Chemoradiotherapy in Gastrointestinal Malignancies

Enhancing Combined Immunotherapy and Radiotherapy through Nanomedicine

Radiotherapy and immunotherapy are two key treatments for cancer. There is growing evidence that they are also synergistic, and combination treatments are being studied extensively in the clinical setting. In addition, there is emerging evidence that nanotechnology-enabled therapeutics can potentiate both radiotherapy and immunotherapy, in turn improving both treatments. This is an exciting new area of interdisciplinary science and has significant potential for major clinical impact. Some of the approaches in this area have already reached the clinical stage. In this review, we will discuss recent advances in the interface between radiotherapy, immunotherapy, and nanomedicine. We plan to review the many approaches to combine these three fields for cancer treatment.

Improving Cancer Chemoradiotherapy Treatment by Dual Controlled Release of Wortmannin and Docetaxel in Polymeric Nanoparticles

Combining molecularly targeted agents and chemotherapeutics is an emerging strategy in cancer treatment. We engineered sub-50 nm diameter diblock copolymer nanoparticles (NPs) that can sequentially release wortmannin (Wtmn, a cell signaling inhibitor) and docetaxel (Dtxl, genotoxic anticancer agent) to cancer cells. These NPs were studied in chemoradiotherapy, an important cancer treatment paradigm, in the preclinical setting. We demonstrated that Wtmn enhanced the therapeutic efficacy of Dtxl and increased the efficiency of radiotherapy (XRT) in H460 lung cancer and PC3 prostate cells in culture. Importantly, we showed that NPs containing both Wtmn and Dtxl release the drugs in a desirable sequential fashion to maximize therapeutic efficacy in comparison to administering each drug alone. An in vivo toxicity study in a murine model validated that NPs containing both Dtxl and Wtmn do not have a high toxicity profile. Lastly, we demonstrated that Dtxl/Wtmn-coencapsulated NPs are more efficient than each single-drug-loaded NPs or a combination of both single-drug-loaded NPs in chemoradiotherapy using xenograft models. Histopathological studies and correlative studies support that the improved therapeutic efficacy is through changes in signaling pathways and increased tumor cell apoptosis. Our findings suggest that our nanoparticle system led to a dynamic rewiring of cellular apoptotic pathways and thus improve the therapeutic efficiency.

Molecular classification and prediction in gastric cancer

Gastric cancer, a highly heterogeneous disease, is the second leading cause of cancer death and the fourth most common cancer globally, with East Asia accounting for more than half of cases annually. Alongside TNM staging, gastric cancer clinic has two well-recognized classification systems, the Lauren classification that subdivides gastric adenocarcinoma into intestinal and diffuse types and the alternative World Health Organization system that divides gastric cancer into papillary, tubular, mucinous (colloid), and poorly cohesive carcinomas. Both classification systems enable a better understanding of the histogenesis and the biology of gastric cancer yet have a limited clinical utility in guiding patient therapy due to the molecular heterogeneity of gastric cancer. Unprecedented whole-genome-scale data have been catalyzing and advancing the molecular subtyping approach. Here we cataloged and compared those published gene expression profiling signatures in gastric cancer. We summarized recent integrated genomic characterization of gastric cancer based on additional data of somatic mutation, chromosomal instability, EBV virus infection, and DNA methylation. We identified the consensus patterns across these signatures and identified the underlying molecular pathways and biological functions. The identification of molecular subtyping of gastric adenocarcinoma and the development of integrated genomics approaches for clinical applications such as prediction of clinical intervening emerge as an essential phase toward personalized medicine in treating gastric cancer.

Proton pump inhibitors (PPIs) impact on tumour cell survival, metastatic potential and chemotherapy resistance, and affect expression of resistance-relevant miRNAs in esophageal cancer

Background

Neoadjuvant treatment plays a crucial role in the therapy of advanced esophageal cancer. However, response to radiochemotherapy varies widely. Proton pump inhibitors (PPIs) have been demonstrated to impact on chemotherapy in a variety of other cancers. We analyzed the impact of PPI treatment on esophageal cancer cell lines, and investigated mechanisms that mediate the effect of PPI treatment in this tumour.

Methods

We investigated the effect of esomeprazole treatment on cancer cell survival, adhesion, migration and chemotherapy in human adeno-(OE19) and squamous-cell-carcinoma (KYSE410) cell lines. Furthermore, we investigated the effect of PPI treatment on intra-/extracellular pH and on expression of resistance-relevant miRNAs.

