Gemcitabine-radiotherapy in patients with locally advanced pancreatic cancer

Impact of Short-Course Palliative Radiation Therapy on Pancreatic Cancer-Related Pain: Prospective Phase 2 Nonrandomized PAINPANC Trial

PURPOSE

Clinical evidence is limited regarding palliative radiation therapy for relieving pancreatic cancer-related pain. We prospectively investigated pain response after short-course palliative radiation therapy in patients with moderate-to-severe pancreatic cancer-related pain.

METHODS AND MATERIALS

In this prospective phase 2 single center nonrandomized trial, 30 patients with moderate-to-severe pain (5-10, on a 0-10 scale) of pancreatic cancer refractory to pain medication, were treated with a short-course palliative radiation therapy; 24 Gy in 3 weekly fractions (2015-2018). Primary endpoint was defined as a clinically relevant average decrease of ≥2 points in pain severity, compared with baseline, within 7 weeks after the start of treatment. Secondary endpoint was global quality of life (QoL), with a clinically relevant increase of 5 to 10 points (0-100 scale). Pain severity reduction and QoL were assessed 9 times using the Brief Pain Inventory and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C15-PAL, respectively. Both outcomes were analyzed using joint modeling. In addition, acute toxicity based on clinician reporting and overall survival (OS) were assessed.

RESULTS

Overall, 29 of 30 patients (96.7%) received palliative radiation therapy. At baseline, the median oral morphine equivalent daily dose was 129.5 mg (range, 20.0-540.0 mg), which decreased to 75.0 mg (range, 15.0-360.0 mg) after radiation (P = .021). Pain decreased on average 3.15 points from baseline to 7 weeks (one-sided P = .045). Patients reported a clinically relevant mean pain severity reduction from 5.9 to 3.8 points (P = .011) during the first 3 weeks, which further decreased to 3.2 until week 11, ending at 3.4 (P = .006) in week 21 after the first radiation therapy fraction. Global QoL significantly improved from 50.5 to 60.8 during the follow-up period (P = .001). Grade 3 acute toxicity occurred in 3 patients and no grade 4 to 5 toxicity was observed. Median OS was 11.8 weeks, with a 13.3% 1-year actuarial OS rate.

CONCLUSIONS

Short-course palliative radiation therapy for pancreatic cancer-related pain was associated with rapid, clinically relevant reduction in pain severity, and clinically relevant improvement in global QoL, with mostly mild toxicity.

Dosimetric evaluation of magnetic resonance imaging-guided adaptive radiation therapy in pancreatic cancer by extent of re-contouring of organs-at-risk

PURPOSE

The safety of online contouring and planning for adaptive radiotherapy is unknown. This study aimed to evaluate the dosimetric difference of the organ-at-risk (OAR) according to the extent of contouring in stereotactic magnetic resonance image-guided adaptive RT (SMART) for pancreatic cancer.

MATERIALS AND METHODS

We reviewed the treatment plan data used for SMART in patients with pancreatic cancer. For the online contouring and planning, OARs within 2 cm from the planning target volume (PTV) in the craniocaudal direction were re-controlled daily at the attending physician's discretion. The entire OARs were re-contoured retrospectively for data analysis. We termed the two contouring methods the Rough OAR and the Full OAR, respectively. The proportion of dose constraint violation and other dosimetric parameters was analyzed.

RESULTS

Nineteen patients with 94 fractions of SMART were included in the analysis. The dose constraint was violated in 10.6% and 43.6% of the fractions in Rough OAR and Full OAR methods, respectively (p = 0.075). Patients with a large tumor, a short distance from gross tumor volume (GTV) to OAR, and a tumor in the body or tail were associated with more occult dose constraint violations-large tumor (p = 0.027), short distance from GTV to OAR (p = 0.061), tumor in body or tail (p = 0.054). No dose constraint violation occurred outside 2 cm from the PTV.

CONCLUSION

More occult dose constraint violations can be found by the Full OAR method in patients with pancreatic cancer with some clinical factors in the online re-planning for SMART. Re-contouring all the OARs would be helpful to detect occult dose constraint violations in SMART planning. Since the dosimetric profile of SMART cannot be represented by a single fraction, patient selection for the Full OAR method should be weighted between the clinical usefulness and the time and workforce required.

Synthetic CT-aided multiorgan segmentation for CBCT-guided adaptive pancreatic radiotherapy

PURPOSE

The delineation of organs at risk (OARs) is fundamental to cone-beam CT (CBCT)-based adaptive radiotherapy treatment planning, but is time consuming, labor intensive, and subject to interoperator variability. We investigated a deep learning-based rapid multiorgan delineation method for use in CBCT-guided adaptive pancreatic radiotherapy.

METHODS

To improve the accuracy of OAR delineation, two innovative solutions have been proposed in this study. First, instead of directly segmenting organs on CBCT images, a pretrained cycle-consistent generative adversarial network (cycleGAN) was applied to generating synthetic CT images given CBCT images. Second, an advanced deep learning model called mask-scoring regional convolutional neural network (MS R-CNN) was applied on those synthetic CT to detect the positions and shapes of multiple organs simultaneously for final segmentation. The OAR contours delineated by the proposed method were validated and compared with expert-drawn contours for geometric agreement using the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD95), mean surface distance (MSD), and residual mean square distance (RMS).

RESULTS

Across eight abdominal OARs including duodenum, large bowel, small bowel, left and right kidneys, liver, spinal cord, and stomach, the geometric comparisons between automated and expert contours are as follows: 0.92 (0.89-0.97) mean DSC, 2.90 mm (1.63-4.19 mm) mean HD95, 0.89 mm (0.61-1.36 mm) mean MSD, and 1.43 mm (0.90-2.10 mm) mean RMS. Compared to the competing methods, our proposed method had significant improvements (p < 0.05) in all the metrics for all the eight organs. Once the model was trained, the contours of eight OARs can be obtained on the order of seconds.

CONCLUSIONS

We demonstrated the feasibility of a synthetic CT-aided deep learning framework for automated delineation of multiple OARs on CBCT. The proposed method could be implemented in the setting of pancreatic adaptive radiotherapy to rapidly contour OARs with high accuracy.

Maximizing Tumor Control and Limiting Complications With Stereotactic Body Radiation Therapy for Pancreatic Cancer

PURPOSE

Stereotactic body radiation therapy (SBRT) and stereotactic ablative body radiation therapy is being increasingly used for pancreatic cancer (PCa), particularly in patients with locally advanced and borderline resectable disease. A wide variety of dose fractionation schemes have been reported in the literature. This HyTEC review uses tumor control probability models to evaluate the comparative effectiveness of the various SBRT treatment regimens used in the treatment of patients with localized PCa.

METHODS AND MATERIALS

A PubMed search was performed to review the published literature on the use of hypofractionated SBRT (usually in 1-5 fractions) for PCa in various clinical scenarios (eg, preoperative [neoadjuvant], borderline resectable, and locally advanced PCa). The linear quadratic model with α/β= 10 Gy was used to address differences in fractionation. Logistic tumor control probability models were generated using maximum likelihood parameter fitting.

