Guo-Liang Jiang

Metformin is associated with reduced risk of pancreatic cancer in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

AIMSnRecent epidemiological studies indicated that use of metformin might decrease the risk of various cancers among patients with type 2 diabetes mellitus (T2DM). However, its influence on pancreatic cancer was controversial. Therefore, we did a meta-analysis of currently available observational studies on the issue.nnnMETHODSnWe did a PubMed and ISI Web of Science search for observational articles. The pooled relative risk (RR) was estimated using a random-effect model. Heterogeneity was evaluated using I(2) statistic. Subgroup analysis was performed to explore the source of heterogeneity and confirm the overall estimates. Publication bias was also examined.nnnRESULTSnThe analysis included 11 articles (13 studies) comprising 10 cohort studies and 3 case-control studies. Use of metformin was associated with a significant lower risk of pancreatic cancer [RR 0.63, 95% confidence internal (CI) 0.46-0.86, p=0.003]. In a total 11 subgroup analyses, 5 provided the consistent result with pooled effect estimates of overall analysis. No publication bias was detected by Beggs (Z=-0.79, p=0.428) and Eggers test (t=-0.92, p=0.378).nnnCONCLUSIONSnFrom present observational studies, use of metformin appears to be associated with a reduced risk of pancreatic cancer in patients with T2DM. Further investigation is needed.

THREE-DIMENSIONAL CONFORMAL RADIATION THERAPY FOR ESOPHAGEAL SQUAMOUS CELL CARCINOMA: IS ELECTIVE NODAL IRRADIATION NECESSARY?

PURPOSEnTo evaluate the local control, survival, and toxicity associated with three-dimensional conformal radiotherapy (3D-CRT) for squamous cell carcinoma (SCC) of the esophagus, to determine the appropriate target volumes, and to determine whether elective nodal irradiation is necessary in these patients.nnnMETHODS AND MATERIALSnA prospective study of 3D-CRT was undertaken in patients with esophageal SCC without distant metastases. Patients received 68.4 Gy in 41 fractions over 44 days using late-course accelerated hyperfractionated 3D-CRT. Only the primary tumor and positive lymph nodes were irradiated. Isolated out-of-field regional nodal recurrence was defined as a recurrence in an initially uninvolved regional lymph node.nnnRESULTSnAll 53 patients who made up the study population tolerated the irradiation well. No acute or late Grade 4 or 5 toxicity was observed. The median survival time was 30 months (95% confidence interval, 17.7-41.8). The overall survival rate at 1, 2, and 3 years was 77%, 56%, and 41%, respectively. The local control rate at 1, 2, and 3 years was 83%, 74%, and 62%, respectively. Thirty-nine of the 53 patients (74%) showed treatment failure. Seventeen of the 39 (44%) developed an in-field recurrence, 18 (46%) distant metastasis with or without regional failure, and 3 (8%) an isolated out-of-field nodal recurrence only. One patient died of disease in an unknown location.nnnCONCLUSIONSnIn patients treated with 3D-CRT for esophageal SCC, the omission of elective nodal irradiation was not associated with a significant amount of failure in lymph node regions not included in the planning target volume. Local failure and distant metastases remained the predominant problems.

Application of active breathing control in 3-dimensional conformal radiation therapy for hepatocellular carcinoma: The feasibility and benefit

BACKGROUND AND PURPOSEnTo investigate the feasibility and effectiveness of utilizing active breathing coordinator (ABC) in 3DCRT for HCC.nnnMATERIALS AND METHODSnA dosimetric comparison between the free-breathing (FB) plan and ABC plan in HCC 3DCRT was performed. Set-up errors and reproducibility of diaphragm position using ABC were measured, and patients acceptance was also recorded.nnnRESULTSnFrom April 2005 to February 2007, 28 HCC were irradiated with ABC and they tolerated ABC well. The mean dose to normal liver was reduced from 16.9Gy in FB plan to 14.3Gy in ABC plan. PTV for ABC and FB plans were 529cm(3) and 781cm(3), respectively, and V(23) were reduced from 45% to 30%. The predicted incidences of radiation-induced liver disease by Lyman model were 1% and 2.5%, respectively, in favor of ABC plan. The systematic and random errors for the ABC and FB plans were 1.2mm vs. 4.7mm, 1.6mm vs. 3.5mm, and 1.8mm vs. 2.7mm, respectively, in cranio-caudal, anterior-posterior, and left-right directions. The average intrafraction reproducibility of diaphragm position in cranio-caudal direction was 1.6mm, and the interfraction, 6.7mm.nnnCONCLUSIONSnThe utilization of ABC in HCC 3DCRT is feasible, and can reduce liver irradiation.

