Pre-therapeutic molecular biomarkers of pathological response to neoadjuvant chemotherapy in gastric and esophago-gastric junction adenocarcinoma: A systematic review and meta-analysis

PURPOSE

Multimodal treatment is the standard of care in patients with locally advanced gastric cancer. Unfortunately, the response rate after neoadjuvant treatment remains limited. The ability to predict the response has a potential to improve patient outcomes by promoting a more individualized approach. We sought to describe the current state of research in pre-treatment molecular biomarkers of response to neoadjuvant therapy in gastric adenocarcinoma available for testing before the initiation of treatment and to perform a systematic review and meta-analysis in order to summarize and evaluate the potential methods.

METHODS

A systematic MEDLINE, EMBASE and CENTRAL literature search was conducted to extract articles on potentially predictive molecular biomarkers of pathological response to neoadjuvant therapy in patients with gastric- and esophago-gastric junction adenocarcinoma. Fixed and random effects models were used to undertake the meta-analysis when appropriate.

RESULTS

Data on predictive biomarkers was reported in 38 studies. These articles described 47 biomarkers showing statistical significance. After evaluation of all reported biomarkers, 3 of them met the inclusion criteria for meta-analysis. The meta-analysis results indicate that >5 ​ng/mL pre-therapeutic serum concentration of carcinoembryonic antigen (CEA; norm <5 ​ng/mL) is significantly associated with tumor response (RR ​= ​5.13, 95% CI 2.53-10.43, P ​= ​0.026).

CONCLUSION

Previous studies describe a large number of candidate biomarkers. Our meta-analysis indicated pre-therapeutic serum concentration of CEA >5 ​ng/mL as a potential and easy-accessible biomarker available for use before initiation of treatment. However, it could be only an additional tool for complex qualification for neoadjuvant therapy.

Response to Neoadjuvant Treatment is Influenced by Grade in Gastric Cancer

Neoadjuvant therapy is commonly used in the management of gastric cancer. Primary tumor response to treatment correlates with prognosis. Published studies have compared efficacy of neoadjuvant therapy based on stage but not grade. The objective of this study was to determine the change in staging of gastric cancer after neoadjuvant therapy and resection based on grade. A retrospective analysis of gastric cancer patients treated at our institution between 2005 and 2017 was performed. Patient demographics, tumor characteristics, clinical and pathological stage, and microscopic treatment response were analyzed based on grade. Of the 269 patients identified during this period, 82 patients underwent definitive surgical resection, of which 38 patients received neoadjuvant therapy (low grade (grades 1 and 2), n = 17; high grade (grade 3), n = 18; and unknown grade, n = 3). Pathologic downstaging was observed in 52.9 per cent (9/17) of low-grade tumors compared with 22.2 per cent (4/18) of high-grade tumors. Majority of high-grade tumors (77.8%, 14/18) had either upstaging or unchanged stage. High-grade gastric cancers often lack response to neoadjuvant therapy. Novel targeted therapies based on biologic behavior should be evaluated and incorporated into neoadjuvant treatment. Neoadjuvant studies should stratify patients based on grade and report response by grade.

RBBP7 is a prognostic biomarker in patients with esophageal squamous cell carcinoma

Retinoblastoma-binding protein 7 (RBBP7) is an important component of several complexes that regulate chromatin metabolism. It is overexpressed in certain cancer types and serves conflicting roles in tumor progression. In the present study, the expression and roles of RBBP7 were explored in esophageal squamous cell carcinoma (ESCC). Immunohistochemical staining was used to detect RBBP7 expression in ESCC tissues. The mRNA sequencing profiles from the Cancer Genome Atlas and Genotype-Tissue Expression databases were mined to analyze the mRNA expression of RBBP7 in tissues. Proliferation, clone formation, apoptosis and Transwell invasion/migration assays were performed to explore the roles of RBBP7 in ESCC. RBBP7 was highly expressed in ESCC tissues. The protein and mRNA expression levels of RBBP7 were significantly elevated in tumor tissues compared with paired adjacent normal tissues. RBBP7 overexpression was associated with a poor overall survival in patients with ESCC. Furthermore, higher RBBP7 expression was significantly correlated with poor tumor differentiation, advanced regional lymph node involvement, and pathological TNM staging. Knockdown of RBBP7 in ESCC cells did not affect tumor apoptosis or tumor growth. However, the overexpression of RBBP7 significantly enhanced the invasion and migration of ESCC cells, whereas the knockdown of RBBP7 resulted in significantly decreased invasion and migration. The present study indicated that RBBP7 is a novel biomarker and prognosticator for patients with ESCC. Furthermore, RBBP7 serves crucial roles in promoting ESCC invasion and migration.

