Transcriptomic Profile of Lymphovascular Invasion, a Known Risk Factor of Pancreatic Ductal Adenocarcinoma Metastasis

Extranodal extension influences prognosis in pancreatic body/tail cancer: A retrospective cohort study

BACKGROUND/PURPOSE

Extranodal extension (ENE) is an established prognostic factor in various malignancies, affecting survival in pancreatic head cancer (PHC). However, its significance in pancreatic body/tail cancer (PBTC) remains unclear. Therefore, we aimed to investigate the impact of ENE on PTBC prognosis.

METHODS

We analyzed data collected from electronic medical records of patients with PBTC who underwent distal pancreatectomy at a single center between January 2011 and December 2015. The patients were categorized based on ENE presence and prognostic implications were evaluated using Kaplan-Meier survival curves and Cox proportional hazards model.

RESULTS

PBTC cases involving lymph node (LN) metastasis and ENE exhibited significantly lower disease-free (DFS) and overall survival (OS) rates compared to cases without LN metastasis or ENE (median DFS; N0, 23 months; LN+/ENE-, 10 months; LN+/ENE+, 5 months; p < .001). No statistically significant difference was observed in DFS and OS rates between patients with N1/N2 in the group without ENE and those with ENE+. Multivariate analysis confirmed ENE as a significant adverse prognostic factor.

CONCLUSIONS

ENE significantly predicts poor prognosis in PBTC, particularly in cases with nodal metastasis. The current cancer staging system for PBTC should incorporate ENE status. Moreover, different staging systems should be considered for PHC and PBTC.

Nuclear medicine radiomics in digestive system tumors: Concept, applications, challenges, and future perspectives

Radiomics aims to develop novel biomarkers and provide relevant deeper subvisual information about pathology, immunophenotype, and tumor microenvironment. It uses automated or semiautomated quantitative analysis of high-dimensional images to improve characterization, diagnosis, and prognosis. Recent years have seen a rapid increase in radiomics applications in nuclear medicine, leading to some promising research results in digestive system oncology, which have been driven by big data analysis and the development of artificial intelligence. Although radiomics advances one step further toward the non-invasive precision medical analysis, it is still a step away from clinical application and faces many challenges. This review article summarizes the available literature on digestive system tumors regarding radiomics in nuclear medicine. First, we describe the workflow and steps involved in radiomics analysis. Subsequently, we discuss the progress in clinical application regarding the utilization of radiomics for distinguishing between various diseases and evaluating their prognosis, and demonstrate how radiomics advances this field. Finally, we offer our viewpoint on how the field can progress by addressing the challenges facing clinical implementation.

Radiographic duodenal invasion is associated with poor prognosis and early recurrence in patients with pancreatic ductal adenocarcinoma

BACKGROUND

The prognostic impact of radiographic duodenal invasion (rDI) of pancreatic ductal adenocarcinoma (PDAC) has yet to be fully elucidated. This retrospective study aimed to investigate the prognostic and clinicopathological significance of rDI in patients with PDAC after pancreatoduodenectomy (PD).

MATERIALS AND METHODS

We retrospectively analyzed 223 consecutive patients with resectable (R) and borderline resectable (BR)-PDAC that underwent up-front PD between 2002 and 2018. rDI was assessed by preoperative multi-detector row computed tomography.

RESULTS

Ninety-three (42%) patients with PDAC had rDI, and all of them had pathological DI (pDI). The rDI(+) group had larger tumor size, BR-PDAC was more common, there was higher serum CA19-9 level, and microscopic lymphovascular invasion was more common than in the rDI(-) group. rDI was associated with significant reduction in overall survival (OS) (P < 0.001) and recurrence-free survival (RFS) (P < 0.001). In multivariate analysis, rDI was an independent prognostic factor in OS [hazard ratio (HR) = 0.52; 95% confidence interval (CI) 0.38-0.73, P < 0.001] and RFS [HR = 0.56; 95% CI 0.40-0.78, P = 0.001]. rDI was also an independent risk factor for early recurrence within 12 months [odds ratio (OR) = 0.36; 95% CI 0.18-0.73, P = 0.005]. rDI had positive correlation with liver recurrence (P = 0.024).

CONCLUSION

Biological aggressiveness of PDAC with rDI implies short OS and early recurrence with frequent liver metastasis. Aggressive perioperative chemotherapy is recommended to improve prognosis, especially for R-PDAC patients with rDI.

High Mesothelin expression in pancreatic adenocarcinoma is associated with aggressive tumor features but not prognosis

