Gastric Cancer Maximum Tumour Diameter Reduction Rate at CT Examination as a Radiological Index for Predicting Histopathological Regression after Neoadjuvant Treatment: A Multicentre GIRCG Study

International consensus on the management of metastatic gastric cancer: step by step in the foggy landscape : Bertinoro Workshop, November 2022

BACKGROUND

Many gastric cancer patients in Western countries are diagnosed as metastatic with a median overall survival of less than twelve months using standard chemotherapy. Innovative treatments, like targeted therapy or immunotherapy, have recently proved to ameliorate prognosis, but a general agreement on managing oligometastatic disease has yet to be achieved. An international multi-disciplinary workshop was held in Bertinoro, Italy, in November 2022 to verify whether achieving a consensus on at least some topics was possible.

METHODS

A two-round Delphi process was carried out, where participants were asked to answer 32 multiple-choice questions about CT, laparoscopic staging and biomarkers, systemic treatment for different localization, role and indication of palliative care. Consensus was established with at least a 67% agreement.

RESULTS

The assembly agreed to define oligometastases as a "dynamic" disease which either regresses or remains stable in response to systemic treatment. In addition, the definition of oligometastases was restricted to the following sites: para-aortic nodal stations, liver, lung, and peritoneum, excluding bones. In detail, the following conditions should be considered as oligometastases: involvement of para-aortic stations, in particular 16a2 or 16b1; up to three technically resectable liver metastases; three unilateral or two bilateral lung metastases; peritoneal carcinomatosis with PCI ≤ 6. No consensus was achieved on how to classify positive cytology, which was considered as oligometastatic by 55% of participants only if converted to negative after chemotherapy.

CONCLUSION

As assessed at the time of diagnosis, surgical treatment of oligometastases should aim at R0 curativity on the entire disease volume, including both the primary tumor and its metastases. Conversion surgery was defined as surgery on the residual volume of disease, which was initially not resectable for technical and/or oncological reasons but nevertheless responded to first-line treatment.

Imaging advances in efficacy assessment of gastric cancer neoadjuvant chemotherapy

Effective neoadjuvant chemotherapy (NAC) can improve the survival of patients with locally progressive gastric cancer, but chemotherapeutics do not always exhibit good efficacy in all patients. Therefore, accurate preoperative evaluation of the effect of neoadjuvant therapy and the appropriate selection of surgery time to minimize toxicity and complications while prolonging patient survival are key issues that need to be addressed. This paper reviews the role of three imaging methods, morphological, functional, radiomics, and artificial intelligence (AI)-based imaging, in evaluating NAC pathological reactions for gastric cancer. In addition, the advantages and disadvantages of each method and the future application prospects are discussed.

The role of computed tomography features in assessing response to neoadjuvant chemotherapy in locally advanced gastric cancer

OBJECTIVE

To compare the computed tomography (CT) images of patients with locally advanced gastric cancer (GC) before and after neoadjuvant chemotherapy (NAC) in order to identify CT features that could predict pathological response to NAC.

METHODS

We included patients with locally advanced GC who underwent gastrectomy after NAC from September 2016 to September 2021. We retrieved and collected the patients' clinicopathological characteristics and CT images before and after NAC. We analyzed CT features that could differentiate responders from non-responders and established a logistic regression equation based on these features.

RESULTS

We included 97 patients (69 [71.1%] men; median [range] age, 60 [26-75] years) in this study, including 66 (68.0%) responders and 31 (32.0%) non-responders. No clinicopathological variable prior to treatment was significantly associated with pathological response. Out of 16 features, three features (ratio of tumor thickness reduction, ratio of reduction of primary tumor attenuation in arterial phase, and ratio of reduction of largest lymph node attenuation in venous phase) on logistic regression analysis were used to establish a regression equation that demonstrated good discrimination performance in predicting pathological response (area under receiver operating characteristic curve 0.955; 95% CI, 0.911-0.998).

CONCLUSION

Logistic regression equation based on three CT features can help predict the pathological response of patients with locally advanced GC to NAC.

