Pathological evaluation of neoadjuvant chemotherapy in advanced gastric cancer

ypTNM staging is a potentially useful prognostic stratification tool in patients with advanced gastric cancer after preoperative chemotherapy

PURPOSE

Although the usefulness of the ypStage in neoadjuvant chemotherapy for advanced gastric cancer (GC) has been reported, whether or not the ypStage is applicable to all GC patients who receive preoperative chemotherapy, including conversion surgery cases, is unclear. Therefore, this retrospective study evaluated the value of the ypTNM staging system in all advanced GC patients who received chemotherapy prior to gastrectomy.

METHODS

A total of 66 patients who underwent chemotherapy prior to gastrectomy for advanced GC at Chiba University Hospital from January 2008 to December 2020 were enrolled in the current study. The prognostic impact of the ypStage on the overall survival (OS) and relapse-free survival (RFS) were examined via univariate and multivariate analyses.

RESULTS

The 5-year OS rates for ypStage I, II, III, and IV were 87.5%, 64.7%, 52.9%, and 28.6%, respectively, while the 5-year RFS rates were 81.3%, 57.4%, 44.4%, and 28.6%, respectively. The univariate analysis revealed that the ypStage was significantly correlated with the OS (p = 0.037) and the ypT status and ypStage showed a significant correlation with the RFS (p = 0.043 and p = 0.021, respectively). The multivariate analysis demonstrated that only the ypStage was an independent prognostic factor for the OS and RFS (p = 0.024 and p = 0.018, respectively).

CONCLUSION

The ypTNM stage may be a useful tool for the risk stratification of all advanced GC patients treated with chemotherapy followed by gastrectomy, including not only neoadjuvant but also conversion surgery cases.

A radiomics nomogram analysis based on CT images and clinical features for preoperative Lauren classification in gastric cancer

PURPOSE

To develop a combined radiomics nomogram based on computed tomography (CT) images and clinical features to preoperatively distinguish Lauren's diffuse-type gastric cancer (GC) from intestinal-type GC.

METHODS

Ninety-five patients with Lauren's intestinal or diffuse-type GC confirmed by postoperative pathology had their preoperative clinical information and dynamic contrast CT images retrospectively analyzed and were subdivided into training and test groups in a 7:3 ratio. To select the optimal features and construct the radiomic signatures, we extracted, filtered, and minimized the radiomic features from arterial phase (AP) and venous phase (VP) CT images. We constructed four models (clinical model, AP radiomics model, VP radiomics model, and radiomics-clinical model) to assess and compare their predictive performance between the intestinal- and diffuse-type GC. Receiver-operating characteristic (ROC) curve, area under the ROC curve (AUC), and the DeLong test were used for assessment and comparison. In this study, radiomic nomograms integrating combined radiomic signatures and clinical characteristics were developed.

RESULTS

Compared to the AP radiomics model, the VP radiomics model had better performance, with an AUC of 0.832 (95% confidence interval [CI], 0.735, 0.929) in the training cohort and 0.760 (95% CI 0.580, 0.940) in the test cohort. Among the combined models that assessed Lauren's type GC, the model including age and VP radiomics showed the best performance, with an AUC of 0.849 (95% CI 0.758, 0.940) in the training cohort and 0.793 (95% CI 0.629, 0.957) in the test cohort.

CONCLUSIONS

Nomogram incorporating radiomic signatures and clinical features effectively differentiated Lauren's diffuse-type from intestinal-type GC.

Naples Prognostic Score Predicts Tumor Regression Grade in Resectable Gastric Cancer Treated with Preoperative Chemotherapy

Simple Summary

Multimodal treatment of locally advanced gastric cancer is still debated today due to controversial results in different trials. Nevertheless, perioperative chemotherapy with radical surgery certainly shows a better long-term outcome than surgery alone, so much so it is the main multimodal treatment offered in Europe, at the present. Tumor regression grade is the objective response to preoperative chemotherapy and its extent, in terms of reduction of neoplastic cells in the resected specimen, is strongly affected by Lauren’s classification, TNM stage, and tumor grading. Therefore, since this information can be achieved only after surgical resection, the return of chemotherapy is quite unpredictable in advance and, in about half cases, it is definitely ineffective. Naples Prognostic Score, that mirrors the immune–nutritional conditions, tested on 59 consecutive advanced gastric cancer patients undergoing multimodal treatment, showed a strong power in predicting tumor regression grade and therefore is strictly correlated with long-term outcome and survival.