Mesothelin is a cell surface marker expressed on most pancreatic cancers and has been associated with aggressive biology. Despite its popularity as a drug target, clinical relevance of Mesothelin expression in pancreatic cancer is unclear. We set out to define transcriptomic signatures associated with high Mesothelin expression and identify its role in tumor biology and its clinical relevance. We analyzed pancreatic adenocarcinomas in the cancer genome atlas (TCGA), (n = 145) and the results were validated using GSE62452 cohort (n = 69). We divided the cohorts into high and low Mesothelin expression by the median. High Mesothelin was not associated with progression-free, disease-free, disease specific, nor overall survival in TCGA cohort. Despite this, high Mesothelin expression was associated with high Ki67 expression and enriched all five cell proliferation-related Hallmark gene sets, but not with previously investigated pathways: TNF-alpha, PI3K, nor angiogenesis. Mesothelin expression did not correlate with MUC16 expression. The high Mesothelin pancreatic cancers demonstrated higher homologous recombination deficiency, fraction altered, and silent and non-silent mutation rates (all P < 0.001) that indicate aggressive cancer biology. However, lymphocyte infiltration score, TIL regional fraction, TCR richness, infiltration of CD8 T-cells, and cytolytic activity were all significantly lower in Mesothelin high tumors (all P < 0.015). Finally, we found that Mesothelin expression significantly correlated with sensitivity to cytotoxic chemotherapy in pancreatic cancer cell lines. In conclusion, high Mesothelin expression is associated with enhanced proliferation, depressed immune response, and sensitivity to cytotoxic chemotherapy, which may explain there was no difference in survival in pancreatic cancer patients.

Pancreatic ductal adenocarcinoma with a high expression of alcohol dehydrogenase 1B is associated with less aggressive features and a favorable prognosis

Alcohol dehydrogenase (ADH) oxidizes alcohol into acetaldehyde (AA), which is a known carcinogen. Aldehyde dehydrogenase (ALDH) oxidizes AA into acetate. Therefore, pancreatic cancer that expresses a high level of ADH1B that generates more AA is expected to be associated with aggressive cancer. On the other hand, given that the differentiated cells that retain their cellular functions typically exhibit lower proliferation rates, it remains unclear whether pancreatic adenocarcinoma (PDAC) with high ADH1B gene expression is linked to aggressive features in patients. The Cancer Genome Atlas (n = 145) was used to obtain data of PDAC patients and GSE62452 cohort (n = 69) was used as a validation cohort. PDAC with high ADH1B expression was associated with less cancer cell proliferation as evidenced by lower MKI67 expression and lower histological grade; with a higher fraction of stromal cells consistent with less proliferative cancer. PDAC with high ADH1B expression also had lower homologous recombination deficiency and mutation rates, lower KRAS and TP53 mutation rates. ADH1B expression correlated with ALDH2 expression in PDAC, but not with DNA repair genes. High ADH1B expression PDAC was associated with high infiltration of anti-cancerous CD8+ T cells and pro-cancerous M2 macrophages but with lower levels of Th1 T cells, with a higher cytolytic activity. PDAC patients with a high ADH1B expression had better disease-specific survival (DSS) and overall survival (OS) and ADH1B was an independent prognostic biomarker for both DSS (HR = 0.89, 95% CI = 0.80-0.99, P = 0.045) and OS (HR = 0.90, 95% CI = 0.82-0.99, P = 0.044) in multivariate analysis. In conclusion, PDAC with high ADH1B expression had less cell proliferation and malignant features, along with higher immune cell infiltration, and had a better prognosis.

Immunohistochemical analysis of a panel of cancer stem cell markers and potential therapeutic markers in pancreatic ductal adenocarcinoma

PURPOSE

Pancreatic Ductal Adenocarcinoma (PDAC) is the most common type of pancreatic malignancies. It is known for its aggressive nature and high mortality rate. This calls for an urgent need of new prognostic and therapeutic markers that can be targeted for personalized treatment of the patient.

METHODS

Among 142 patients diagnosed with pancreatic cancers at Aga Khan University Hospital, a total of 62 patients were selected based on their confirmed diagnosis of PDAC. Immunohistochemistry was performed on Formalin-Fixed Paraffin-Embedded (FFPE) sections using selected antibodies (CD44, CD133, L1CAM, HER2, PD-L1, EGFR, COX2 and cyclin D1). All the slides were scored independently by two pathologists as per the set criteria.

RESULTS

Expression of all cancer stem cell markers was found to be significantly associated with one or more potential therapeutic markers. CD44 expression was significantly associated with HER2 (p = 0.032), COX2 (p = 0.005) and EGFR expression (p = 0.008). CD133 expression also showed significant association with HER2 (p = 0.036), COX2 (p = 0.004) and EGFR expression (p = 0.018). L1CAM expression was found to be associated with expression of COX2 (p = 0.017). None of the proteins markers showed association with overall survival of the patient. On the other hand, among the clinicopathological characteristics, histological differentiation (p = 0.047), lymphovascular invasion (p = 0.021) and perineural invasion (p = 0.014) were found to be significantly associated with patient's overall survival.

CONCLUSION

Internationally, this is the first report that assesses the selected panel of cancer stem cell markers and potential therapeutic targets in a single study and evaluates its combined expression. The study clearly demonstrates association between expression of cancer stem cell markers and therapeutic targets hence paves a way for precision medicine for pancreatic cancer patients.

