Risk of endocrine pancreatic insufficiency in patients receiving adjuvant chemoradiation for resected gastric cancer

Gastroprotective and microbiome-modulating effects of ubiquinol in rats with radiation-induced enteropathy

Radiation enteritis is a frequently encountered issue for patients receiving radiotherapy and has a significant impact on cancer patients' quality of life. The gut microbiota plays a pivotal role in intestinal function, yet the impact of irradiation on gut microorganisms is not fully understood. This study explores the gastroprotective effect and gut microbiome-modulating potential of ubiquinol (Ubq), the reduced form of the powerful antioxidant CoQ-10. For this purpose, male albino rats were randomly assigned to four groups: Control, IRR (acute 7 Gy γ-radiation), Ubq_Post (Ubq for 7 days post-irradiation), and Ubq_Pre/Post (Ubq for 7 days pre and 7 days post-irradiation). The fecal microbiomes of all groups were profiled by 16S rRNA amplicon sequencing followed by bioinformatics and statistical analysis. Histopathological examination of intestinal tissue indicated severe damage in the irradiated group, which was mitigated by ubiquinol with enhanced regeneration, goblet cells, and intestinal alkaline phosphatase expression. Compared to the irradiated group, the Ubq-treated groups had a significant recovery of intestinal interleukin-1β, caspase-3, nitric oxide metabolites, and thio-barbituric reactive substances to near-healthy levels. Ubq_Pre/Post group displayed elevated peroxisome proliferator-activated receptor (PPAR-γ) level, suggesting heightened benefits. Serum insulin reduction in irradiated rats improved post-Ubq treatment, with a possible anti-inflammatory effect on the pancreatic tissue. Fecal microbiota profiling revealed a dysbiosis state with a reduction of bacterial diversity post-irradiation, which was re-modulated in the Ubq treated groups to profiles that are indistinguishable from the control group. These findings underscore Ubq's gastroprotective effects against radiation-induced enteritis and its potential in restoring the gut microbiota's diversity and balance.

The impact of apelin-13 on cisplatin-induced endocrine pancreas damage in rats: an in vivo study

Apelin-13 is a peptide hormone that regulates pancreatic endocrine functions, and its benefits on the endocrine pancreas are of interest. This study aims to investigate the potential protective effects of apelin-13 in cisplatin-induced endocrine pancreatic damage. Twenty-four rats were divided into four groups: control, apelin-13, cisplatin, and cisplatin + apelin-13. Caspase-3, TUNEL, and Ki-67 immunohistochemical staining were used as markers of apoptosis and mitosis. NF-κB/p65 and TNFα were used to show inflammation. β-cells and α-cells were also evaluated with insulin and glucagon staining in the microscopic examination. Pancreatic tissue was subjected to biochemical analyses of glutathione (GSH) and malondialdehyde (MDA). Apelin-13 ameliorated cisplatin-induced damage in the islets of Langerhans. The immunopositivity of apelin-13 on β-cells and α-cells was found to be increased compared to the cisplatin group (p = 0.001, p = 0.001). Mitosis and apoptosis were significantly higher in the cisplatin group (p = 0.001). Apelin-13 reduced TNFα, NF-κB/p65 positivity, and apoptosis caused by cisplatin (p = 0.001, p = 0.001, p = 0.001). While cisplatin caused a significant increase in MDA levels (p = 0.001), apelin caused a significant decrease in MDA levels (p = 0.001). The results demonstrated a significant decrease in pancreatic tissue GSH levels following cisplatin treatment (p = 0.001). Nevertheless, apelin-13 significantly enhanced cisplatin-induced GSH reduction (p = 0.001). On the other hand, the serum glucose level, which was measured as 18.7 ± 2.5 mmol/L in the cisplatin group, decreased to 13.8 ± 0.7 mmol/L in the cisplatin + apelin-13 group (p = 0.001). The study shows that apelin-13 ameliorated cisplatin-induced endocrine pancreas damage by reducing oxidative stress and preventing apoptosis.

The potential antioxidant effect of N-acetylcysteine on X-ray ionizing radiation-induced pancreas islet cell toxicity

PURPOSE

Previous research has highlighted the impact of X-ray irradiation-induced organ damage, on cancer patients after radiation therapy. The ionizing radiation-induced oxidative stress causes injury to the pancreatic islet cells of Langerhans. We used histopathological, immunohistochemical, and biochemical analyses to examine α- and β-cells in the islets of Langerhans in rats undergoing whole-body x-ray ionizing radiation, a group of which was treated with NAC.

MATERIAL AND METHODS

Twenty-four male rats were randomly divided into 3 groups, one control, and two experimental groups. Group I (Control) was administered only saline solution (0.09% NaCl) by oral gavage for 7 days. Group II (IR) was administrated whole body single dose 6 Gray ionizing radiation (IR) and saline solution (0.09% NaCl) by oral gavage for 7 days. Group III (IR + NAC) was administered 300 mg/kg NAC (N-acetylcysteine) by oral gavage for 7 days, 5 days before, and 2 days after 6 Gray IR application.