RESULTS

After converting to 3-fraction equivalent doses, the pooled reported data and associated models suggests that 1-year local control (LC) without surgery is ≈79% to 86% after the equivalent of 30 to 36 Gy in 3 fractions, showing a dose response in the range of 25 to 36 Gy, and decreasing to less than 70% 1-year LC at doses below 24 Gy in 3 fractions. The 33 Gy in 5 fraction regimen (Alliance A021501) corresponds to 28.2 Gy in 3 fractions, for which the HyTEC pooled model had 77% 1-year LC without surgery. Above an equivalent dose of 28 Gy in 3 fractions, with margin-negative resection the 1-year LC exceeded 90%.

CONCLUSIONS

Pooled analyses of reported tumor control probabilities for commonly used SBRT dose-fractionation schedules for PCa suggests a dose response. These findings should be viewed with caution given the challenges and limitations of this review. Additional data are needed to better understand the dose or fractionation-response of SBRT for PCa.

Methodological Development of Combination Drug and Radiotherapy in Basic and Clinical Research

Newer technical improvements in radiation oncology have been rapidly implemented in recent decades, allowing an improved therapeutic ratio. The development of strategies using local and systemic treatments concurrently, mainly targeted therapies, has however plateaued. Targeted molecular compounds and immunotherapy are increasingly being incorporated as the new standard of care for a wide array of cancers. A better understanding of possible prior methodology issues is therefore required and should be integrated into upcoming early clinical trials including individualized radiotherapy-drug combinations. The outcome of clinical trials is influenced by the validity of the preclinical proofs of concept, the impact on normal tissue, the robustness of biomarkers and the quality of the delivery of radiation. Herein, key methodological aspects are discussed with the aim of optimizing the design and implementation of future precision drug-radiotherapy trials.

Phase II Study of Induction Chemotherapy with Gemcitabine plus 5-Fluorouracil Followed by Gemcitabine-Based Concurrent Chemoradiotherapy for Unresectable Locally Advanced Pancreatic Cancer

Aims and background

To evaluate the efficacy and tolerability of a new treatment approach including induction chemotherapy (CT) and concurrent chemoradiotherapy (CRT) in unresectable, locally advanced pancreatic cancer (LAPC).

Patients and methods

Twenty-four patients with LAPC were enrolled in the study. They first received induction CT consisting of 5-fluorouracil (5FU) (500 mg/m2) and gemcitabine (1000 mg/m2), which were given weekly for 3 weeks of every 4. Patients showing a response or disease stabilization after 2 cycles of induction CT received CRT consisting of external beam radiotherapy (50.4-54 Gy in fractions of 1.8 Gy/day) and gemcitabine (350 mg/m2, weekly for 6 weeks). Patients without disease progression received 2 additional cycles of CT consisting of 5FU plus gemcitabine with the same doses and schedule as given in the induction CT.

Results

After the end of the study, 2 (8%) and 5 (21%) patients showed complete and partial responses, respectively. Five patients (21%) had disease stabilization. The grade 3 and 4 toxicities associated with CT were neutropenia (21%) and thrombocytopenia (4%). The grade 3 and 4 toxicities occurring in patients who received CRT were neutropenia (24%), thrombocytopenia (24%), diarrhea (18%), and nausea (12%). The median progression-free survival for all patients was 6 months (95% CI, 3.6-8.4), and the median overall survival was 11 months (95% CI, 8.16-13.84).

Conclusions

The CRT approach of this study is moderately active and has an acceptable toxicity profile. However, the incor-poration of combination CT into CRT at the present schedule could not produce any additional benefit over CRT alone. Newer agents with more systemic activity are clearly warranted.

Discovery and characterization of small molecule Rac1 inhibitors

Aberrant activation of Rho GTPase Rac1 has been observed in various tumor types, including pancreatic cancer. Rac1 activates multiple signaling pathways that lead to uncontrolled proliferation, invasion and metastasis. Thus, inhibition of Rac1 activity is a viable therapeutic strategy for proliferative disorders such as cancer. Here we identified small molecule inhibitors that target the nucleotide-binding site of Rac1 through in silico screening. Follow up in vitro studies demonstrated that two compounds blocked active Rac1 from binding to its effector PAK1. Fluorescence polarization studies indicate that these compounds target the nucleotide-binding site of Rac1. In cells, both compounds blocked Rac1 binding to its effector PAK1 following EGF-induced Rac1 activation in a dose-dependent manner, while showing no inhibition of the closely related Cdc42 and RhoA activity. Furthermore, functional studies indicate that both compounds reduced cell proliferation and migration in a dose-dependent manner in multiple pancreatic cancer cell lines. Additionally, the two compounds suppressed the clonogenic survival of pancreatic cancer cells, while they had no effect on the survival of normal pancreatic ductal cells. These compounds do not share the core structure of the known Rac1 inhibitors and could serve as additional lead compounds to target pancreatic cancers with high Rac1 activity.

Phase I study of chemoradiotherapy using gemcitabine plus nab-paclitaxel for unresectable locally advanced pancreatic cancer

PURPOSE

For unresectable locally advanced (UR-LA) pancreatic cancer, chemoradiotherapy has been recommended by the NCCN guidelines. We designed a chemoradiotherapy protocol using nab-paclitaxel combined with gemcitabine (GnP) for patients with UR-LA pancreatic cancer. The purpose of this phase I study was to determine a recommended dose (RD) for this novel regimen.

METHODS

Patients with UR-LA pancreatic cancer were eligible. The frequency of dose-limiting toxicities (DLTs) was evaluated, and the RD was determined. Patients were classified according to the designated dose levels of chemoradiotherapy using the GnP regimen. After additional 6 cycles of the GnP regimen were administered, surgery was considered if the patients had stable disease and tumor marker levels had normalized.

RESULTS

DLT (grade 4 thrombocytopenia) was observed only in 1 of 12 patients, and the RD was set at level 3. Grade 3-4 leukopenia was observed in 9 (75.0%) patients, and neutropenia in 7 (58.3%). The response rate was 41.7%, and the disease control rate was 100%. Conversion surgery was performed in 6 (50%) patients, and curative resection (R0) was performed in all 6 patients (100%). Stratification according to the Evans classification system demonstrated one patient with grade 1b, one with grade 2, two with grade 3, and two with grade 4 disease.

CONCLUSION

The RD for weekly administration was 800 mg/m² for gemcitabine and 100 mg/m² for nab-paclitaxel with a 50.4 Gy radiation. The GnP regimen at this dosage was promising with 6 of 12 patients proceeding to conversion surgery, and should be evaluated further in a phase II trial.