Association between Pre-Treatment Biological Indicators and Compliance to Neoadjuvant/Perioperative Chemotherapy in Operable Gastric Cancer

BACKGROUND AND AIMS

Perioperative treatment is currently the gold standard approach in Europe for locally advanced gastric cancer (GC). Unfortunately, the phenomenon of patients dropping out of treatment has been frequently observed. The primary aims of this study were to verify if routine blood parameters, inflammatory response markers, sarcopenia, and the depletion of adipose tissues were associated with compliance to neoadjuvant/perioperative chemotherapy.

METHODS AND STUDY DESIGN

Blood samples were considered before the first and second cycles of chemotherapy. Sarcopenia and adipose indices were calculated with a CT scan before starting chemotherapy and before surgery. Odds ratios (OR) from univariable and multivariable models were calculated with a 95% confidence interval (95% CI).

RESULTS

A total of 84 patients with locally advanced GC were identified between September 2010 and January 2021. Forty-four patients (52.4%) did not complete the treatment according to the number of cycles planned/performed. Eight patients (9.5%) decided to suspend chemotherapy, seven patients (8.3%) discontinued because of clinical decisions, fourteen patients (16.7%) discontinued because of toxicity and fifteen patients (17.9%) discontinued for miscellaneous causes. Seventy-nine (94%) out of eighty-four patients underwent gastrectomy, with four patients having surgical complications, which led to a suspension of treatment. Sarcopenia was present in 38 patients (50.7%) before chemotherapy began, while it was present in 47 patients (60%) at the CT scan before the gastrectomy. At the univariable analysis, patients with basal platelet to lymphocyte ratio (PLR) ≥ 152 (p = 0.017) and a second value of PLR ≥ 131 (p = 0.007) were more frequently associated with an interruption of chemotherapy. Patients with increased PLR (p = 0.034) compared to the cut-off were associated with an interruption of chemotherapy, while patients with increased monocytes between the first and second cycles were associated with a lower risk of treatment interruption (p = 0.006); patients who underwent 5-fluorouracil plus cisplatin or oxaliplatin had a higher risk of interruption (p = 0.016) compared to patients who underwent a 5-fluorouracil plus leucovorin, oxaliplatin and docetaxel (FLOT) regimen. The multivariable analysis showed a higher risk of interruption for patients who had higher values of PLR compared to the identified cut-off both at pretreatment and second-cycle evaluation (OR: 5.03; 95% CI: 1.34-18.89; p = 0.017) as well as for patients who had a lower PLR than the identified cut-off at pretreatment evaluation and had a higher PLR value than the cut-off at the second cycle (OR: 4.64; 95% CI: 1.02-21.02; p = 0.047). Becker regression was neither affected by a decrease of sarcopenia ≥ 5% (p = 0.867) nor by incomplete compliance with chemotherapy (p = 0.281).

CONCLUSIONS

Changes in PLR values which tend to increase more than the cut-off seem to be an immediate indicator of incomplete compliance with neoadjuvant/perioperative treatment. Fat loss and sarcopenia do not appear to be related to compliance. More information is needed to reduce the causes of interruption.

Response Evaluation after Neoadjuvant Chemotherapy for Resectable Gastric Cancer

BACKGROUND

The method of response evaluation following neoadjuvant chemotherapy (NAC) in resectable gastric cancer has been widely debated. An essential prerequisite is the ability to stratify patients into subsets of different long-term survival rates based on the response mode. Histopathological measures of regression have their limitations, and interest resides in CT-based methods that can be used in everyday settings.

METHODS

We conducted a population-based study (2007-2016) on 171 consecutive patients with gastric adenocarcinoma who were receiving NAC. Two methods of response evaluation were investigated: a strict radiological procedure using RECIST (downsizing), and a composite radiological/pathological procedure comparing the initial radiological TNM stage to the pathological ypTNM stage (downstaging). Clinicopathological variables that could predict the response were searched for, and correlations between the response mode and long-term survival rates were assessed.

RESULTS

RECIST failed to identify half of the patients progressing to metastatic disease, and it was unable to assign patients to subsets with different long-term survival rates based on the response mode. However, the TNM stage response mode did achieve this objective. Following re-staging, 48% (78/164) were downstaged, 15% (25/164) had an unchanged stage, and 37% (61/164) were upstaged. A total of 9% (15/164) showed a histopathological complete response. The 5-year overall survival rate was 65.3% (95% CI 54.7-75.9%) for TNM downstaged cases, 40.0% (95% CI 20.8-59.2%) for stable disease, and 14.8% (95% CI 6.0-23.6%) for patients with TNM progression, p < 0.001. In a multivariable ordinal regression model, the Lauren classification and tumor site were the only significant determinants of the response mode.

