The Role of Mucin Expression in the Diagnosis of Oesophago-Gastric Cancer: A Systematic Literature Review

Survival in oesophago-gastric cancer (OGC) is poor due to early diagnostic challenges. Non-invasive risk stratification may identify susceptible patients with pre-malignant or benign disease. Following diagnostic confirmation with endoscopic biopsy, early OGC may be treated sooner. Mucins are transmembrane glycoproteins implicated in OGC with potential use as biomarkers of malignant transformation. This systematic review defines the role of mucins in OGC diagnosis. A literature search of MEDLINE, Web of Science, Embase and Cochrane databases was performed following PRISMA protocols for studies published January 1960-December 2022. Demographic data and data on mucin sampling and analysis methods were extracted. The review included 124 studies (n = 11,386 patients). Gastric adenocarcinoma (GAc) was the commonest OG malignancy (n = 101) followed by oesophageal adenocarcinoma (OAc, n = 24) and squamous cell carcinoma (OSqCc, n = 10). Mucins MUC1, MUC2, MUC5AC and MUC6 were the most frequently implicated. High MUC1 expression correlated with poorer prognosis and metastases in OSqCc. MUC2 expression decreases during progression from healthy mucosa to OAc, causing reduced protection from gastric acid. MUC5AC was upregulated, and MUC6 downregulated in GAc. Mucin expression varies in OGC; changes may be epigenetic or mutational. Profiling upper GI mucin expression in OGC, with pre-malignant, benign and healthy controls may identify potential early diagnostic biomarkers.

Machine Learning for Risk Prediction of Oesophago-Gastric Cancer in Primary Care: Comparison with Existing Risk-Assessment Tools

Simple Summary

Oesophago-gastric cancer is one of the commonest cancers worldwide, yet it can be particularly difficult to diagnose given that initial symptoms are often non-specific and routine screening is not available. Cancer risk-assessment tools, which calculate cancer risk based on symptoms and other risk factors present in the primary care record, can aid decisions on referrals for cancer investigations, facilitating earlier diagnosis. Diagnosing common cancers earlier could help improve survival rates. Using UK primary care electronic health record data, we compared five different machine learning techniques for probabilistic classification of cancer patients against a current widely used UK primary care cancer risk-assessment tool. The machine learning algorithms outperformed the current risk-assessment tool, with a higher overall accuracy and an ability to reasonably identify 11–25% more cancer patients. We conclude that machine-learning-based risk-assessment tools could help better identify suitable patients for further investigation and support earlier diagnosis.

Abstract

Oesophago-gastric cancer is difficult to diagnose in the early stages given its typical non-specific initial manifestation. We hypothesise that machine learning can improve upon the diagnostic performance of current primary care risk-assessment tools by using advanced analytical techniques to exploit the wealth of evidence available in the electronic health record. We used a primary care electronic health record dataset derived from the UK General Practice Research Database (7471 cases; 32,877 controls) and developed five probabilistic machine learning classifiers: Support Vector Machine, Random Forest, Logistic Regression, Naïve Bayes, and Extreme Gradient Boosted Decision Trees. Features included basic demographics, symptoms, and lab test results. The Logistic Regression, Support Vector Machine, and Extreme Gradient Boosted Decision Tree models achieved the highest performance in terms of accuracy and AUROC (0.89 accuracy, 0.87 AUROC), outperforming a current UK oesophago-gastric cancer risk-assessment tool (ogRAT). Machine learning also identified more cancer patients than the ogRAT: 11.0% more with little to no effect on false positives, or up to 25.0% more with a slight increase in false positives (for Logistic Regression, results threshold-dependent). Feature contribution estimates and individual prediction explanations indicated clinical relevance. We conclude that machine learning could improve primary care cancer risk-assessment tools, potentially helping clinicians to identify additional cancer cases earlier. This could, in turn, improve survival outcomes.

A pooled analysis of molecularly targeted agents for treatment of metastatic oesophago-gastric cancer in elderly patients

INTRODUCTION

The aim of the present study was to assess the efficacy of molecularly targeted agents (MTAs) in the treatment of elderly patients with metastatic oesophago-gastric cancer (mOGC).