Safety of selective internal radiation therapy (SIRT) with yttrium-90 microspheres combined with systemic anticancer agents: expert consensus

Selective internal radiation therapy (SIRT) with microspheres labelled with the β-emitter yttrium-90 (Y-90) enables targeted delivery of radiation to hepatic tumors. SIRT is primarily used to treat inoperable primary or metastatic liver tumors. Eligible patients have usually been exposed to a variety of systemic anticancer therapies, including cytotoxic agents, targeted biologics, immunotherapy and peptide receptor radionuclide therapy (PRRT). All these treatments have potential interactions with SIRT; however, robust evidence on the safety of these potential combinations is lacking. This paper provides current clinical experiences and expert consensus guidelines for the use of SIRT in combination with the anticancer treatment agents likely to be encountered in clinical practice. It was agreed by the expert panel that precautions need to be taken with certain drugs, but that, in general, systemic therapies do not necessarily have to be stopped to perform SIRT. The authors recommend stopping vascular endothelial growth factor inhibitors 4-6 weeks before SIRT, and restart after the patient has recovered from the procedure. It may also be prudent to stop potent radiosensitizers such as gemcitabine therapy 4 weeks before SIRT, and restart treatment at least 2‒4 weeks later. Data from phase III studies combining SIRT with fluorouracil (5FU) or folinic acid/5FU/oxaliplatin (FOLFOX) suggest that hematological toxicity is more common from the combination than it is from chemotherapy without SIRT. There is no evidence to suggest that chemotherapy increases SIRT-specific gastro-intestinal or liver toxicities.

A current perspective on stereotactic body radiation therapy for pancreatic cancer

Pancreatic cancer is a formidable malignancy with poor outcomes. The majority of patients are unable to undergo resection, which remains the only potentially curative treatment option. The management of locally advanced (unresectable) pancreatic cancer is controversial; however, treatment with either chemotherapy or chemoradiation is associated with high rates of local tumor progression and metastases development, resulting in low survival rates. An emerging local modality is stereotactic body radiation therapy (SBRT), which uses image-guided, conformal, high-dose radiation. SBRT has demonstrated promising local control rates and resultant quality of life with acceptable rates of toxicity. Over the past decade, increasing clinical experience and data have supported SBRT as a local treatment modality. Nevertheless, additional research is required to further evaluate the role of SBRT and improve upon the persistently poor outcomes associated with pancreatic cancer. This review discusses the existing clinical experience and technical implementation of SBRT for pancreatic cancer and highlights the directions for ongoing and future studies.

Predictive dosimetric parameters for gastrointestinal toxicity with hypofractioned radiotherapy in pancreatic adenocarcinoma

To better guide the development and optimization of radiotherapy planning, to reduce the incidence of radiation reactions, and to improve the quality of life of the patients with pancreatic cancer using radiotherapy, we conducted this study to explore the dosimetric parameters that predict the risk of gastrointestinal (GI) toxicity with hypofractioned radiotherapy for pancreatic cancer. Between January 2014 and January 2015, the medical records of 68 patients with pancreatic cancer who underwent helical tomotherapy at the Air Force General Hospital were analyzed. The doses delivered to the planning target volume, clinical target volume, and gross tumor volume-internal gross tumor volume of the primary pancreatic lesions were 50, 60, and 70-80 Gy in 15-20 fractions, respectively. GI toxicity was scored according to version 4.0 of the National Cancer Institute Common Terminology Criteria for Adverse Events. The stomach and duodenum were contoured separately to determine the dose-volume histogram parameters. Univariate and multivariate analyses were adopted to identify clinical and physical risk factors associated with GI toxicity. The median follow-up was 9 months (range: 4-16 months). Eighteen patients had grade II acute GI toxicity, one patient had grade III acute GI toxicity, 17 patients had grade II late GI toxicity, and one patient had grade III late GI toxicity. On univariate analysis, the volume, the average dose D mean, the maximum dose to 1, 3, 5, and 10 cm(3) of the stomach and duodenum (D1, D3, D5, and D10), and the relative volumes receiving 5-40 Gy (V5-V40), and the absolute volumes receiving 5-45 Gy (aV5-aV45) of the duodenum were significantly associated with grade II or higher GI toxicity (P<0.05). On multivariate analysis, aV45 of the duodenum was an independent predictor for grade II or higher GI toxicity (P=0.031). The receiver operating characteristic analysis also showed that an aV45 of 0.5 cm(3) was the optimal threshold to predict GI toxicity for the entire cohort. Our findings indicate that many dosimetric parameters of the duodenum correlate with grade II or higher GI toxicity. To reduce GI toxicity, the absolute volume of the irradiated duodenum should be reduced.

Concurrent radiotherapy with oral fluoropyrimidine versus gemcitabine in locally advanced pancreatic cancer: a systematic review and meta-analysis

Background

Gemcitabine (GEM) is the most widely utilized systemic agent in combination with radiation therapy (RT) for treating locally advanced pancreatic cancer (LAPC) in the concurrent setting. Despite recent interest in using two novel oral fluoropyrimidines (FUs), capecitabine and S-1, in this setting, there is a lack of randomized controlled trials (RCTs) to support this approach.

Methods

Trials published between 1994 and 2014 were identified by an electronic search of public databases (Medline, Embase, and the Cochrane Library). All prospective studies were independently identified by two authors for inclusion. Demographic data, treatment response, objective response rate (ORR), progression-free and overall survival (PFS and OS, respectively), and toxicities were extracted and analyzed using comprehensive meta-analysis software (version 2.0).

Results

Twenty-three cohorts with 843 patients were included: 497 patients were treated with GEM and 346 patients were treated with oral FU. Pooled OS was significantly higher at 1 and 2 years for S-1 plus RT than for GEM plus RT (relative risk [RR] 1.27; 95% confidence interval [CI], 1.00–1.65; P=0.03; and RR 1.75; 95% CI, 1.18–2.60, P=0.002, respectively), while 1-year PFS and ORR were not significantly different between S-1 and GEM-based chemoradiotherapy (P=0.37 and P=0.06, respectively). Additionally, comparable efficacy was found between capecitabine and GEM-based chemoradiotherapy in terms of OS, PFS, and ORR. As for grade 3 and 4 acute toxicity, oral FU plus RT significantly reduced the risk of developing hematologic toxicities, nausea, and vomiting when compared to GEM plus RT (P<0.001).

Conclusions

Oral FU plus RT may be a safe and feasible regimen for patients with LAPC, with similar efficacy and low rate of toxicities compared with GEM plus RT. Our findings support the need to compare S-1 with GEM in the concurrent setting in large prospective RCTs due to its potential survival benefits.

Phase II trial of selective internal radiation therapy and systemic chemotherapy for liver-predominant metastases from pancreatic adenocarcinoma

BACKGROUND

This prospective, open-label phase II study assessed the impact of liver-directed therapy with selective internal radiation therapy (SIRT) and systemic chemotherapy on progression-free survival (PFS) in liver-dominant metastatic pancreatic adenocarcinoma.

METHODS

Patients received yttrium-90-labelled ((90)Y) resin microspheres (SIR-Spheres; Sirtex Medical Limited, Sydney, Australia) as a single procedure on day 2 of the first weekly cycle of 5-fluorouracil (5FU; 600 mg/m(2)) with the option to switch to gemcitabine (1000 mg/m(2)) after 8 weeks of 5FU. Statistical analysis was conducted using Microsoft Excel (Microsoft Corporation, Redmond, Washington, USA). The primary endpoint of the study was PFS in the liver, with a median of ≥ 16 weeks defined as the threshold for clinical significance. PFS and overall survival (OS) were summarised by the Kaplan-Meier method using non-parametric estimates of the survivor function.

