Obstruction is associated with perineural invasion in T3/T4 colon cancer

Does Colorectal Stenting as a Bridge to Surgery for Obstructive Colorectal Cancer Increase Perineural Invasion?

Objectives

To clarify whether self-expandable metallic stent (SEMS) placement for obstructive colorectal cancer (CRC) increases perineural invasion (PNI), thereby worsening the prognosis.

Methods

In total, 1022 patients with pathological T3 or T4 colon or rectosigmoid cancer who underwent resection were retrospectively reviewed. The study patients were divided into a no obstruction group (n=693), obstruction without stent group (n=251), and obstruction with stent group (n=78), and factors demonstrating an independent association with PNI, the difference in PNI incidence and severity between groups, and the association between PNI and the duration from SEMS placement to surgery were investigated. Survival analysis was performed for each group.

Results

On multivariate analysis, SEMS placement (hazard ratio [HR]: 2.08) was independently associated with PNI whereas SEMS placement was not. PNI occurred in 39%, 45%, and 68% of the no obstruction, obstruction without stent, and obstruction with stent group, respectively. In the obstruction with stent group, the proportion of PNI was not associated with the duration from SEMS placement to surgery. Extramural PNI, an advanced form of PNI, demonstrated no increase with increasing interval. The five-year OS was 86.3%, 76.7%, and 73.1% in no obstruction, obstruction without stent, and obstruction with stent group, respectively. On multivariate analysis, obstruction was an independent risk factor of decreased OS (HR: 1.57) whereas SEMS placement was not.

Conclusions

The prognosis was comparable between patients with SEMS placement and those with an obstruction who did not undergo SEMS placement, thus demonstrating that SEMS is a viable, therapeutic option for BTS.

Perineural invasion in colorectal cancer: mechanisms of action and clinical relevance

BACKGROUND

In recent years, the significance of the nervous system in the tumor microenvironment has gained increasing attention. The bidirectional communication between nerves and cancer cells plays a critical role in tumor initiation and progression. Perineural invasion (PNI) occurs when tumor cells invade the nerve sheath and/or encircle more than 33% of the nerve circumference. PNI is a common feature in various malignancies and is associated with tumor invasion, metastasis, cancer-related pain, and unfavorable clinical outcomes. The colon and rectum are highly innervated organs, and accumulating studies support PNI as a histopathologic feature of colorectal cancer (CRC). Therefore, it is essential to investigate the role of nerves in CRC and comprehend the mechanisms of PNI to impede tumor progression and improve patient survival.

CONCLUSION

This review elucidates the clinical significance of PNI, summarizes the underlying cellular and molecular mechanisms, introduces various experimental models suitable for studying PNI, and discusses the therapeutic potential of targeting this phenomenon. By delving into the intricate interactions between nerves and tumor cells, we hope this review can provide valuable insights for the future development of CRC treatments.

Development and validation of a nomogram for preoperative prediction of tumor deposits in colorectal cancer

BACKGROUND

Based on the clinical data of colorectal cancer (CRC) patients who underwent surgery at our institution, a model for predicting the formation of tumor deposits (TDs) in this patient population was established.

AIM

To establish an effective model for predicting TD formation, thus enabling clinicians to identify CRC patients at high risk for TDs and implement personalized treatment strategies.

METHODS

CRC patients (n = 645) who met the inclusion criteria were randomly divided into training (n = 452) and validation (n = 193) cohorts using a 7:3 ratio in this retrospective analysis. Least absolute shrinkage and selection operator regression was employed to screen potential risk factors, and multivariable logistic regression analysis was used to identify independent risk factors. Subsequently, a predictive model for TD formation in CRC patients was constructed based on the independent risk factors. The discrimination ability of the model, its consistency with actual results, and its clinical applicability were evaluated using receiver-operating characteristic curves, area under the curve (AUC), calibration curves, and decision curve analysis (DCA).