Tumor microenvironment interactions with cancer stem cells in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer in the United States. Additionally, the low survival rate makes PDAC the third-leading cause of cancer-related mortality in the United States, and it is projected that by 2030, it will become the second-leading cause of cancer mortality. Several biological factors contribute to PDAC aggressiveness, and their understanding will narrow the gap from biology to clinical care of PDAC, leading to earlier diagnoses and the development of better treatment options. In this review, we describe the origins of PDAC highlighting the role of cancer stem cells (CSC). CSC, also known as tumor initiating cells, which exhibit a unique metabolism that allows them to maintain a highly plastic, quiescent, immune- and therapy-evasive state. However, CSCs can exit quiescence during proliferation and differentiation, with the capacity to form tumors while constituting a small population in tumor tissues. Tumorigenesis depends on the interactions between CSCs and other cellular and non-cellular components in the microenvironment. These interactions are fundamental to support CSC stemness and are maintained throughout tumor development and metastasis. PDAC is characterized by a massive desmoplastic reaction, which result from the deposition of high amounts of extracellular matrix components by stromal cells. Here we review how this generates a favorable environment for tumor growth by protecting tumor cells from immune responses and chemotherapy and inducing tumor cell proliferation and migration, leading to metastasis formation ultimately leading to death. We emphasize the interactions between CSCs and the tumor microenvironment leading to metastasis formation and posit that better understanding and targeting of these interactions will improve patient outcomes.

Clinical Impact of Preoperative Biliary Drainage in Patients with Ductal Adenocarcinoma of the Pancreatic Head

Our aim was to study the association between preoperative biliary drainage (PBD) and morbidity following cephalic pancreaticoduodenectomy (CPD) for pancreatic ductal adenocarcinoma (PDAC) and its prognostic impact, which is still controversial in the literature. A retrospective study was conducted, which included 128 patients who underwent CPD for PDAC, divided into two groups: those who underwent PBD (group 1) and those who did not undergo this procedure (group 2). Group 1 was subdivided according to the drainage route: endoscopic retrograde cholangiopancreatography (ERCP), group 1.1, and percutaneous transhepatic cholangiography (PTC), group 1.2. 34.4% of patients underwent PBD, and 47.7% developed PBD-related complications, with 37% in group 1.1 and 64.7% in group 1.2 (p = 0.074). There was a significant difference between group 1 and 2 regarding bacterial colonization of the bile (45.5% vs. 3.6%, p < 0.001), but no difference was found in the colonization by multidrug-resistant bacteria, the development of Clavien–Dindo ≥ III complications, clinically relevant pancreatic fistula and delayed gastric emptying (DGE), intra-abdominal abscess, hemorrhage, superficial surgical site infection (SSI), and readmission. Between groups 1.1 and 1.2, there was a significant difference in clinically relevant DGE (44.4% vs. 5.9%, p = 0.014) and Clavien–Dindo ≥ III complications (59.3% vs. 88.2%, p = 0.040). There were no significant differences in median overall survival and disease-free survival (DFS) between groups 1 and 2. Groups 1.1 and 1.2 had a significant difference in DFS (10 vs. 5 months, p = 0.017). In this group of patients, PBD was associated with increased bacterial colonization of the bile, without a significant increase in postoperative complications or influence in survival. ERCP seems to contribute to the development of clinically significant DGE. Patients undergoing PTC appear to have an early recurrence.

Clinical application of AI-based PET images in oncological patients

Based on the advantages of revealing the functional status and molecular expression of tumor cells, positron emission tomography (PET) imaging has been performed in numerous types of malignant diseases for diagnosis and monitoring. However, insufficient image quality, the lack of a convincing evaluation tool and intra- and interobserver variation in human work are well-known limitations of nuclear medicine imaging and restrict its clinical application. Artificial intelligence (AI) has gained increasing interest in the field of medical imaging due to its powerful information collection and interpretation ability. The combination of AI and PET imaging potentially provides great assistance to physicians managing patients. Radiomics, an important branch of AI applied in medical imaging, can extract hundreds of abstract mathematical features of images for further analysis. In this review, an overview of the applications of AI in PET imaging is provided, focusing on image enhancement, tumor detection, response and prognosis prediction and correlation analyses with pathology or specific gene mutations in several types of tumors. Our aim is to describe recent clinical applications of AI-based PET imaging in malignant diseases and to focus on the description of possible future developments.

Extranodal extension influences prognosis in pancreatic head cancer: A retrospective cohort study

BACKGROUND

Extranodal extension (ENE) is an established prognostic factor in several gastrointestinal cancers. However, the prognostic impact remains unclear. Here, we investigated the prognostic implications of ENE in patients with surgically resected pancreatic cancer.

METHODS

We retrospectively reviewed 476 surgically resected pancreatic head cancer patients who consecutively underwent upfront pancreaticoduodenectomy for pathologically confirmed pancreatic ductal adenocarcinoma between January 2009 and December 2013. We compared the disease-free survival (DFS) rates of the patients according to ENE status.

RESULTS

Among the 476 patients, patients with ENE had lower DFS rates than those without ENE (N0, 13 months; LN+/ENE-, 7 months; LN+/ENE+, 6 months; P < .001). In addition, even in the same N stage, patients with ENE had lower DFS rates than those without ENE (N0, 13 months; N1/ENE- 8 months; N1/ENE+, 7 months; N2/ENE-, 7 months; N2/ENE+, 4 months, P < .001). However, there was no significant difference in survival rates between patients in the N1/ENE+ group and those in the N2/ENE- group. Additionally, ENE was an independent prognostic factor for pancreatic cancer.

CONCLUSIONS

Extranodal extension significantly predicted a poor prognosis among patients with pancreatic head cancer, especially those with nodal metastasis. Therefore, ENE should be considered a prognostic factor in future editions of the staging system.

