Perineural invasion as a predictive factor for survival outcome in gastric cancer patients: a systematic review and meta-analysis

Preoperative Prediction of Perineural Invasion and Prognosis in Gastric Cancer Based on Machine Learning through a Radiomics-Clinicopathological Nomogram

PURPOSE

The aim of this study was to construct and validate a nomogram for preoperatively predicting perineural invasion (PNI) in gastric cancer based on machine learning, and to investigate the impact of PNI on the overall survival (OS) of gastric cancer patients.

METHODS

Data were collected from 162 gastric patients and analyzed retrospectively, and radiomics features were extracted from contrast-enhanced computed tomography (CECT) scans. A group of 42 patients from the Cancer Imaging Archive (TCIA) were selected as the validation set. Univariable and multivariable analyses were used to analyze the risk factors for PNI. The t-test, Max-Relevance and Min-Redundancy (mRMR) and the least absolute shrinkage and selection operator (LASSO) were used to select radiomics features. Radscores were calculated and logistic regression was applied to construct predictive models. A nomogram was developed by combining clinicopathological risk factors and the radscore. The area under the curve (AUC) values of receiver operating characteristic (ROC) curves, calibration curves and clinical decision curves were employed to evaluate the performance of the models. Kaplan-Meier analysis was used to study the impact of PNI on OS.

RESULTS

The univariable and multivariable analyses showed that the T stage, N stage and radscore were independent risk factors for PNI (p < 0.05). A nomogram based on the T stage, N stage and radscore was developed. The AUC of the combined model yielded 0.851 in the training set, 0.842 in the testing set and 0.813 in the validation set. The Kaplan-Meier analysis showed a statistically significant difference in OS between the PNI group and the non-PNI group (p < 0.05).

CONCLUSIONS

A machine learning-based radiomics-clinicopathological model could effectively predict PNI in gastric cancer preoperatively through a non-invasive approach, and gastric cancer patients with PNI had relatively poor prognoses.

Implication of perineural invasion in patients with stage II gastric cancer

BACKGROUND

Perineural invasion (PNI) is regarded as a prognostic factor for patients with GC. However, the significance of PNI in patients with stage II GC remains unclear. This study aimed to investigate the clinical implication of PNI in patients with stage II GC undergoing curative resection.

METHODS

Patients with stage II GC who underwent curative resection were retrospectively evaluated from January 2010 to July 2019. According to PNI status, all patients were divided into two groups: with or without PNI. The prognostic value of PNI was analyzed by univariate and multivariate Cox proportional hazards regression models.

RESULTS

A total of 233 patients were included in this study. There were 100 patients with PNI (42.92%) and 133 patients without PNI (57.08%). The overall survival (OS) and disease-free survival (DFS) rates for patients with PNI were significantly lower than that for patients without PNI (p = 0.019 and p = 0.032, respectively). Multivariate analysis indicated that the presence of PNI was an independent risk factor for OS (hazard ratio (HR): 1.76, 95% confidence interval (CI) 1.02-3.06, p = 0.044) and DFS (HR: 1.70, 95% CI 1.04-2.80, p = 0.035), while adjuvant chemotherapy (AC) was an independent protective factor for OS (HR: 0.51, 95% CI 0.30-0.88, p = 0.016) and DFS (HR: 0.52, 95% CI 0.31-0.86, p = 0.011). Furthermore, among patients with PNI, those who received AC had better OS (p = 0.022) and DFS (p = 0.027) than their counterparts. When patients with PNI received AC, the OS (p = 0.603) and DFS (p = 0.745) appeared to be similar to those without PNI and no AC.

CONCLUSION

In patients with stage II GC undergoing curative resection, the presence of PNI was associated with worse survival, which appeared to improve with the treatment of AC, indicating a potential need for more intensive AC.

Collagen-related gene expression level predicts the prognosis and immune therapy response

BACKGROUND

Gastric cancer patients responded differently to the same treatment strategy and had various prognoses for the lack of biomarkers to guide the therapy choice.

