Transcriptomic biomarkers for predicting response to neoadjuvant treatment in oesophageal cancer

Oesophageal cancer is a devastating disease with poor outcomes and is the sixth leading cause of cancer death worldwide. In the setting of resectable disease, there is clear evidence that neoadjuvant chemotherapy and chemoradiotherapy result in improved survival. Disappointingly, only 15%-30% of patients obtain a histopathological response to neoadjuvant therapy, often at the expense of significant toxicity. There are no predictive biomarkers in routine clinical use in this setting and the ability to stratify patients for treatment could dramatically improve outcomes. In this review, we aim to outline current progress in evaluating predictive transcriptomic biomarkers for neoadjuvant therapy in oesophageal cancer and discuss the challenges facing biomarker development in this setting. We place these issues in the wider context of recommendations for biomarker development and reporting. The majority of studies focus on messenger RNA (mRNA) and microRNA (miRNA) biomarkers. These studies report a range of different genes involved in a wide variety of pathways and biological processes, and this is explained to a large extent by the different platforms and analysis methods used. Many studies are also vastly underpowered so are not suitable for identifying a candidate biomarker. Multiple molecular subtypes of oesophageal cancer have been proposed, although little is known about how these relate to clinical outcomes. We anticipate that the accumulating wealth of genomic and transcriptomic data and clinical trial collaborations in the coming years will provide unique opportunities to stratify patients in this poor-prognosis disease and recommend that future biomarker development incorporates well-designed retrospective and prospective analyses.

Verification of the Optimal Interval Before Esophagectomy After Preoperative Neoadjuvant Chemoradiotherapy for Locally Advanced Thoracic Esophageal Cancer

BACKGROUND

The interval between preoperative chemoradiotherapy and surgery reportedly affects perioperative outcomes and survival; however, the optimal interval in esophageal cancer patients remains uncertain.

OBJECTIVE

Our aim was to determine whether a prolonged interval between preoperative neoadjuvant chemoradiotherapy (NACRT) and esophagectomy affects the outcomes of esophageal cancer patients.

METHODS

A total of 131 patients with esophageal cancer received curative surgery following NACRT at Akita University Hospital between 2009 and 2017. We divided these patients into two groups based on the median interval from NACRT to esophagectomy, and compared the rates of pathological complete response (pCR), surgical outcomes, and survival.

RESULTS

The median interval from NACRT to esophagectomy was 39 days (range 21-95). Of the 131 patients, 70 (53%) received esophagectomy after 39 days or more from completion of NACRT. There were no significant differences in the clinicopathological features, including pCR rates, between the two groups. Prolongation of the interval from NACRT to esophagectomy was significantly associated with an increased rate of anastomotic leakage and recurrent laryngeal nerve palsy (p = 0.0225 and p = 0.0022, respectively); however, no association with overall survival was detected.

CONCLUSIONS

A prolonged interval between NACRT and esophagectomy had no impact on pCR rates or survival. However, delaying esophagectomy may increase the likelihood of surgical complications such as anastomotic leakage and recurrent laryngeal nerve palsy.

Alteration of plasma metabolites associated with chemoradiosensitivity in esophageal squamous cell carcinoma via untargeted metabolomics approach

BACKGROUND

To investigate the differences in plasma metabolomic characteristics between pathological complete response (pCR) and non-pCR patients and identify biomarker candidates for predicting the response to neoadjuvant chemoradiotherapy (nCRT) in esophageal squamous cell carcinoma (ESCC).

METHODS

A total of 46 ESCC patients were included in this study. Gas chromatography time-of- flight mass spectrometry (GC-TOF/MS) technology was applied to detect the plasma samples collected before nCRT via untargeted metabolomics analysis.

RESULTS

Five differentially expressed metabolites (out of 109) was found in plasma between pCR and non-pCR groups. Compared with non-pCR group, isocitric acid (p = 0.0129), linoleic acid (p = 0.0137), citric acid (p = 0.0473) were upregulated, while L-histidine (p = 0.0155), 3'4 dihydroxyhydrocinnamic acid (p = 0.0339) were downregulated in the pCR plasma samples. Pathway analyses unveiled that citrate cycle (TCA cycle), glyoxylate and dicarboxylate metabolic pathway were associated with ESCC chemoradiosensitivity.