Abstract

Despite recent progresses, locally advanced gastric cancer remains a daunting challenge to embrace. Perioperative chemotherapy and D2-gastrectomy depict multimodal treatment of gastric cancer in Europe, shows better results than curative surgery alone in terms of downstaging, micrometastases elimination, and improved long-term survival. Unfortunately, preoperative chemotherapy is useless in about 50% of cases of non-responder patients, in which no effect is registered. Tumor regression grade (TRG) is directly related to chemotherapy effectiveness, but its understanding is achieved only after surgical operation; accordingly, preoperative chemotherapy is given indiscriminately. Conversely, Naples Prognostic Score (NPS), related to patient immune-nutritional status and easily obtained before taking any therapeutic decision, appeared an independent prognostic variable of TRG. NPS was calculated in 59 consecutive surgically treated gastric cancer patients after neoadjuvant FLOT4-based chemotherapy. 42.2% of positive responses were observed: all normal NPS and half mild/moderate NPS showed significant responses to chemotherapy with TRG 1–3; while only 20% of the worst NPS showed some related benefits. Evaluation of NPS in gastric cancer patients undergoing multimodal treatment may be useful both in selecting patients who will benefit from preoperative chemotherapy and for changing immune-nutritional conditions in order to improve patient’s reaction against the tumor.

Is there still a place for conventional histopathology in the age of molecular medicine? Laurén classification, inflammatory infiltration and other current topics in gastric cancer diagnosis and prognosis

Gastric cancer (GC) is the fifth most common cancer and the third cause of cancer-related deaths worldwide. In western countries, more than half of GC patients are diagnosed at advanced stages and 5-year survival rates range between 20-30%. The only curative treatment is surgery, and despite recent advances in oncological therapies, GC prognosis is still poor. The main prognostic tool for patient categorization and treatment selection is the TNM classification, but its limitations are being increasingly recognized. Early recurrences may occur in early-stage disease, and patients at the same stage show heterogeneous outcomes. Thus, there is a need to improve GC stratification and to identify new prognostic factors, which may allow us to select drug-susceptible populations, refine patient grouping for clinical trials and discover new therapeutic targets. Molecular classifications have been developed, but they have not been translated to the clinical practice. On the other hand, histological assessment is cheap and widely available, and it is still a mainstay in the era of molecular medicine. Furthermore, histological features are acquiring new roles as reflectors of the genotype-phenotype correlation, and their potential impact on patient management is currently being analyzed. The aim of this literature review is to provide a modern overview of the histological assessment of GC. In this study, we discuss recent topics on the histological diagnosis of GC, focusing on the current role of Laurén classification and the potential value of new histological features in GC, such as inflammatory infiltration and tumor budding.

Optimal Timing to Surgery After Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer

BACKGROUND

The relationship between time to surgery (TTS) and survival benefit is not sufficiently demonstrated by previous studies in locally advanced gastric cancer (LAGC). This study aims to assess the impact of TTS after neoadjuvant chemotherapy (NACT) on long-term and short-term outcomes in LAGC patients.

METHODS

Data were collected from patients with LAGC who underwent NACT between January 2007 and January 2018 at our institution. Outcomes assessed were long-term survival, pathologic complete response (pCR) rate, and postoperative complications.

