence of 253LN metastasis in left-sided CRLM was 20.64% (58/281). Those with 253LN positive were T4 stage, N2 stage, and D1/D2 lymph nodes metastatic. About 10.3% (8/78) 253LN positive patients were D1/D2 negative. The 253LN metastasis was an independent risk factor for relapse after curative surgery, but not for OS. Patients with 253LN metastasis had worse RFS, especially in female, adenocarcinoma, poorly differentiated, pT3, preoperative serum CA199 < 37 U/mL, bilobar liver metastasis, without preoperative chemotherapy, KRAS, NRAS, or BRAF wild type.

Conclusion:

The incidence of 253LN metastasis in left-sided CRLM is 20.64%, and skip metastasis rate is 10.3%. The 253LN status is an independent prognostic risk factor for RFS but not for OS after curative surgery. Routine resection of 253LN should be applied in curative surgery of left-sided CRLM.

Is low tie ligation truly reproducible in colorectal cancer surgery? Anatomical study of the inferior mesenteric artery division branches

AIM

Curative surgery is the standard treatment for colorectal cancer. The ligation level of the inferior mesenteric artery (IMA) is still debated, as neither low tie (LT) nor high tie ligation (HT) has shown any benefit on the patients' overall survival. We examined whether LT is standardizable and easily reproducible from an anatomical point of view.

METHOD

One hundred CT angiographies of healthy patients were analysed for the anatomy of the IMA and its division branches: left colic artery (LCA), sigmoid arteries trunk and superior rectal artery. Data analysed comprised angles between the IMA and the aorta, diameters of the IMA and its branches, repartition of the branches and distances between the origin of the branches and the origin of the IMA.

RESULTS

IMA anatomy showed no variation. In contrast, its division branches showed important variability in terms of distance to the origin and repartition: in 19.9% of the patients, the IMA directly splits into three branches, and in 17.6% of the patients, the LCA originated at more than 5 cm from the origin of the IMA. These frequent variations led us to assume that the standardization of LT is very difficult in a context of neoplasm, where the quality of the lymphadenectomy is fundamental.

CONCLUSION

The division branches of the IMA are extremely subject to interindividual variations, making it difficult if not impossible to reproduce identically a surgical procedure based on their anatomy. HT appears to us as the only relevant procedure for colorectal cancer.

A scoring system to predict inferior mesenteric artery lymph node metastasis and prognostic value of its involvement in rectal cancer

PURPOSE

The aim of this study is to establish a prediction scoring system for inferior mesenteric artery (IMA) lymph node metastasis and to assess the prognostic impact of dissection of positive IMA node on patients with stage III rectal cancer.

METHODS

A retrospective study was performed in 264 patients with stage III rectal cancer undergoing curative surgery. Clinicopathological, survival, and recurrence data were compared between 29 patients with positive IMA nodes and 235 patients with negative IMA nodes. Clinicopathological data which were found to be significantly associated with IMA nodal status were incorporated into a scoring system.

RESULTS

In the training samples, tumor differentiation and preoperative serum CEA were significant predictors of IMA node metastasis in multivariate analysis, which were incorporated into a scoring system. Using receiver operating characteristic curve analysis, we determined a cutoff value of 46.5 for scores, at which the system's sensitivity was 86 % and specificity 61 %. When applied to testing sample, the sensitivity was 80 % and specificity 60 %. Survival analysis showed that 5-year disease-free survival rate (5-DFS) and 5-year overall survival (5-OS) in the positive IMA node group (24.4 and 27.6 %, respectively) were significantly lower than in the negative IMA node group (61.8 and 71.3 %, respectively) (P < 0.001). Furthermore, multivariate analysis indicated that IMA lymph node metastasis was an unfavorable independent prognostic factor for 5-DFS and 5-OS.

CONCLUSIONS

IMA lymph node metastasis is an independent poor prognostic factor for stage III rectal cancer. The prediction scoring system for IMA node metastasis would be beneficial in determining the appropriate level of IMA ligation.