Nrf2 promotes oesophageal cancer cell proliferation via metabolic reprogramming and detoxification of reactive oxygen species

Cancer cells consume a large amount of energy and maintain high levels of anabolism to promote cell proliferation via metabolic reprogramming. Nuclear factor erythroid 2-related factor 2 (Nrf2; NFE2L2) is a master transcription regulator of stress responses and promotes metabolic reprogramming to support cell proliferation in various types of cancer. As oesophageal cancer is one of the most aggressive gastrointestinal cancers, we aimed to clarify the effect of Nrf2 on metabolic reprogramming in oesophageal cancer. The relationship between Nrf2 expression and clinical outcome was evaluated using a database comprising 201 oesophageal cancers. Using in vitro assays and metabolome analysis, we examined the mechanism by which Nrf2 affects malignant phenotype. High-level immunohistochemical expression of Nrf2 was significantly associated with poor recurrence-free survival (HR = 2.67, p = 0.0004) and overall survival (HR = 2.90, p < 0.0001) in oesophageal cancer patients. In an in vitro assay with siRNA in TE-11 cells, which showed high Nrf2 expression, Nrf2 depletion significantly decreased cell growth and enhanced G1 cell cycle arrest and apoptosis. In addition, reactive oxygen species (ROS) were not removed by detoxification via the Nrf2 pathway, with concomitant induction of the p38 mitogen-activated protein kinase pathway. The metabolome analysis showed that Nrf2 strongly promoted metabolic reprogramming to glutathione metabolism, which synthesizes the essential fuels for cancer progression. Furthermore, metabolome analysis using oesophageal cancer specimens confirmed that samples displaying high Nrf2 expression promoted glutathione synthesis. Metabolic reprogramming to glutathione metabolism, and ROS detoxification by activation of Nrf2, enhanced cancer progression and led to a poor clinical outcome in oesophageal cancer patients. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Approaches and genetic determinants in predicting response to neoadjuvant chemotherapy in locally advanced gastric cancer

Gastric cancer remains a major health burden worldwide. There is near-universal agreement that neoadjuvant chemotherapy (NAC) is a preferred management for locally advanced gastric cancer (LAGC). However, the optimal approach for an individual patient is still not clear and remains controversial, which could be at least partly explained by the lack of predictive tools. The ability to predict chemosensitivity from NAC in routine clinical practice is difficult and is an area of intense investigation, especially in the Precision-Medicine Era. Available consistent evidence suggests that a favorable tumor histopathological response to NAC may be a useful positive prognostic marker in gastric cancer. Hence, it is reasonable to speculate that making the histopathological response from NAC predictable will dramatically facility the NAC and improve patients' outcome. This review provides an overview on the current status of predictive biomarkers for histopathological response from NAC in LAGC, including clinicopathological variables, imaging and molecular testing. Furthermore, limitations and future perspectives are also discussed.

Human Microbiome Fusobacterium Nucleatum in Esophageal Cancer Tissue Is Associated with Prognosis

PURPOSE

Fusobacterium nucleatum (F. nucleatum) is a component of the human microbiome that primarily inhabits the oral cavity. It causes periodontal disease and has also been implicated in the development of human cancers. Although there are several reports of the relationship between F. nucleatum and the clinical outcome in human cancers, its prognostic significance in esophageal cancer remains unclear.

EXPERIMENTAL DESIGN

We quantified F. nucleatum DNA in 325 resected esophageal cancer specimens by qPCR. Significant pathways in F. nucleatum-positive esophageal cancer tissues were identified by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis using microarray data.