RESULTS

Fourteen eligible patients were enrolled; ten had primary tumour in situ and eight had liver-only metastases. Patients received a median (90)Y activity of 1.1 GBq and 8 weekly doses of 5FU; seven patients received a median of two doses of gemcitabine. Disease control in the liver was 93% (two confirmed partial responses [PR], one unconfirmed PR, ten stable disease). Median reduction in cancer antigen 19-9 was 72%. Median PFS was 5.2 months in the liver, which met the primary endpoint of the study, and 4.4 months at any site. PFS was prolonged in those with a resected primary compared with patients with primary in situ (median 7.8 vs. 3.4 months; p = 0.017). Median OS was 5.5 months overall and 13.6 months in patients with a resected primary. Grade 3/4 adverse events occurred in eight (57%) patients during days 0-60. There was one sudden death and another patient who died from possible treatment-related liver failure 7.0 months after SIRT.

CONCLUSIONS

SIRT and chemotherapy appears to be an effective treatment for liver metastases from pancreatic cancer, likely to be of most benefit in selected patients with a resected primary tumour and liver only disease. Significant toxicity was observed and the safety of this approach in patients with metastatic pancreatic cancer will need to be confirmed in subsequent studies. Further study is warranted with SIRT and modern chemotherapies.

TRIAL REGISTRATION

ACTRN12606000015549.

Inhibition of RAC1 GTPase sensitizes pancreatic cancer cells to γ-irradiation

Radiation therapy is a staple treatment for pancreatic cancer. However, owing to the intrinsic radioresistance of pancreatic cancer cells, radiation therapy often fails to increase survival of pancreatic cancer patients. Radiation impedes cancer cells by inducing DNA damage, which can activate cell cycle checkpoints. Normal cells possess both a G1 and G2 checkpoint. However, cancer cells are often defective in G1 checkpoint due to mutations/alterations in key regulators of this checkpoint. Accordingly, our results show that normal pancreatic ductal cells respond to ionizing radiation (IR) with activation of both checkpoints whereas pancreatic cancer cells respond to IR with G2/M arrest only. Overexpression/hyperactivation of Rac1 GTPase is detected in the majority of pancreatic cancers. Rac1 plays important roles in survival and Ras-mediated transformation. Here, we show that Rac1 also plays a critical role in the response of pancreatic cancer cells to IR. Inhibition of Rac1 using specific inhibitor and dominant negative Rac1 mutant not only abrogates IR-induced G2 checkpoint activation, but also increases radiosensitivity of pancreatic cancer cells through induction of apoptosis. These results implicate Rac1 signaling in the survival of pancreatic cancer cells following IR, raising the possibility that this pathway contributes to the intrinsic radioresistance of pancreatic cancer.

Phase I Clinical Trial to Determine the Feasibility and Maximum Tolerated Dose of Panitumumab to Standard Gemcitabine-Based Chemoradiation in Locally Advanced Pancreatic Cancer

PURPOSE

Epidermal growth factor receptor (EGFR) inhibitors may improve both the therapeutic efficacy of radiotherapy and the radiosensitizing activity of gemcitabine. Based on this rationale and the nonoverlapping toxicity profiles of gemcitabine and the monoclonal EGFR antibody panitumumab, we designed a phase I trial to investigate the maximum-tolerated dose (MTD), safety, and activity of panitumumab added to gemcitabine-based chemoradiotherapy (CRT) in patients with locally advanced pancreatic cancer (LAPC).

EXPERIMENTAL DESIGN

Patients with LAPC and WHO performance status 0 to 1 were treated with weekly panitumumab at four dose levels (1-2.5 mg/kg), combined with weekly gemcitabine 300 mg/m(2) and radiotherapy (50.4 Gy in 28 fractions) for 6 weeks, followed by gemcitabine 1,000 mg/m(2) weekly for 3 weeks every 4 weeks until disease progression or unacceptable toxicity. Each cohort was monitored during the combination therapy to establish dose limiting toxicity. Tumor evaluation was performed after CRT and during gemcitabine monotherapy.

RESULTS

Fourteen patients were enrolled; 14 were evaluable for toxicity and 13 for response. The MTD for panitumumab was 1.5 mg/kg. Three of the 6 patients, treated at MTD, experienced grade 3 adverse events during the combination therapy; neutropenia (n = 2; 33%), fatigue (n = 1; 17%), nausea (n = 1; 17%), and vomiting (n = 1; 17%). Partial response was achieved by 3 patients (23%), 1 in each dose cohort. Median progression free survival of the three cohorts together was 8.9 months.

CONCLUSIONS

The addition of panitumumab to gemcitabine-based chemoradiotherapy in LAPC has manageable toxicity and potential clinical efficacy.

Multidisciplinary neoadjuvant management for potentially curable pancreatic cancer

Pancreatic adenocarcinoma remains the fourth leading cause of cancer mortality in the U.S. Despite advances in surgical technique, radiotherapy technologies, and chemotherapeutics, the 5-year survival rate remains approximately 20% for the 15% of patients who are eligible for surgical resection. The majority of this group suffers metastatic recurrence. However, despite advances in therapies for patients with advanced pancreatic cancer, only surgery has consistently proven to improve long-term survival. Various combinations of chemotherapy, biologic-targeted therapy, and radiotherapy have been evaluated in different settings to improve outcomes. In this context, a neoadjuvant (preoperative) treatment strategy offers numerous potential benefits: (1) ensuring delivery of early, systemic therapy, (2) improving selection of patients for surgical therapy with truly localized disease, (3) potential downstaging of the neoplasm facilitating a negative margin resection in patients with locally advanced disease, and (4) providing a superior clinical trial mechanism capable of rapid assessment of the efficacy of novel therapeutics. This article reviews the recent trends in the management of pancreatic adenocarcinoma, with a particular emphasis on a multidisciplinary neoadjuvant approach to treatment.

Radiation plus docetaxel and cisplatin in locally advanced pancreatic carcinoma: a non-comparative randomized phase II trial

BACKGROUND

We performed a randomized, non-comparative phase II study evaluating docetaxel in combination with either daily continuous (protracted IV) 5-fluorouracil or cisplatin administered weekly, concurrent to radiotherapy in the treatment of locally advanced pancreatic carcinoma. Results of the docetaxel plus cisplatin regimen are reported.

METHODS

Forty chemotherapy-naive patients with locally advanced pancreatic carcinoma were randomly assigned to receive 5-fluorouracil and docetaxel or docetaxel 20mg/m(2) and cisplatin 20mg/m(2)/week, plus concurrent radiotherapy for 6 weeks. The radiation dose to the primary tumour was 54Gy in 30 fractions. The trial's primary endpoint was the 6-month crude non-progression rate.