RESULTS

This cohort of 426 patients was divided into five groups by weeks of TTS. Under cox regression, compared to other groups, the 22-28 days and 29-35 days groups revealed a better OS (≤21 vs. 22-28 days: HR 1.54, 95% CI = 0.81-2.93, P = 0.185; 36-42 vs. 22-28 days: HR 2.20, 95% CI = 1.28-3.79, P = 0.004; 43-84 vs. 22-28 days: HR 1.83, 95% CI = 1.09-3.06, P = 0.022) and PFS (≤21 vs. 22-28 days: HR 1.54, 95% CI = 0.81-2.93, P = 0.256; 36-42 vs. 22-28 days: HR 2.20, 95% CI = 1.28-3.79, P = 0.111; 43-84 vs. 22-28 days: HR 1.83, 95% CI = 1.09-3.06, P = 0.047). Further analysis revealed a better prognosis in patients with TTS within 22-35 days (OS: HR 1.78 95% CI = 1.25-2.54, P = 0.001; PFS: HR 1.49, 95% CI = 1.07-2.08, P = 0.017). Postoperative stay was significantly higher in the ≤21 days group, while other parameters revealed no statistical significance (P > 0.05). Restricted cubic spline depicted the nonlinear relationship between TTS and OS/PFS.

CONCLUSION

Patients who received surgery within 3-5 weeks experienced the maximal survival benefit without an increase in postoperative complications or lowering the rate of pCR. Further investigations are warranted.

Nomogram based on clinical characteristics for preoperative prediction of perineural invasion in gastric cancer

Purpose

Gastric cancer (GC) has a poor prognosis and high rate of recurrence. Perineural invasion (PNI) is a prognostic factor in GC that is associated with a high risk of systemic recurrence. Preoperative identification of PNI may facilitate patient stratification and optimal preoperative treatment. We therefore developed and validated a nomogram for the preoperative prediction of PNI.

Methods

We retrospectively collected clinical data from 261 GC patients, who were randomly assigned to training (n = 185) and validation (n = 76) sets. The least absolute shrinkage and selection operator regression model was used to identify potentially relevant clinical parameters, and multivariable logistic regression analysis was used to develop the nomogram.

Results

The nomogram consisted of body mass index, immunoglobulin A level, and computed tomography-based T- and N-stages. Good calibration was observed for both the training and validation sets, with areas under the curve of 0.77 and 0.79, respectively. Decision curve analysis revealed that the nomogram was clinically relevant.

Conclusion

We developed and validated a nomogram for the preoperative prediction of PNI in patients with GC. Our nomogram may facilitate the identification of high-risk patients and optimization of preoperative decision-making.

Modified ypTNM Staging Classification for Gastric Cancer after Neoadjuvant Therapy: A Multi-Institutional Study

BACKGROUND

The benefits of neoadjuvant therapy for patients with locally advanced gastric cancer (GC) are increasingly recognized. The 8th edition of the American Joint Committee on Cancer (AJCC) Staging Manual first proposed ypTNM staging, but its accuracy is controversial. This study aims to develop a modified ypTNM staging.

PATIENTS AND METHODS

Clinicopathological data of 1,791 patients who underwent curative-intent gastrectomy after neoadjuvant therapy in the Surveillance, Epidemiology, and End Results database, as the development cohort, were retrospectively analyzed. Modified ypTNM staging was established based on overall survival (OS). We compared the prognostic performance of the AJCC 8th edition ypTNM staging and the modified staging for patients after neoadjuvant therapy.

RESULTS

In the development cohort, the 5-year OS for AJCC stages I, II, and III was 58.8%, 39.1%, and 21.6%, respectively, compared with 69.9%, 54.4%, 34.4%, 24.1%, and 13.6% for modified ypTNM stages IA, IB, II, IIIA, and IIIB. The modified staging had better discriminatory ability (C-index: 0.620 vs. 0.589, p < .001), predictive homogeneity (likelihood ratio chi-square: 140.71 vs. 218.66, p < .001), predictive accuracy (mean difference in Bayesian information criterion: 64.94; net reclassification index: 35.54%; integrated discrimination improvement index: 0.032; all p < .001), and model stability (time-dependent receiver operating characteristics curves) over AJCC. Decision curve analysis showed that the modified staging achieved a better net benefit than AJCC. In external validation (n = 266), the modified ypTNM staging had superior prognostic predictive power (all p < .05).

CONCLUSION

We have developed and validated a modified ypTNM staging through multicenter data that is superior to the AJCC 8th edition ypTNM staging, allowing more accurate assessment of the prognosis of patients with GC after neoadjuvant therapy.