RESULTS

Esophageal cancer tissues contained significantly more F. nucleatum DNA than matched normal esophageal mucosa (P = 0.021; n = 60). F. nucleatum DNA was detected in 74 of 325 cases (23%). F. nucleatum DNA positivity was significantly associated with tumor stage, but not with sex, age, performance status, tobacco use, alcohol use, histology, tumor location, or preoperative treatment. F. nucleatum DNA positivity was also significantly associated with cancer-specific survival [log-rank P = 0.0039; univariate HR = 2.01; 95% confidence interval (CI), 1.22-3.23; P = 0.0068; multivariate HR = 1.78; 95% CI, 1.06-2.94; P = 0.031]. The top-ranked KEGG pathway in F. nucleatum-positive tissues was "cytokine-cytokine receptor interaction." A significant relationship between F. nucleatum and the chemokine CCL20 was validated by IHC.

CONCLUSIONS

F. nucleatum in esophageal cancer tissues was associated with shorter survival, suggesting a potential role as a prognostic biomarker. F. nucleatum might also contribute to aggressive tumor behavior through activation of chemokines, such as CCL20. Clin Cancer Res; 22(22); 5574-81. ©2016 AACR.

Dysphagia is not a Valuable Indicator of Tumor Response after Preoperative Chemotherapy for R0 Resected Patients with Adenocarcinoma of the Gastroesophageal Junction

Background:

Monitoring treatment response to preoperative chemotherapy is of utmost importance to avoid treatment toxicity, especially in non-responding patients. Currently, no reliable methods exist for tumor response assessment after preoperative chemotherapy. Therefore, the aim of this study was to evaluate dysphagia as a predictor of tumor response after preoperative chemotherapy and as a predictor of recurrence and survival.

Methods:

Patients with adenocarcinoma of the gastroesophageal junction, treated between 2010 and 2012, were retrospectively reviewed. Dysphagia scores (Mellow-Pinkas) were obtained before and after three cycles of perioperative chemotherapy together with clinicopathological patient characteristics. A clinical response was defined as improvement of dysphagia by at least 1 score from the baseline. The tumor response was defined as down staging of T-stage from initial computer tomography (CT) scan (cT-stage) to pathologic staging of surgical specimen (pT-stage). Patients were followed until death or censored on June 27th, 2014.

Results:

Of the 110 included patients, 59.1% had improvement of dysphagia after three cycles of perioperative chemotherapy, and 31.8% had a chemotherapy-induced tumor response after radical resection of tumor. Improvement of dysphagia was not correlated with the tumor response in the multivariate analysis (p = 0.23). Moreover, the presence of dysphagia was not correlated with recurrence (p = 0.92) or survival (p = 0.94) in the multivariate analysis.

Conclusion:

In our study, improvement of dysphagia was not valid for tumor response evaluation after preoperative chemotherapy and was not correlated with the tumor response. The presence of dysphagia does not seem to be a predictor of recurrence or survival.

Therapeutic approaches to gastroesophageal junction adenocarcinomas

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the distinction between adenocarcinomas above, below, or within the gastroesophageal junction; combined modality therapy; tumor markers for use in personalized medicine; PET-CT and endoscopic biopsies in the evaluation of response to neoadjuvant chemoradiation therapy; a standardized grading system for tumor regression in squamous cell cancer and adenocarcinoma; the experimental basis for new approaches to medical treatment; the criteria measuring response in esophageal cancer; and the impact of novel imaging on staging and response assessment.

Undervalued criteria in the evaluation of multimodal trials for upper GI cancers

Global economies and their health systems face a huge challenge from cancer: 1 in 3 women and 1 in 2 men will develop cancer in their lifetime. In the less developed countries, the volume of cancer patients will overwhelm the existing healthcare systems. Even in developed regions, patients with upper gastrointestinal (GI) cancer usually present with locally advanced tumors that their prognosis is poor. A detailed knowledge of anatomy, embryology, epidemiology, tumor classifications and tumor growth is key understanding and evaluating the relevant research. We review undervalued criteria necessary to evaluate the response to multimodal therapy for upper GI cancers.

Association of cancer metabolism-related proteins with oral carcinogenesis - indications for chemoprevention and metabolic sensitizing of oral squamous cell carcinoma?