RESULTS

51 patients from 7 centres were included in the docetaxel-cisplatin treatment group. Six-month non-progression rate was 39% (95% confidence interval: 26-53). Median overall survival was 9.6 months (95% confidence interval: 2.4-60.7); 6 complete and 8 partial responses were obtained. Six patients survived more than 2 years after their inclusion in the trial. Grade ≥3 toxicity was reported in 63% of patients; no treatment-related death occurred. Severe toxicities were mainly anorexia (22%), vomiting (20%) and fatigue (24%).

CONCLUSIONS

Despite inadequate efficacy according to the main end point, this regimen gave a satisfactory rate of objective response (27%) with tolerable toxicity.

Upper gastrointestinal complications associated with gemcitabine-concurrent proton radiotherapy for inoperable pancreatic cancer

BACKGROUND

Little is known about acute upper gastrointestinal (GI) complications associated with gemcitabine-concurrent proton radiotherapy (GPT) for inoperable pancreatic cancer. We investigated acute GI complications following GPT in patients with inoperable pancreatic cancer using small-bowel endoscopy.

METHODS

This prospective single center observational study was conducted at the Hyogo Ion Beam Medical Center from January 2010 to January 2012. Ninety-one patients who had clinically and medically inoperable pancreatic cancer treated by GPT were analyzed. Endoscopic examinations were performed before and after GPT to clarify the incidence rates of radiation-induced ulcers, GI hemorrhage, and GI perforation associated with GPT.

RESULTS

Post-treatment endoscopic examinations revealed that 45 (49.4 %) patients had radiation-induced ulcers in the stomach and duodenum. Of those, many ulcerative lesions were found in the lower stomach (51 %) and horizontal part of the duodenum (39 %), regardless of the primary tumor site in the pancreas. Neither GI hemorrhage, nor perforation, was found in post-treatment endoscopy examinations.

CONCLUSION

Approximately half of the patients treated with GPT for inoperable pancreatic cancer exhibited radiation-induced ulcers in the stomach and duodenum.

Induction gemcitabine plus concurrent gemcitabine and radiotherapy for locally advanced unresectable or resected pancreatic cancer

AIMS

To determine the efficacy of induction gemcitabine followed by biweekly gemcitabine concurrent with radiotherapy for locally advanced pancreatic cancer.

MATERIALS AND METHODS

Between March 2001 and August 2009, 90 patients with unresectable (78) or resected (12) pancreatic cancer were treated with a standard treatment policy of induction gemcitabine (seven doses of weekly gemcitabine at 1000 mg/m(2)) followed by concurrent radiotherapy (52.5 Gy) and biweekly gemcitabine (40 mg/m(2)).

RESULTS

After induction gemcitabine, 17.8% of patients did not proceed to chemoradiotherapy, due to either disease progression, performance status deterioration or gemcitabine toxicity. Of the patients who received chemoradiotherapy, 68.9% completed the course of 52.5 Gy, whereas 79.7% received more than 45 Gy. Chemoradiotherapy was stopped early due to treatment toxicity in 22.9% of patients. On intention to treat analysis, the median overall survival was 12.7 months in the locally advanced group and 18.2 months in the resected group. On multivariate analysis for the unresectable patients, a larger gross tumour volume was a significant poor prognostic factor for overall survival and local progression-free survival.

CONCLUSION

This large series confirms, in a standard practice setting, similar efficacy and tolerability of treatment as previously reported in our phase I-II study. The benefit to patients with a gross tumour volume >48 cm(3) may be limited.

Dosimetric and clinical predictors of toxicity following combined chemotherapy and moderately hypofractionated rotational radiotherapy of locally advanced pancreatic adenocarcinoma

BACKGROUND AND PURPOSE

Hypofractionated radiotherapy (RT) of pancreatic adenocarcinoma is limited by the tolerance of adjacent normal tissues. A better understanding of the influence of dosimetric variables on the rate of toxicity after RT must be considered an important goal.

METHODS AND MATERIALS

Sixty-one patients with histologically proven locally advanced disease (LAPD) were analyzed. The therapeutic strategy consisted of induction chemotherapy (ChT) followed by concurrent chemoradiotherapy (CRT). In 39 out of 61 patients the target volume was based on a four-dimensional CT (4D-CT) procedure. Delivered dose was 44.25Gy in 15 fractions to PTV2, which consisted of pancreatic tumor and regional lymph nodes considered radiologically involved; 23 out of 61 patients received a simultaneous integrated boost (SIB) to a tumor sub-volume infiltrating the great abdominal vessels (PTV1) with dose in the range of 48-58Gy. RT was delivered with Helical Tomotherapy. Dose-volume histograms (DVHs) of target volumes and organs at risk (OARs) were collected for analysis. The predictive value of clinical/dosimetric parameters was tested by univariate/multivariate analyses.

RESULTS

The crude incidence of acute gastrointestinal (GI) grade 2 toxicity was 33%. The 12-month actuarial rate of "anatomical" (gastro-duodenal mucosa damage) toxicity was 13% (95% CI: 4-22%). On univariate analysis, several stomach and duodenum DVH endpoints are predictive of toxicity after moderately hypofractionated radiotherapy. Multivariate analysis confirmed that baseline performance status and the stomach V20[%] were strong independent predictors of acute GI grade ⩾2 toxicity. The high-dose region of duodenum DVH (V45[%]; V40[%]) was strongly correlated with grade ⩾2 "anatomical" toxicity; the best V40[%] and V45[%] cut-off values were 16% and 2.6% respectively.

CONCLUSION

Regarding dosimetric indices, stomach V20[%] correlates with a higher rate of acute toxicity; more severe acute and late anatomical toxicities are related to the high dose region of duodenum DVH.

Radiation dose responses for chemoradiation therapy of pancreatic cancer: an analysis of compiled clinical data using biophysical models

PURPOSE

We analyzed recent clinical data obtained from chemoradiation of unresectable, locally advanced pancreatic cancer (LAPC) in order to examine possible benefits from radiation therapy dose escalation.

METHODS AND MATERIALS

A modified linear quadratic model was used to fit clinical tumor response and survival data of chemoradiation treatments for LAPC reported from 20 institutions. Biophysical radiosensitivity parameters were extracted from the fits.

RESULTS

Examination of the clinical data demonstrated an enhancement in tumor response with higher irradiation dose, an important clinical result for palliation and quality of life. Little indication of improvement in 1-year survival with increased radiation dose was observed. Possible dose escalation schemes are proposed based on calculations of the biologically effective dose required for a 50% tumor response rate.

CONCLUSIONS

Based on the evaluation of tumor response data, the escalation of radiation dose presents potential clinical benefits which when combined with normal tissue complication analyses may result in improved treatment outcome for locally advanced pancreatic cancer patients.

High-dose helical tomotherapy with concurrent full-dose chemotherapy for locally advanced pancreatic cancer

PURPOSE

To improve poor therapeutic outcome of current practice of chemoradiotherapy (CRT), high-dose helical tomotherapy (HT) with concurrent full-dose chemotherapy has been performed on patients with locally advanced pancreatic cancer (LAPC), and the results were analyzed.