High beta integrin expression is differentially associated with worsened pancreatic ductal adenocarcinoma outcomes

Outcomes in pancreatic ductal adenocarcinoma (PDAC) are known to be worse in tumors with high integrin β1 expression, but targeted monotherapy against this integrin has not been effective. Seven other beta integrins are expressed in mammalian biology and they are known to have overlapping and compensatory signaling in biological systems. However, their roles in PDAC are poorly understood and have not been systematically compared to integrin β1 biology. In this study, we analyzed the clinical outcomes against beta integrin 1-8 (ITGB1-8) expression in PDAC samples from two large independent cohorts, The Cancer Genome Atlas (TCGA) and GSE21501. Biological function and tumor microenvironment composition were studied using Gene Set Enrichment Analysis and xCell. Expression of all eight beta integrins is significantly increased in PDACs relative to normal pancreatic tissues (all P<0.001). ITGB1, 2, 5, and 6 have similarly enriched gene patterns related to transforming growth factor (TGF)-β, epithelial mesenchymal transition, inflammation, stemness, and angiogenesis pathways. Homologous recombination defects and neoantigens are increased in high-ITGB4, 5, and 6 tumors, with decreased overall survival in high-ITGB1, 5, and 6 tumors compared to low expression tumors (hazard ratios 1.5-2.0). High-ITGB1, 2, and 5 tumors have increased fibroblast infiltration (all P<0.01) while endothelial cells are increased in high-ITGB2 and 3 tumors (all P<0.05). Overall, beta integrin expression does not correlate to immune cell populations in PDACs. Therefore, while all beta integrins are overexpressed in PDACs, they exert differential effects on PDAC biology. ITGB2, 5, and 6 have a similar profile to ITGB1, suggesting that future research in PDAC integrin therapy needs to consider the complementary signaling profiles mediated by these integrins.

Cell Dissemination in Pancreatic Cancer

Pancreatic cancer is a disease notorious for its high frequency of recurrence and low survival rate. Surgery is the most effective treatment for localized pancreatic cancer, but most cancer recurs after surgery, and patients die within ten years of diagnosis. The question persists: what makes pancreatic cancer recur and metastasize with such a high frequency? Herein, we review evidence that subclinical dormant pancreatic cancer cells disseminate before developing metastatic or recurring cancer. We then discuss several routes by which pancreatic cancer migrates and the mechanisms by which pancreatic cancer cells adapt. Lastly, we discuss unanswered questions in pancreatic cancer cell migration and our perspectives.

Low adipocyte hepatocellular carcinoma is associated with aggressive cancer biology and with worse survival

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide, and non-alcoholic fatty liver disease is strongly associated with its development. To explore the role of adipocytes in HCC, we investigated intratumoral adipocytes, also known as cancer-associated adipocytes (CAA). Based on our prior breast cancer findings, we hypothesized that low intratumoral adipocytes would be associated with aggressive cancer biology, worse tumor microenvironment (TME), and clinical outcomes. The Cancer Genome Atlas (TCGA) was used and validated by the Gene Expression Omnibus (GEO) cohort. xCell algorithm was used to quantify intratumoral adipocytes and top 90% were defined as adipocyte high (AH) and bottom 10% as adipocyte low (AL). We found that AL-HCC was significantly associated with worse disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). AL-HCC were higher-grade, had high MKI67 expression, enriched cell proliferation-related gene sets, and had increased altered fraction, aneuploidy, and homologous recombination defects. Also, anti-cancer immune cells, CD8, Th1, and M1 cells, as well as pro-cancer Th2 cells were increased in AL-HCC. Micro-RNAs miR-122 (associated with cholesterol metabolism) and miR-885 (associated with liver pathologies) were significantly increased in the AL TME. In conclusion, we found that AL-HCC has worse patient outcomes and is biologically more aggressive with enhanced cell proliferation. Our findings take initial steps to clarify the role of adipocytes in HCC.

Intraoperative Positive Pancreatic Parenchymal Resection Margin: Is It a True Indication of Completion Total Pancreatectomy after Partial Pancreatectomy for Pancreatic Ductal Adenocarcinoma?

Background: Total pancreatectomy (TP) can be performed in cases with positive resection margin after partial pancreatectomy for pancreatic cancer. However, despite complete removal of the residual pancreatic parenchyme, it is questionable whether an actual R0 resection and favorable survival can be achieved. This study aimed to identify the R0 resection rate and postoperative outcomes, including survival, following completion TP (cTP) performed due to intraoperative positive margin. Methods: From 1995 to 2015, 1096 patients with pancreatic ductal adenocarcinoma underwent elective pancreatectomy at the Samsung Medical Center. Among these, 25 patients underwent cTP, which was converted during partial pancreatectomy because of a positive resection margin. To compare survival after R0 resection between the cTP R0 and pancreaticoduodenectomy (PD) R0 cases, propensity score matching was conducted to balance the baseline characteristics. Results: The R0 rate of cTP performed due to intraoperative positive margin was 84% (21/25). The overall 5-year survival rate (5YSR) in the 25 cTP cases was 8%. There was no difference in the 5YSR between the cTP R0 and cTP R1 groups (9.5% versus 0.0%, p = 0.963). However, the 5YSR of the cTP R0 group was significantly lower than that of the PD R0 group (9.5% versus 20.0%, p = 0.022). There was no distinct difference in postoperative complications between the cTP R0 versus cTP R1 and cTP R0 versus PD R0 groups. Conclusions: In cases with intraoperative positive pancreatic parenchymal resection margin, survival after cTP was not favorable. Careful patient selection is needed to perform cTP in such cases.