METHODS

RNA data of a local gastric cancer cohort with 103 patients were processed and used to explore potential treatment guiding factors. Cluster analysis was performed by non-negative matrix factorization. The expression level of collagen-related genes was evaluated by ssGSEA named collagen score (CS). Data from TCGA, ACRG, and an immune therapy cohort were utilized to explore prognosis and efficacy. Prognostic predictive power of CS was assessed using the nomogram.

RESULTS

In our study, local RNA data were processed by cluster analysis, and it was found that cluster 2 contained a worse tumor infiltration status. The GSEA result showed that collagen-related pathways were differentially activated in two clusters. In TCGA and ACRG cohorts, the CS can be used as an independent prognostic factor (TCGA OS: p = 0.018, HR = 3.5; ACRG OS: p = 0.014, HR = 4.88). An immunotherapy cohort showed that the patients with higher CS had a significantly worse ORR (p = 0.0025). The high CS group contained several cell death pathways down-regulated and contained the worse tumor microenvironment. The nomogram demonstrated the survival prediction capability of collagen score.

CONCLUSION

CS was verified as an independent prognostic factor and potentially reflected the therapeutic effect of immunotherapy. The CS could provide a new way to evaluate the clinical prognosis and response information helping develop the collagen-targeted treatment.

Performance of endoscopic submucosal dissection for undifferentiated early gastric cancer: a multicenter retrospective cohort

Background and study aims Undifferentiated early gastric cancer (UD-EGC) represents an extended indication for endoscopic submucosal dissection (ESD) based on the existing guidelines. This study evaluated the prevalence of UD-EGC recurrence after ESD, and potentially implicated risk factors. Patients and methods Data from 17 centers were collected retrospectively including demographics, endoscopic and pathological findings, and follow-up data from UD-EGC cases treated by ESD. Patients with incomplete resection or advanced disease were excluded. Descriptive statistics quantified variables and calculated the incidence of recurrence. Chi-square test was applied to assess any link between independent variables and relapse; significantly associated variables were inserted to a multivariable regression model. Results Seventy-one patients were eligible, with 2:1 female to male ratio and age of 65.8 ± 11.8 years. Mean lesion size was 33.5 ± 18.8 mm and the most frequent histological subtype was signet ring-cells UGC (2:1). Patients were followed-up every 5.6 ± 3.7 months with a mean surveillance period of 29.3 ± 15.3 months until data collection. Four patients (5.6%) developed local recurrence 8.8 ± 6.5 months post-ESD, with no lymph node or distal metastases been reported. Lesion size was not associated with recurrence ( P = 0.32), in contrast to lymphovascular and perineural invasion which were independently associated with local recurrence ( P = 0.006 and P < 0.001, respectively). Conclusions ESD could be considered as the initial step to manage UD-EGC, providing at least an "entire-lesion" biopsy to guide therapeutic strategy. When histology confirms absence of lymphovascular and perineural invasion, this modality could be therapeutic, providing low recurrence rates.

The value of machine learning based radiomics model in preoperative detection of perineural invasion in gastric cancer: a two-center study

Purpose

To establish and validate a machine learning based radiomics model for detection of perineural invasion (PNI) in gastric cancer (GC).

Methods

This retrospective study included a total of 955 patients with GC selected from two centers; they were separated into training (n=603), internal testing (n=259), and external testing (n=93) sets. Radiomic features were derived from three phases of contrast-enhanced computed tomography (CECT) scan images. Seven machine learning (ML) algorithms including least absolute shrinkage and selection operator (LASSO), naïve Bayes (NB), k-nearest neighbor (KNN), decision tree (DT), logistic regression (LR), random forest (RF), eXtreme gradient boosting (XGBoost) and support vector machine (SVM) were trained for development of optimal radiomics signature. A combined model was constructed by aggregating the radiomic signatures and important clinicopathological characteristics. The predictive ability of the radiomic model was then assessed with receiver operating characteristic (ROC) and calibration curve analyses in all three sets.