METHODS AND MATERIALS

We retrospectively reviewed 39 patients with LAPC treated with radiotherapy using HT (median, 58.4 Gy; range, 50.8-59.9 Gy) and concomitant chemotherapy between 2006 and 2009. Radiotherapy was directed to the primary tumor with a 0.5-cm margin without prophylactic nodal coverage. Twenty-nine patients (79%) received full-dose (1000 mg/m(2)) gemcitabine-based chemotherapy during HT. After completion of CRT, maintenance chemotherapy was administered to 37 patients (95%).

RESULTS

The median follow-up was 15.5 months (range, 3.4-43.9) for the entire cohort, and 22.5 months (range, 12.0-43.9) for the surviving patients. The 1- and 2-year local progression-free survival rates were 82.1% and 77.3%, respectively. Eight patients (21%) were converted to resectable status, including 1 with a pathological complete response. The median overall survival and progression-free survival were 21.2 and 14.0 months, respectively. Acute toxicities were acceptable with no gastrointestinal (GI) toxicity higher than Grade 3. Severe late GI toxicity (≥ Grade 3) occurred in 10 patients (26%); 1 treatment-related death from GI bleeding was observed.

CONCLUSION

High-dose helical tomotherapy with concurrent full-dose chemotherapy resulted in improved local control and long-term survival in patients with LAPC. Future studies are needed to widen the therapeutic window by minimizing late GI toxicity.

A phase II study of gemcitabine in combination with radiation therapy in patients with localized, unresectable, pancreatic cancer: a Hoosier Oncology Group study

OBJECTIVE

A Phase II study was conducted at Indiana University to evaluate the safety and efficacy of combined weekly Gemcitabine (GEM) with external beam radiotherapy (RT) in unresectable, locally advanced pancreatic cancer (LAPC).

METHODS

Eligible patients had biopsy-proven LAPC without evidence of metastatic disease. In part A of the treatment plan, patients received GEM 600 mg/m(2) IV weekly, with concurrent RT (50.4 Gy in 28 fractions, 1.8 Gy/d, 5 days per week). Part B of the treatment plan began approximately 4 weeks after completing part A: patients without disease progression received weekly GEM 1000 mg/m(2) on days 1, 8, and 15 of a 28-day cycle for 6 cycles or until disease progression.

RESULTS

From April 2001 to June 2003, of 28 patients evaluated, 24 (86%) completed part A. About 22 patients had grade 3 toxicities, primarily hematologic (43%) and gastrointestinal (36%). Three patients (11%) had grade 4 toxicities (one each for hyperbilirubinemia, infection, and dyspnea). The median follow-up was 10 months (1-63 months) for all enrolled patients. Six patients (21%) had a radiologic partial response, 16 (57%) had stable disease, 5 (18%) had progressive disease, and 1 patient (4%) had an unevaluable response at last follow-up. Four patients (14%) underwent surgical resection (2 with R0 resection). Median time to progression was 6 months (0-36 months). Median survival time was 10.3 months (95% confidence interval, 7.9-14.6 months). The 1- and 2-year actuarial survival rates were 30% and 11%. At last analysis, all but 2 patients died.

CONCLUSION

The activity and toxicity profile of combination GEM and RT indicates that this can be safely administered for patients with LAPC.

Gemcitabine alone versus gemcitabine plus radiotherapy in patients with locally advanced pancreatic cancer: an Eastern Cooperative Oncology Group trial

PURPOSE

The purpose of this trial was to evaluate the role of radiation therapy with concurrent gemcitabine (GEM) compared with GEM alone in patients with localized unresectable pancreatic cancer.

PATIENTS AND METHODS

Patients with localized unresectable adenocarcinoma of the pancreas were randomly assigned to receive GEM alone (at 1,000 mg/m(2)/wk for weeks 1 to 6, followed by 1 week rest, then for 3 of 4 weeks) or GEM (600 mg/m(2)/wk for weeks 1 to 5, then 4 weeks later 1,000 mg/m(2) for 3 of 4 weeks) plus radiotherapy (starting on day 1, 1.8 Gy/Fx for total of 50.4 Gy). Measurement of quality of life using the Functional Assessment of Cancer Therapy-Hepatobiliary questionnaire was also performed.

RESULTS

Of 74 patients entered on trial and randomly assigned to receive GEM alone (arm A; n = 37) or GEM plus radiation (arm B; n = 34), patients in arm B had greater incidence of grades 4 and 5 toxicities (41% v 9%), but grades 3 and 4 toxicities combined were similar (77% in A v 79% in B). No statistical differences were seen in quality of life measurements at 6, 15 to 16, and 36 weeks. The primary end point was survival, which was 9.2 months (95% CI, 7.9 to 11.4 months) and 11.1 months (95% CI, 7.6 to 15.5 months) for arms A and B, respectively (one-sided P = .017 by stratified log-rank test).

CONCLUSION

This trial demonstrates improved overall survival with the addition of radiation therapy to GEM in patients with localized unresectable pancreatic cancer, with acceptable toxicity.

A phase 2 trial of gemcitabine, 5-fluorouracil, and radiation therapy in locally advanced nonmetastatic pancreatic adenocarcinoma : cancer and Leukemia Group B (CALGB) 80003

BACKGROUND

The purpose of this study was to assess the efficacy and safety of 5-fluorouracil (5FU) and gemcitabine administered concurrently with radiation in patients with locally advanced, nonmetastatic pancreatic cancer.

METHODS

Eligible patients had histologically confirmed pancreatic adenocarcinoma deemed locally unresectable without evidence of metastatic disease. In addition, all patients underwent laparoscopy or laparotomy before study entry to rule out peritoneal carcinomatosis. Patients received radiation therapy (50.4 Gy) with concurrent infusional 5FU (200 mg/m(2) 5 days/week) and weekly gemcitabine (200 mg/m(2) ). After a 3-week break, patients received weekly gemcitabine at 1000 mg/m(2) for 3 of 4 weeks, for 4 cycles. The primary endpoint of the trial was the proportion of patients surviving 9 months from study entry. Secondary endpoints included objective tumor response, CA19-9 response, overall survival (OS) time to progression (TTP), and toxicity.

RESULTS

Between November 2001 and October 2004, 81 patients were enrolled, 78 of whom were eligible for analysis. With a median follow-up of 55.2 months, the median OS was 12.2 months (95% confidence interval [CI], 10.9-14.9) and the median TTP was 10 months (95% CI, 6.4-12.0). An objective tumor response was seen in 19 patients (25%), and among 56 patients with an elevated CA19-9 at baseline, 29 (52%) had a sustained CA19-9 response. Overall, 41% of patients had grade 3 or greater treatment-related gastrointestinal adverse events.

CONCLUSIONS

The combination of 5FU, gemcitabine, and radiation is well tolerated. Survival is comparable with the best results of other recent studies of 5FU and radiation or gemcitabine and radiation.

Gemcitabine in the chemoradiotherapy for locally advanced pancreatic cancer: a meta-analysis

AIMS

Whether gemcitabine based chemoradiotherapy (GEM-based CRT) is superior to 5-fluorouracil based chemoradiotherapy (5-FU-based CRT) for locally advanced pancreatic cancer (LAPC) remains uncertain. The aim of the present study was to evaluate the effect of GEM-based CRT compared with 5-FU-based CRT.