Perineural Invasion Is a Significant Indicator of High Malignant Degree and Poor Prognosis in Esophageal Cancer: A Systematic Review and Meta-Analysis

Background

Perineural invasion (PNI) is a malignant metastatic mode of tumors and has been reported in many tumors including esophageal cancer (EC). However, the role of PNI in EC has been reported differently. This systematic review and meta-analysis aims to focus on the role of PNI in EC.

Methods

Eight databases of CNKI, VIP, Wanfang, Scopus, Wiley, ISI, PubMed, and EBSCO are used for literature search. The association of PNI with gender, pathological stages of T and N (pT and pN), lymphovascular invasion (LVI), lymph node metastasis, 5-year overall survival (OS), and 5-year disease-free survival (DFS) was examined in the meta-analysis by Revman5.0 Software. The pooled OR/HR and 95% CI were used to assess the risk and prognostic value.

Results

Sixty-nine published studies were screened for analysis of PNI in EC. The incidence of PNI in esophageal squamous carcinoma (ESCC) and esophageal adenocarcinoma (EAC) was different, but not statistically significant (p > 0.05). The PNI-positive patients had a significantly higher risk of pT stage (OR = 3.85, 95% CI = 2.45–6.05, p < 0.00001), pN stage (OR = 1.86, 95% CI = 1.52–2.28, p < 0.00001), LVI (OR = 2.44, 95% CI = 1.55–3.85, p = 0.0001), and lymph node metastasis (OR = 2.87, 95% CI = 1.56–5.29, p = 0.0007). Furthermore, the cumulative analysis revealed a significant correlation between PNI and poor OS (HR = 1.37, 95% CI = 1.24–1.51, p < 0.0001), as well as poor DFS (HR = 1.55, 95% CI = 1.38–1.74, p < 0.0001).

Conclusion

PNI occurrence is significantly related to tumor stage, LVI, lymph node metastasis, OS, and DFS. These results indicate that PNI can serve as an indicator of high malignant degree and poor prognosis in EC.

The impact of lymphovascular invasion in patients treated with radical nephroureterectomy for upper tract urothelial carcinoma: An extensive updated systematic review and meta-analysis

Patients with upper tract urothelial carcinoma (UTUC) often have a delayed diagnosis and by then, present with advanced disease which has been shown to be associated with lymphovascular invasion (LVI). It has been suggested to be involved in the metastatic cascade of the disease. In this review, we provide an extensive up-to-date summary of the current knowledge about the prognostic impact of LVI in patients undergoing radical nephroureterectomy (RNU). A systematic search of PubMed/MEDLINE, Scopus, EMBASE, and Web of Science for all reports published from 2010 through 2021 was performed. We performed pooled analyses of hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) of series that evaluated LVI as a prognostic factor in adults with UTUC who underwent RNU. The assessed oncological outcomes were disease recurrence, cancer-specific and overall survival. A meta-regression analysis was used to explore potential heterogeneity. A total of 58 series met the eligibility criteria for qualitative and quantitative synthesis. We included 29,829 patients, ranging from 101 to 2492 per study. All series were retrospective. LVI was present in 7,818 patients (26.2%). The median age of the patients was 69 years and the median follow-up was 40 months. In 40 of 58 studies (68.9%), adjuvant chemotherapy was given. The pooled HRs show that LVI predicts a greater risk of recurrence of the disease (pooled HR 1.43, 95% CI: 1.31-1.55, P = 0.000; I² = 76.3%), and decreases cancer-specific survival (pooled HR 1.53, 95% CI: 1.41-1.66, P = 0.000; I² = 72.3%) and overall survival (HR 1.56, 95% CI 1.45-1.69, P = 0.000; I² = 62.9%). It can be concluded that LVI is a common histologic pattern in surgical specimen in patients undergoing RNU for UTUC. LVI predicts a greater risk of recurrence and mortality, thus it should be carefully assessed in clinical practice to determine prognosis, and for optimal decision-making within the concept of personalized therapies.

Radiomics in Gastric Cancer: First Clinical Investigation to Predict Lymph Vascular Invasion and Survival Outcome Using 18F-FDG PET/CT Images

Background

Lymph vascular invasion (LVI) is an unfavorable prognostic indicator in gastric cancer (GC). However, there are no reliable clinical techniques for preoperative predictions of LVI. The aim of this study was to develop and validate PET/CT-based radiomics signatures for predicting LVI of GC preoperatively. Radiomics nomograms were also established to predict patient survival outcomes.