CONCLUSION

The present study provided supporting evidence that GC-TOF/MS based metabolomics approach allowed identification of metabolite differences between pCR and non-pCR patients in plasma levels, and the systemic metabolic status of patients may reflect the response of ESCC patient to neoadjuvant chemoradiotherapy.

Human umbilical cord mesenchymal stem cells-derived exosomes deliver microRNA-375 to downregulate ENAH and thus retard esophageal squamous cell carcinoma progression

Background

Exosomal microRNAs (miRNAs or miRs) from bone marrow-derived mesenchymal stem cells (UCMSCs) have emerged as promising therapeutic strategies for cancer treatment. The current study aimed to elucidate the underlying mechanism of human umbilical cord mesenchymal stem cells (hUCMSCs)-derived exosomal miR-375 in esophageal squamous cell carcinoma (ESCC).

Methods

After determining the expression of miR-375 and its putative target enabled homolog (ENAH) in ESCC tissues and cells, we tested effects of their altered expression on ESCC proliferation, invasion, migration, and tumorsphere formation was subsequently measured. Transfected hUCMSCs-derived exosomes (hUCMSCs-exo) were isolated and co-cultured with ESCC cells to measure the effects of miR-375 delivered by hUCMSCs-exo on ESCC development. Finally, we investigated the effect of miR-375 on tumor growth in vivo.

Results

The expression of miR-375 was reduced, while the expression of ENAH was elevated in ESCC. ENAH was identified as a target gene of miR-375. Elevated miR-375 or depleted ENAH expression inhibited ESCC cell proliferation, invasion, migration, tumorsphere formation, and promoted apoptosis. Moreover, miR-375 delivered by hUCMSCs-exo could suppress ESCC cell proliferation, invasion, migration, tumorsphere formation, but promoted apoptosis in vitro, as well as inhibiting tumor growth in vivo.

Conclusions

Taken together, hUCMSCs-exo can deliver miR-375 to suppress ENAH expression and subsequently inhibit the initiation and progression of ESCC.

Patients with Non-response to Neoadjuvant Chemoradiation for Esophageal Cancer Have No Survival Advantage over Patients Undergoing Primary Esophagectomy

BACKGROUND

Survival for patients with locally advanced esophageal cancer remains dismal. Non-response to neoadjuvant chemoradiation (nCRT) portends worse survival. We hypothesized that patients undergoing up-front esophagectomy may have better survival than those who do not respond to nCRT.

METHODS

We identified all patients undergoing esophagectomy with a pathologic stage of II or greater at our institution between 1994 and 2015 and separated them into two groups: those who received nCRT and those undergoing up-front esophagectomy. The neoadjuvant group was further separated into patients downstaged to pathologic stage 0 or I (responders) and patients with either the same or higher pathologic stage after nCRT, or with pathologic stage II disease or greater (non-responders). Overall survival was compared between groups using Kaplan-Meier statistics. Covariate-adjusted Cox modeling was used to estimate hazard ratios (HR) for mortality associated with non-response.

RESULTS

Overall, 287 patients met inclusion criteria. Fifty-nine percent of the responders had pathologic complete response (pCR). The majority of non-responders and primary esophagectomy patients had stage II or III disease (94%). Median survival was 58.3 months in responders, 23.9 months in non-responders, and 29.1 months in primary esophagectomy patients (p < 0.01). The HR for mortality associated with non-response was 1.82 compared to response to nCRT (p < 0.01) and 1.09 compared to primary esophagectomy (p = 0.71).

CONCLUSIONS

In patients with esophageal cancer who do not respond to nCRT, neoadjuvant therapy may represent a toxic and costly treatment modality that does not improve survival and may delay potentially curative resection. Further research is needed to identify potential non-responders with advanced resectable disease and allow individual tailoring of pre-surgical decision-making.