CONCLUSIONS

Downsizing, as a method for evaluating the response to NAC in gastric cancer, is discouraged. TNM re-staging by comparing the baseline radiological CT stage to the pathological stage following NAC is suggested as a useful method that may be used in everyday situations.

Some Concerns from a Radiological Point of View. Comment on Huang et al. Outcomes of Conversion Surgery for Metastatic Gastric Cancer Compared with In-Front Surgery Plus Palliative Chemotherapy or In-Front Surgery Alone. J. Pers. Med. 2022, 12, 555

We read, with great interest, the article by Huang Ruo-Yi and colleagues entitled “Outcomes of Conversion Surgery for Metastatic Gastric Cancer Compared with In-Front Surgery Plus Palliative Chemotherapy or In-Front Surgery Alone”, published on 1 April 2022 [...]

Structured and shared CT radiological report of gastric cancer: a consensus proposal by the Italian Research Group for Gastric Cancer (GIRCG) and the Italian Society of Medical and Interventional Radiology (SIRM)

OBJECTIVES

Written radiological report remains the most important means of communication between radiologist and referring medical/surgical doctor, even though CT reports are frequently just descriptive, unclear, and unstructured. The Italian Society of Medical and Interventional Radiology (SIRM) and the Italian Research Group for Gastric Cancer (GIRCG) promoted a critical shared discussion between 10 skilled radiologists and 10 surgical oncologists, by means of multi-round consensus-building Delphi survey, to develop a structured reporting template for CT of GC patients.

METHODS

Twenty-four items were organized according to the broad categories of a structured report as suggested by the European Society of Radiology (clinical referral, technique, findings, conclusion, and advice) and grouped into three "CT report sections" depending on the diagnostic phase of the radiological assessment for the oncologic patient (staging, restaging, and follow-up).

RESULTS

In the final round, 23 out of 24 items obtained agreement ( ≥ 8) and consensus ( ≤ 2) and 19 out 24 items obtained a good stability (p > 0.05).

CONCLUSIONS

The structured report obtained, shared by surgical and medical oncologists and radiologists, allows an appropriate, clearer, and focused CT report essential to high-quality patient care in GC, avoiding the exclusion of key radiological information useful for multidisciplinary decision-making.

KEY POINTS

• Imaging represents the cornerstone for tailored treatment in GC patients. • CT-structured radiology report in GC patients is useful for multidisciplinary decision making.

Down-staging depth score could be a survival predictor for locally advanced gastric cancer patients after preoperative chemoradiotherapy

Objective

The predictive effect of preoperative chemoradiotherapy (CRT) is low and difficult in guiding individualized treatment. We examined a surrogate endpoint for long-term outcomes in locally advanced gastric cancer patients after preoperative CRT.

Methods

From April 2012 to April 2019, 95 patients with locally advanced gastric cancer who received preoperative concurrent CRT and who were enrolled in three prospective studies were included. All patients were stage T_3/4N₊. Local control, distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) were evaluated. Clinicopathological factors related to long-term prognosis were analyzed using univariate and multivariate analyses. The down-staging depth score (DDS), which is a novel method of evaluating CRT response, was used to predict long-term outcomes.

Results

The median follow-up period for survivors was 30 months. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve predicted by the DDS was 0.728, which was better than the pathological complete response (pCR), histological response and ypN0. Decision curve analysis further affirmed that DDS had the largest net benefit. The DDS cut-off value was 4. pCR and ypN0 were associated with OS (P=0.026 and 0.049). Surgery and DDS are correlated with DMFS, DFS and OS (surgery: P=0.001, <0.001 and <0.001, respectively; and DDS: P=0.009, 0.013 and 0.032, respectively). Multivariate analysis showed that DDS was an independent prognostic factor of DFS (P=0.021).

Conclusions

DDS is a simple, short-term indicator that was a better surrogate endpoint than pCR, histological response and ypN0 for DFS.