Methods

This retrospective study registered 148 GC patients with histopathological confirmation for LVI status, who underwent pre-operative PET/CT scans (Discovery VCT 64 PET/CT system) from December 2014 to June 2019. Clinic-pathological factors (age, gender, and tumor grade, etc.) and metabolic PET data (maximum and mean standardized uptake value, total lesion glycolysis and metabolic tumor volume) were analyzed to identify independent LVI predictors. The dataset was randomly assigned to either the training set or test set in a 7:3 ratios. Three-dimensional (3D) radiomics features were extracted from each PET- and CT-volume of interests (VOI) singularly, and then a radiomics signature (RS) associated with LVI status is built by feature selection. Four models with different modalities (PET-RS: only PET radiomics features; CT-RS: only CT radiomics features; PET/CT-RS: both PET and CT radiomics features; PET/CT-RS plus clinical data) were developed to predict LVI. Patients were postoperatively followed up with PET/CT every 6-12 months for the first two years and then annually up to five years after surgery. The PET/CT radiomics score (Rad-scores) was calculated to assess survival outcome, and corresponding nomograms with radiomics (NWR) or without radiomics (NWOR) were established.

Results

Tumor grade and maximum standardized uptake value (SUVmax) were the independent LVI predictor. 1037 CT and PET 3D radiomics features were extracted separately and reduced to 4 and 5 features to build CT-RS and PET-RS, respectively. PET/CT-RS and PET/CT-RS plus clinical data (tumor grade and SUVmax) were also developed. The ROC analysis demonstrated clinical usefulness of PET/CT-RS plus clinical data (AUC values for training and validation, respectively 0.936 and 0.914) and PET/CT-RS (AUC values for training and validation, respectively 0.881 and 0.854), which both are superior to CT-RS (0.838 and 0.824) and PET-RS (0.821 and 0.812). SUVmax and LVI were independent prognostic indicators of both OS and PFS. Decision curve analysis (DCA) demonstrated NWR outperformed NWOR and was established to assess survival outcomes. For estimation of OS and PFS, the C-indexes of the NWR were 0. 88 and 0.88 in the training set, respectively, while the C-indexes of the NWOR were 0. 82 and 0.85 in the training set, respectively.

Conclusions

The PET/CT-based radiomics analysis might serve as a non-invasive approach to predict LVI status in GC patients and provide effective predictors of patient survival outcomes.

Sphingosine 1-phosphate (S1P) produced by sphingosine kinase 1 (SphK1) and exported via ABCC1 is related to hepatocellular carcinoma (HCC) progression

Sphingosine-1-Phosphate (S1P) is produced by Sphingosine Kinase 1 (SphK1) in the cell and is transported out of the cells by ABCC1 transporter. S1P induces inflammation, angiogenesis and modulates tumor immune microenvironment (TIME) in autocrine and paracrine manner. We hypothesized that high S1P export is associated with hepatocellular carcinoma (HCC) progression and worse survival. Transcriptome linked with clinical data were obtained from a total of 533 patients from TCGA (The Cancer Genome Atlas)-HCC (n = 350), GSE6764 (n = 75), and GSE89377 (n = 108) cohorts. Both SphK1 and ABCC1 were expressed higher in aggressive HCC than normal liver or cirrhosis and correlated with MKi67 expression. High S1P export by high expression of both SphK1 and ABCC1 enriched gene sets related with cell proliferation (E2F targets, G2M checkpoint, MYC targets), inflammation (Inflammatory response, TNFα, IL6), angiogenesis, metastasis (TGF-β, epithelial-mesenchymal transition), and immune response (allograft rejection, complement, interferon-gamma) in gene set enrichment analysis. High S1P export was associated with elevation of HGF, HSP90AA1, TRAF2, and AKR1B10. It was also associated with high intratumor heterogeneity, leucocyte fraction, macrophage regulation and lymphocyte infiltration, as well as T helper type2 cells, macrophages, dendritic cells, CD4⁺ T memory activated cells, B-cells and cytolytic activity score in TIME. High S1P export was associated with significantly worse disease specific survival (P = 0.034) and overall survival (P = 0.004) compared to low S1P export group. In conclusion, simultaneous high expression of SphK1 and ABCC1 that reflect S1P export is associated with enhancement of both HCC progression and immune response. Given that S1P export was also associated with worse survival, we cannot help but speculate that pro-cancer pathways activated by S1P may overwhelm the anti-cancer immune response mediated by S1P.

A prognostic score based on long-term survivor unique transcriptomic signatures predicts patient survival in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is known for its poor prognosis with few long-term survivors. This study aimed to establish a prognostic score using unique transcriptomic profiles of long-term survivors to be used as a patient selection tool for meaningful clinical intervention in PDAC. In TCGA PDAC cohort, 16 genes were significantly upregulated in the long-term survivor tumors. A prognostic score was established using these 16 genes by LASSO Cox regression, and PHKG1, HOXA4, ISL2, DMRT3 and TRA2A gene expressions were included in the score. The prognostic value was confirmed in both testing and validation cohorts. The characteristics of the high score tumor was investigated by bioinformatical approach. The high score tumor was associated with TP53 mutation but not with other commonly enhanced signaling pathways in PDAC. The high score tumor was associated with higher tumor mutational burden and unfavorable tumor microenvironment (TME), such as lower infiltration of CD8-positive T cells and dendritic cells, and less cell composition of mature blood vessels and fibroblasts. The high score tumor was also associated with enhanced cell proliferation and margin positivity after surgery. The impact of score component genes on the cell proliferation was investigated by in vitro experiments. Silencing of the score component genes promoted cell proliferation. In conclusion, the prognostic score predicted PDAC patient survival and was associated with cancer aggressiveness such as unfavorable TME and enhanced cell proliferation.