Autophagy modulators for the treatment of oral and esophageal squamous cell carcinomas

Oral squamous cell carcinomas (OSCC) and esophageal squamous cell carcinomas (ESCC) exhibit a survival rate of less than 60% and 40%, respectively. Late-stage diagnosis and lack of effective treatment strategies make both OSCC and ESCC a significant health burden. Autophagy, a lysosome-dependent catabolic process, involves the degradation of intracellular components to maintain cell homeostasis. Targeting autophagy has been highlighted as a feasible therapeutic strategy with clinical utility in cancer treatment, although its associated regulatory mechanisms remain elusive. The detection of relevant biomarkers in biological fluids has been anticipated to facilitate early diagnosis and/or prognosis for these tumors. In this context, recent studies have indicated the presence of specific proteins and small RNAs, detectable in circulating plasma and serum, as biomarkers. Interestingly, the interplay between biomarkers (eg, exosomal microRNAs) and autophagic processes could be exploited in the quest for targeted and more effective therapies for OSCC and ESCC. In this review, we give an overview of the available biomarkers and innovative targeted therapeutic strategies, including the application of autophagy modulators in OSCC and ESCC. Additionally, we provide a viewpoint on the state of the art and on future therapeutic perspectives combining the early detection of relevant biomarkers with drug discovery for the treatment of OSCC and ESCC.

Volumetric histogram analysis of apparent diffusion coefficient for predicting pathological complete response and survival in esophageal cancer patients treated with chemoradiotherapy

BACKGROUND

The purpose of the study was to evaluate whether histogram analysis of apparent diffusion coefficient (ADC) can predict pathological complete response (pCR) and survival in patients with esophageal squamous cell carcinoma (ESCC) after chemoradiotherapy (CRT).

METHODS

We retrospectively identified 58 patients with ESCC who underwent surgery after CRT between 2007 and 2016. Associations of pretreatment histogram derived ADC parameters with pathological response and survival were analyzed.

RESULTS

Tumors achieved pCR (10 patients, 17.2%) showed significant lower ADC, higher kurtosis, and higher skewness than those of non-pCR (p = 0.005, 0.007, <0.001, respectively). Receiver operating characteristics analysis demonstrated skewness was the best predictor for pCR (AUC = 0.86), with a cut off value of 0.50 (accuracy, 86.2%). In Kaplan-Meier analysis, patients with higher skewness tumors (≥0.50) showed a significantly better recurrence free survival (p = 0.032, log-rank).

CONCLUSIONS

Histogram analysis of ADC can enable prediction of pCR and survival in ESCC patients treated with preoperative CRT.

A SHORT SUMMARY

ADC histogram analysis can be an imaging biomarker for esophageal cancer patients treated with CRT.

The crucial role of blood VEGF kinetics in patients with locally advanced esophageal squamous cell carcinoma receiving curative concurrent chemoradiotherapy

Background

To evaluate the role of blood vascular endothelial growth factor (VEGF) kinetics in patients with locally advanced esophageal squamous cell carcinoma (ESCC) receiving curative concurrent chemoradiotherapy (CCRT).

Methods

A total of 97 locally advanced ESCC patients were enrolled. All the patients had their blood drawn at three time points to determine their levels of VEGF, including pre-chemotherapy (day 0), post-chemotherapy (day 5), and pre-cycle 2 chemotherapy (day 28). The VEGF levels were evaluated according to the day 0 value, day 5 value, day 28 value, day 5/day 0 ratio, day 28/day 0 ratio, and day 28/day 5 ratio. A VEGF cut-off level of 80 pg/mL was applied.

Results

In the analysis of progression-free survival (PFS), the patients less than 60 years old had significantly superior PFS compared to those more than 60 years old. Patients who had VEGF < 80 pg/mL at day 28 and a day 28/day 5 ratio < 1 had better PFS than those with VEGF > 80 pg/mL and a day 28/day 5 ratio > 1, respectively. In the analysis of overall survival (OS), patients with N0–1 status had significantly superior OS compared to those with N2–3 status. Furthermore, patients who had VEGF < 80 pg/mL at day 28, a day 5/day 0 ratio < 1, and a day 28/day 5 ratio < 1 had superior OS compared to those patients with VEGF > 80 pg/mL, a day 5/day 0 ratio > 1, and a day 28/day 5 ratio > 1, respectively. In the multivariate analysis, only VEGF < 80 pg/mL at day 28 and a day 28/day 5 ratio < 1 represented independent prognostic factors of superior PFS and OS.