The value of restaging CT following neoadjuvant chemotherapy for resectable gastric cancer. A population-based study

Background

Response evaluation following neoadjuvant chemotherapy (NAC) in gastric cancer is debated. The aim of this study was to investigate the value of UICC-downstaging as mode of response evaluation following a MAGIC-style regimen of NAC.

Methods

Retrospective, population-based study on consecutive patients with resectable gastric adenocarcinoma receiving NAC from 2007 to 2016. CT-scan was obtained at diagnosis (rTNM) and repeated following NAC (yrTNM) to evaluate response in terms of downstaging. Further, yrTNM stage was crosstabulated to pathologic stage (ypTNM) to depict correlation between radiologic and pathologic assessment.

Results

Of 171 patients receiving NAC, 169 were available for response evaluation. For TNM-stages, 43% responded, 50% had stable disease and 7% progressed at CT. Crosstabulating yrTNM stage to ypTNM stage, 24% had concordant stages, with CT overstaging 38% and understaging 38% of the tumours, Cohen kappa ƙ = 0,06 (95%CI 0.004–0.12). Similar patterns of discordance were found for T-stages and N-stages separately. For M-category, restaging CT detected 12 patients with carcinomatosis, with an additional 14 diagnosed with carcinomatosis only at operation. No patient developed parenchymal or extra abdominal metastases, and none developed locally non-resectable tumour during delivery of NAC. Restaging CT with response evaluation was not able to stratify patients into groups of different long-term survival rates based on response mode.

Conclusions

Routine CT-scan following NAC is of limited value. Accuracy of CT staging compared to final pathologic stage is poor, and radiologic downstaging as measure of response evaluation is unreliable and unable to discriminate long-term survival rates based on response mode.

Delta-radiomics and response to neoadjuvant treatment in locally advanced gastric cancer-a multicenter study of GIRCG (Italian Research Group for Gastric Cancer)

Background

To predict response to neoadjuvant chemotherapy (NAC) of gastric cancer (GC), prior to surgery, would be pivotal to customize patient treatment. The aim of this study is to investigate the reliability of computed tomography (CT) texture analysis (TA) in predicting the histo-pathological response to NAC in patients with resectable locally advanced gastric cancer (AGC).

Methods

Seventy (40 male, mean age 63.3 years) patients with resectable locally AGC, treated with NAC and radical surgery, were included in this retrospective study from 5 centers of the Italian Research Group for Gastric Cancer (GIRCG). Population was divided into two groups: 29 patients from one center (internal cohort for model development and internal validation) and 41 from other four centers (external cohort for independent external validation). Gross tumor volume (GTV) was segmented on each pre- and post-NAC multidetector CT (MDCT) image by using a dedicated software (RayStation), and 14 TA parameters were then extrapolated. Correlation between TA parameters and complete pathological response (tumor regression grade, TRG1), was initially investigated for the internal cohort. The univariate significant variables were tested on the external cohort and multivariate logistic analysis was performed.

Results

In multivariate logistic regression the only significant TA variable was delta gray-level co-occurrence matrix (GLCM) contrast (P=0.001, Nagelkerke R²: 0.546 for the internal cohort and P=0.014, Nagelkerke R²: 0.435 for the external cohort). Receiver operating characteristic (ROC) curves, generated from the logistic regression of all the patients, showed an area under the curve (AUC) of 0.763.

Conclusions

Post-NAC GLCM contrast and dissimilarity and delta GLCM contrast TA parameters seem to be reliable for identifying patients with locally AGC responder to NAC.

A preoperative risk prediction model for high malignancy potential gastrointestinal stromal tumors of the stomach

BACKGROUND

Gastric gastrointestinal stromal tumors (GISTs) exhibit various degrees of aggression and malignant potential. However, no systematic preoperative evaluation strategy to predict the malignancy potential of gastric GISTs has yet been developed. This study aimed to develop a reliable and easy-to-use preoperative risk-scoring model for predicting high malignancy potential (HMP) gastric GISTs.

METHODS

The data of 542 patients with pathologically confirmed gastric GISTs who underwent resection were reviewed. Multivariate logistic regression analysis was used to identify significant predictors of HMP. The risk-scoring system (RSS) was based on the predictive factors for HMP, and its performance was validated using a split-sample approach.