Results

The PNI rates for the training, internal testing, and external testing sets were 22.1, 22.8, and 36.6%, respectively. LASSO algorithm was selected for signature establishment. The radiomics signature, consisting of 8 robust features, revealed good discrimination accuracy for the PNI in all three sets (training set: AUC = 0.86; internal testing set: AUC = 0.82; external testing set: AUC = 0.78). The risk of PNI was significantly associated with higher radiomics scores. A combined model that integrated radiomics and T stage demonstrated enhanced accuracy and excellent calibration in all three sets (training set: AUC = 0.89; internal testing set: AUC = 0.84; external testing set: AUC = 0.82).

Conclusion

The suggested radiomics model exhibited satisfactory prediction performance for the PNI in GC.

Inclusion of Perineural Invasion with AJCC-TNM Staging: Outcomes from a South Asian Cohort of Curatively Treated Gastric Cancer Patients

BACKGROUND

The incidence of perineural invasion (PNI) in patients with gastric cancer (GC) is high, and patients with PNI positive disease have a poor prognosis compared to PNI-negative disease. The present study aims to study the incidence and evaluate the impact of PNI on the survival outcome of a cohort of South Asian GC patients.

MATERIAL AND METHODS

All consecutive patients undergoing curative gastrectomy were included in the study. The incidence of PNI and correlation with different clinico-pathological features and overall survival was performed.

RESULTS

A total of 59.54% had PNI-positive disease and the median OS of PNI + ve patients was 29.3 months, while it was not reached in PNI-ve patients. The PNI positivity was a significant prognostic factor for overall survival both on univariate and multivariate analysis. On TNM-PNI staging, those with TNM stage I/II patients with PNI + ve disease had similar OS to all stage III patients (p = 0.835) and were worse than that of PNI-ve patients (p < 0.05).

CONCLUSION

The incidence of PNI in gastric cancer is high. The inclusion of PNI with AJCC-TNM staging may better stratify prognostic staging in curatively treated gastric cancer patients.

Elevation of preoperative serum hs-CRP is an independent risk factor for malnutrition in patients with gastric cancer

Background

Recent studies have reported hypersensitive C-reactive protein (hs-CRP) linked to clinicopathological characteristics and nutritional status of the tumor, but its clinical significance in GC remains unclear. This study aimed to investigate the relationship between preoperative serum hs-CRP level and clinicopathological features and nutritional status in gastric cancer (GC) patients.

Methods

The clinical data of 628 GC patients who met the study criteria were analyzed retrospectively. The preoperative serum hs-CRP level was divided into two groups (<1 mg/L and ≥1 mg/L) to evaluate clinical indicators. Nutritional Risk Screening and nutritional assessment of GC patients were performed by the Nutritional Risk Screening 2002 (NRS2002) and the Patient-Generated Subjective Global Assessment (PG-SGA), respectively. The data were subjected to chi-square test, univariate and multivariate logistic regression analyses, respectively.

Results

The analysis of 628 GC cases revealed that 338 patients (53.8%) were on malnutrition risk(NRS2002≥3 points), and 526(83.8%) had suspected/moderate to severe malnutrition(PG-SGA≥ 2 points). Preoperative serum hs-CRP level was significantly correlated with age, tumor maximum diameter (TMD), peripheral nerve invasion (PNI), lymph-vascular invasion (LVI), depth of tumor invasion (DTI), lymph node metastasis (LNM), pTNM stage, body weight loss (BWL), body mass index (BMI), NRS2002 score, PG-SGA grade, hemoglobin (HB), total protein (TP), albumin (ALB), prealbumin (PAB) and total lymphocyte count (TLC). Multivariate logistic regression analysis revealed that hs-CRP (OR=1.814, 95%CI=1.174-2.803; P=0.007), age, ALB, BMI, BWL and TMD were independent risk factors for existing malnutritional risk in GC. Similarly, non-malnutrition and suspected/moderate to severe malnutrition groups presented that hs-CRP (OR=3.346, 95%CI=1.833-6.122; P< 0.001), age, HB, ALB, BMI and BWL were independent risk factors for malnutrition in GC.

Conclusion

In addition to the generally used nutritional evaluation indicators such as age, ALB, BMI, and BWL, the hs-CRP level may be used as a nutritional screening and evaluation indicator for GC patients.