Conclusions

Our study suggests that VEGF kinetics is a prognostic factor for locally advanced ESCC patients receiving curative CCRT. For these patients, lower post-treatment VEGF levels and decreasing levels of VEGF during CCRT are significantly associated with better clinical outcomes.

Identification of serum biomarkers of chemoradiosensitivity in esophageal cancer via the targeted metabolomics approach

AIM

To identify the serum metabolomics signature that is correlated with the chemoradiosensitivity of esophageal squamous cell carcinoma (ESCC).

MATERIALS & METHODS

Untargeted and targeted metabolomics analysis of serum samples from 26 ESCC patients, which were collected before the neoadjuvant chemoradiotherapy, was performed.

RESULTS

On receiving the results of untargeted metabolomics analysis, we performed the targeted metabolomics analysis of the six metabolites (arabitol, betaine, glycine, L-serine, L-arginine and L-aspartate). The serum levels of the four metabolites (arabitol, glycine, L-serine and L-arginine) were significantly lower in the patients who achieved pathological complete response with neoadjuvant chemoradiotherapy compared with the patients who did not achieve pathological complete response (p = 0.0086, 0.0345, 0.0106 and 0.0373, respectively).

CONCLUSION

The serum levels of metabolites might be useful for predicting the chemoradiosensitivity of ESCC patients.

18F-fluorodeoxyglucose positron emission computed tomography for monitoring tumor response in esophageal carcinoma treated with concurrent chemoradiotherapy

The aim of the present study was to explore the value of ^18F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) in monitoring the early tumor response of esophageal squamous cell carcinoma (ESCC) treated with concurrent chemoradiotherapy (CRT). A total of 48 patients with pathologically proven ESCC were retrospectively analyzed. All patients underwent two serial ¹⁸F-FDG PET scans at baseline (pre-CRT) and 40 Gy/4 weeks of starting radiation therapy (inter-CRT). All patients received intensity-modulated radiotherapy (with a total radiation dose of 59.6 Gy) concurrently with cisplatin-based chemotherapy. The maximum standardized uptake value (SUV_max) and metabolic tumor volume (MTV) were measured using ¹⁸F-FDG PET. The percentage changes (Δ) in SUV_max and MTV between two serial scans were calculated and were revealed to be associated with the objective tumor response (oTR), according to the Response Evaluation Criteria in Solid Tumors 1.1. Among the 48 patients, 20.8% achieved a complete response, 68.8% exhibited a partial response and the oTR rate was 89.6%. On the pre-CRT PET scans, the mean SUV_max and MTV were 14.1±5.8 and 58.2±25.4 cm³, respectively. Following 40 Gy irradiation over 4 weeks, the mean SUV_max and MTV significantly decreased to 4.3±3.5 and 19.0±12.1 cm³, respectively (P<0.001). A significantly higher ΔSUV_max and ΔMTV was observed in the responders compared with that in the non-responders [0.71±0.16 vs. 0.51±0.26 (P=0.015); and 0.64±0.13 vs. 0.42±0.09 (P=0.001), respectively]. Univariate analysis revealed that ΔSUV_max and ΔMTV were significantly associated with oTR (P=0.010 and P=0.001, respectively). ΔMTV was used as a predictor and a cut-off value of 54% discriminated responders from non-responders with a sensitivity of 69.8% and a specificity of 100% (P=0.001). The area under the receiver operating characteristic curve was 0.837 (95% confidence interval, 0.702-0.928). The results of the present study indicated that interim ¹⁸F-FDG PET scans may provide early prognostic value for determining oTR in patients with ESCC undergoing treatment with CRT.