MATERIAL AND METHODS

We systematically searched electronic databases and abstracts presented at American Society of Clinical Oncology (ASCO) meetings up to January 31, 2017. Hazard ratios (HRs) were used to estimate overall survival (OS) and progression-free survival (PFS). Subgroup analysis and publication bias were also evaluated. All statistical analysis was conducted using Comprehensive Meta Analysis software (Version 2.0).

RESULTS

A total of 2,149 elderly patients with mOGC from thirteen trials were included. Compared to non-MTA-containing regimens, OS was significantly improved in the MTA-containing regimens (HR = 0.86, 95% CI: 0.75-0.99, p = 0.037), but not for PFS (HR = 1.05, 95% CI: 0.85-1.30, p = 0.67). In addition, subgroup analysis indicated that MTA-containing regimens as second-line therapy in elderly mOGC patients significantly improved PFS (HR = 0.58; 95% CI: 0.39-0.85, p = 0.005) and OS (HR = 0.82, 95% CI: 0.70-0.96, p = 0.016), but did not significantly improve PFS (HR = 1.36; 95% CI: 1.06-1.76, p = 0.017) and OS (HR = 0.98, 95% CI: 0.77-1.27, p = 0.90) for MTA-containing regimens as first-line therapy in these patients. No publication bias was detected by Begg's and Egger's tests for OS and PFS.

CONCLUSIONS

Our results indicate that the MTA-containing therapies significantly improve OS but not for PFS in elderly mOGC patients. Sub-group analysis shows that improved efficacy is only observed in the second-line setting and not in the first-line setting. Our findings support the use of angiogenesis as second-line treatment for elderly mOGC patients.

Prognostic value of neutrophil-to-lymphocyte ratio in advanced oesophago-gastric cancer: exploratory analysis of the REAL-2 trial

BACKGROUND

The REAL-2 trial demonstrated that capecitabine and oxaliplatin were effective alternatives to fluorouracil and cisplatin, respectively, when used in triplet chemotherapy regimens for previously untreated oesophago-gastric cancer. The aim of the current analysis was to evaluate the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in the REAL-2 cohort.

MATERIAL AND METHODS

A post hoc exploratory analysis was carried out on REAL-2 patients with the available absolute neutrophil count and absolute lymphocyte count. A high NLR was defined using a cut-off value of >3.0. The NLR was then correlated with clinical outcomes including overall survival (OS), progression-free survival (PFS) and objective response rate. Survival curves were generated using the Kaplan-Meier method and comparison between groups was carried out using Cox regression.

RESULTS

Data were available in 908 of the 1002 REAL-2 participants. Of these, 516 (56.8%) were deemed to have a high NLR. In univariate analysis, high NLR was associated with a hazard ratio (HR) for OS of 1.73 (1.50-2.00), P < 0.001, compared with low NLR, equating to median OS values of 9.1 [95% confidence interval (CI) 8.0-9.6] and 12.7 months (95% CI 10.8-14.4), respectively. The NLR remained highly significant for OS (P < 0.001) in a multivariate model including performance status, age, disease extent, presence of liver metastases and presence of peritoneal metastases. For PFS, high NLR was associated with an HR of 1.63 (1.41-1.87), P < 0.001, compared with low NLR in univariate analysis. No significant interaction was found between NLR status and treatment arm, 13% of all patients with low NLR achieving survival beyond 24 months compared with only 6% of patients with high NLR (P < 0.001).

CONCLUSION

Our results confirm that high NLR status had a significant negative prognostic effect in the REAL-2 trial population. Based on the multivariate analysis, this effect was independent of other known prognostic factors.

