Multicenter randomized phase II study of cisplatin and fluorouracil plus docetaxel (DCF) compared with cisplatin and fluorouracil plus Adriamycin (ACF) as preoperative chemotherapy for resectable esophageal squamous cell carcinoma (OGSG1003)

BACKGROUND

This phase II trial evaluated the efficacy of cisplatin and fluorouracil (CF)-based combination neoadjuvant chemotherapy on the outcome of patients with resectable locally advanced esophageal squamous cell carcinoma (ESCC). We compared the recurrence-free survival (RFS) associated with CF plus Adriamycin (ACF) with that associated with CF plus docetaxel (DCF) to select an alternative regimen in a new phase III trial investigating the optimal neoadjuvant treatment of patients with ESCC.

PATIENTS AND METHODS

Patients with resectable advanced ESCC were randomly assigned to either ACF (Adriamycin 35 mg/m2, cisplatin 70 mg/m2 i.v. on day 1, fluorouracil 700 mg/m2 continuous infusion for 7 days) every 4 weeks or DCF (docetaxel 70 mg/m2, cisplatin 70 mg/m2 i.v. on day 1, fluorouracil 700 mg/m2 continuous infusion for 5 days) every 3 weeks. Surgery was scheduled after completion of two cycles of chemotherapy. The primary end point was RFS, analyzed by the intention-to-treat.

RESULTS

Between October 2011 and October 2013, 162 patients at 10 institutions were enrolled in the study, all of whom were eligible and randomly assigned to the two groups (81 to the ACF group and 81 to the DCF group). The R0 resection rates for the ACF and DCF groups were equivalent (95.9% versus 96.2%, P = 0.93). The 2-year RFS and overall survival rates for DCF versus ACF were 64.1% versus 42.9% (hazard ratio 0.53, 95% confidence interval 0.33-0.83, P = 0.0057) and 78.6% versus 65.4% (P = 0.08), respectively.

CONCLUSION

Compared with ACF, DCF chemotherapy was associated with prolonged RFS for patients with resectable advanced ESCC. Thus, DCF chemotherapy has potential as a standard neoadjuvant therapy for resectable ESCC.

CLINICAL TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry of Japan (identification number UMIN000004555/000004616).

Impact of number of [(18)F]fluorodeoxyglucose-PET-positive lymph nodes on survival of patients receiving neoadjuvant chemotherapy and surgery for oesophageal cancer

BACKGROUND

[(18) F]fluorodeoxyglucose (FDG)-PET has been used to evaluate the response of primary tumours to neoadjuvant therapy for oesophageal cancer. The clinical significance of the number of PET-positive nodes before and after therapy has not been investigated previously.

METHODS

[(18) F]FDG-PET was performed before and 2-3 weeks after completion of neoadjuvant chemotherapy to identify the number of PET-positive nodes, and these numbers were assessed in relation to metabolic changes in the primary tumour.

RESULTS

Of 302 patients in total, 90 had no PET-positive nodes, 83 had one, 59 had two and 70 patients had three or more positive nodes before therapy. After treatment, the numbers were: none in 207 patients, one in 59, two in 20 and three or more in 16 patients. The number of PET-positive nodes after treatment was influenced by both the number of PET-positive nodes before therapy and the response to preoperative therapy, and correlated with the number of metastatic lymph nodes. Overall survival was longer in patients who had no PET-positive nodes after treatment than in those who had one or more. Multivariable analysis identified the numbers of PET-positive nodes before and after chemotherapy as independent prognostic factors, together with clinical response, tumour depth and lymph node involvement.

CONCLUSION

The number of PET-positive nodes after treatment correlated with survival in patients with oesophageal cancer who underwent neoadjuvant chemotherapy.

Exosomal microRNA in serum is a novel biomarker of recurrence in human colorectal cancer

Background:

Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the early detection of recurrence in human colorectal cancer (CRC).

Methods:

Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT–PCR.

Results:

Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001).

Conclusions:

Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.

The AURKA/TPX2 axis drives colon tumorigenesis cooperatively with MYC

BACKGROUND

The MYC oncogene has long been established as a central driver in many types of human cancers including colorectal cancer. However, the realization of MYC-targeting therapies remains elusive; as a result, synthetic lethal therapeutic approaches are alternatively being explored. A synthetic lethal therapeutic approach aims to kill MYC-driven tumors by targeting a certain co-regulator on the MYC pathway.