RESULTS

In the X-ray irradiation group, we observed diffuse necrotic endocrine cells in the islets of Langerhans. In addition, we found that Caspase-3, malondialdehyde (MDA) levels increased, and insulin, glucagon, and glutathione (GSH) levels decreased in the IR group compared to the control group. In contrast, we observed a decrease in Caspase-3, and MDA levels in necrotic endocrine cells, and an increase in insulin, glucagon, and GSH levels in the IR + NAC group compared to the IR group.

CONCLUSION

This study provides evidence for the beneficial effects of N-acetyl cysteine on islets of Langerhans cells with X-ray ionizing-radiation-induced damage in a rat model.

Radioprotective effects of α2-adrenergic receptor agonist dexmedetomidine on X-ray irradiation-induced pancreatic islet cell damage

Comprehensive epidemiological analyses conducted in the last 30 years have revealed a link between radiation and DM. We aimed to determine the effects of dexmedetomidine pretreatment on radiation-induced pancreatic islet cell damage. Twenty-four rats were divided into three groups: group 1 (control group), group 2 (only X-ray irradiation group), and group 3 (X-ray irradiation + dexmedetomidine). We observed necrotic cells with vacuoles accompanying loss of cytoplasm in the islets of Langerhans, extensive edematous areas, and vascular congestions in group 2. In group 3, we observed a decrease in necrotic cells in the islets of Langerhans, and edematous areas and vascular congestion was also reduced. We determined a decrease in β-cells, α-cells, and D-cells in the islets of Langerhans in group 2 compared to the control group. In group 3, β-cells, α-cells, and D-cells were elevated compared to group 2. Ionizing radiation may induce DM. Dexmedetomidine appears to exert a radioprotective effect.

Response Evaluation Following Radiation Therapy With 18F-FDG PET/CT: Common Variants of Radiation-Induced Changes and Potential Pitfalls

Radiation therapy (RT) is one of the cornerstones in cancer treatment and approximately half of all patients will receive some form of RT during the course of their cancer management. Response evaluation after RT and follow-up imaging with ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) can be complicated by RT-induced acute, chronic or consequential effects. There is a general consensus that ¹⁸F-FDG PET/CT for response evaluation should be delayed for 12 weeks after completing RT to minimize the risk of false-positive findings. Radiation-induced late side effects in normal tissue can take years to develop and eventually cause symptoms that on imaging can potentially mimic recurrent disease. Imaging findings in radiation induced injuries depend on the normal tissue included in the irradiated volume and the radiation therapy regime including the total dose delivered, dose per fraction and treatment schedule. The intent for radiation therapy should be taken in consideration when evaluating the response on imaging, that is palliative vs curative or neoadjuvant vs adjuvant RT. Imaging findings can further be distorted by altered anatomy and sequelae following surgery within the radiation field. An awareness of common PET/CT-induced changes/injuries is essential when interpreting ¹⁸F-FDG PET/CT as well as obtaining a complete medical history, as patients are occasionally scanned for an unrelated cause to previously RT treated malignancy. In addition, secondary malignancies due to carcinogenic effects of radiation exposure in long-term cancer survivors should not be overlooked. ¹⁸F-FDG PET/CT can be very useful in response evaluation and follow-up in patients treated with RT, however, variants and pitfalls are common and it is important to remember that radiation-induced injury is often a diagnosis of exclusion.

Tumor microenvironment responsive Mn3O4 nanoplatform for in vivo real-time monitoring of drug resistance and photothermal/chemodynamic synergistic therapy of gastric cancer

Background

Postoperative chemotherapy for gastric cancer often causes multidrug resistance (MDR), which has serious consequences for therapeutic effects. Individualized treatment based on accurate monitoring of MDR will greatly improve patient survival.

Results

In this article, a self-enhanced Mn₃O₄ nanoplatform (MPG NPs) was established, which can react with glutathione to produce Mn²⁺ to enhance T1-weighted magnetic resonance imaging (MRI) and mediate in vivo real-time MDR monitoring. In vitro MRI results showed that MRI signals could be enhanced in the presence of hydrogen peroxide and glutathione and at acidic pH. In vivo MRI results indicated that MPG NPs could specifically target MDR cells, thereby realizing real-time monitoring of MDR in gastric cancer. Furthermore, MPG NPs have good chemodynamic activity, which can convert the endogenous hydrogen peroxide of tumor cells into highly toxic hydroxyl radical through Fenton-like reaction at acidic pH to play the role of chemodynamic therapy. In addition, Mn₃O₄ can significantly enhance the chemodynamic therapy effect because of its good photothermal conversion effect. Furthermore, in situ photothermal/chemodynamic synergistic therapy obtained remarkable results, the tumors of the mice in the synergistic therapy group gradually became smaller or even disappeared.

Conclusions

MPG NPs have good biocompatibility, providing a good nanoplatform for real-time monitoring and precise diagnosis and treatment of MDR in gastric cancer.

Graphical Abstract

Supplementary information

The online version contains supplementary material available at 10.1186/s12951-022-01441-6.