RESULTS

A total of 239 of 542 (44.1%) surgically resected gastric GISTs had HMP. Multivariate analysis demonstrated that tumor size, location, and surface changes were independent risk factors for HMP. Based on the accordant regression coefficients, the presence of surface ulceration was assigned 1 point. Tumor sizes of 4-6 cm and > 6 cm were assigned 2 and 5 points, respectively. Two points were assigned to cardia or fundus locations. A score of 3 points was the optimal cut-off value for HMP prediction. HMP were found in 19.8% and 82.7% of the low and high-risk groups of the RSS, respectively. The area under the receiver-operating characteristic curve for predicting HMP was 0.81 (95% confidence interval (CI) 0.75-0.86). Discrimination was good after validation (0.75, 95% CI 0.69-0.81).

CONCLUSION

This simple RSS could be useful for predicting the malignancy potential of gastric GISTs and may aid preoperative clinical decision making to ensure optimal treatment.

Gastrointestinal Applications of Iodine Quantification Using Dual-Energy CT: A Systematic Review

Dual-energy computed tomography (DECT) can estimate tissue vascularity and perfusion via iodine quantification. The aim of this systematic review was to outline current and emerging clinical applications of iodine quantification within the gastrointestinal tract using DECT. The search was conducted with three databases: EMBASE, Pubmed and The Cochrane Library. This identified 449 studies after duplicate removal. From a total of 570 selected studies, 30 studies were enrolled for the systematic review. The studies were categorized into four main topics: gastric tumors (12 studies), colorectal tumors (8 studies), Crohn’s disease (4 studies) and miscellaneous applications (6 studies). Findings included a significant difference in iodine concentration (IC) measurements in perigastric fat between T1–3 vs. T4 stage gastric cancer, poorly and well differentiated gastric and colorectal cancer, responders vs. non-responders following chemo- or chemoradiotherapy treatment among cancer patients, and a positive correlation between IC and Crohn’s disease activity. In conclusion, iodine quantification with DECT may be used preoperatively in cancer imaging as well as for monitoring treatment response. Future studies are warranted to evaluate the capabilities and limitations of DECT in splanchnic flow.

Gastrointestinal stromal tumors (GIST): a proposal of a "CT-based predictive model of Miettinen index" in predicting the risk of malignancy

PURPOSE

To identify the predictors of malignancy on CT for the evaluation of gastrointestinal stromal tumors (GIST) by correlating CT findings with the mitotic index in order to propose a "CT-based predictive model of Miettinen index."

METHODS

One radiologist and one resident in radiology with 14- and 4-year experience in oncological field reviewed the CT findings of 42 patients by consensus, with respect to lesion site, size, contour, tumor growth pattern, enhancing pattern, degree of enhancement of tumor, percentage of tumor necrosis, mesenteric fat infiltration, ulceration, calcification, regional lymphadenopathy, direct invasion to adjacent organs, and distant metastasis. All parameters were correlated with the mitotic index evaluated at histopathological analysis following surgery. Normality of variables was evaluated using Shapiro-Wilk test. Pearson's correlation test was used to assess the interaction between variables. The diagnostic accuracy percentage of tumor necrosis was measured by receiver operating characteristic (ROC) analysis for detecting whether the number of mitosis per 50 high-power fields was > 5.

RESULTS

A significant statistical correlation was found between percentage of tumor necrosis and the mitotic index (p < 0.005), dimension, and location of the tumor.

CONCLUSION

CT could be an accurate technique in the prediction of malignancy of GIST in a CT risk assessment system, based on the location of the tumor, its size, and the percentage of tumor necrosis.

STAMBPL1 knockdown has antitumour effects on gastric cancer biological activities