Long noncoding RNA DIAPH2-AS1 promotes neural invasion of gastric cancer via stabilizing NSUN2 to enhance the m5C modification of NTN1

Neural invasion (NI) is a vital pathological characteristic of gastric cancer (GC), which correlates with tumor recurrence and a worse prognosis. Long noncoding RNAs (lncRNAs) play critical roles in various biological processes. However, the involvement of lncRNAs in NI of GC (GC-NI) remains unclear. DIAPH2-AS1 was upregulated in NI-positive GC tissues, which was confirmed by qRT-PCR. The higher expression of DIAPH2-AS1 predicted NI and worse survival for GC patients. Both in vitro and in vivo experiments, including wound-healing assay, Transwell assay, DRG-GC cells co-culture model, the mouse sciatic nerve model, and the lung metastasis model, indicated that DIAPH2-AS1 promoted the migration, invasion, and NI potential of GC cells. Mechanistically, pulldown assay and RNA immunoprecipitation assay revealed that DIAPH2-AS1 interacted with NSUN2. Subsequent experiments indicated that DIAPH2-AS1 stabilized NSUN2 from ubiquitin-proteasomal degradation via masking the K577 and K579 of NSUN2. The protection of DIAPH2-AS1 on NSUN2 improved the stability of NTN1 mRNA via m5C modification, which finally induced GC-NI. Our work uncovered DIAPH2-AS1 as a novel oncogenic lncRNA in GC-NI and validated the DIAPH2-AS1-NSUN2-NTN1 axis as a potential therapeutic target for NI-positive GC.

Expectation-maximization algorithm leads to domain adaptation for a perineural invasion and nerve extraction task in whole slide digital pathology images

In addition to lymphatic and vascular channels, tumor cells can also spread via nerves, i.e., perineural invasion (PNI). PNI serves as an independent prognostic indicator in many malignancies. As a result, identifying and determining the extent of PNI is an important yet extremely tedious task in surgical pathology. In this work, we present a computational approach to extract nerves and PNI from whole slide histopathology images. We make manual annotations on selected prostate cancer slides once but then apply the trained model for nerve segmentation to both prostate cancer slides and head and neck cancer slides. For the purpose of multi-domain learning/prediction and investigation on the generalization capability of deep neural network, an expectation-maximization (EM)-based domain adaptation approach is proposed to improve the segmentation performance, in particular for the head and neck cancer slides. Experiments are conducted to demonstrate the segmentation performances. The average Dice coefficient for prostate cancer slides is 0.82 and 0.79 for head and neck cancer slides. Comparisons are then made for segmentations with and without the proposed EM-based domain adaptation on prostate cancer and head and neck cancer whole slide histopathology images from The Cancer Genome Atlas (TCGA) database and significant improvements are observed.

The clinical implications and molecular features of intrahepatic cholangiocarcinoma with perineural invasion

BACKGROUND

Perineural invasion (PNI) is associated with metastasis in malignancies, including intrahepatic cholangiocarcinoma (ICC), and is correlated with poor prognosis.

METHODS

The study included three large cohorts: ZS-ICC and TMA cohorts from our team, MSK cohort from a public database, and a small cohort named cohort 4. Prognostic implications of PNI were investigated in MSK cohort and TMA cohort. PNI-related genomic and transcriptomic profiles were analyzed in MSK and ZS-ICC cohorts. GO, KEGG, and ssGSEA analyses were performed. Immunohistochemistry was used to investigate the relationship between PNI and markers of neurons, hydrolases, and immune cells. The efficacy of adjuvant therapy in ICC patients with PNI was also assessed.

RESULTS

A total of 30.6% and 20.7% ICC patients had PNI in MSK and TMA cohorts respectively. Patients with PNI presented with malignant phenotypes such as high CA19-9, the large bile duct type, lymph node invasion, and shortened overall survival (OS) and relapse-free survival (RFS). Nerves involved in PNI positively express tyrosine hydroxylase (TH), a marker of sympathetic nerves. Patients with PNI showed high mutation frequency of KRAS and an immune suppressive metastasis prone niche of decreased NK cell, increased neutrophil, and elevated PD-L1, CD80, and CD86 expression. Patients with PNI had an extended OS after adjuvant therapy with TEGIO, GEMOX, or capecitabine.