Deterioration of pancreatic exocrine function in carbon ion radiotherapy for pancreatic cancer

Background and purpose

In radiotherapy (RT) for pancreatic cancer, the pancreas is considered an important organ at risk. However, there are insufficient reports on pancreatic function deterioration after X-ray RT as organ at risk, and there are no reports on those after carbon ion (C-ion) RT. Here, we evaluated pancreatic exocrine insufficiency (PEI) after C-ion RT using dose-volume histogram (DVH) analysis.

Materials and methods

Data were retrospectively collected from patients who had undergone C-ion RT for pancreatic cancer between July 2013 and June 2019. The prescribed C-ion doses were 55.2 Gy (relative biological effectiveness) in 12 fractions. Serum pancreatic amylase and lipase values were measured before and after C-ion RT. In DVH analysis, we assessed V_5Gy-50Gy and V_{<5 Gy-50Gy} of pancreatic volume and analyzed whether these DVH parameters involved PEI.

Results

Thirty-three patients were included in the analysis. The median follow-up duration after the initiation of C-ion RT in these patients was 15.8 months (range, 4.3-64.8). During and after treatment, 57.6% of patients developed PEI within 13.6 months, defined as pancreatic amylase and lipase deficiencies. In DVH analysis, V_<5Gy was the most effective factor for the PEI, and the cutoff value for developing PEI in V_<5Gy was 4.57 cm³.

Conclusion

We showed that pancreatic exocrine function declined after C-ion RT for pancreatic cancer and that PEI was initiated early in the course of C-ion RT. Additionally, a low dose of DVH parameters, such as V_<5Gy, was a prognostic factor of PEI.

Radiation therapy-associated toxicity: Etiology, management, and prevention

Radiation therapy (RT) is a curative treatment for many malignancies and provides effective palliation in patients with tumor-related symptoms. However, the biophysical effects of RT are not specific to tumor cells and may produce toxicity due to exposure of surrounding organs and tissues. In this article, the authors review the clinical context, pathophysiology, risk factors, presentation, and management of RT side effects in each human organ system. Ionizing radiation works by producing DNA damage leading to tumor death, but effects on normal tissue may result in acute and/or late toxicity. The manifestation of toxicity depends on both cellular characteristics and affected organs' anatomy and physiology. There is usually a direct relationship between the radiation dose and volume to normal tissues and the risk of toxicity, which has led to guidelines and recommended dose limits for most tissues. Side effects are multifactorial, with contributions from baseline patient characteristics and other oncologic treatments. Technological advances in recent decades have decreased RT toxicity by dramatically improving the ability to deliver RT that maximizes tumor dose and minimizes organ dose. Thus the study of RT-associated toxicity is a complex, core component of radiation oncology training that continues to evolve alongside advances in cancer management. Because RT is used in up to one-half of all patients with cancer, an understanding of its acute and late effects in different organ systems is clinically pertinent to both oncologists and nononcologists.

Exocrine pancreatic insufficiency in long-term follow-up after curative gastric resection with D2 lymphadenectomy: A cross-sectional study

BACKGROUND

Exocrine pancreatic insufficiency (EPI) can be a problem following gastrectomies. This study aimed to reveal the EPI prevalence and its possible causes in gastric cancer patients that underwent subtotal or total gastrectomy, with completed oncological treatments, and with long-term disease-free survival success. Additionally, we also sought to determine whether there were any relations between EPI and blood biomarkers, weight change, malnutrition parameters, and quality of life after gastrectomy.

METHODS

A total of 69 gastric cancer patients whose oncological treatments had already been completed, with a minimum follow-up period of 16 months, were included in the study. Fecal samples were taken from all patients for the Fecal Elastase-1 Test, and patients were stratified into three groups based on the results: low (<100 μg/g), moderate (100-200 μg/g), and normal (>200 μg/g). These results were compared with patients' clinical characteristics, blood nutrition biomarkers, Maastricht indexes (MI), Bristol stool scale, and Gastrointestinal Quality of Life Index (GIQLI) scores.

RESULTS

FE-1 levels were low in 33 (47.8%) of the patients, moderate in 11 (15.9%), and normal in 25 (36.2%). The rate of patients receiving chemoradiotherapy (CRT) in the low FE-1 group was higher than the normal FE-1 and moderate FE-1 groups (P < 0.001 and P = 0.012, respectively). The serum total protein and lipase levels were lower in the low FE-1 group than in the normal FE-1 group (P = 0.023 and P < 0.001, respectively). When compared to the normal FE-1 group, the MI score of the low FE-1 group was higher (P = 0.018). The low FE-1 group had lower GIQLI gastrointestinal symptom scores than the normal FE-1 group (P = 0.046).

CONCLUSIONS

During long-term follow-up, EPI can be seen in more than half of patients with gastric cancer after curative gastrectomy. Radiotherapy as an adjunct to adjuvant treatment in the postoperative period is considered a serious risk factor for EPI development. EPI contributes to malnutrition development after gastrectomy and negatively affects the patients' quality of life, especially in terms of gastrointestinal symptoms.