Background

Tumor metabolism is a crucial factor for the carcinogenesis of oral squamous cell carcinoma (OSCC).

Methods

Expression of IGF-R1, glycolysis-related proteins (GLUT-1, HK 2, PFK-1, LDHA, TKTL1), mitochondrial enzymes (SDHA, SDHB, ATP synthase) were analyzed in normal oral mucosa (n = 5), oral precursor lesions (simple hyperplasia, n = 11; squamous intraepithelial neoplasia, SIN I-III, n = 35), and OSCC specimen (n = 42) by immunohistochemistry and real-time polymerase chain reaction (qPCR) analysis in OSCC cell lines. Metabolism-related proteins were correlated with proliferation activity (Ki-67) and apoptotic properties (TUNEL assay) in OSCC. Specificity of antibodies was confirmed by western blotting in cancer cell lines.

Results

Expression of IGF-R1, glycolysis-related proteins (GLUT-1, HK 2, LDHA, TKTL1), and mitochondrial enzymes (SDHA, SDHB, ATP synthase) were significantly increased in the carcinogenesis of OSCC. Metabolic active regions of OSCC were strongly correlated with proliferating cancer (Ki-67+) cells without detection of apoptosis (TUNEL assay).

Conclusions

This study provides the first evidence of the expression of IGF-R1, glycolysis-related proteins GLUT-1, HK 2, PFK-1, LDHA, and TKTL1, as well as mitochondrial enzymes SDHA, SDHB, and ATP synthase in the multi-step carcinogenesis of OSCC. Both, hypoxia-related glucose metabolism and mitochondrial oxidative phosphorylation characteristics are associated with the carcinogenesis of OSCC. Acidosis and OXPHOS may drive a metabolic shift towards the pentose phosphate pathway (PPP). Therefore, inhibition of the PPP, glycolysis, and targeted anti-mitochondrial therapies (ROS generation) by natural compounds or synthetic vitamin derivatives may act as sensitizer for apoptosis in cancer cells mediated by adjuvant therapies in OSCC.

[Importance of PET in surgery of esophageal cancer]

Perioperative or preoperative radiochemotherapy (RCTx) is nowadays standard for locally advanced esophageal cancer in Europe, as randomized studies have shown a significant survival benefit for patients with multimodal treatment. As responders and nonresponders have a significantly different prognosis, a response-based tailored preoperative treatment would be of utmost interest. An established method is a metabolic response evaluation by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). The level of metabolic response is known to be dependent on the localization, tumor entity and type of preoperative treatment. Association of FDG-PET with later response and prognosis was shown for absolute standardized uptake values (SUV) or a decrease of SUV levels before and after therapy but there are also contradictory findings in the literature and no prospective validation. However, neither time points nor cut-off for metabolic response evaluation have been defined so far. The most interesting approach seems to be early response monitoring during preoperative chemotherapy, which has shown promising results in prospective single center trials (MUNICON I/II) during chemotherapy of adenocarcinoma of the esophagogastric junction (AEG), but needs to be validated in prospective multicenter trails.

Imagine a world without cancer

Background

Since the “War on Cancer” was declared in 1971, the United States alone has expended some $300 billion on research, with a heavy focus on the role of genomics in anticancer therapy. Voluminous data have been collected and analyzed. However, in hindsight, any achievements made have not been realized in clinical practice in terms of overall survival or quality of life extended. This might be justified because cancer is not one disease but a conglomeration of multiple diseases, with widespread heterogeneity even within a single tumor type.

Discussion

Only a few types of cancer have been described that are associated with one major signaling pathway. This enabled the initial successful deployment of targeted therapy for such cancers. However, soon after this targeted approach was initiated, it was subverted as cancer cells learned and reacted to the initial treatments, oftentimes rendering the treatment less effective or even completely ineffective. During the past 30 plus years, the cancer classification used had, as its primary aim, the facilitation of communication and the exchange of information amongst those caring for cancer patients with the end goal of establishing a standardized approach for the diagnosis and treatment of cancers. This approach should be modified based on the recent research to affect a change from a service-based to an outcome-based approach. The vision of achieving long-term control and/or eradicating or curing cancer is far from being realized, but not impossible. In order to meet the challenges in getting there, any newly proposed anticancer strategy must integrate a personalized treatment outcome approach. This concept is predicated on tumor- and patient-associated variables, combined with an individualized response assessment strategy for therapy modification as suggested by the patient’s own results. As combined strategies may be outcome-orientated and integrate tumor-, patient- as well as cancer-preventive variables, this approach is likely to result in an optimized anticancer strategy.