RESULTS

Thirty-four (7.5%) patients with TDs were identified in the training cohort based on postoperative pathological specimens. Multivariate logistic regression analysis identified female sex, preoperative intestinal obstruction, left-sided CRC, and lymph node metastasis as independent risk factors for TD formation. The AUCs of the nomogram models constructed using these variables were 0.839 and 0.853 in the training and validation cohorts, respectively. The calibration curve demonstrated good consistency, and the training cohort DCA yielded a threshold probability of 7%-78%.

CONCLUSION

This study developed and validated a nomogram with good predictive performance for identifying TDs in CRC patients. Our predictive model can assist surgeons in making optimal treatment decisions.

Recurrence After Colectomy for Locally Advanced Colon Cancer: Experience from a Developing Country

Risk factors for disease recurrence following curative resection for locally advanced colon cancer (LACC) remain unclear as conflicting results have been reported in the literature. The aim of this study was to examine these factors in the setting of developing country's health care system affected by limited accessibility to the multimodal cancer treatment. Patients who had undergone curative colon resection for LACC between 2004 and 2018 were included. Data were obtained from a prospectively maintained database. Factors associated with disease recurrence, types of recurrence and recurrence-free survival were studied. A total of 118 patients with LACC were operated within the study period. Median follow-up was 36 (2-147) months. Adjuvant therapy was used in 41 (34.7%) patients and 62 (52.5%) were diagnosed with recurrence. In the multivariable analysis, disease recurrence was associated with tumor and nodal stages, as well as with the lymph node yield. Local recurrence, distant metastases, and peritoneal carcinomatosis were observed in 8 (6.8%), 30 (25.4%), and 24 (20.3%) patients, respectively. Early recurrence was diagnosed in 27 (22.9%) cases with peritoneal carcinomatosis being its most common type. Preoperative serum CA 19-9 levels, tumor, and nodal stages were linked to recurrence-free survival in the univariable analysis. Only tumor stage remained such in the multivariable model. Our findings suggest that lymph node yield, tumor, and nodal stages are associated with recurrence following curative resection for LACC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-022-01672-x.

Preoperative computed tomography assessment of circumferential resection margin in retroperitonealized colon cancer predicts disease-free survival

OBJECTIVES

The aim of this retrospective study was to predict circumferential resection margin (CRM) involvement on preoperative CT, and prognostic impact of CRM assessment by CT (ctCRM) in patients with retroperitonealized colon cancer.

METHODS

This study included patients who underwent resection for ascending or descending colon cancer between July 2010 and February 2013. Positive ctCRM was defined as tumor distance to the retromesenteric plane of ≤ 1 mm. The origin of positive CRM was divided into primary tumor or other tumor components including lymph nodes, tumor deposits, or extramural venous invasions. Logistic regression analysis was performed to identify preoperative factors to predict pathologic CRM (pCRM). A Cox proportional hazards model was used in multivariable analysis to determine the preoperative factors affecting disease-free survival (DFS).

RESULTS

A total of 274 patients (mean age, 64.0 years ± 11.0 [standard deviation]; 157 men) with retroperitonealized colon cancer were evaluated. Of 274 patients, 67 patients (24.5%) had positive CRM on surgical pathology. The accuracy of preoperative CT in predicting pCRM was 79.6% (218/274). Among preoperative factors, only CRM assessment on CT was independently associated with pCRM (p < 0.001). Positive ctCRM by primary tumor was an independent factor for DFS (HR, 3.362 [1.714-6.593]) and systemic recurrence (HR, 3.715 [1.787-7.724], but not for local recurrence on multivariable analyses.

CONCLUSIONS

Preoperative CT can accurately predict pCRM, and positive ctCRM by primary tumor is an independent risk factor for DFS and systemic recurrence, but not for local recurrence in retroperitonealized colon cancer.