Comparison between radioimmunotherapy and external beam radiation therapy for patients with hepatocellular carcinoma

Abstract. It has previously been observed in animal studies that, at equivalent doses, radioimmunotherapy (RIT) is 2.5 times more effective than multiple fractions of external beam radiation therapy (EBRT) in inhibiting tumour growth. In this study, we compared the use of RIT and EBRT in patients with hepatocellular carcinoma (HCC), treated during the past 10 years. Of 67 patients without extrahepatic involvement, 32 were treated with hepatic artery ligation combined with RIT (the RIT group) while 35 were treated with a combination of hepatic arterial chemo-embolisation and EBRT (the EBRT group). The patients in the RIT group received 131I-Hepama-1 monoclonal antibody, which was infused through the hepatic artery catheter. The patients in the EBRT group received transcatheter arterial chemo-embolisation and limited-field EBRT using a linear accelerator. Parameters observed include tumour response, alpha-fetoprotein (AFP) level in serum, human anti-murine antibody (HAMA) assay, T lymphocyte subsets, survival rates, routine parameters, sequential resection rates and histopathological status of the resection specimens. The sequential resection rates were 53% (17/32) and 23% (8/35), and tumour response rates were 72% (23/32) and 86% (30/35) in the RIT and EBRT groups, respectively. The main side-effects in the RIT group were mild allergic reactions. The most common toxicity in the EBRT group was an increase in liver enzymes. The liver tissue in the target volume was injured by EBRT. The injured liver tissue revealed a low-attenuation area adjacent to the hepatic tumour within the target volume on follow-up computed tomography studies after EBRT. On pathological evaluation, the low-attenuation area revealed hyperaemia, distended hepatic sinusoids packed with erythrocytes and hepatic cell loss. The sequential resection specimens from both the RIT and the EBRT group showed residual cancer tissue located at the edge of the mass. The residual cancer cells presented as giant cells under microscopy. T lymphocyte subsets observed prior to treatment did not significantly change after RIT, but were significantly disturbed by EBRT. HAMA formation was the major reason for discontinuing RIT, the incidence being as high as 34% (11/32). Intrahepatic and pulmonary metastases occurred more frequently in the EBRT group (63%) than in the RIT group (22%). The 1-, 2-, 3- and 4-year survival rates were 50%, 41%, 34% and 31% in the RIT group, and 77%, 39%, 11% and 7% in the EBRT group, respectively. It is interesting that the serum AFP level showed a transient increase, the mechanism and importance of which are not known, but are discussed. Both RIT and EBRT are useful treatment modalities for unresectable HCC, serving to prolong survival. However, RIT is much less toxic than EBRT, the side-effects of which include radiation injury to the liver and disturbance of T lymphocyte subsets.

Use of combined maximum and minimum intensity projections to determine internal target volume in 4-dimensional CT scans for hepatic malignancies