PATIENTS AND METHODS

We analyzed copy number and expression profiles from 130 colorectal cancer tumors together with publicly available datasets to identify co-regulators on the MYC pathway. Candidates were functionally tested by in vitro assays using colorectal cancer and normal fibroblast cell lines. Additionally, survival analyses were carried out on another 159 colorectal cancer patients and public datasets.

RESULTS

Our in silico screening identified two MYC co-regulator candidates, AURKA and TPX2, which are interacting mitotic regulators located on chromosome 20q. We found the two candidates showed frequent co-amplification with the MYC locus while expression levels of MYC and the two genes were positively correlated with those of MYC downstream target genes across multiple cancer types. In vitro, the aberrant expression of MYC, AURKA and TPX2 resulted in more aggressive anchorage-independent growth in normal fibroblast cells. Furthermore, knockdown of AURKA or TPX2, or treatment with an AURKA-specific inhibitor effectively suppressed the proliferation of MYC-expressing colorectal cancer cells. Additionally, combined high expression of MYC, AURKA and TPX2 proved to be a poor prognostic indicator of colorectal cancer patient survival.

CONCLUSIONS

Through bioinformatic analyses and experiments, we proposed TPX2 and AURKA as novel co-regulators on the MYC pathway. Inhibiting the AURKA/TPX2 axis would be a novel synthetic lethal therapeutic approach for MYC-driven cancers.

Monitoring gastric cancer progression with circulating tumour DNA

Background:

Circulating tumour DNA (ctDNA) is an emerging candidate biomarker for malignancies and may be useful for monitoring the disease status of gastric cancer.

Methods:

We performed targeted deep sequencing of plasma cell-free DNA (cfDNA) by massively parallel sequencing in patients with tumours harbouring TP53 mutations. The quantitative values of TP53-ctDNA during the clinical course were compared with the tumour status.

Results:

Three out of ten patients with TP53 mutations in primary tumours showed detectable TP53 mutation levels in preoperative cfDNA. Although the cfDNA concentrations were not always reflective of the disease course, the ctDNA fraction correlated with the disease status.

Conclusions:

ctDNA may serve as a useful biomarker to monitor gastric cancer progression and residual disease.

Laparoscopic intraoperative navigation surgery for gastric cancer using real-time rendered 3D CT images

PURPOSE

Recent advances in laparoscopic surgical technology have made it possible to perform advanced high-level surgery, such as lymph node dissection for malignancy. Grasping the anatomy during such procedures is important for a safe operation. We have developed a new image information system that provides three-dimensional (3D) reconstructed CT images synchronized with the motion of the laparoscope. This study assesses this new navigation system.

METHODS

Enhanced CT using a custom-made software program can provide 3D angiography images reconstructed as a laparoscopic view. A motion sensor mounted on the laparoscope can detect the direction angle of the laparoscope. The real-time rendered 3D CT images are synchronized with the laparoscopic video images according to the motion of the scope. These 3D CT images are projected on another monitor close to the laparoscopic video monitor. Lymph node dissection can be performed with the help of the real-time navigation system that provides a detailed 3D view of the vasculature.

RESULTS

Ten laparoscopic gastrectomies were performed using this navigation system. Real-time intraoperative navigation of the vasculature was available, allowing for an excellent surgical outcome. No complications occurred in this series.

CONCLUSION

Our intraoperative navigation system allows for safe laparoscopic gastric lymph node dissection.

MicroRNA-1246 expression associated with CCNG2-mediated chemoresistance and stemness in pancreatic cancer

Background:

Pancreatic cancer has a poor prognosis because of its high refractoriness to chemotherapy and tumour recurrence, and these properties have been attributed to cancer stem cells (CSCs). MicroRNA (miRNA) regulates various molecular mechanisms of cancer progression associated with CSCs. This study aimed to identify the candidate miRNA and to characterise the clinical significance.

Methods:

We established gemcitabine-resistant Panc1 cells, and induced CSC-like properties through sphere formation. Candidate miRNAs were selected through microarray analysis. The overexpression and knockdown experiments were performed by evaluating the in vitro cell growth and in vivo tumourigenicity. The expression was studied in 24 pancreatic cancer samples after laser captured microdissection and by immunohistochemical staining.