KEY POINTS

• Preoperative CT can predict pathologic circumferential resection margin (CRM) with approximately 80% of accuracy in patients with retroperitonealized colon cancer. • Positive CRM by a primary tumor on preoperative CT is a poor prognostic factor for disease-free survival and systemic recurrence in patients with retroperitonealized colon cancer. • CRM involvement on CT was not associated with local recurrence in patients with retroperitonealized colon cancer.

Tumor Deposits and Perineural Invasion had Comparable Impacts on the Survival of Patients With Non-metastatic Colorectal Adenocarcinoma: A Population-Based Propensity Score Matching and Competing Risk Analysis

BACKGROUND

Both tumor deposits (TD) and perineural invasion (PNI) have been identified as risk factors for poor survival in patients with non-metastatic colorectal adenocarcinoma (CRC). However, the adverse impacts of TD and PNI on the survival of patients with non-metastatic CRC have not been compared.

METHOD

Patients with non-metastatic CRC with known TD and PNI status were selected from the Surveillance, Epidemiology, and End Results (SEER) database. First, bivariate logistic regression analysis was utilized to identify the factors associated with TD and PNI status. Then, patients were divided into four groups, according to TD and PNI status. Propensity score matching (PSM) was performed to balance the baseline covariates. The impact of TD and PNI on survival was assessed by analyzing overall survival (OS) and cancer-specific mortality (CSM) rates. OS was calculated by the Kaplan-Meier method with log-rank analysis. CSM was estimated by competing risk analysis using the Fine and Gray model.

RESULTS

A total of 70 689 patients with CRC met the inclusion and exclusion criteria. The positive rates of TD and PNI were 9.37% and 9.91%, respectively. For TD, the most important risk factor was N stage. With respect to PNI, the most significant factor was T stage. Tumor location, tumor size, differentiation grade, and serum CEA level were also correlated with TD and PNI status. After PSM, 1849 pairs were selected. Patients with TD⁺PNI⁺ status had the worst 5 year CSM and 5 year OS. In addition, the long-term survival outcomes of patients with TD⁺PNI^- and TD^-PNI⁺ status were comparable.

CONCLUSION

The adverse impacts of TD and PNI on the survival of patients with non-metastatic CRC were comparable. CRC patients with both TD and PNI positive had the worst survival outcome.

Does preoperative stent positioning in obstructive left sided colon cancer increase the risk of perineural invasion?

Colonic stenting as a bridge to surgery has been shown to be a safe and effective treatment for left-sided malignant colonic obstruction depending on local expertise. However, concerns still exist regarding its oncological safety. In particular, several reports showed an increased prevalence of perineural tumor invasion following stent placement. Since perineural invasion negatively affects oncological outcomes, the present study sought to evaluate this controversial association. We retrospectively reviewed 114 patients presenting with left-side obstructing colon cancer over a 10-year period. The relationship between perineural invasion and colonic stenting was analyzed using univariate and multivariate analyses. Perineural invasion was found to be strongly associated with pathological features, including TNM stage, (p < 0.001), poor differentiation (p = 0.002), vascular invasion (p < 0.001), lymphatic invasion (p < 0.001), whereas no significant association with preoperative stenting was observed (p = 0.918) after performing univariate analysis. In the multivariate model, only TNM stage III-IV (OR: 6.810, 95% CI 1.972-23.518, p = 0.002) and venous invasion (OR: 5.325, 95% CI 1.911-14.840, p = 0.001) were independently associated with perineural invasion. The results of this study suggest no association between preoperative colonic stenting and perineural invasion.