Increased Risk of Diabetes after Definitive Radiotherapy in Patients with Indolent Gastroduodenal Lymphoma

Purpose

This study aimed to evaluate the effect of radiotherapy (RT) on the risk of diabetes by assessing hemoglobin A1c (HbA1c) levels in patients with gastroduodenal indolent lymphoma.

Materials and Methods

This retrospective study included patients with stage I extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue or follicular lymphoma of the gastroduodenal region who were treated with Helicobacter pylori eradication and/or RT between 2000 and 2019 in our institution. Of total 79 patients with HbA1c test, 17 patients received RT (RT group), while 62 patients did not receive RT (control group). A diabetes-associated event (DAE) was defined as a ≥ 0.5% increase in HbA1c levels from baseline, and diabetes event (DE) were defined as HbA1c level of ≥ 6.5%.

Results

During the median follow-up of 49 months, no local failure occurred after RT and no patients died of lymphoma. The RT group had significantly higher risk for DAEs on univariable analysis (hazard ratio [HR], 4.18; 95% confidence interval [CI], 1.64 to 10.66; p < 0.01) and multivariable analysis (HR, 3.68; 95% CI, 1.42 to 9.56; p=0.01). Further, the DE risk was significantly higher in the RT group than in the control group (HR, 4.32; 95% CI, 1.08 to 17.30; p=0.04) and in patients with increased baseline HbA1c levels (HR, 35.83; 95% CI, 2.80 to 459.19; p=0.01). On multivariable analysis, RT significantly increased the risk of DEs (HR, 4.55; 95% CI, 1.08 to 19.19; p=0.04), even after adjusting baseline HbA1c level (HR, 40.97; 95% CI, 3.06 to 548.01; p=0.01).

Conclusion

Patients who received RT for gastroduodenal indolent lymphoma had an increased risk of diabetes compared to those who did not.

Glycemic variability in patients with gastrointestinal cancer: An integrative review

PURPOSE

Glycemic variability is associated with risks for adverse events in patients with cancer. Several studies have evaluated the presence and impact of hyperglycemia and/or hypoglycemia in patients with cancer; however, few studies have evaluated glycemic variability. The purpose of this integrative review of studies in patients with gastrointestinal cancers was to investigate the presence and methods of reporting glycemic variability during and following treatments.

METHODS

A comprehensive review of the literature was conducted. PubMed, CINAHL, EMBASE, and Cochrane databases were searched for publications between 1/1/1969 and 7/24/2019. Studies of patients with gastrointestinal cancer following surgery, during treatment, and <5 years following treatment were included and evaluated by cancer type and method of glucose and glycemic variability measurement.

RESULTS

Among 1526 patients with gastrointestinal cancer across 19 studies, gastric and pancreatic cancers were most prevalent. Timing of glucose testing and methods of analyzing glycemic variability varied. Most analyses used the standard deviation or interquartile range. Glycemic variability was more prevalent among patients with Type 2 Diabetes and among those with pancreatic cancer. In some patients glycemic variability remained notable > one year following surgery despite improvements in glycemic control.

CONCLUSION

Patients with gastrointestinal cancer experience glycemic variability during and up to one year following treatment. There was heterogeneity in methods related to timing of testing and reporting glycemic variability among the 19 studies in this review. Future investigations need to identify the presence and define the methods of measuring glycemic variability in patients with gastrointestinal cancer.

The analysis of absorbed dose by pancreas during gastric cancer radiotherapy

INTRODUCTION

The toxicity of radiotherapy is a very important issue in the everyday work of radiation oncologist. The tolerance to certain doses of radiotherapy in organs at risk determines the safety of radiotherapy. Despite the increasing number of publications concerning the injury of the pancreas after radiotherapy, this organ does not have common directives. We decided to reanalyse our previously published data in terms of the dose of radiation absorbed by the pancreas to determine a dose-effect relationship with the use of radiation-induced hypoamylasaemia and hypolipasaemia.

MATERIALS AND METHODS

We reanalysed a group of 127 gastric cancer patients after preoperative or postoperative chemoradiotherapy who were treated with a total dose of 45 Gy administered in 25 fractions. To identify the absorbed doses, the pancreas was contoured based on the CT scans used for radiotherapy planning and divided into anatomical parts: the head, the body and the tail.

RESULTS

We found that 80% of the whole pancreatic volume absorbed at least 44.5 Gy. The body, tail and head absorbed 100%, 90% and 70% of the abovementioned dose, respectively. The mean dose absorbed by the whole pancreas ranged from 32 to 48 Gy, with a mean of 44 Gy. A total dose of 45 Gy administered to gastric cancer patients can lead to subclinical insufficiency of the pancreas (hypolipasaemia and hypoamylasaemia). This dose is not able to cause symptomatic damage to the pancreas.

Long-Term Endocrine and Exocrine Insufficiency After Pancreatectomy

PURPOSE

To identify peri-operative risk factors and time to onset of pancreatic endocrine/exocrine insufficiency.