METHODS

Electronic database including Medline, Embase, Cochrane controlled trials register, PubMed (update to December 2010) and manual bibliography searches were carried out. A meta-analysis of all randomized clinical trials (RCTs) or other comparative studies comparing GEM-based CRT and 5-FU-based CRT were performed.

RESULTS

Three RCTs and one retrospective comparative study including 229 patients were assessed. Meta-analysis showed survival advantage of GEM-based CRT compared with 5-FU-based CRT for 12-month (12-mo) survival rates (SRs) (RR=1.54, 95% CI 1.05-2.26, p=0.03). Moreover, there were also trends of benefit for SR after 6-months (RR 1.13, 95% CI 0.98-1.30, p=0.09) and 24-months (24-mo: RR 2.41, 95% CI 0.90-6.48, p=0.08), though the trends did not reach statistical significance. More frequent severe acute hematologic toxicities were found in the GEM-based CRT group.

CONCLUSIONS

The meta-analysis found that GEM-based CRT was better than 5-FU-based CRT in the treatment of LAPC, especially for 12-mo SRs. However, the acute toxicity should be carefully regarded.

Single-fraction stereotactic body radiation therapy and sequential gemcitabine for the treatment of locally advanced pancreatic cancer

PURPOSE

This Phase II trial evaluated the toxicity, local control, and overall survival in patients treated with sequential gemcitabine and linear accelerator-based single-fraction stereotactic body radiotherapy (SBRT).

METHODS AND MATERIALS

Twenty patients with locally advanced, nonmetastatic pancreatic adenocarcinoma were enrolled on this prospective single-institution, institutional review board-approved study. Gemcitabine was administered on Days 1, 8, and 15, and SBRT on Day 29. Gemcitabine was restarted on Day 43 and continued for 3-5 cycles. SBRT of 25 Gy in a single fraction was delivered to the internal target volume with a 2- 3-mm margin using a nine-field intensity-modulated radiotherapy technique. Respiratory gating was used to account for breathing motion. Follow-up evaluations occurred at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT.

RESULTS

All patients completed SBRT and a median of five cycles of chemotherapy. Follow-up for the 2 remaining alive patients was 25.1 and 36.4 months. No acute Grade 3 or greater nonhematologic toxicity was observed. Late Grade 3 or greater toxicities occurred in 1 patient (5%) and consisted of a duodenal perforation (G4). Three patients (15%) developed ulcers (G2) that were medically managed. Overall, median survival was 11.8 months, with 1-year survival of 50% and 2-year survival of 20%. Using serial computed tomography, the freedom from local progression was 94% at 1 year.

CONCLUSION

Linear accelerator-delivered SBRT with sequential gemcitabine resulted in excellent local control of locally advanced pancreatic cancer. Future studies will address strategies for reducing long-term duodenal toxicity associated with SBRT.

Stereotactic Body Radiation Therapy (SBRT) for Unresectable Pancreatic Carcinoma

Survival in patients with unresectable pancreatic carcinoma is poor. Studies by Mayo Clinic and the Gastrointestinal Tumor Study Group (GITSG) have established combined modality treatment with chemotherapy and radiation as the standard of care. Use of gemcitabine-based chemotherapy alone has also been shown to provide a benefit, but 5‑year overall survival still remains less than 5%. Conventional radiotherapy is traditionally delivered over a six week period and high toxicity is seen with the concomitant use of chemotherapy. In contrast, SBRT can be delivered in 3–5 days and, when used as a component of combined modality therapy with gemcitabine, disruption to the timely delivery of chemotherapy is minimal. Early single-institution reports of SBRT for unresectable pancreatic carcinoma demonstrate excellent local control with acceptable toxicity. Use of SBRT in unresectable pancreatic carcinoma warrants further investigation in order to improve the survival of patients with historically poor outcomes.

A dosimetric model of duodenal toxicity after stereotactic body radiotherapy for pancreatic cancer

INTRODUCTION

Dose escalation for pancreas cancer is limited by the tolerance of adjacent normal tissues, especially with stereotactic body radiotherapy (SBRT). The duodenum is generally considered to be the organ at greatest risk. This study reports on the dosimetric determinants of duodenal toxicity with single-fraction SBRT.

METHODS AND MATERIALS

Seventy-three patients with locally advanced unresectable pancreatic adenocarcinoma received 25 Gy in a single fraction. Dose-volume histogram (DVH) endpoints evaluated include V(5) (volume of duodenum that received 5 Gy), V(10), V(15), V(20), V(25), and D(max) (maximum dose to 1 cm(3)). Normal tissue complication probability (NTCP) was evaluated with a Lyman model. Univariate and multivariate analyses were conducted with Kaplan-Meier and Cox regression models.

RESULTS

The median time to Grade 2-4 duodenal toxicity was 6.3 months (range, 1.6-11.8 months). The 6- and 12-month actuarial rates of toxicity were 11% and 29%, respectively. V(10)-V(25) and D(max) all correlated significantly with duodenal toxicity (p<0.05). In particular, V(15)≥9.1 cm(3) and V(15)<9.1 cm(3) yielded duodenal toxicity rates of 52% and 11%, respectively (p=0.002); V(20)≥3.3 cm(3) and V(20)<3.3 cm(3) gave toxicity rates of 52% and 11%, respectively (p=0.002); and D(max)≥23 Gy and D(max)<23 Gy gave toxicity rates of 49% and 12%, respectively (p=0.004). Lyman NTCP model optimization generated the coefficients m=0.23, n=0.12, and TD(50)=24.6 Gy. Only the Lyman NTCP model remained significant in multivariate analysis (p=0.001).

CONCLUSIONS

Multiple DVH endpoints and a Lyman NTCP model are strongly predictive of duodenal toxicity after SBRT for pancreatic cancer. These dose constraints will be valuable in future abdominal SBRT studies.

Concurrent chemoradiotherapy with gemcitabine plus regional hyperthermia for locally advanced pancreatic carcinoma: initial experience

PURPOSE

The aim of this study was to evaluate the efficacy and toxicity of concurrent chemoradiotherapy (CRT) with gemcitabine plus regional hyperthermia (HT) for locally advanced pancreatic carcinoma (LAPC).

MATERIALS AND METHODS

A total of 29 patients with LAPC treated with concurrent CRT using gemcitabine were retrospectively analyzed. Radiotherapy was administered with a median total dose of 61.2 Gy. Of the 29 patients, 20 (69%) also underwent regional HT during CRT (CRHT group). The remaining 9 patients did not receive regional HT (CRT group) because of a common bile duct stent placement, patient refusal, older age, or obesity. The efficacy and toxicity of the treatments and the predictors of good outcome were evaluated.

RESULTS

The median disease progression-free and overall survival times were significantly better for the CRHT group than for the CRT group (8.8 vs. 4.9 months, P = 0.02, and 18.6 vs. 9.6 months, P = 0.01), respectively. Grade 3-4 hematological toxicities for the CRHT group were detected in eight patients (40%) and grade 3 nonhematologic toxicity in one (diarrhea).