BackgroundTo evaluate the accuracy of the combined maximum and minimum intensity projection-based internal target volume (ITV) delineation in 4-dimensional (4D) CT scans for liver malignancies.Methods4D CT with synchronized IV contrast data were acquired from 15 liver cancer patients (4 hepatocellular carcinomas; 11 hepatic metastases). We used five approaches to determine ITVs: (1). ITVAllPhases: contouring gross tumor volume (GTV) on each of 10 respiratory phases of 4D CT data set and combining these GTVs; (2). ITV2Phase: contouring GTV on CT of the peak inhale phase (0% phase) and the peak exhale phase (50%) and then combining the two; (3). ITVMIP: contouring GTV on MIP with modifications based on physicians visual verification of contours in each respiratory phase; (4). ITVMinIP: contouring GTV on MinIP with modification by physician; (5). ITV2M: combining ITVMIP and ITVMinIP. ITVAllPhases was taken as the reference ITV, and the metrics used for comparison were: matching index (MI), under- and over-estimated volume (Vunder and Vover).Results4D CT images were successfully acquired from 15 patients and tumor margins were clearly discernable in all patients. There were 9 cases of low density and 6, mixed on CT images. After comparisons of metrics, the tool of ITV2M was the most appropriate to contour ITV for liver malignancies with the highest MI of 0.93 ± 0.04 and the lowest proportion of Vunder (0.07 ± 0.04). Moreover, tumor volume, target motion three-dimensionally and ratio of tumor vertical diameter over tumor motion magnitude in cranio-caudal direction did not significantly influence the values of MI and proportion of Vunder.ConclusionThe tool of ITV2M is recommended as a reliable method for generating ITVs from 4D CT data sets in liver cancer.

Radiosensitization of metformin in pancreatic cancer cells via abrogating the G2 checkpoint and inhibiting DNA damage repair

Recent evidences have demonstrated the potential of metformin as a novel agent for cancer prevention and treatment. Here, we investigated its ability of radiosensitization and the underlying mechanisms in human pancreatic cancer cells. In this study, we found that metformin at 5u2009mM concentration enhanced the radiosensitivity of MIA PaCa-2 and PANC-1 cells, with sensitization enhancement ratios of 1.39 and 1.27, respectively. Mechanistically, metformin caused abrogation of the G2 checkpoint and increase of mitotic catastrophe, associated with suppression of Wee1 kinase and in turn CDK1 Tyr15 phosphorylation. Furthermore, metformin inhibited both expression and irradiation-induced foci formation of Rad51, a key player in homologous recombination repair, ultimately leading to persistent DNA damage, as reflected by γ-H2AX and 53BP1 signaling. Finally, metformin-mediated AMPK/mTOR/p70S6K was identified as a possible upstream pathway controlling translational regulation of Wee1 and Rad51. Our data suggest that metformin radiosensitizes pancreatic cancer cells in vitro via abrogation of the G2 checkpoint and inhibition of DNA damage repair. However, the in vivo study is needed to further confirm the findings from the in vitro study.

Long-term outcome of irradiation with or without chemotherapy for esophageal squamous cell carcinoma: a final report on a prospective trial

PurposeTo investigate the long-term outcome of esophageal squamous cell carcinoma (SCC) treated by irradiation with or without concurrent chemotherapy.Methods and materialsA prospective clinical trial was carried out from 1998 to 2000. One hundred and eleven patients were randomly enrolled to receive either late course accelerated hyperfractionated irradiation (LCAF) or LCAF with concurrent chemotherapy (LCAF + CT). For LCAF, 41.4u2009Gy in 23 fractions was first delivered at five fractions per week, followed by 27u2009Gy in 18 fractions at two 1.5u2009Gy fractions a day. Concurrent chemotherapy of cis-platinum and 5-fluorouracil was administered for four cycles. Overall survival (OS), locoregional recurrence and distant metastasis were observed. Late toxicity was scored by RTOG criteria, and quality of life (QOL) was also evaluated.ResultsThe median follow-up time was 24u2009months for all patients and 138u2009months for 17 living patients. Median survival time was 25u2009months and 32u2009months in LCAF and LCAF + CT (pu2009=u20090.653), respectively. For an entire group of patients, overall survivals were 34%, 27% and 22%; locoregional recurrence rates were 30%, 36% and 41%; and distant metastasis rates were 26%, 28% and 29% at 5-yr, 8-yr and 10-yr, respectively. Incidences of ≥ Grade 3 late toxicity were 29% at 10-yr. There were no statistically significant differences between LCAF and LCAF + CT with respect to the parameters mentioned above. Cumulative incidence of late toxicities of ≥ Grade 3 increased sharply after the attained age of 70u2009years. Eighty-eight percent of patients lived with good KPS (≥ 90) and 94% could eat regular or soft diet.ConclusionThe long-term outcome of esophageal SCC patients who received LCAF or LCAF + CT was good. The locoregional and distant failures occurred more often in the first three years after treatment, but could continuously occur up to 10u2009years. The late toxicity was acceptable. Late toxicities ≥ Grade 3 were more likely to occur in elderly patients. QOL was good in living patients.