METHODS

We retrospectively analyzed a single institutional series of patients who underwent pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) between 2000 and 2015. Endocrine/exocrine insufficiencies were defined as need for new pharmacologic intervention. Cox proportional modeling was used to identify peri-operative variables to determine their impact on post-operative pancreatic insufficiency.

RESULTS

A total of 1717 patient records were analyzed (75.47% PD, 24.53% DP) at median follow-up 17.88 months. Average age was 62.62 years, 51.78% were male, and surgery was for malignancy in 74.35% of patients. Post-operative endocrine insufficiency was present in 20.15% (n = 346). Male gender (p = 0.015), increased body mass index (BMI) (p < 0.001), tobacco use (p = 0.011), family history of diabetes (DM) (p < 0.001), personal history of DM (p ≤ 0.001), and DP (p ≤ 0.001) were correlated with increased risk. Mean time to onset was 20.80 ± 33.60 (IQR: 0.49-28.37) months. Post-operative exocrine insufficiency was present in 36.23% (n = 622). Race (p = 0.014), lower BMI (p < 0.001), family history of DM (p = 0.007), steatorrhea (p < 0.001), elevated pre-operative bilirubin (p = 0.019), and PD (p ≤ 0.001) were correlated with increased risk. Mean time to onset was 14.20 ± 26.90 (IQR: 0.89-12.69) months.

CONCLUSIONS

In this large series of pancreatectomy patients, 20.15% and 36.23% of patients developed post-operative endocrine and exocrine insufficiency at a mean time to onset of 20.80 and 14.20 months, respectively. Patients should be educated regarding post-resection insufficiencies and providers should have heightened awareness long-term.

Volumetric decrease of pancreas after abdominal irradiation, it is time to consider pancreas as an organ at risk for radiotherapy planning

Background

Volumetric shrinkage of normal tissues such as salivary glands, kidneys, hippocampus are observed after radiotherapy. We aimed to assess the alterations in pancreatic volume of patients who received abdominal radiotherapy and define pancreas as an organ at risk for radiation treatment planning.

Material-methods

Forty-nine patients operated for gastric adenocarcinoma who received adjuvant abdominal radiotherapy were in the study group, 27 patients with early stage disease who did not need adjuvant treatment after surgery comprised the control group. An experienced radiologist contoured the pancreas of all the patients from computed tomographies imported to the planning system obtained either for radiation planning purpose or for follow-up after surgery. The same procedure was repeated one year later for both groups. Measured volume of the pancreas was expressed in cm³.

Results

Mean pancreatic volumes were similar in both groups at the onset of the study, 51,34 ± 20,33 cm³, and 50,12 ± 23,75 cm³ in the irradiated and the control groups respectively (p = 0,63). One year later, mean pancreatic volumes were significantly decreased in each group; 22,48 ± 10,53 cm³, 44,18 ± 23,08 cm³ respectively, p < 0,001. However, the decrease in pancreatic volume was significantly more pronounced in the irradiated group in comparison to the control group, p < 0,001.

Conclusion

Volumetric decrease in normal tissues after radiotherapy is responsible for loss of organ function and radiation related late side effects. Although pancreas is a radiation sensitive organ losing its volume and function after radiation exposure, it is not yet considered as an organ at risk for radiation treatment planning. Pancreas should be contoured as an organ at risk, dose-volume histogram for the organ should be created, and safe organ doses should be determined. This is the first study declaring pancreas as an organ at risk for radiation toxicity and the necessity of defining dose constraints for the organ.

Osteoporosis development and vertebral fractures after abdominal irradiation in patients with gastric cancer

Background

Decrease in bone mineral density, osteoporosis development, bone toxicity and resulting insufficiency fractures as late effect of radiotherapy are not well known. Osteoporosis development related to radiotherapy has not been investigated properly and insufficiency fractures are rarely reported for vertebral bones.

Methods

Ninety-seven patients with gastric adenocarcinoma were evaluated for adjuvant treatment after surgery. While 73 out of 97 patients treated with adjuvant chemoradiotherapy comprised the study group, 24 out of 97 patients with early stage disease without need of adjuvant treatment comprised the control group. Bone mineral densities (BMD) of lumbar spine and femoral neck were measured by dual energy x-ray absorptiometry after surgery, and one year later in both groups.

Results

There was statistically significant decline in BMDs after one year in each group itself, however the decline in BMDs of the patients in the irradiated group was more pronounced when compared with the patients in the control group; p values were 0.02 for the decline in BMDs of lumbar spine, and 0.01 for femoral neck respectively. Insufficiency fractures were observed only in the irradiated patients (7 out of 73 patients) with a cumulative incidence of 9.6%.

Conclusions

Abdominal irradiation as in the adjuvant treatment of gastric cancer results in decrease in BMD and osteoporosis. Insufficiency fracture risk in the radiation exposed vertabral bones is increased. Calcium and vitamin D replacement and other measures for prevention of osteoporosis and insufficiency fractures should be considered after abdominal irradiation.