IMPLICATIONS FOR PRACTICE

The 8th edition of the American Joint Committee on Cancer (AJCC) Staging Manual first proposed ypTNM staging, but its accuracy is controversial. Based on multi-institutional data, this study developed a modified ypTNM staging, which is superior to the AJCC 8th edition ypTNM staging, allowing more accurate assessment of the prognosis of patients with gastric cancer after neoadjuvant therapy.

Efficacy and safety of nanosomal docetaxel lipid suspension based chemotherapy in gastric and gastroesophageal junction adenocarcinoma

The current retrospective multicenter study evaluated the efficacy and safety of nanosomal docetaxel lipid suspension (NDLS; DoceAqualip) based chemotherapy in patients with gastric and gastroesophageal junction (GEJ) adenocarcinoma. The medical charts of patients with gastric and GEJ adenocarcinoma, who were treated with NDLS (50-75 mg/m²; 3 weekly cycles) based chemotherapy and followed-up from April 2014 to September 2018, were analyzed. The study endpoints included overall response rate (ORR) and disease control rate (DCR) in neoadjuvant and metastatic settings. Overall survival (OS) and safety were also evaluated. Of the 43 patients with gastric (n=39) and GEJ (n=4) adenocarcinoma, efficacy evaluation was available in 35 (neoadjuvant, 17/18 patients; metastatic, 18/25 patients). In the neoadjuvant setting, an ORR of 58.82% and a DCR of 94.11% were observed, whereas in the metastatic setting, the ORR was 77.77% and the DCR was 83.33%. In the neoadjuvant setting, at a follow-up ranging from 0.7 to 41.2 months, the median OS was not reached. In the metastatic setting, the median OS was 31.9 months at a follow-up ranging from 0.2 to 50.3 months. At least one adverse event (AE) was reported in 24 patients. Anemia, lymphopenia and thrombocytopenia were the most common hematological AEs, while nausea, vomiting and weakness were the most common non-hematological AEs. NDLS based treatment was well-tolerated without any new safety concerns. Overall, NDLS-based chemotherapy was effective and well-tolerated in the management of gastric and GEJ adenocarcinoma.

A cohort study and meta-analysis of the evidence for consideration of Lauren subtype when prescribing adjuvant or palliative chemotherapy for gastric cancer

Background

The association between the survival or efficacy of chemotherapy and the Lauren subtype of gastric cancer (GC) remains unclear. We aimed to clarify whether patients with different Lauren subtypes have different survival after treatment with systemic chemotherapy: intestinal gastric cancer (IGC) patients survived better than patients with mixed type gastric cancer (MGC) or diffuse gastric cancer (DGC) after treatment with systemic chemotherapy.

Patients & methods

Relevant studies for the meta-analysis were identified through searching Pubmed, Embase, Cochrane and Ovid up to March 2020. We also included our own prospectively collected cohort of patients that were followed over a 10-year period. Sub-group and sensitivity analyses were also performed.

Results

In our prospective cohort, the overall survival (OS) of IGC patients receiving systemic chemotherapy (chemoIGC) [median OS 5.01 years, interquartile range (IQR) 2.63-6.71] was significantly higher than that of DGC patients receiving the same chemotherapy (chemoDGC) (median OS 1.33 years, IQR 0.78-3.33, p = 0.0001). After adjusting for age, gender and cancer stage, there was a significant difference in OS in patients treated with chemotherapy based on the Lauren classification of GC {hazard ratio (HR) for OS of the IGC versus DGC 0.33, [95% confidence interval (CI), 0.17-0.65; p < 0.001]}. In the IGC patients, the adjusted HR associated with chemotherapy was 0.26 (95% CI, 0.12-0.56; p = 0.001), whereas the association was 0.64 (95% CI, 0.30-1.33; p = 0.23) in the DGC patient group.In our meta-analysis, 33 studies comprising 10,246 patients treated with systemic chemotherapy (chemoIGC n = 4888, chemoDGC n = 5358) met all the selection criteria. While we accounted for much of the heterogeneity in these studies, we found that chemoIGC patients showed significantly improved OS [HR, 0.76 (95% CI, 0.71-0.82); p < 0.00001] when compared with similarly treated chemoDGC patients.