Results:

The in vitro drug sensitivity of pancreatic cancer cells was altered according to the miR-1246 expression via CCNG2. In vivo, we found that miR-1246 could increase tumour-initiating potential and induced drug resistance. A high expression level of miR-1246 was correlated with a worse prognosis and CCNG2 expression was significantly lower in those patients.

Conclusions:

miR-1246 expression was associated with chemoresistance and CSC-like properties via CCNG2, and could predict worse prognosis in pancreatic cancer patients.

Amplification of PVT-1 is involved in poor prognosis via apoptosis inhibition in colorectal cancers

Background:

We previously conducted gene expression microarray analyses to identify novel indicators for colorectal cancer (CRC) metastasis and prognosis from which we identified PVT-1 as a candidate gene. PVT-1, which encodes a long noncoding RNA, mapped to chromosome 8q24 whose copy-number amplification is one of the most frequent events in a wide variety of malignant diseases. However, PVT-1 molecular mechanism of action remains unclear.

Methods:

We conducted cell proliferation and invasion assays using colorectal cancer cell lines transfected with PVT-1siRNA or negative control siRNA. Gene expression microarray analyses on these cell lines were also carried out to investigate the molecular function of PVT-1. Further, we investigated the impact of PVT-1 expression on the prognosis of 164 colorectal cancer patients by qRT–PCR.

Results:

CRC cells transfected with PVT-1 siRNA exhibited significant loss of their proliferation and invasion capabilities. In these cells, the TGF-β signalling pathway and apoptotic signals were significantly activated. In addition, univariate and multivariate analysis revealed that PVT-1 expression level was an independent risk factor for overall survival of colorectal cancer patients.

Conclusion:

PVT-1, which maps to 8q24, generates antiapoptotic activity in CRC, and abnormal expression of PVT-1 was a prognostic indicator for CRC patients.

Relevance of [18F]fluorodeoxyglucose positron emission tomography-positive lymph nodes after neoadjuvant chemotherapy for squamous cell oesophageal cancer

Background

Several studies have examined the clinical significance of metabolic response in primary tumours by [18F]fluorodeoxyglucose positron emission tomography (18F-FDG-PET) in patients with oesophageal cancer who undergo neoadjuvant therapy. The relevance of the metabolic response in lymph nodes is unclear.

Methods

Consecutive patients with oesophageal cancer who underwent neoadjuvant chemotherapy followed by surgery were studied. 18F-FDG-PET was performed before and 2–3 weeks after completion of neoadjuvant chemotherapy, assessing FDG uptake in primary tumours and lymph nodes considered to be metastatic.

Results

Before therapy, 156 (73·9 per cent) of 211 patients had PET-positive nodes, of whom 89 (57.1 per cent) had no evidence of metabolic activity in these lymph nodes following chemotherapy. There was a significant relationship between post-treatment lymph node status assessed by FDG-PET and numbers of pathologically confirmed metastatic lymph nodes. Patients with post-treatment PET-positive nodes had shorter survival than those without (5-year survival rate 25 versus 62·6 per cent; P &lt; 0·001). There was no difference in survival between patients with PET-positive nodes before but not after therapy and patients who had PET-negative nodes throughout (5-year survival rate 59 versus 71 per cent respectively; P = 0·207). Multivariable analysis identified post-treatment nodal status assessed by FDG-PET and tumour depth as independent prognostic factors.

Conclusion

Identification of PET-positive lymph nodes after completion of chemotherapy is a predictor of poor prognosis of patients with oesophageal cancer scheduled for surgery. FDG-PET lymph node status after neoadjuvant chemotherapy is more important than that before chemotherapy.

miR-320c regulates gemcitabine-resistance in pancreatic cancer via SMARCC1

Background:

Gemcitabine-based chemotherapy is the standard treatment for pancreatic cancer. However, the issue of resistance remains unresolved. The aim of this study was to identify microRNAs (miRNAs) that govern the resistance to gemcitabine in pancreatic cancer.