Results

Esomeprazole significantly inhibited tumour cell survival (in a dose-dependent manner), adhesion and migration in both tumour subtypes. Furthermore, esomeprazole augmented the cytotoxic effect of cisplatin and 5-FU in both tumour subtypes. Surprisingly, PPI treatment led to a significant increase of intracellular pH and a decrease of the extracellular pH. Finally, we found esomeprazole affected expression of resistance-relevant miRNAs. Specifically, miR-141 and miR-200b were upregulated, whereas miR-376a was downregulated after PPI treatment in both tumour types.

Conclusion

Our study demonstrates for the first time that PPIs impact on tumour cell survival, metastatic potential and sensitivity towards chemotherapy in esophageal cancer cell lines. Furthermore, we observed that in this tumour entity, PPIs do not lead to intracellular acidification, but affect the expression of resistance-relevant miRNAs.

Polysilsesquioxane nanoparticles for triggered release of cisplatin and effective cancer chemoradiotherapy

Chemoradiotherapy is a well-established treatment paradigm in oncology. There has been strong interest in identifying strategies to further improve its therapeutic index. An innovative strategy is to utilize nanoparticle (NP) chemotherapeutics in chemoradiation. Since the most commonly utilized chemotherapeutic with radiotherapy is cisplatin, the development of an NP cisplatin for chemoradiotherapy has the highest potential impact on this treatment. Here, we report the development of an NP comprised of polysilsesquioxane (PSQ) polymer crosslinked by a cisplatin prodrug (Cisplatin-PSQ) and its utilization in chemoradiotherapy using non-small cell lung cancer as a disease model. Cisplatin-PSQ NP has an exceptionally high loading of cisplatin. Cisplatin-PSQ NPs were evaluated in chemoradiotherapy in vitro and in vivo. They demonstrated significantly higher therapeutic efficacy when compared to cisplatin. These results suggest that the Cisplatin-PSQ NP holds potential for clinical translation in chemoradiotherapy.

Nanomedicine in chemoradiation

Chemoradiotherapy, the concurrent administration of chemotherapy and radiotherapy, is a treatment paradigm in oncology. It is part of the standard of care and curative treatment of many cancers. Given its importance, one of the primary goals of cancer research has been to identify agents and/or strategies that can improve the therapeutic index of chemoradiation. Recent advances in nanomedicine have provided a unique and unprecedented opportunity for improving chemoradiotherapy. Nanoparticles possess properties that are ideally suited for delivering chemotherapy in the chemoradiation setting. The goal of this review is to examine the role of incorporating nanomedicine into chemoradiation and the potential impact of nanomedicine to chemoradiotherapy.

Trends in the use of postoperative radiation therapy in patients with localized resectable pancreatic cancer

OBJECTIVES

: Results from European Study Group for Pancreatic Cancer (ESPAC)-1, first published in 2001, suggested that postoperative radiation therapy (PORT) was detrimental in pancreatic patients. The potential association between the publication of ESPAC-1 and the use of PORT in the United States is examined in this study.

METHODS

: Data from the Surveillance, Epidemiology, and End Results program were used to identify pancreatic patients treated with surgical resection followed by PORT. The use of PORT was examined in the 5-year time period preceding and after the publication of ESPAC-1.

RESULTS

: Univariable analysis of the use of PORT found significantly less use of PORT in the postpublication period [odds ratio (OR) for the use of PORT in prepublication period=1.19, 95% confidence interval (CI), 1.04-1.35]. A multivariable analysis, performed to account for imbalances in clinical and demographic variables between the 2 time periods, found similar results (OR=1.18, 95% CI, 1.03-1.35). When other types of radiation, such as preoperative radiation were included, no significant difference between time periods was found (OR=0.99, 95% CI, 0.76-1.30).

CONCLUSIONS

: Although there continues to be frequent use of PORT in the United States, the publication of ESPAC-1 seems to be associated with a small but significant change in its use. However, it is important to note that further analyses suggest that a small shift toward more preoperative radiation may also account for the decrease in PORT.

Concomitant chemo-radiotherapy for unresectable oesophageal cancer: A mono-institutional study on 40 patients

BACKGROUND/AIM

To analyse clinical response, overall (OS) and disease free survival (DFS) and toxicity in patients with unresectable oesophageal cancer treated by concomitant chemo-radiotherapy (CRT).

MATERIALS AND METHODS

Forty patients with stage IIa-IVa biopsy proven oesophageal carcinoma were treated with CRT. All patients were studied with endoscopy and CT and judged unresectable after multidisciplinary discussion. CRT consisted of 3 cycles of cisplatin 100 mg/m(2) or carboplatin 300 mg/m(2) on day 1 and 5-fluorouracil 1000 mg/m(2) as a continuous infusion of 96 h associated with concurrent 3D-conformal RT. By using 15 MeV X-rays, a total dose of 60-66 Gy was delivered with daily fractions of 1.8-2.0 Gy.