Three-dimensional conformal radiation therapy for squamous cell carcinoma of the esophagus: A prospective phase I/II study

PURPOSEnA prospective phase I-II study was conducted to determine the tolerance and local control rate of three-dimensional conformal radiotherapy (3-DCRT) for esophageal squamous cell carcinoma (SCC).nnnMETHODS AND MATERIALSnThirty patients underwent 3-DCRT for thoracic esophageal SCC. PTV1 composed of a 1.2-1.5 cm margin lateral around GTV and 3.0 cm margin superior/inferior of GTV. PTV2 encompassed GTV with a margin of 0.5-0.7 cm. The dose for PTV1 was 50 Gy in 2 Gy daily fractions; PTV2 received a boost of 16 Gy in 2 Gy daily fractions to a total dose of 66 Gy.nnnRESULTSnMedian follow-up time was 18 months. The most common acute toxicity was esophagitis in 63% of patients with RTOG grades 1-2, and in 3% with grade 3. RTOG grades 1-2 radiation pneumonitis developed in 27% of patients. One patient developed pulmonary fibrosis RTOG grade 2 and another patient experienced grade 3 pulmonary fibrosis. Two patients developed mild esophageal stricture requiring dilatation. Two-year overall survival, local disease progression-free rate, and distant metastasis-free rate were 69%, 36% and 56%, respectively.nnnCONCLUSIONSnAlthough 3-DCRT to 66 Gy for esophageal SCC was well tolerated, the local control was disappointing. The result supports the use of chemoradiation as the standard care for esophageal SCC.

Improved Survival in Patients with Resected Pancreatic Carcinoma Using Postoperative Intensity-Modulated Radiotherapy and Regional Intra-Arterial Infusion Chemotherapy

Background We assessed the role of adjuvant intensity-modulated radiotherapy (IMRT) in combination with chemotherapy for pancreatic carcinomas after curative resection and identified prognostic factors related to pancreatic carcinoma after multidisciplinary treatment strategies. Material/Methods Pancreatic carcinoma patients (n=61) who received adjuvant radiotherapy after resection (median dose, 50.4 Gy) between 2010 and 2016 were retrospectively identified. Sixty patients received chemotherapy, including concurrent chemoradiotherapy (CCRT), systemic chemotherapy, and regional intra-arterial infusion chemotherapy (RIAC). The Kaplan-Meier method was used to measure the 3-year overall survival (OS) and disease-free survival (DFS) rates. Log-rank univariate analysis and multivariate Cox regression model analysis were used to identify prognostic factors. Results Median follow-up time was 25.5 (range, 4.9–59.7) months. The 3-year OS and DFS rates were 31.0% and 16.1%, respectively. The median OS and DFS were 27.4 and 16.7 months, respectively. Multivariate analysis indicated that independent favorable predictors for OS were CCRT (p=0.039) and postoperative RIAC (p=0.044). Moreover, postoperative RIAC (p=0.027), and pre-radiotherapy CA19-9 ≤37 U/mL (p=0.0080) were independent favorable predictors for DFS. The combination of radiotherapy and chemotherapy was tolerated well by the patients, and no treatment-related death occurred. Conclusions Combined IMRT and adjuvant chemotherapy appeared safe and effective for pancreatic carcinoma. CCRT was associated with improved survival with acceptable toxicity. We propose that radiotherapy could be a part of postoperative treatment, but it should be administered concurrently with chemotherapy. Adding RIAC was associated with improved OS and DFS and it could be integrated into the postoperative treatment regimen.