CONCLUSION

Our study deciphered the genomic features and the immune suppressive metastasis-prone niche in ICC with PNI. Patients with PNI showed a poor prognosis after surgery but a good response to adjuvant chemotherapy.

Tumor Characteristics Associated with Lymph Node Metastasis and Prognosis in Patients with ERBB2-Positive Gastric Cancer

Gastric cancers (GCs) that express human erb-b2 receptor tyrosine kinase 2 (ERBB2, also known as HER2) account for 7.3%–20.2% of GCs. The pathological and prognostic factors associated with lymph node metastasis of such tumors are still unclear. Therefore, we aimed to identify the risk factors for lymph node metastasis and prognostic factors of patients with ERBB2-positive GC. We conducted a retrospective analysis of pathological specimens after D2 radical surgery for locally advanced GC and D1+ surgery performed for early GC in our hospital from January 2015 to December 2018. Patients with ERBB2-positive GC were selected and the potential risk factors for lymph node metastasis and potential factors affecting prognosis were evaluated. Among 1,124 GC patients, 122 diagnosed with ERBB2-positive GC were included in the study. We found that risk factors for lymph node metastasis included tumor size (hazard ratio (HR)- 6.213, 95% confidence interval (CI)- 2.097–18.407, p = 0.001), neural invasion (HR- 2.876, 95% CI - 1.011–8.184, p = 0.048), and vascular invasion (HR- 16.881, 95% CI - 5.207–54.727, p < 0.001). T stage (HR- 4.615, 95% CI - 2.182–9.759, p < 0.001) and vascular invasion (HR- 3.036, 95% CI - 1.369–6.736, p = 0.006) were significant prognostic variables. These findings shed new light on the pathology and prognosis of patients with ERBB2-positive GC.

Spatial and Transcriptomic Analysis of Perineural Invasion in Oral Cancer

PURPOSE

Perineural invasion (PNI), a common occurrence in oral squamous cell carcinomas, is associated with poor survival. Consequently, these tumors are treated aggressively. However, diagnostic criteria of PNI vary and its role as an independent predictor of prognosis has not been established. To address these knowledge gaps, we investigated spatial and transcriptomic profiles of PNI-positive and PNI-negative nerves.

EXPERIMENTAL DESIGN

Tissue sections from 142 patients were stained with S100 and cytokeratin antibodies. Nerves were identified in two distinct areas: tumor bulk and margin. Nerve diameter and nerve-to-tumor distance were assessed; survival analyses were performed. Spatial transcriptomic analysis of nerves at varying distances from tumor was performed with NanoString GeoMx Digital Spatial Profiler Transcriptomic Atlas.

RESULTS

PNI is an independent predictor of poor prognosis among patients with metastasis-free lymph nodes. Patients with close nerve-tumor distance have poor outcomes even if diagnosed as PNI negative using current criteria. Patients with large nerve(s) in the tumor bulk survive poorly, suggesting that even PNI-negative nerves facilitate tumor progression. Diagnostic criteria were supported by spatial transcriptomic analyses of >18,000 genes; nerves in proximity to cancer exhibit stress and growth response changes that diminish with increasing nerve-tumor distance. These findings were validated in vitro and in human tissue.

CONCLUSIONS

This is the first study in human cancer with high-throughput gene expression analysis in nerves with striking correlations between transcriptomic profile and clinical outcomes. Our work illuminates nerve-cancer interactions suggesting that cancer-induced injury modulates neuritogenesis, and supports reclassification of PNI based on nerve-tumor distance rather than current subjective criteria.