RESULTS

Complete response (CR), partial response (PR) and no response (NR) were observed in 50%, 20% and 20% of cases, respectively. Of the 20 patients with CR, 15 developed loco-regional recurrent disease. OS and DFS rates at 3 and 5 years were 38%, 8%, 49% and 10%, respectively. Total radiation dose ≥60 Gy improved loco-regional control and complete response (CR vs. PR + NR; p = 0.004) influenced both DFS and loco-regional control. Grade 3 gastrointestinal and haematological acute toxicity occurred in 3/40 patients (7.5%). One patient developed grade 4 renal failure. Late toxicity was reported in 2/40 patients (5.0%), consisting of grade 3 radiation pneumonitis.

CONCLUSIONS

Concomitant CRT for unresectable oesophageal cancer can result in an acceptable loco-regional control with limited toxicity. Response after treatment and total radiation dose influenced the outcome.

Revival of the abandoned therapeutic wortmannin by nanoparticle drug delivery

One of the promises of nanoparticle (NP) carriers is the reformulation of promising therapeutics that have failed clinical development due to pharmacologic challenges. However, current nanomedicine research has been focused on the delivery of established and novel therapeutics. Here we demonstrate proof of the principle of using NPs to revive the clinical potential of abandoned compounds using wortmannin (Wtmn) as a model drug. Wtmn is a potent inhibitor of phosphatidylinositol 3' kinase-related kinases but failed clinical translation due to drug-delivery challenges. We engineered a NP formulation of Wtmn and demonstrated that NP Wtmn has higher solubility and lower toxicity compared with Wtmn. To establish the clinical translation potential of NP Wtmn, we evaluated the therapeutic as a radiosensitizer in vitro and in vivo. NP Wtmn was found to be a potent radiosensitizer and was significantly more effective than the commonly used radiosensitizer cisplatin in vitro in three cancer cell lines. The mechanism of action of NP Wtmn radiosensitization was found to be through the inhibition of DNA-dependent protein kinase phosphorylation. Finally, NP Wtmn was shown to be an effective radiosensitizer in vivo using two murine xenograft models of cancer. Our results demonstrate that NP drug-delivery systems can promote the readoption of abandoned drugs such as Wtmn by overcoming drug-delivery challenges.

Modern radiation therapy techniques for pancreatic cancer

Radiation therapy is a rapidly evolving field, and recent technical advances have spurred an increasing number of new treatments as well as marked improvements in previously existing treatments. Despite a growing body of published evidence demonstrating that radiotherapy for the treatment of pancreatic cancer is improving in efficacy and safety, the ultimate effect on patient outcomes remains to be seen. It is an unfortunate fact that the majority of pancreatic cancer patients will ultimately have metastases and succumb to distant disease. Thus, improvements in local tumor control engendered by these recent advances will have little impact on overall survival without the coincident development of better systemic treatment regimens.

Standard protocol for assessment of colon cancer improves the quality of pathology

AIM

Tumour stage is the most important prognostic factor in colon cancer. The aim of this study was to examine the impact on the quality of pathology of the use of a standardized pathological and anatomical (PAD) protocol.

METHOD

A standardized PAD protocol for colorectal cancer was developed and all patients subjected to colon resection due to adenocarcinomas between 2004 and 2006 were analysed regarding lymph node status, circumferential resection margin (CRM), and intravascular and perineural growth. Moreover, usage of the PAD protocol and whether a pathologist or biomedicine analytical technician (BMA) performed the lymph node dissection was noted, and also whether the surgical procedure was elective or acute.

RESULTS

During the study period 302 colon resections were carried out. The standard protocol was employed in 68% of the cases, varying from 0% to 100% between pathologists. The median number of investigated lymph nodes was 16 ± 11. When the lymph node dissection was performed by a BMA, significantly more lymph nodes were examined; 22 ± 15 and 14 ± 9, respectively (P < 0.01). There was a positive correlation between application of the standard protocol and the number of analysed lymph nodes (< 0.05). Comments on CRM, perineural growth and intravascular growth were also significantly more frequent when the protocol was used. Emergency surgery did not influence the handling of the specimens.

CONCLUSION

Minor changes in procedure in terms of a standard protocol for pathology and specimen dissection by BMAs, leading to an increased quality of the PAD-report, may also improve the long-term outcome for patients.