Perineural invasion is increased in patients receiving colonic stenting as a bridge to surgery: a systematic review and meta-analysis

BACKGROUND

In recent years, there has been growing concern about the potential association of stent placement as a bridge to surgery in malignant colon obstruction and some anatomopathological findings that could lead to worsening long-term cancer outcomes, such as perineural, vascular and lymphatic invasion. The aim of the present review was to assess the pathological changes found in surgical specimens after stent placement for obstructing colon cancer vs. emergency surgery, and the impact of perineural invasion on survival rates METHODS: MEDLINE, Cochrane Library, Ovid and ISRCTN Registry were searched, with no restrictions. We performed four meta-analyses to estimate the pooled effect sizes using a random effect model. The outcomes were perineural, vascular and lymphatic invasion rates, and 5-year overall survival rate in patients with obstructive colon cancer, depending on the presence or absence of perineural invasion.

RESULTS

Ten studies with a total of 1273 patients were included in the meta-analysis. We found that patients in the stent group had a significantly higher risk of perineural (OR 1.98, 95% CI 1.22-3.21; p = 0.006) and lymphatic invasion (OR 1.45, 95% CI 1.10-1.90; p = 0.008). Furthermore, patients with positive perineural invasion had almost twice the risk of dying compared to those with no perineural invasion (HR 1.92, 95% CI 1.22-3.02; p = 0.005).

CONCLUSIONS

Stent placement as a bridge to surgery in colorectal cancer patients modifies the pathological characteristics such as perineural and lymphatic invasion, and this may worsen the long-term prognosis of patients. The presence of perineural infiltration in obstructed colon cancer decreases the long-term survival of patients.

Comparison of safety between self-expanding metal stents as a bridge to surgery and emergency surgery based on pathology: a meta-analysis

BACKGROUND

To explore the long-term oncological safety of using self-expanding metal stents (SEMS) as a bridge to surgery for acute obstructive colorectal cancer by comparing the pathological results of emergency surgery (ES) with elective surgery after the placement of SEMS.

METHODS

Studies comparing SEMS as a bridge to surgery with emergency surgery for acute obstructive colorectal cancer were retrieved through the databases of Pubmed, Embase, and Cochrane libraries, and a meta-analysis was conducted based on the pathological results of the two treatments. Risk ratios (OR) or mean differences (MD) with 95% confidence intervals (CI) were calculated for the outcomes under random effects model.

RESULTS

A total of 27 studies were included, including 3 randomized controlled studies, 2 prospective studies, and 22 retrospective studies, with a total of 3737 patients. The presence of perineural invasion (RR = 0.58, 95% CI 0.48, 0.71, P < 0.00001), lymphovascular invasion (RR = 0.68, 95% CI 0.47, 0.99, P = 0.004) and vascular invasion (RR = 0.66, 95% CI 0.45, 0.99, P = 0.04) in SEMS group were significantly higher than those in ES group, and there was no significant difference in lymphatic invasion (RR = 0.92, 95% CI 0.77, 1.09, P = 0.33). The number of lymph nodes harvested in SEMS group was significantly higher than that in ES group (MD = - 3.18, 95% CI - 4.47, - 1.90, P < 0.00001). While no significant difference was found in the number of positive lymph nodes (MD = - 0.11, 95% CI - 0.63, 0.42, P = 0.69) and N stage [N0 (RR = 1.03, 95% CI 0.92, 1.15, P = 0.60), N1 (RR = 0.99, 95% CI 0.87, 1.14, P = 0.91), N2 (RR = 0.94, 95% CI 0.77, 1.15, P = 0.53)].

CONCLUSIONS

SEMS implantation in patients with acute malignant obstructive colorectal cancer may lead to an increase in adverse tumor pathological characteristics, and these characteristics are mostly related to the poor prognosis of colorectal cancer. Although the adverse effect of SEMS on long-term survival has not been demonstrated, their adverse effects cannot be ignored. The use of SEMS as the preferred treatment for patients with resectable obstructive colorectal cancer remains to be carefully weighed, especially when patients are young or the surgical risk is not very high.