Adhesion of Gastric Cancer Cells to the Enteric Nervous System: Comparison between the Intestinal Type and Diffuse Type of Gastric Cancer

Background: Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. The enteric nervous system (ENS) has been suggested to be involved in cancer development and spread. Objective: To analyze the GC cell adhesion to the ENS in a model of co-culture of gastric ENS with GC cells. Methods: Primary culture of gastric ENS (pcgENS), derived from a rat embryo stomach, was developed. The adhesion of GC cells to pcgENS was studied using a co-culture model. The role of N-Cadherin, a cell-adhesion protein, was evaluated. Results: Compared to intestinal-type GC cells, the diffuse-type GC cancer cells showed higher adhesion to pcgENS (55.9% ± 1.075 vs. 38.9% ± 0.6611, respectively, p < 0.001). The number of diffuse-type GC cells adherent to pcgENS was significantly lower in neuron-free pcgENS compared to neuron-containing pcgENS (p = 0.0261 and 0.0329 for AGS and MKN45, respectively). Confocal microscopy showed that GC cells adhere preferentially to the neurons of the pcgENS. N-Cadherin blockage resulted in significantly decreased adhesion of the GC cells to the pcgENS (p < 0.01). Conclusion: These results suggest a potential role of enteric neurons in the dissemination of GC cells, especially of the diffuse-type, partly through N-Cadherin.

Prognostic Significance of Perineural Invasion in Patients with Stage II/III Gastric Cancer Undergoing Radical Surgery

The prognostic significance of perineural invasion in patients with gastric cancer (GC) is controversial. This study aimed to determine the prognostic value of perineural invasion in patients with stage II/III GC undergoing radical surgery. A total of 1913 patients with stage II/III GC who underwent curative resection between 1994 and 2015 were recruited. Clinicopathological factors, tumor recurrence patterns, disease-free survival, and cancer-specific survival were compared in terms of perineural invasion. The prognostic factors of disease-free survival and cancer-specific survival were determined using univariate and multivariate analyses. Perineural invasion was found in 57.1% of the patients. Age of <65 years, female sex, large tumor size, upper tumor location, total gastrectomy, advanced tumor invasion depth and nodal involvement, greater metastatic to examined lymph node ratio, undifferentiated tumor, and presence of lymphatic or vascular invasion were significantly associated with perineural invasion. The patients with perineural invasion had higher locoregional/peritoneal recurrence rates than those without. Perineural invasion was independently associated with disease-free survival and cancer-specific survival. In conclusion, perineural invasion positivity is associated with aggressive tumor behaviors and higher locoregional/peritoneal recurrence rates in patients with stage II/III GC undergoing curative surgery. It is an independent unfavorable prognostic factor of disease recurrence and cancer-specific survival.

Comparison of treatment outcomes of pelvis external radiotherapy with and without vaginal brachytherapy for cervical cancer patients with positive or close vaginal resected margins

BACKGROUND

We evaluated whether there is a difference in the local recurrence and survival after pelvic external radiotherapy (ERT) with and without boost vaginal brachytherapy (VB) in cervical cancer patients with positive or close vaginal resected margins (RM).

METHODS

We retrospectively reviewed FIGO stage IA-IIB cervical cancer patients treated with postoperative ERT between 1997 and 2018. The sixty patients showing close (safety margin < 5 mm) or positive vaginal RM were included. ERT was delivered with median 50.4 Gy in 28 fractions to the pelvis and VB with median 30 Gy in 6 fractions.

RESULTS

The median follow-up duration was 46 months. Five out of 30 patients treated with ERT alone experienced vaginal recurrence within 2 years after surgery. The 5-year local control (LC) was 100% in patients receiving ERT + VB compared with 81.3% in patients receiving ERT alone (log rank p = 0.022). The 5-year pelvic control (PC) was 95.8% for patients receiving ERT + VB and 76.8% for ERT alone (p = 0.041). The 5-year overall survival and recurrence-free survival (RFS) were not significantly different between treatment groups. In multivariate analysis, perineural invasion was a significant risk factor for PC (p = 0.024). Parametrial involvement (p = 0.044) and vascular invasion (p = 0.032) were unfavorable prognostic factors for RFS. Late toxicity occurrences were not significant in both groups.

CONCLUSION

VB after ERT improved LC and PC in cervical cancer patients with close or positive RM after hysterectomy. The toxicities were not increased after VB was added to ERT.