Risk of diabetes after para-aortic radiation for testicular cancer

Background

While the risk of diabetes is increased following radiation exposure to the pancreas among childhood cancer survivors, its association among testicular cancer (TC) survivors has not been investigated.

Methods

Diabetes risk was studied in 2998 1-year TC survivors treated before 50 years of age with orchidectomy with/without radiotherapy between 1976 and 2007. Diabetes incidence was compared with general population rates. Treatment-specific risk of diabetes was assessed using a case–cohort design.

Results

With a median follow-up of 13.4 years, 161 TC survivors were diagnosed with diabetes. Diabetes risk was not increased compared to general population rates (standardised incidence ratios (SIR): 0.9; 95% confidence interval (95% CI): 0.7–1.1). Adjusted for age, para-aortic radiotherapy was associated with a 1.66-fold (95% CI: 1.05–2.62) increased diabetes risk compared to no radiotherapy. The excess hazard increased with 0.31 with every 10 Gy increase in the prescribed radiation dose (95% CI: 0.11–0.51, P = 0.003, adjusted for age and BMI); restricted to irradiated patients the excess hazard increased with 0.33 (95% CI: −0.14 to 0.81, P = 0.169) with every 10 Gy increase in radiation dose.

Conclusion

Compared to surgery only, para-aortic irradiation is associated with increased diabetes risk among TC survivors.

Pancreatic radiation effect in apoptosis-related rectal radiation toxicity

Pancreatic radiation effect (PRE) can be a component of gastrointestinal tract (GIT) radiotoxicity. This inter-organ correlation between the GIT and the pancreas was assessed through a rat model. Separate local irradiation to the abdomen and the pelvis was applied concurrently for 8-week-old male Sprague Dawley rats. Abdominal irradiation was categorized into pancreatic shield (PS) and non-pancreatic shield (NPS) irradiation. After 5 Gy and 15 Gy irradiation, the rectal mucosa was analyzed at the first week (early phase, Ep) and the 14th week (late phase, Lp). A slow gain in body weight was observed initially, particularly in the NPS group receiving a 15 Gy dose (P < 0.001). The large number of apoptotic bodies after 15 Gy at Ep decreased at Lp. At Ep for the 5-Gy group, the NPS group revealed more fibrotic change than the PS group (P = 0.002). Cleaved caspase-3 (CCP3) expression was greater at Lp, and the Ep-Lp increase was prominent in the NPS-15-Gy group (P = 0.010). At Lp, for 15 Gy irradiation, CCP3 was expressed more in the NPS group than in the PS group (P = 0.032). Despite no direct toxicity difference between the PS and NPS groups, small changes in parameters such as fibrosis or CCP3 expression suggest that pancreatic shielding does have an effect on the radiation response in the rectal mucosa, which suggests a need for a multi-organ effect-based approach in GIT radiotoxicity assessment.

Predictive value of pancreatic dose-volume metrics on sarcopenia rate in gastric cancer patients treated with adjuvant chemoradiotherapy

OBJECTIVE

To evaluate the relationship of sarcopenia with the pancreatic dose-volume histogram (DVH) in gastric cancer patients treated with adjuvant chemoradiotherapy (CRT) after radical gastrectomy.

METHODS

A retrospective study was performed on the data in Zhongnan Hospital of Wuhan University from January 2008 to December 2016. Skeletal muscle index (SMI) was analyzed by cross-sectional areas of body composition at the level of third lumbar (L3) vertebrae, which was measured using single-slice computer tomograph (CT) prior to CRT, at 6 months and 12 months after CRT respectively. Logistic regression analysis was conducted to explore the potential clinical risk factors of sarcopenia in this patients cohort. Regarding the dosimetrics of pancreas, the sarcopenia rate was compared between the two groups divided according to the cut-off value determined by the receiver operating characteristic (ROC) curves.

RESULTS

One hundred and fifty-three gastric cancer patients were eligible in this study. The median postoperative follow-up was 36 (7-115) months. The mean dose of pancreas was 4399.7 ± 396.0 cGy. The incidence of sarcopenia prior to CRT, at 6 months and 12 months later were 29.4% (45/153), 27.3% (35/128) and 37.0% (37/100). Both sarcopenia at 6 months (HR = 2.038, 95%CI = 1.084-3.833, P = 0.027) and sarcopenia at 12 months (HR = 2.216, 95%CI = 1.007-4.873, P = 0.048) were the independent prognostic factor of gastric cancer patients. V46 remained to be the only independent risk factor of sarcopenia at 6 months (OR = 3.889, 95%CI = 1.099-13.764, P = 0.035) and 12 months (OR = 6.067, 95%CI = 1.687-21.821, P = 0.006) in multivariate logistic regression analysis. Among the dosimetric parameters used for ROC analysis, the V46 showed the highest area under the curve (AUC = 0.707). Here is the relationship between sarcopenia rate and the cut-off value for V46. Higher sarcopenia rate at 6 months was noted in 42.6% patients with V46 ≥ 57% compared with 9% of patients with V46 < 57% (P < 0.001). The sarcopneia rate at 12 months was 52% with V46 ≥ 57% and 25% with V46 < 57% (P = 0.010).