Prognostic Significance of Microvascular Invasion in Pancreatic Ductal Adenocarcinoma: A Systematic Review and Meta-Analysis

BACKGROUND The incidence, pathogenesis, and prognostic effect of microvascular invasion on pancreatic ductal adenocarcinoma (PDAC) remain controversial. This study aimed to summarize the incidence, pathogenesis, role in clinical management, recurrence, and prognostic significance of microvascular invasion in PDAC. MATERIAL AND METHODS A literature review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Systematic literature searches were conducted using PubMed and Google Scholar up to February 2021. RESULTS Seventeen studies were included in the meta-analysis. The incidence of microvascular invasion was 49.0% (95% confidence interval [CI], 43.8-54.5%) among PDAC patients who underwent surgery. The weighted multivariate Cox proportional hazards model hazard ratio for disease-free survival of 8 studies was 1.78 (95% CI 1.53-2.08, P<0.001), and there was no statistically significant difference between the subgroups (P=0.477). The hazard ratio for overall survival of 14 studies was 1.49 (95% CI 1.27-1.74, P<0.001), and there was no statistically significant difference between the subgroups (P=0.676). CONCLUSIONS Microvascular invasion occurred in nearly half of PDAC patients after surgery and was closely related to disease-free and overall survival. Understanding the role of microvascular invasion in PDAC will help provide more personalized and effective preoperative or postoperative strategies to achieve better survival outcomes.

Prognostic significance of residual lymphovascular invasion after resection of locally advanced and borderline resectable pancreatic adenocarcinomas treated by neoadjuvant chemotherapy

BACKGROUND

The current study aimed to identify histological prognostic factors after resection of locally advanced (LA) and borderline (BL) pancreatic adenocarcinomas treated by neoadjuvant chemotherapy (NC).

METHODS

A retrospective review was performed of patients with LA and BL adenocarcinomas operated after NC between January 2010 and April 2018. Prognostic factors for survival were assessed by multivariate Cox analysis.

RESULTS

Of the 84 patients, 29 had BL and 55 had LA pancreatic adenocarcinomas. Seventy-five patients underwent synchronous venous resection and 57 underwent arterial resection. The median overall survival from surgery was 21.10 months (BL 23-LA 21) (95% CI: 14.8-30.3) with 1-, 3-, and 5-year overall survival rates of 73%, 32%, and 20%, respectively. Multivariate analysis identified lymphovascular invasion (LVI) as an independent prognostic factor for overall survival (HR: 2.32, 95% CI: 1.28-4.22; p = 0.004). Patients without LVI (n = 37) had superior median overall and 5-year survival rates (31.0 months [40 from diagnosis]; 39%) compared to patients with LVI (n = 47; 14.4 months [22 from diagnosis]; 7%). The absence of residual LVI was associated with major pathologic response rates (p < 0.05).

CONCLUSION

The persistence of LVI at pathology after resection of LA and BL treated by neoadjuvant chemotherapy predicts poor response and limited long-term survival.

Collective metastasis: coordinating the multicellular voyage

The metastatic process is arduous. Cancer cells must escape the confines of the primary tumor, make their way into and travel through the circulation, then survive and proliferate in unfavorable microenvironments. A key question is how cancer cells overcome these multiple barriers to orchestrate distant organ colonization. Accumulating evidence in human patients and animal models supports the hypothesis that clusters of tumor cells can complete the entire metastatic journey in a process referred to as collective metastasis. Here we highlight recent studies unraveling how multicellular coordination, via both physical and biochemical coupling of cells, induces cooperative properties advantageous for the completion of metastasis. We discuss conceptual challenges and unique mechanisms arising from collective dissemination that are distinct from single cell-based metastasis. Finally, we consider how the dissection of molecular transitions regulating collective metastasis could offer potential insight into cancer therapy.

Low expression of miR-29a is associated with aggressive biology and worse survival in gastric cancer

Advanced gastric cancer (GC) is one of the most lethal cancer types, thus a better understanding of its biology in patients is urgently needed. MicroRNA (miR)-29a is a known tumor suppressive miR that is related to metastasis, but its clinical relevance in GC remains ambiguous. Here, using a large GC patient cohort we hypothesized that low expression of miR-29a in GC is associated with aggressive cancer biology and worse survival. We demonstrated that low miR-29a GC enriched cell proliferation, apoptosis, metastasis, and angiogenesis related gene sets, as well as the higher expression of related genes. Low miR-29a GC was associated with less anti-cancer immune cell infiltration as well as immune related scoring. Low miR-29a GC demonstrated a worse overall survival (OS) as well as disease specific survival (DSS) compared with high expressing miR-29a GC. Notably, low miR-29a expression was the only factor, other than residual tumor status, to be an independent prognostic biomarker of worse OS and DSS. In conclusion, low miR-29a GC was associated with aggressive cancer biology and worse OS as well as DSS. Additionally, low expression of miR-29a was an independent prognostic biomarker of OS and DSS in gastric cancer patients.