Summary

Herein, we introduce such an anticancer strategy for all cancer patients, experts, and organizations: Imagine a World without Cancer.

A multifactorial histopathologic score for the prediction of prognosis of resected esophageal adenocarcinomas after neoadjuvant chemotherapy

BACKGROUND

For esophageal adenocarcinoma treated with neoadjuvant chemotherapy, postoperative staging classifications initially developed for non-pretreated tumors may not accurately predict prognosis. We tested whether a multifactorial TNM-based histopathologic prognostic score (PRSC), which additionally applies to tumor regression, may improve estimation of prognosis compared with the current Union for International Cancer Control/American Joint Committee on Cancer (UICC) staging system.

PATIENTS AND METHODS

We evaluated esophageal adenocarcinoma specimens following cis/oxaliplatin-based therapy from two separate centers (center 1: n = 280; and center 2: n = 80). For the PRSC, each factor was assigned a value from 1 to 2 (ypT0-2 = 1 point; ypT3-4 = 2 points; ypN0 = 1 point; ypN1-3 = 2 points; ≤ 50 % residual tumor/tumor bed = 1 point; >50 % residual tumor/tumor bed = 2 points). The three-tiered PRSC was based on the sum value of these factors (group A: 3; group B: 4-5; group C: 6) and was correlated with patients' overall survival (OS).

RESULTS

The PRSC groups showed significant differences with respect to OS (p < 0.0001; hazard ratio [HR] 2.2 [95 % CI 1.7-2.8]), which could also be demonstrated in both cohorts separately (center 1 p < 0.0001; HR 2.48 [95 % CI 1.8-3.3] and center 2 p = 0.015; HR 1.7 [95 % CI 1.1-2.6]). Moreover, the PRSC showed a more accurate prognostic discrimination than the current UICC staging system (p < 0.0001; HR 1.15 [95 % CI 1.1-1.2]), and assessment of two goodness-of-fit criteria (Akaike Information Criterion and Schwarz Bayesian Information Criterion) clearly supported the superiority of PRSC over the UICC staging.

CONCLUSION

The proposed PRSC clearly identifies three subgroups with different outcomes and may be more helpful for guiding further therapeutic decisions than the UICC staging system.

Predicting the response to chemotherapy in gastric adenocarcinoma: who benefits from neoadjuvant chemotherapy?

Despite a decline in the overall incidence, gastric adenocarcinoma remains the second most common cause of cancer death worldwide and thus a significant global health problem. Even in early-stage locoregional confined disease the 5-year survival rarely exceeds 25-35 %. Randomized trials have demonstrated a benefit from neoadjuvant and perioperative chemotherapy. However the optimal approach in individual patients is not clear and remains controversial. A consistent finding is that patients who have a histopathological response to neoadjuvant therapy are more likely to receive a survival benefit. These clinical data provide a strong argument for the urgent development of methods to predict histopathological response to neoadjuvant therapies for gastric adenocarcinomas. Published data demonstrate that clinico-pathological features (tumour histology and location), imaging through metabolic response by FDG-PET and tissue/molecular biomarkers may all have a predictive value for neoadjuvant therapies. However it is still uncertain from published data whether or not they will be useful for clinical decision making in individual patients. Existing candidate biomarkers need to be properly qualified and validated and novel biomarkers are required and an optimal approach should involve the combination and integration of clinical, imaging, pathological and molecular biomarkers.