Cost-effectiveness studies in radiation therapy

The field of radiation therapy has made dramatic technical advances over the past 20 years. 3D conformal radiotherapy, intensity-modulated radiation therapy and proton beam therapy have all been developed in an attempt to improve the therapeutic ratio: higher cure rates with lower toxicity. Unfortunately, although the costs of radiation therapy are certainly increasing, it is unclear whether its clinical benefit has also improved. Cost-effectiveness analyses are designed to formally evaluate the cost of a treatment relative to an associated change in quality-adjusted survival. As the cost of oncologic care is increasing, it is critically important to assess the cost-effectiveness of radiation therapy. This article will describe the issues surrounding the delivery and cost of radiation therapy, and it will summarize the work that has been done to evaluate the use of cost-effectiveness in radiation oncology.

Chemoradiotherapy with or without induction chemotherapy for locally advanced pancreatic cancer: a UK multi-institutional experience

AIMS

The optimal management for patients with unresectable locally advanced adenocarcinoma of the pancreas (LAPC) is unclear. The aim of this study was to determine the outcome of patients treated with chemoradiotherapy (CRT) with or without induction chemotherapy.

MATERIALS AND METHODS

We conducted a multi-centre retrospective analysis of 48 patients with biopsy-proven LAPC treated with CRT in four regional oncology centres in the UK between March 2000 and October 2007. The prescribed radiotherapy dose was 4500-5040 cGy in 25-28 fractions and was given concurrent with gemcitabine (n=37), gemcitabine/cisplatin (n=9), 5-fluorouracil (n=1) or capecitabine (n=1).

RESULTS

Four patients (8.3%) did not complete the intended treatment due to CRT-related toxicities. The disease control rate (Objective response rate (ORR) and stable disease (SD)) was 81.3%. The median overall survival was 17 months (range 5-66 months). In subgroup analysis, a trend towards improved survival was seen in patients who completed the intended treatment (17.1 months vs 11.0 months, P=0.06) and in patients undergoing surgery (27 months vs 16 months, P=0.023).

CONCLUSIONS

This is the largest reported series from the UK focussing on patients who received CRT for pancreas cancer. It shows that it is possible to deliver pancreatic CRT with acceptable toxicity. Induction chemotherapy followed by gemcitabine-based CRT shows promising activity and should be evaluated in phase III studies.

Gene expression profiles of epidermal growth factor receptor, vascular endothelial growth factor and hypoxia-inducible factor-1 with special reference to local responsiveness to neoadjuvant chemoradiotherapy and disease recurrence after rectal cancer surgery

AIMS

To establish a causal relationship between the gene expression profiles of angiogenetic molecular markers, including epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1), in rectal cancer and the local responsiveness to neoadjuvant chemoradiotherapy and subsequent disease recurrence.

MATERIALS AND METHODS

We examined the pre-treatment tumour biopsies (n=40) obtained from patients with rectal adenocarcinoma (clinical International Union Against Cancer stage ll/III) who were scheduled to receive neoadjuvant 5-fluorouracil-based chemoradiotherapy for EGFR, VEGF and HIF-1 expression by quantitative real-time polymerase chain reaction.

RESULTS

Responders (patients with significant tumour regression, i.e. pathological grades 2/3) showed significantly lower VEGF, HIF-1 and EGFR gene expression levels than the non-responders (patients with insignificant tumour regression, i.e. pathological grades 0/1) in the pre-treatment tumour biopsies. The elevated expression level of each gene could predict patients with a low response to chemoradiation. During the median follow-up of all patients (41 months; 95% confidence interval 28-60 months), 6/40 (15%) developed disease recurrence. Although local responsiveness to neoadjuvant chemoradiotherapy was associated with neither local nor systemic disease recurrence, lymph node metastasis and an elevated VEGF gene expression level were independent predictors of systemic disease recurrence. The 3-year disease-free survival rates of the patients with lower VEGF or EGFR expression levels were significantly lower than those of patients with higher VEGF or EGFR expression levels.

CONCLUSIONS

Analysing VEGF expression levels in rectal cancer may be of benefit in estimating the effects of neoadjuvant chemoradiotherapy and in predicting systemic recurrence after rectal cancer surgery.

Physical activity and gastrointestinal cancer survivorship

Research examining physical activity in gastrointestinal cancer survivors is in its early stages and has focused primarily on colorectal cancer. Moreover, the majority of the research to date has been observational in nature, with very little interventional research. Though limited, the results of this research have been promising in nature, showing positive associations between physical activity and quality of life as well as disease outcomes, including improved disease-free and overall survival. The potential benefits of physical activity for gastrointestinal cancer survivors warrant further research on the underlying mechanisms of the relationship between physical activity and colorectal cancer disease outcomes, to determine if these associations extend to other gastrointestinal cancers, and to determine appropriate physical activity interventions to realize any potential supportive care benefits in various gastrointestinal cancer survivor groups.