Conclusion

Our results support the consideration of Lauren subtype when prescribing systemic chemotherapy for GC, particularly for MGC or DGC, which may not benefit from chemotherapy. Lauren classification should be considered to stratify chemotherapy regimens to GC patients in future clinical trials, with particular relevance to MGC or DGC, which is more difficult to treat with current regimens.

Lymph node regression after neoadjuvant chemotherapy: A predictor of survival in gastric cancer

BACKGROUND AND OBJECTIVE

Neoadjuvant chemotherapy (nCMT) has been increasingly used in advanced gastric cancer (GC). However, the prognostic impact of tumor response remains unclear. This study aimed to evaluate if tumor response at the primary site and lymph nodes (LN) correlate with survival in GC patients after nCMT.

METHODS

Patients with gastric adenocarcinoma treated with nCMT followed by gastrectomy were evaluated. Residual tumor was graded from 0% to 100%, defining two groups: poor (PR) and major response (MR). LN regression rate (LNRR) was determined based on tumor/fibrosis examination at each LN and a cutoff value established by receiver operating characteristic curve.

RESULTS

Among 62 cases, 20 (32.2%) had MR and 42 (67.7%) PR. Smaller size, diffuse histology, lower ypT status and less advanced stage were associated with the MR group. Based on cutoff value of 57, 45.6% and 54.4% patients were classified as low-LNRR and high-LNRR. High-LNRR correlated with absence of venous, lymphatic and perineural invasion, and less advanced stage. Survival was equivalent between MR and PR (P = .956). High-LNRR had better disease-free survival (DFS) than low-LNRR (P < .001). In multivariate analysis, only LNRR associated with DFS.

CONCLUSION

High-LNRR associates with DFS in GC treated with nCMT. Response at the primary site does not correlate with survival.

Circular RNA circHIAT1 inhibits proliferation and epithelial-mesenchymal transition of gastric cancer cell lines through downregulation of miR-21

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide. Circular RNA circHIAT1 has been proved to play an antitumor role. We aimed to explore the function and mechanism of circHIAT1 in GC. MKN28 and MKN45 cells were transfected with PLCDH-circHIAT1, miR-21 mimic, and relative control. Cell viability and apoptosis were examined through Cell Counting Kit-8 and flow cytometry, respectively. CircHIAT1 expression and other relative factors were tested through quantitative reverse transcription-polymerase chain reaction and Western blot analysis, respectively. Our findings demonstrated that circHIAT1 was lowly expressed in GC tissues. After transfection with PLCDH-circHIAT1 in MKN28 and MKN45 cells, cell viability was decreased, while the expression levels of p53 and p21 were raised, as well as apoptosis. Besides this, the epithelial-mesenchymal transition process was inhibited by PLCDH-circHIAT1 transfection. Mechanistically, miR-21 expression was upregulated in GC tissues and could be negatively regulated by circHIAT1. Further experiments showed that the addition of miR-21 mimic reversed the growth inhibition effects of circHIAT1 overexpression. Moreover, circHIAT1 inhibited the activation of phosphatase and tensin homolog/phosphatidylinositol 3 kinase/protein kinase B and extracellular signal-regulated kinase signal pathways via downregulating miR-21. CircHIAT1 functioned as a tumor inhibitor in GC cells through downregulating miR-21, and could be a novel target for GC treatment.

Potential value of CT radiomics in the distinction of intestinal-type gastric adenocarcinomas

OBJECTIVE

The purpose of the study was to investigate the role of CT radiomics for the preoperative distinction of intestinal-type gastric adenocarcinomas.

MATERIALS AND METHODS

A total of 187 consecutive patients with preoperative contrast CT examination and pathologically proven gastric adenocarcinoma were retrospectively collected. Patients were divided into a training set (n = 150) and a test set (n = 37). Arterial phase (AP), portal phase (PP), and delay phase (DP) images were retrieved for analysis. A dedicated postprocessing software was used to segment the lesions and extract radiomics features. Random forest (RF) algorithm was applied to construct the classifier models. A nomogram was developed by incorporating multiphase radiomics scores. Receiver operating characteristic (ROC) curves were used to evaluate the performance of the radiomics model and nomogram in both sets.