Pyrosequencing assay to measure LINE-1 methylation level in esophageal squamous cell carcinoma

BACKGROUND

Genome-wide DNA hypomethylation plays a role in genomic instability and carcinogenesis. DNA methylation in the long interspersed nucleotide element 1 L1 (LINE-1) repetitive element is a good indicator of global DNA methylation level. LINE-1 methylation is a useful marker for predicting cancer prognosis and monitoring efficacy of adjuvant therapy. Nonetheless, no study has examined LINE-1 methylation in esophageal squamous cell carcinoma (ESCC). The aim of this study is to assess the precision of sodium bisulfite conversion and polymerase chain reaction (PCR) pyrosequencing assay for evaluating LINE-1 methylation in ESCC.

METHODS

To measure assay precision, we performed bisulfite conversion on 5 different DNA specimen aliquots (bisulfite-to-bisulfite) and repeated PCR pyrosequencing five times (run to run). Second, to assess heterogeneity of LINE-1 methylation levels within tumor, we made 5 different tissue sections from one tumor and examined LINE-1 methylation level of each section (section to section). Third, to evaluate LINE-1 methylation status in ESCC, we applied this assay to 30 ESCCs and 30 matched normal esophageal mucosa.

RESULTS

Bisulfite-to-bisulfite standard deviation (SD) ranged from 1.44 to 2.90 (median 2.32) in ESCCs; and 0.57 to 4.02 (median 1.23) in normal esophagus. Run-to-run SD ranged from 0.63 to 3.25 (median 1.54) in ESCCs. Section-to-section SD ranged from 1.37 to 3.31 (median 1.94). ESCC tissues showed significantly lower levels of LINE-1 methylation than matched normal mucosa (P < .0001; n = 30). There was no significant relationship between LINE-1 methylation level and tumor stage (P = 0.14).

CONCLUSIONS

Bisulfite conversion and PCR pyrosequencing assay can measure LINE-1 methylation in ESCC, and may be useful in clinical and research settings.

Trimodal therapy in squamous cell carcinoma of the esophagus

Patients with ESCC (squamous cell carcinoma of the esophagus) are most commonly diagnosed with locally advanced tumor stages. Early metastatic disease and late diagnosis are common reasons responsible for this tumor's poor clinical outcome. The prognosis of esophageal cancer is very poor because patients usually do not have symptoms in early disease stages. Squamous cell carcinoma of the esophagus frequently complicates patients with multiple co-morbidities and these patients often require interdisciplinary diagnosis and treatment procedures. At present time, neoadjuvant radiation therapy and chemotherapy followed by surgery are regarded as the international standard of care. Meta-analyses have confirmed that this approach provides the patient with better local tumor control and an increased overall survival rate. It is recommended that patients with positive tumor response to neoadjuvant therapy and who are poor surgical candidates should consider definitive radiochemotherapy without surgery as a treatment option. In future, EGFR antibodies may also be administered to patients during therapy to improve the current treatment effectiveness. Positron-emission tomography proves to be an early response-imaging tool used to evaluate the effect of the neoadjuvant therapy and could be used as a predictive factor for the survival rate in ESCC. The percentage proportions of residual tumor cells in the histopathological analyses represent a gold standard for evaluating the response rate to radiochemotherapy. In the future, early response evaluation and molecular biological tests could be important diagnostic tools in influencing the treatment decisions of ESCC patients.

Barrett's esophagus: treatments of adenocarcinomas II

The following topics are explored in this collection of commentaries on treatments of adenocarcinomas related to Barrett's esophagus: the importance of intraoperative frozen sections of the margins for the detection of high dysplasia; the preferable way for sentinel node dissection; the current role of robotic surgery and of video-endoscopic approach; the value of the Siewert's classification of adenocarcinomas; the indications of two-step esophagectomy; the evaluation of pathological complete response; the role of PET scan in staging and response assessment; the role of p53 in the selection of adenocarcinomas patients; chemotherapy regimens for adenocarcinomas; the use of monoclonal antibodies in the control of cell proliferation; he attempt to define a stage-specific strategy, and the possible indications of selective therapy; and changes in mortality rates from esophageal cancer.