Annexin A1 Expression Is Associated with Epithelial-Mesenchymal Transition (EMT), Cell Proliferation, Prognosis, and Drug Response in Pancreatic Cancer

Annexin A1 (ANXA1) is a calcium-dependent phospholipid-binding protein overexpressed in pancreatic cancer (PC). ANXA1 expression has been shown to take part in a wide variety of cancer biology, including carcinogenesis, cell proliferation, invasion, apoptosis, and metastasis, in addition to the initially identified anti-inflammatory effect in experimental settings. We hypothesized that ANXA1 expression is associated with cell proliferation and survival in PC patients. To test this hypothesis, we analyzed 239 PC patients in The Cancer Genome Atlas (TCGA) and GSE57495 cohorts. ANXA1 expression correlated with epithelial-mesenchymal transition (EMT) but weakly with angiogenesis in PC patients. ANXA1-high PC was significantly associated with a high fraction of fibroblasts and keratinocytes in the tumor microenvironment. ANXA1 high PC enriched multiple malignant gene sets, including hypoxia, tumor necrosis factor (TNF)-α signaling via nuclear factor-kappa B (NF-kB), and MTORC1, as well as apoptosis, protein secretion, glycolysis, and the androgen response gene sets consistently in both cohorts. ANXA1 expression was associated with TP53 mutation alone but associated with all KRAS, p53, E2F, and transforming growth factor (TGF)-β signaling pathways and also associated with homologous recombination deficiency in the TCGA cohort. ANXA1 high PC was associated with a high infiltration of T-helper type 2 cells in the TME, with advanced histological grade and MKI67 expression, as well as with a worse prognosis regardless of the grade. ANXA1 expression correlated with a sensitivity to gemcitabine, doxorubicin, and 5-fluorouracil in PC cell lines. In conclusion, ANXA1 expression is associated with EMT, cell proliferation, survival, and the drug response in PC.

Abundance of Regulatory T Cell (Treg) as a Predictive Biomarker for Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer

Regulatory CD4+ T cell (Treg), a subset of tumor-infiltrating lymphocytes (TILs), are known to suppress anticancer immunity but its clinical relevance in human breast cancer remains unclear. In this study, we estimated the relative abundance of Tregs in breast cancer of multiple patient cohorts by using the xCell algorithm on bulk tumor gene expression data. In total, 5177 breast cancer patients from five independent cohorts (TCGA-BRCA, GSE96058, GSE25066, GSE20194, and GSE110590) were analyzed. Treg abundance was not associated with cancer aggressiveness, patient survival, or immune activity markers, but it was lower in metastatic tumors when compared to matched primary tumors. Treg was associated with a high mutation rate of TP53 genes and copy number mutations as well as with increased tumor infiltration of M2 macrophages and decreased infiltration of T helper type 1 (Th1) cells. Pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) was significantly associated with low Treg abundance in triple negative breast cancer (TNBC) but not in ER-positive/Her2-negative subtype. High Treg abundance was significantly associated with high tumor expression of multiple immune checkpoint inhibitor genes. In conclusion, Treg abundance may have potential as a predictive biomarker of pCR after NAC in TNBC.

High G2M Pathway Score Pancreatic Cancer is Associated with Worse Survival, Particularly after Margin-Positive (R1 or R2) Resection

Pancreatic cancer is highly mortal due to uncontrolled cell proliferation. The G2M checkpoint pathway is an essential part of the cell cycle. We hypothesized that a high G2M pathway score is associated with cell proliferation and worse survival in pancreatic cancer patients. Gene set variation analysis using the Hallmark G2M checkpoint gene set was used as a score to analyze a total of 390 human pancreatic cancer patients from 3 cohorts (TCGA, GSE62452, GSE57495). High G2M score tumors enriched other cell proliferation genes sets as well as MKI67 expression, pathological grade, and proliferation score. Independent of other prognostic factors, G2M score was predictive of disease-specific survival in pancreatic cancer. High G2M tumor was associated with high mutation rate of KRAS and TP53 and significantly enriched these pathway gene sets, as well as high infiltration of Th2 cells. High G2M score consistently associated with worse overall survival in 3 cohorts, particularly in R1/2 resection, but not in R0. High G2M tumor in R1/2 highly enriched metabolic and cellular components' gene sets compared to R0. To our knowledge, this is the first study to use gene set variation analysis as a score to examine the clinical relevancy of the G2M pathway in pancreatic cancer.

ITPKC as a Prognostic and Predictive Biomarker of Neoadjuvant Chemotherapy for Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with higher mortality than the others. Pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) is considered as a surrogate to predict survival. Inositol 1,4,5-trisphosphate 3-kinase C (ITPKC) is a negative regulator of T cell activation, and reduction in ITPKC function is known to promote Kawasaki disease. Given the role of tumor infiltrating lymphocytes in NAC and since TNBC has the most abundant immune cell infiltration in breast cancer, we hypothesized that the ITPKC expression level is associated with NAC response and prognosis in TNBC. The ITPKC gene was expressed in the mammary gland, but its expression was highest in breast cancer cells among other stromal cells in a bulk tumor. ITPKC expression was highest in TNBC, associated with its survival, and was its independent prognostic factor. Although high ITPKC was not associated with immune function nor with any immune cell fraction, low ITPKC significantly enriched cell proliferation-related gene sets in TNBC. TNBC with low ITPKC achieved a significantly higher pCR rate after NAC. To the best of our knowledge, this is the first report to demonstrate that ITPKC gene expression may be useful as a prognostic and predictive biomarker in TNBC.