The present study aimed to investigate the effects and mechanisms of STAM binding protein-like 1 (STAMBPL1) knockdown in the suppression of gastric cancer activities. Pathological data and STAMBPL1 protein expression were analysed in 36 patients with gastric cancer, including 24 stage I-II and 12 stage III-IV patients, by haematoxylin and eosin staining and immunohistochemistry. In vitro cell experiments were performed to measure AGS cell proliferation, apoptosis, invasion and migration by MTT, Celigo cell count, flow cytometry, Transwell and wound healing assays following STAMBPL1 knockdown. The relative protein expression levels were evaluated by western blotting. When compared with the adjacent normal tissues, STAMBPL1 protein expression in the gastric cancer tissues with increasing stages was significantly upregulated (P<0.01 or P<0.001). STAMBPL1 gene expression was not identified to be significantly different between AGS and MGC80-3 gastric cancer cells (P>0.05). Following STAMBPL1 knockdown by short hairpin RNA (sh)STAMBPL1, cell proliferation was significantly suppressed, the cell apoptosis rate was significantly upregulated, and the numbers of invasive AGS cells and the AGS wound healing rate were significantly decreased (P<0.01 and P<0.001, respectively), compared with those in the shControl group. Additionally, STAMBPL1 and NF-κB protein expression levels were significantly downregulated in the shSTAMBPL1 group (P<0.001, respectively). STAMBPL1 may be oncogenic in gastric cancer, and STAMBPL1 knockdown may suppress gastric cancer development.

Update in diagnostic imaging of the thymus and anterior mediastinal masses

Anterior mediastinal masses include a wide spectrum of malignant and benign pathologies with a large percentage represented by thymic lesions. Distinguishing these masses on diagnostic imaging is fundamental to guide the proper management for each patient. This review illustrates possibilities and limits of different imaging modalities to diagnose a lesion of the anterior mediastinum with particular attention to thymic disease.

Clinical significance of expression of CBX2 in gastric cancer

BACKGROUND

The incidence of gastric cancer (GC) is high in recent years and it is very urgent to explore new targets for the diagnosis and treatment of GC.

AIM

To investigate the expression and clinical significance of chromobox homolog 2 (CBX2) in GC cells and tissues.

METHODS

The expression levels of CBX2 mRNA and protein in GC cells, normal gastric mucosal epithelial cells, GC tissues, and their adjacent normal tissues were detected by real-time fluorescent quantitative PCR and Western blot, respectively. The expression of CBX2 in 66 cases of GC and matched paracancerous tissues was detected by immunohistochemistry. The relationship between the expression of CBX2 and the clinicopathological features and prognosis of GC patients was analyzed.

RESULTS

The expression of CBX2 mRNA in GC cells was higher than that in normal gastric mucosal epithelial cells (P < 0.05). The expression of CBX2 mRNA and protein in GC tissues was higher than that in adjacent tissues (P < 0.05). The positive expression rate of CBX2 in GC tissues was 40.9% (27/66), and it was 12.1% (8/66) in normal tissues adjacent to cancer. CBX2 was positively expressed in GC tissues. The expression rate was higher than that of adjacent tissues (P < 0.05). The expression of CBX2 protein was correlated with tumor metastasis (P < 0.05).

CONCLUSION

CBX2 is overexpressed in GC cells and tissues, and it has a certain degree of connection with the prognosis and outcome of patients with GC.

T and N Staging of Gastric Cancer Using Dual-Source Computed Tomography

Aim

This study is aimed at comparing gastric cancer T and N staging between virtual monochromatic energy images and fusion images generated by dual-source computed tomography (DSCT) dual-energy mode data acquisition prospectively while measuring the iodine concentration of gastric cancer and lymph nodes at different T and N stages from iodine map retrospectively.

Methods

A total of 71 patients (50 males and 21 females; mean age: 59 ± 11 years) confirmed with gastric cancer by endoscopic biopsy with no neoadjuvant chemotherapy were enrolled for the CT examination before surgeries. The preoperative T and N staging results were compared between groups with pathological results as the gold standard. The iodine concentrations of the gastric lesions and LNs were measured on the iodine-based material decomposition images. All iodine concentration values were normalized against those in the abdominal aorta and defined as normalized iodine concentration (nIC) values. The short axis length of LNs and nIC values were statistically analyzed.

Results

Group A was better than group B for T3 and T4 staging. No statistically significant difference in the overall accuracies for N staging was found between groups. For the late arterial and delayed phases, T3 and T4 nIC values of the extraserosal adipose tissue showed statistically significant differences. The nIC values between N0 and Nm (N1-N3) showed statistically significant differences in the portal phase only.

Conclusions

T3 and T4 nIC values of the extraserosal adipose tissue showed statistically significant differences. Hence, dual-source CT may be helpful in the differential diagnosis between T3 and T4.