RESULTS

The radiomics model showed a favorable capability in the distinction of intestinal-type gastric adenocarcinomas. The areas under curves (AUCs) of the AP, PP, and DP radiomics models were 0.754 (95% CI: 0.676, 0.820), 0.815 (95% CI: 0.744, 0.874), and 0.764 (95% CI: 0.688, 0.829) in the training set, respectively, which were confirmed in the test set with AUCs of 0.742 (95% CI: 0.572, 0.872), 0.775 (95% CI: 0.608, 0.895), and 0.857 (95% CI: 0.703, 0.950), respectively. The nomogram yielded excellent performance for distinguishing intestinal-type adenocarcinomas in both sets, with AUCs of 0.928 (95%: 0.875, 0.964) and 0.904 (95% CI: 0.761, 0.976).

CONCLUSIONS

The multiphase CT radiomics nomogram holds promise for the individual preoperative discrimination of intestinal-type gastric adenocarcinoma.

KEY POINTS

• CT radiomics has a potential role in the distinction of intestinal-type gastric adenocarcinomas. • Single-phase enhanced CT-based radiomics showed favorable capability in distinguishing intestinal-type tumors. • The nomogram which incorporates the multiphase radiomics scores could facilitate the individual prediction of intestinal-type lesions.

Conversion Surgery for Stage IV Gastric Cancer

The prognosis of stage IV gastric cancer (GC) is poor, with palliative chemotherapy remaining the main therapeutic option. Studies increasingly indicate that patients with unresectable stage IV GC, who undergo gastrectomy with radical intention after responding to several regimens of combined chemotherapy, can achieve good survival outcomes. Thus, surgery aiming at radical resection for unresectable stage IV GC after combined chemotherapy has received increasing attention in recent years. This novel therapeutic strategy was defined as conversion surgery in patients with unresectable stage IV GC and it can associate with significant improved survival when R0 resection can be achieved. Despite the recent advances in conversion surgery for patients with unresectable stage IV GC, selection criteria for combination chemotherapy regimens, indications for conversion surgery, optimal timing to surgery, and postoperative chemotherapy all remain controversial. This article reviews the current state of conversion surgery for unresectable stage IV GC.

miR-107 regulates growth and metastasis of gastric cancer cells via activation of the PI3K-AKT signaling pathway by down-regulating FAT4

PURPOSE

To investigate the effect of miR-107 on the growth and metastasis of gastric cancer (GC) and elucidate the probable mechanisms.

METHODS

The expression of miR-107 and FAT4 in GC tissues and cells were detected using qRT-PCR. Bioinformatics and dual luciferase reporter gene assays were used to analyze the relationship between miR-107 and FAT4. miR-NC, miR-107 inhibitor, pcDNA3.1-FAT4 and siRNA-FAT4 were transfected into AGS and MKN-45 GC cell lines, respectively. The proliferation and migration abilities of GC cells after transfection were evaluated using the MTT assay, scratch test and transwell assay. The expression of epithelial-mesenchymal transition (EMT) markers: E-cadherin, N-cadherin, vimentin and related proteins of the PI3K/AKT signaling pathway were determined using western blot. The xenograft tumors of nude mice were observed to assess the tumorigenicity of GC cells in vivo.

RESULTS

MiR-107 was up-regulated, while FAT4 was down-regulated in GC tissues and cells (P < 0.05); FAT4 was targeted and negatively regulated by miR-107. Down-regulating miR-107 or up-regulating FAT4 inhibited the GC cells proliferation, migration, invasion and tumorigenicity, and could also reduce the expression of N-cadherin, vimentin, p-PI3K and p-Akt expression and up-regulate E-cadherin.

CONCLUSIONS

miR-107 promotes growth and metastasis in GC via activation of PI3K-AKT signaling by targeting FAT4, which may be a target for GC treatment.