Establishment of a Convenient System for the Culture and Study of Perineurium Barrier In Vitro

The perineurium serves as a selective, metabolically active diffusion barrier in the peripheral nervous system, which is composed of perineurial cells joined together by tight junctions (TJs). Not only are these junctions known to play an essential role in maintaining cellular polarity and tissue integrity, but also limit the paracellular diffusion of certain molecules and ions, whereas loss of TJs barrier function is imperative for tumour growth, invasion and metastasis. Hence, a detailed study on the barrier function of perineurial cells may provide insights into the molecular mechanism of perineural invasion (PNI). In this study, we aimed to develop an efficient procedure for the establishment of perineurial cell lines as a tool for investigating the physiology and pathophysiology of the peripheral nerve barriers. Herein, the isolation, expansion, characterization and maintenance of perineurial cell lines under favourable conditions are presented. Furthermore, the analysis of the phenotypic features of these perineurial cells as well as the barrier function for the study of PNI are described. Such techniques may provide a valuable means for the functional and molecular investigation of perineurial cells, and in particular may elucidate the pathogenesis and progression of PNI, and other peripheral nerve disorders.

Comparison of Clinical Outcomes and Pathological Characteristics of Self-Expandable Stent Bridge to Surgery and Emergency Surgery in Obstructive Colon Cancer

Aim

Obstructive colon cancer can be treated by self-expanding metal stents (SEMS) prior to definitive surgery. However, the oncological outcome remains controversial, especially regarding whether stent placement or obstruction results in more perineural invasion (PNI) or lymphovascular invasion (LVI). This study aimed to compare clinical outcomes of emergency surgery (ES) and stent as bridge to surgery (SBTS) in patients with obstructive colon cancer. The pathological characteristics were also compared between obstructive and nonobstructive cancer.

Methods

This study included 880 patients (including 47 ES and 45 SBTS) admitted to Peking University Third Hospital from January 2010 to December 2018. Short-term and long-term outcomes were compared. The pathological differences between an equal number of obstructive and nonobstructive patients matched using propensity scores were investigated.

Results

SBTS patients had less intraoperative blood loss (P < 0.001), shorter ICU stay time (P = 0.007), lower incidence of colostomy (P < 0.001), and higher laparoscopic achievement (P < 0.001) than did ES patients. No pathological difference was found between the two groups. SBTS patients showed better overall survival (86.7% vs 68.1%, P = 0.029), but not disease-free survival (68.9% vs 59.6%, P = 0.211) than did ES patients. PNI was significantly higher in obstructive cancer than in nonobstructive cancer (29.3% vs 16.3%, P = 0.035).

Conclusion

SBTS had a lower incidence of short-term complications and did not affect long-term prognosis compared with that of ES, indicating that SBTS is a safe and effective treatment. Further, PNI may be associated with obstruction, but not with stent insertion.

Accelerated perineural invasion in colitis-associated cancer: A retrospective cohort study

Perineural invasion (PNI) is a prognostic factor in patients with colorectal cancer. Neurotrophic factors, molecular determinants of PNI, are altered in their expression levels in patients with ulcerative colitis. In this study, we evaluated the frequency of PNI in colitis-associated cancer (CAC) and sporadic cancer.We retrospectively reviewed 778 colorectal cancers with pathological T3-T4 in 761 patients all of whom were surgically resected without preoperative treatment. The lesions were classified into either CAC or sporadic cancer based on the clinical information. Clinicopathological findings including PNI were compared between CACs and sporadic cancers. Moreover, we analyzed the risk factors for positive PNI by multivariate analysis using a logistic regression model.Ten of the cancers (1.3%) were diagnosed as CACs, and the remaining 768 as sporadic cancers. CACs were characterized by being nonobstructive and predominantly located in the rectum. The CACs had a larger size and more frequent undifferentiated histology than sporadic cancers. PNI was observed more frequently in CACs (90%) than in sporadic cancers without obstruction (45%, P = .007). On multivariate analysis, CAC was one of the significant factors associated with PNI (odds ratio: 9.05, P = .040).Our results suggest that CAC was more likely to exhibit PNI than sporadic colorectal cancer.