Methods:

miRNA microarray analysis using gemcitabine-resistant clones of MiaPaCa2 (MiaPaCa2-RGs), PSN1 (PSN1-RGs), and their parental cells (MiaPaCa2-P, PSN1-P) was conducted. Changes in the anti-cancer effects of gemcitabine were studied after gain/loss-of-function analysis of the candidate miRNA. Further assessment of the putative target gene was performed in vitro and in 66 pancreatic cancer clinical samples.

Results:

miR-320c expression was significantly higher in MiaPaCa2-RGs and PSN1-RGs than in their parental cells. miR-320c induced resistance to gemcitabine in MiaPaCa2. Further experiments showed that miR-320c-related resistance to gemcitabine was mediated through SMARCC1, a core subunit of the switch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex. In addition, clinical examination revealed that only SMARCC1-positive patients benefited from gemcitabine therapy with regard to survival after recurrence (P=0.0463).

Conclusion:

The results indicate that miR-320c regulates the resistance of pancreatic cancer cells to gemcitabine through SMARCC1, suggesting that miR-320c/SMARCC1 could be suitable for prediction of the clinical response and potential therapeutic target in pancreatic cancer patients on gemcitabine-based therapy.

Esophageal submucosal dissection under steady pressure automatically controlled endoscopy (SPACE): a randomized preclinical trial

BACKGROUND AND STUDY AIMS

A new overtube system has been developed for steady pressure automatically controlled endoscopy (SPACE) in the gastrointestinal tract. The objectives of this study were to validate the feasibility and safety of SPACE in the esophagus, and to evaluate its potential advantages over conventional (manually insufflating) endoscopy in endoscopic submucosal dissection (ESD).

METHODS

This was a multicenter preclinical trial using acute porcine models (n = 20). In Experiment 1 (feasibility/safety study), SPACE was attempted in the esophagus with continuous monitoring of cardiopulmonary parameters and intraluminal pressures in the downstream bowel. Different insufflation pressures were tested to optimize the insufflation condition. Each session was video-recorded and scored by blinded reviewers. In Experiment 2 (randomized trial), esophageal ESD was attempted using either SPACE or conventional endoscopy, and results were compared.

RESULTS

In Experiment 1, SPACE was performed safely without intraluminal pressure elevation in the downstream bowel. According to video review, SPACE provided more stable, reproducible, and rapid visualization than conventional endoscopy. The insufflation pressure was optimized at 14 mmHg for esophageal SPACE. In Experiment 2, ESD was completed in all animals. The ESD time was significantly shorter with SPACE compared with conventional endoscopy (1326 vs. 1616 seconds; P = 0.009). Responses to questionnaires showed that 94 % - 100 % of participants considered SPACE to provide improved exposure and more uniform tissue tension than conventional endoscopy. Other data were comparable.

CONCLUSIONS

SPACE is feasible, safe, and potentially effective for complicated endoscopic procedures, such as ESD. SPACE improves and standardizes endoscopic exposure and tissue tension. A clinical study is required to further confirm its safety and clinical effectiveness.

High expression of Lin28 is associated with tumour aggressiveness and poor prognosis of patients in oesophagus cancer

BACKGROUND

Lin28 is a negative regulator of the tumour suppressor microRNA, let-7, suggesting its role in tumourigenesis. However, the clinical significance of Lin28 expression in oesophageal cancer has not been elucidated.

METHODS

Lin28 and Lin28B expression was examined by immunohistochemistry in 161 tissues from patients with oesophageal cancer who had undergone curative surgery. The relationship between the expressions of Lin28 and Lin28B and various clinicopathological factors was examined. In vitro assays were conducted to determine the role of Lin28 in aggressiveness of oesophageal cancers using oesophageal cancer cell line.

RESULTS

Lin28 and Lin28B were overexpressed in oesophageal cancer cells compared with non-cancerous epithelial cells, especially in the invasive front. High expression of Lin28 and Lin28B correlated significantly with lymph node metastasis and poor prognosis. High expression of Lin28B expression correlated significantly with low expression of let-7. Multivariate analysis also identified Lin28B expression as an independent prognostic factor. In vitro assays showed that the proliferative and invasive activities were significantly reduced in Lin28B-knockdown cells, compared with control cells.

CONCLUSION

High expression of Lin28 is associated with poor prognosis and high tumour aggressiveness in oesophageal cancer and these effects are mediated through increased proliferation and invasiveness of oesophageal cancer cells.