CONCLUSION

Gastric cancer with sarcopenia after adjuvant CRT had poorer survival. Higher dose and larger irradiated volume of pancreas correlated with higher risk of sarcopenia. Appropriated administration of pancreas dose-volume may be conducive to reduce the risk of sarcopenia and improve survival in gastric cancer patients treated with adjuvant CRT.

Prospective Study of Malabsorption and Malnutrition After Esophageal and Gastric Cancer Surgery

OBJECTIVE

To study malabsorption and malnutrition after curative resection of esophageal and gastric cancer.

DESIGN

Prospective cohort study.

BACKGROUND

Improved cure rates for esophageal and gastric cancer have increased focus on health-related quality of life (HR-QL) in survivorship. Although malnutrition is well described in long-term follow-up, and gastrointestinal symptoms are common, data on gut and pancreatic-related malabsorption are scant.

METHODS

Disease-free patients at least 18 months after esophageal or gastric oncologic resections represented the study cohort. A modified Gastrointestinal Symptom Rating Scale questionnaire was completed, and weight, fecal elastase (FE), albumin, vitamins, and micronutrients measured preoperatively and at 1, 6, and 18 to 24 months postoperatively. Small intestinal bacterial overgrowth (SIBO) and changes in body composition were also evaluated postoperatively.

RESULTS

At a median follow-up of 23 months, 45 of 66 patients in a consecutive series were disease-free. Mean weight (78 ± 19 vs 67 ± 16 kg), body mass index (27 ± 5 vs 24 ± 5 kg/m), Vitamin A (1.7 ± 0.6 vs 1.2 ± 0.4 umol/L), and Vitamin E (28 ± 7 vs 20 ± 7 umol/L) were significantly decreased (P < 0.01) at last follow-up compared with preoperatively. Malabsorption was evident in 73% of patients, of whom 44% had FE < 200 μg/g and 38% had evidence of SIBO. Total body fat-free mass (175 ± 96 vs 84 ± 71, P < 0.001) and skeletal muscle index (44 ± 8 vs 39 ± 8, P = 0.007) were significantly decreased at 18 to 24 months.

CONCLUSIONS

Malabsorption and malnutrition are prevalent in survivorship of esophageal and stomach cancer. This may be underappreciated, and both gut and pancreatic insufficiency represent modifiable targets in the interdisciplinary approach to recovery of HR-QL.

Radiation-induced injury of the exocrine pancreas after chemoradiotherapy for gastric cancer

BACKGROUND AND PURPOSE

The pancreas is located almost entirely within the treatment area for radiotherapy of gastric cancer. The aim of this study was to analyze radiation-induced injury of the exocrine pancreas.

MATERIAL AND METHODS

The study included 127 gastric cancer patients, who underwent preoperative or postoperative chemoradiotherapy. A total dose of 45 Gy was given in 25 fractions. Concurrent chemotherapy was 5-fluorouracil-based. Lipase and α-amylase were assayed before, during and after treatment.

RESULTS

Lipase and α-amylase deficiencies were found in 48.2% and 19.7% of patients, respectively. In the univariant analysis, age and pretreatment α-amylase and lipase activities influenced on risk of injury of the exocrine pancreas (p<0.05). Younger patients (<65 years) had a lower risk of hypoamylasemia than older patients. The probability of insufficiency was lower than 0.2 for patients with pretreatment α-amylase and lipase activities above 50 U/L and 55 U/L, respectively. The multivariate analyses of the time to hypolipasemia showed that only pretreatment lipase activity was significant.

CONCLUSIONS

Gastric cancer patients have an increased risk of exocrine pancreatic insufficiency after chemoradiotherapy. Thus, the pancreas should be regarded as an OAR. Measuring lipase activity should be the standard for assessing radiation-induced pancreatic injury.

β-elemene enhances the radiosensitivity of gastric cancer cells by inhibiting Pak1 activation

AIM: To explore the potential of β-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms.

METHODS: SGC7901, MKN45, MKN28, N87, and AGS human gastric cancer cell lines were used to screen for radioresistant gastric cancer cell lines. A 3-(4,5-dimeth-ylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay was used to determine the effects of β-elemene and IPA-3 on cell viability in MKN45 and SGC7901 gastric cancer cell lines. A clonogenic survival assay and annexin V-FITC/PI apoptosis detection assay were used to evaluate cellular radiosensitivity and radiation-induced cell death, respectively. A proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), was employed to screen the proteins regulated by β-elemene pretreatment prior to ionizing radiation (IR) in SGC7901 gastric cancer cell line. IPA-3 was used as a specific small molecule inhibitor of p21-activated protein kinase 1 (Pak1) to target Pak1 signaling. Protein levels of PAK1IP1 (p21-activated protein kinase-interacting protein 1), total Pak1 (t-Pak1), phospho-Pak1 (T423), phospho-ERK1/2 (Thr202/Tyr204), and cleaved caspase-3 (17 kDa) were assessed by western blotting.