The role of neoadjuvant and adjuvant treatment for adenocarcinoma of the upper gastrointestinal tract

Both locally advanced adenocarcinoma of the stomach and gastro-esophageal junction are associated with poor prognosis due to the lack of effective treatment. Recently multimodal treatment consisting of neoadjuvant chemotherapy in combination with radiotherapy is reported to improve survival when compared to surgery alone. Neoadjuvant therapy in these locally advanced tumors allows for early tumor responses and the extent of tumor regression that can be achieved is considered a significant prognostic factor. This, in turn, increases the resectability of these tumors. Also due to the high frequency of lymph node metastasis, patients with locally advanced adenocarcinoma should undergo a D2 lymphadenectomy. Postoperative chemoradiation and perioperative chemotherapy have been studied in gastric adenocarcinomas and showed a survival benefit. However, the surgical techniques used in these trials are no longer considered to be standard by today's surgical practice. In addition, there are no standard recommendations for adjuvant chemotherapy or chemoradiation after R0 resection and adequate lymph node dissection.

Critical role of surgery in patients with gastroesophageal carcinoma with a poor prognosis after chemoradiation as defined by positron emission tomography

BACKGROUND

The prognosis of patients with localized gastroesophageal carcinoma (LGC) can be defined after chemoradiation by the standardized uptake value (SUV) of positron emission tomography (PET). High SUV (HSUV) after chemoradiation portends a poor prognosis. The authors retrospectively examined the role of surgery in patients with HSUV after chemoradiation.

METHODS

The authors analyzed the postchemoradiation PET scans of 204 LGC patients. One hundred twenty-nine patients had HSUV. Two postchemoradiation variables were evaluated: SUV and surgery and their association with overall survival (OS) and event-free survival (EFS). The log-rank test, multivariate Cox proportional hazards model, and Kaplan-Meier survival plots were used to assess the association between OS or EFS and the dichotomized SUV (using the median SUV as the cutoff) and surgery.

RESULTS

The median SUV was 4.6. The OS of the 52 patients who had an SUV above the median and did not undergo surgery (HSUV-NS) (median OS, 1.22 years; 95% confidence interval [95% CI], 1.02-2.16 years) was much shorter than that of the 77 patients with an SUV above the median who underwent surgery (HSUV-S) (median OS, 2.7 years; 95% CI, 2.43 years to not reached [P<.0001]). Similarly, the EFS for patients with HSUV-NS was significantly shorter than that for patients with HSUV-S (P=.001). In the multivariate analyses, patients who underwent surgery (irrespective of SUV) had a lower risk of death (P=.0001) and disease progression (P=.002).

CONCLUSIONS

The data from the current study suggest that surgery may prolong OS and EFS in patients with a poor prognosis after chemoradiation as defined by PET. However, these data need confirmation.

Pathologic T0N1 esophageal cancer after neoadjuvant therapy and surgery: an orphan status

BACKGROUND

Patients with esophageal carcinoma who appear to have a complete response at the primary tumor site after undergoing neoadjuvant chemoradiotherapy may still have residual disease in regional lymph nodes despite clinically negative restaging (ypT0N1). We hypothesized that these patients would have similar survival to patients with incomplete response to therapy.

METHODS

We reviewed 336 esophageal cancer patients who received neoadjuvant chemoradiotherapy followed by complete resection. We identified 20 patients who obtained complete pathologic response at the primary tumor with persistent metastatic disease to regional lymph nodes (ypT0N1). These patients were compared to 123 patients with pathologic complete response and 193 with partial response for overall survival.

RESULTS

Demographics among the three groups of patients were similar except that this cohort of patients with ypT0N1 had higher initial clinical stage (p = 0.013) and had more squamous cell carcinoma pathology (p = 0.005). Eighty-six percent of the ypT0N1 patients who had modern preoperative staging were felt to have clinical complete response. Five-year survival of ypT0N1 patients was intermediate, similar to pathologic partial response stage II patients in both the sixth and seventh editions of the American Joint Committee on Cancer staging criteria.

CONCLUSIONS

Clinical staging of complete response to chemoradiotherapy may not translate to pathologic complete response. Patients with ypT0N1 disease at resection have intermediate but reasonable survival, justifying an aggressive approach to curative therapy. Future revisions of the staging system should place this group of patients with patients who have metastatic regional lymph nodes, stratified by number of nodes involved.