Docetaxel and its potential in the treatment of refractory esophagogastric adenocarcinoma

Adenocarcinomas of the esophagus and stomach are a major cause of cancer-related morbidity and mortality worldwide. For patients with advanced disease, first-line chemotherapy with platinum-fluoropyrimidine combinations prolongs survival, but inevitably the disease progresses with a median progression-free survival of approximately 6 months. At the time of progression, approximately 40-50% of patients remain fit and eligible for second-line treatment. Docetaxel has been extensively studied in this chemorefractory setting, mostly in small single arm studies, either as a single agent or in combination with platinum agents, fluoropyrimidines or anthracyclines. However, two randomized controlled trials published since 2012 have convincingly shown that treatment with docetaxel modestly prolongs survival compared with best supportive care alone. Moreover, treatment with docetaxel is associated with relief from cancer-related constitutional and gastrointestinal symptoms with manageable, predominantly haematological, toxicity. Therefore, it represents a valuable treatment option for patients with relapsed esophagogastric cancer. Nevertheless, in view of the short survival time for the majority of these patients, further research is necessary to identify, on the one hand, combinations with targeted agents that will further improve outcomes and, on the other, biomarkers that will allow selection of those patients most likely to benefit.

Phase I trials in patients with relapsed, advanced upper gastrointestinal carcinomas: experience in a specialist unit

BACKGROUND

Conventional therapeutic options for patients with advanced upper gastrointestinal cancers (UGIC) are limited. Following first-line treatments, some patients are offered experimental therapies, including participation in Phase I trials. This study aims to describe the experience of UGIC patients treated in a dedicated Phase I unit.

METHODS

Patient, tumour and treatment characteristics, and clinical outcomes of UGIC patients treated consecutively at the Drug Development Unit, Royal Marsden Hospital, between 2005 and 2009, were recorded.

RESULTS

Ninety-six patients who previously received a median of 2 (range 1-4) lines of chemotherapies were treated in 30 Phase I trials. Of 81 evaluable patients, 9 achieved RECIST-objective response (11 %) with a 6-month clinical benefit rate of 14 %. Median progression free and overall survival were 7.7 weeks [95 %CI 7.7 (6.4-9.0)] and 19.1 weeks (95 %CI 17.5-20.8), respectively. Grade 3 or 4 toxicities were observed in 37 patients (39 %) and led to trial discontinuation in 9 (9 %); no toxicity-related death was recorded. In the multivariate analysis, serum albumin (<35 g/dl, HR2.0, p = 0.002) and lactate dehydrogenase (>192 μmol/l, HR1.7, p = 0.016) were prognostic of overall survival.

CONCLUSION

Phase I clinical trials can be considered a reasonable option in selected patients with relapsed UGIC. The use of objective prognosticators may improve selection and risk/benefit profile of patients.

A randomized phase II study of PEP02 (MM-398), irinotecan or docetaxel as a second-line therapy in patients with locally advanced or metastatic gastric or gastro-oesophageal junction adenocarcinoma

BACKGROUND

PEP02 is a novel highly stable liposomal nanocarrier formulation of irinotecan. This randomized phase II study evaluated the efficacy and safety of single agent PEP02 compared with irinotecan or docetaxel in the second-line treatment of advanced oesophago-gastric (OG) cancer.

PATIENTS AND METHODS

Patients with locally advanced/metastatic disease who had failed one prior chemotherapy regimen were randomly assigned to PEP02 120 mg/m(2), irinotecan 300 mg/m(2) or docetaxel (Taxotere) 75 mg/m(2) every 3 weeks. The primary end point was objective response rate (ORR). Simon's two-stage design was used and the ORR of interest was 20% (α = 0.05, type II error β = 0.10, null hypothesis of ORR was 5%).

RESULTS

Forty-four patients per arm received treatment, and 124 were assessable for response. The ORR statistical threshold for the first stage was reached in all arms. In the intent-to-treat (ITT) population, ORRs were 13.6% (6/44), 6.8% (3/44) and 15.9% (7/44) in the PEP02, irinotecan and docetaxel arms, respectively. The median progression-free survival (PFS) and overall survival were similar between the trial arms. Commonest grade 3-4 adverse event reported was diarrhoea in the PEP02 and irinotecan groups (27.3% versus 18.2%).

CONCLUSION

The ORR associated with PEP02 was comparable with docetaxel and numerically greater than that of irinotecan. PEP02 warrants further evaluation in the advanced gastric cancer setting.