Prognostic Value of Perineural Invasion in Oral Tongue Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

OBJECTIVES

A significant number of recently published research has outlined the contribution of perineural invasion (PNI) to clinical outcomes in oral tongue squamous cell carcinoma (OTSCC), but some results remain conflicting. This study aimed to determine whether patients with OTSCC with PNI have a worse prognosis than those without PNI.

MATERIALS AND METHODS

PubMed, Embase, and the Cochrane Library were queried for potentially eligible articles published up to December 2020. The primary outcomes were the hazard ratio (HR) for locoregional recurrence, overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS). The random-effect model was used in all analyses.

RESULTS

Seventeen studies (4445 patients) were included. Using adjusted HRs, the presence of PNI was associated with a higher risk of locoregional recurrence (HR=1.73, 95%CI: 1.07-2.79, P=0.025, I2 = 33.1%, Pheterogeneity=0.224), worse OS (HR=1.94, 95%CI: 1.39-2.72, P<0.001, I2 = 0.0%, Pheterogeneity=0.838), worse DFS (HR=2.13, 95%CI: 1.53-2.96, P<0.001, I2 = 48.4%, Pheterogeneity=0.071), and worse CSS (HR=1.93, 95%CI: 1.40-2.65, P<0.001, I2 = 25.5%, Pheterogeneity=0.251). PNI had an impact on locoregional recurrence in early-stage OTSCC but not in all stages, and on OS, DFS, and CSS in all-stage and early-stage OTSCC. The sensitivity analyses showed that the results were robust.

CONCLUSION

The presence of PNI significantly affects the locoregional recurrence and survival outcomes among patients with OTSCC.

Perineural Invasion Correlates With Common Pathological Variables and Clinical Outcomes of Patients With Squamous Cell Carcinoma of the Vulva Treated With Primary Radical Surgery and Inguinal-femoral Lymphadenectomy

BACKGROUND/AIM

The aims of the study were: i) to assess the incidence of perineural invasion (PNI) in squamous cell carcinoma of the vulva and ii) to correlate PNI with common pathological prognostic variables and clinical outcome of patients.

PATIENTS AND METHODS

The hospital records of 64 patients with vulvar squamous cell carcinoma who underwent primary radical surgery were reviewed.

RESULTS

PNI was significantly related to stage (p=0.038), size (p=0.038), lymph-vascular space involvement (p=0.013) and nodal status (p=0.038), but not to patient age, tumor grade and stromal invasion. Five-year disease-free survival was 30.0% in patients with PNI and 53.1% in those without PNI (p=0.018), and the corresponding 5-year overall survival was 50.0% and 77.1% (p=0.031), respectively.

CONCLUSION

PNI was associated with common pathological prognostic variables and with a poorer clinical outcome in patients with vulvar squamous cell carcinoma.

Prognostic effect of perineural invasion in successive years in patients with locally advanced gastric cancer

Aim

The present study evaluates the prognostic significance of perineural invasion (PNI) on 2-year, 5-year, and overall survival in patients undergoing gastrectomy and D2 lymphadenectomy due to locally advanced gastric cancer.

Materials and Methods

Included in the study were 231 patients who underwent surgery between November 2006 and October 2018 due to stage 1B and over locally advanced gastric cancer, whose records were reviewed retrospectively.

Statistical Analysis

The variables in the presence or absence of PNI were compared between the two groups with a Chi-square test, a Fisher's exact test, a likelihood ratio, and a Mann-Whitney U test. Overall survival data were evaluated with a Kaplan-Meier test. Prognostic factors were evaluated with a stepwise Cox regression analysis.

Results

PNI was identified in 167 (72.3%) of the patients. The 2-year, 5-year, and overall survival rates at the end of the follow-up period were 85.9%, 70.3%, and 64.1% in those without PNI, and 52.7%, 38.3%, and 36.5% in those with PNI, respectively. In a multivariate analysis, PNI appeared to be a significant prognostic factor for 2-year survival (P = 0.04) but had no effect on 5-year and overall survival.

Conclusions

Survival was shorter in patients with PNI than in patients without PNI, and PNI had no effect on overall survival, although it was found to be of prognostic significance for 2-year survival.