RESULTS: MKN45 and SGC7901 gastric cancer cell lines were relatively more resistant to IR. β-elemene pretreatment decreased clonogenic survival following IR in MKN45 and SGC7901 gastric cancer cell lines. Additionally, β-elemene pretreatment prior to IR increased radiation-induced cell death compared with IR alone in MKN45 (10.4% ± 0.9% vs 34.8% ± 2.8%, P < 0.05) and SGC7901 (11.6% ± 0.9% vs 46.7% ± 5.2%, P < 0.05) human gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Through iTRAQ analysis and western blot validation, we found that β-elemene upregulated PAK1IP1 and downregulated phospho-Pak1 (T423) and phospho-ERK1/2 in SGC7901 gastric cancer cells. IR increased the level of phospho-Pak1 (T423). Pretreatment with β-elemene decreased radiation-induced Pak1 and ERK1/2 phosphorylation. Inhibition of Pak1 using IPA-3 decreased clonogenic survival following IR. In addition, IPA-3 increased radiation-induced cell death in MKN45 (13.4% ± 0.3% vs 26.6% ± 1.0%, P < 0.05) and SGC7901 (16.0% ± 0.6% vs 37.3% ± 1.7%, P < 0.05) gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Western blotting showed that IPA-3 decreased radiation-induced Pak1 and ERK1/2 phosphorylation.

CONCLUSION: This is the first demonstration that β-elemene enhances radiosensitivity of gastric cancer cells, and that the mechanism involves inhibition of Pak1 signaling.

Increment of serum C-peptide measured by glucagon test closely correlates with human relative beta-cell area

Pancreatic beta-cell mass contributes to glucose tolerance. The aim of this study was to evaluate the relationships between human beta-cell mass and various clinical parameters, including insulin secretory capacity. The study included 32 Japanese patients who underwent pancreatectomy and were naive to oral hypoglycemic agents and insulin. They were classified into those with normal glucose tolerance (n=13), impaired glucose tolerance (n=9) and diabetes (n=10), and their insulin secretory capacity and insulin resistance were evaluated. Immunohistochemistry was used to determine relative beta-cell area (%) which represented the proportion of insulin-positive cell area to whole pancreatic section. Increment of C-peptide immunoreactivity level by glucagon test (ΔC-peptide, increment of serum C-peptide [nmol/L] at 6 min after intravenous injection of 1-mg glucagon; r=0.64, p=0.002), homeostasis model assessment of beta-cell function (HOMA-beta, fasting immunoreactive insulin [μIU/mL] x 20 / (fasting plasma glucose [mmol/L] - 3.5); r=0.50, p=0.003), C-peptide index (CPI, fasting C-peptide [nmol/L] / fasting plasma glucose [mmol/L]; r=0.36, p=0.042), and fasting immunoreactive insulin (F-IRI [pmol/L]; r=0.36, p=0.044) correlated significantly and positively with the relative beta-cell area. The area under the curve of plasma glucose level from 0 to 120 min by 75 g-OGTT (AUC0-120) also correlated significantly and inversely with the relative beta-cell area (r=-0.36, p=0.045). Stepwise multiple regression analysis identified ΔC-peptide as the only independent and significant determinant of the relative beta-cell area. We conclude that ΔC-peptide, HOMA-beta, CPI, F-IRI and AUC0-120 correlated closely with the relative beta-cell area, and ΔC-peptide was the most valuable index for the prediction of the area.

Preoperative chemoradiotherapy in locally advanced gastric cancer, a phase I/II feasibility and efficacy study

OBJECTIVES

This study was initiated to investigate the feasibility and efficacy of preoperative radiotherapy with weekly paclitaxel and carboplatin in locally advanced gastric cancer.

METHODS

In a prospective study, patients with locally advanced gastric cancer stage IB-IV(M0) were treated with chemoradiotherapy followed by surgery 4-6 weeks after the last irradiation. Chemoradiotherapy consisted of radiation to a total dose of 45 Gy given in 25 fractions of 1.8 Gy, combined with concurrent weekly carboplatin and paclitaxel.

RESULTS

Between December 2007 and January 2012, 25 patients with cT3 (64%) or cT4 (36%) gastric cancer were included. One patient discontinued concurrent chemotherapy in the 4th week due to toxicity, but completed radiotherapy. Another patient discontinued chemoradiotherapy after the 3rd week due to progressive disease. Grade III adverse events of chemoradiotherapy were: gastrointestinal 12%, haematological 12% and other 8%. All patients, except one who developed progressive disease, were operated. Surgical complications were: general/infectious 48%, anastomotic leakage 12%, and bowel perforation 8%. Postoperative mortality was 4%. Microscopically radical resection rate was 72%. Pathological complete response rate was 16% and near complete response rate 24%.

CONCLUSIONS

In this study, preoperative chemoradiotherapy for patients with locally advanced gastric cancer was associated with manageable toxicity and encouraging pathological response rates.