Phosphorylated mTOR expression is associated with poor prognosis for patients with esophageal squamous cell carcinoma

BACKGROUND

The mammalian target of rapamycin (mTOR) plays central roles in the regulation of cell growth and proliferation by monitoring nutrient availability, cellular energy level, oxygen level, and mitogenic signals. The aberrant activation of mTOR in relation to clinical outcome has been reported in several types of cancers. mTOR is increasingly important as a potential target for anticancer therapy. Nonetheless, a prognostic feature of mTOR activation in esophageal squamous cell carcinoma (ESCC) remains uncertain.

MATERIALS AND METHODS

First, in order to validate phospho-specific mTOR antibody (Ser2448), phosphorylated mTOR (p-mTOR) expression levels in five ESCC cell lines under cultural conditions with or without everolimus (mTOR inhibitor, also known as RAD001) were evaluated by in vitro immunohistochemistry and immunoblotting. Second, we examined p-mTOR expression by immunohistochemistry using 143 resected ESCC specimens. Prognostic significance of p-mTOR expression was examined by Cox regression and Kaplan-Meier analyses.

RESULTS

Among 143 patients, 71 (49.7%) were classified into p-mTOR-positive and 72 (50.3%) were classified into p-mTOR-negative. Compared with p-mTOR-negative patients, p-mTOR-positive patients experienced high overall mortality [hazard ratio (HR) 2.44; 95% confidence interval (CI), 1.24-4.83; P = 0.008], which persisted in multivariate analysis (multivariate HR 2.92; 95% CI, 1.48-5.78; P = 0.002). A similar finding was observed for esophageal cancer-specific mortality. p-mTOR expression was not related with any clinical or pathologic variables including age, sex, tumor location, histological grading, operative procedure, T classification (tumor invasion), or lymph-node metastasis.

CONCLUSIONS

p-mTOR overexpression was independently associated with poor prognosis in ESCC, supporting the potential for mTOR as a therapeutic target for ESCC.

Predicting response to treatment in gastroesophageal junction adenocarcinomas: combining clinical, imaging, and molecular biomarkers

The incidence of adenocarcinomas of the gastroesophageal junction (GEJ) is rapidly rising, and even in early-stage locoregional confined disease the 5-year survival rate rarely exceeds 25%-35%. Randomized trials and meta-analyses have demonstrated a benefit with neoadjuvant or perioperative chemotherapy and with neoadjuvant chemoradiotherapy. However, the optimal approach in individual patients is not clear and remains controversial. A consistent finding is that patients who have a histopathological response to neoadjuvant therapy are more likely to receive a survival benefit. These clinical data provide a strong argument for the urgent development of methods to predict histopathological response to neoadjuvant therapies for GEJ adenocarcinoma. Published data demonstrate that clinicopathological features (tumor location), imaging (fluorodeoxyglucose-positron emission tomography "metabolic response"), and tissue/molecular biomarkers may all have a predictive value for neoadjuvant therapies. However, it is uncertain from published data whether or not they will be useful for clinical decision making in individual patients. Existing candidate biomarkers need to be properly qualified and validated and novel biomarkers are required; and an optimal approach should involve the combination and integration of clinical, imaging, and molecular biomarkers. This review presents the evidence base and discusses novel experimental approaches for the combination of biomarker modalities to allow optimization of an individualized treatment approach in GEJ adenocarcinoma patients that may be relevant to other tumor types as well.

[Neoadjuvant therapy in the upper gastro-intestinal tract. Modern strategies for Barrett's cancer]

While primary surgical resection with systematic lymphadenectomy remains the treatment of choice for locoregional Barrett's cancer, neoadjuvant chemotherapy is an increasingly accepted treatment modality for patients with locally advanced tumors and patients with extensive lymphatic spread. In contrast to neoadjuvant radiochemotherapy preoperative chemotherapy alone does not seem to increase peri-operative complications and mortality. Responders to pre-operative treatment clearly have a survival advantage as compared to those who do not respond. The use of positron emission tomography to measure changes in glucose metabolism of the primary tumor can predict response early after initiation of neoadjuvant chemotherapy and thus help to select patients who will or will not benefit from this approach. The best treatment strategy for non-responders to neoadjuvant therapy remains to be defined.