CONCLUSION

Concurrent CRT using gemcitabine with regional HT may be a feasible and promising regimen for LAPC, and the results justified further evaluation in a large number of patients to confirm its definite benefit.

Chemoradiotherapy for unresectable pancreatic cancer

Treatment options for unresectable pancreatic cancer, including concurrent chemoradiotherapy, chemotherapy alone, and chemotherapy followed by chemoradiotherapy, are largely ineffective and result in a median survival of approximately 10-12 months. Although quality data on the benefit of radiotherapy in unresectable pancreatic cancer are lacking, it seems unlikely that the low-efficacy chemotherapy used for pancreatic cancer would control gross disease. Current regimens deliver low, ineffective doses of radiation and are associated with high rates of local failure. New technological advances, such as intensity-modulated radiotherapy, now allow the safe delivery of high-dose, highly conformal radiotherapy concurrently with full systemic doses of chemotherapy. We review new knowledge related to pattern of failure, target definition, and target motion and discuss the implications of these data on modern radiotherapy treatment planning and delivery. While it is clear that breakthroughs in treatment would come mostly from advances in systemic therapy, the evidence suggests that radiotherapy should not fall out of use, but rather be intensified.

Gemcitabine chemotherapy and single-fraction stereotactic body radiotherapy for locally advanced pancreatic cancer

PURPOSE

Fractionated radiotherapy and chemotherapy for locally advanced pancreatic cancer achieves only modest local control. This prospective trial evaluated the efficacy of a single fraction of 25 Gy stereotactic body radiotherapy (SBRT) delivered between Cycle 1 and 2 of gemcitabine chemotherapy.

METHODS AND MATERIALS

A total of 16 patients with locally advanced, nonmetastatic, pancreatic adenocarcinoma received gemcitabine with SBRT delivered 2 weeks after completion of the first cycle. Gemcitabine was resumed 2 weeks after SBRT and was continued until progression or dose-limiting toxicity. The gross tumor volume, with a 2-3-mm margin, was treated in a single 25-Gy fraction by Cyberknife. Patients were evaluated at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT.

RESULTS

All 16 patients completed SBRT. A median of four cycles (range one to nine) of chemotherapy was delivered. Three patients (19%) developed local disease progression at 14, 16, and 21 months after SBRT. The median survival was 11.4 months, with 50% of patients alive at 1 year. Patients with normal carbohydrate antigen (CA)19-9 levels either at diagnosis or after Cyberknife SBRT had longer survival (p <0.01). Acute gastrointestinal toxicity was mild, with 2 cases of Grade 2 (13%) and 1 of Grade 3 (6%) toxicity. Late gastrointestinal toxicity was more common, with five ulcers (Grade 2), one duodenal stenosis (Grade 3), and one duodenal perforation (Grade 4). A trend toward increased duodenal volumes radiated was observed in those experiencing late effects (p = 0.13).

CONCLUSION

SBRT with gemcitabine resulted in comparable survival to conventional chemoradiotherapy and good local control. However, the rate of duodenal ulcer development was significant.

Weekly full-dose gemcitabine and single-dose cisplatin with concurrent radiotherapy in patients with locally advanced pancreatic cancer

The aim of this study was to evaluate the efficacy and the toxicity of a full dose of gemcitabine and a single dose of cisplatin with concurrent radiotherapy in patients with locally advanced pancreatic cancer. Forty-one patients with locally advanced pancreatic cancer were enrolled. Patients received gemcitabine (1000 mg m⁻² on days 1, 8, 15, 29, and 36) and cisplatin (70 mg m⁻² on days 1 and 29) with concurrent radiotherapy (45 Gy in 25 fractions). Treatment was completed in 38 out of 41 patients (92.7%). The overall response rate was 24.4% (two complete and eight partial). Six patients (14.6%) underwent definite pancreatic resection and four had negative surgical margins. The intention of the treatment analysis showed that the median survival time and median time to tumour progression were 16.7 and 8.9 months. The 1- and 2-year survival rates were 63.3 and 27.9%, respectively. Overall survival was significantly longer in the low baseline CA19-9 group and therapeutic responders. Toxicities were tolerable and successfully managed by conservative treatments. The therapeutic scheme of a weekly full dose of gemcitabine and a single dose of cisplatin combined with external radiation is effective and might prolong the survival of patients with locally advanced pancreatic cancer.

Primary advanced unresectable pancreatic cancer

Median as well as overall survival of pancreatic cancer patients in the advanced stage is extremely low despite advances in cancer therapy regarding tumor cell biology, therapy resistance, and diagnosis. In matters of chemoradiation therapy (CRT) in locally advanced pancreatic cancer, favorable positive effect has been reached with different radiotherapy proceedings such as intraoperative radiation therapy with or without external chemo-/radiation therapy or with CRT alone with regard to local tumor pain, local tumor remission, or local control of disease and overall survival. Primary (chemo-) radiation therapy only rarely leads to local remission. Intraoperative radiation therapy (IORT) merely reaches pain palliation in most cases. By administering up-to-date primary CRT, especially with gemcitabine-associated CRT, local remission in up to 50% of patients can be observed. By applying neoadjuvant CRT, better resectability and the reduction of postoperative positive lymph node metastasis has been seen in patients with resectable or possibly resectable pancreatic cancer. With primary CRT, resectability can also be achieved in patients with primary unresectable pancreatic cancer. It has been shown at the evaluation of patients' progression samples--either treated with neoadjuvant or primarily with radiotherapy (with conventional radiation technique)--that the rate of local recurrence or local progression can be reduced in comparison with historical cohorts. By contrast, the rate on distant metastases was not affected. Whereas concurrent CRT leads to favorable local tumor control, this procedure has a minor effect as to the survival in most of the studies. Because metastases occur mostly out of the irradiation field and because of partly advanced local tumor progression, the concept of combined CRT with continuing chemotherapy was developed. Median survival of pancreatic patients in the advanced stage is approx. 3-5 months, with a 12-month survival probability of 10% despite advances in cancer therapy. On the other hand, the 5-year survival probability is 0.4%-3.0%. The causes of such a dismal prognosis can be understood first of all in the commonly late diagnosis, second in the aggressive tumor cell biology with continuing therapy resistance, and finally because an acceptable resection rate can be achieved only in specialized centers. Only 10%-15% of patients can be resected after the diagnosis of pancreatic cancer. Resection is considered a potential curative therapy. However, median survival of these patients amounts to only 13-18 months, with a 5-year survival of 10%-20%. The survival rate did not improve with a radical resection and extended lymphadenectomy. Furthermore, 15%-30% of primary nonmetastatic pancreatic cancer is unresectable due to extended vessel infiltration at time of diagnosis. The prognosis for these patients is very dismal due to lack of specific therapy; moreover, median overall survival is a maximum of 6-8 months.

Phase-I trial of oral fluoropyrimidine anticancer agent (S-1) with concurrent radiotherapy in patients with unresectable pancreatic cancer

In this phase-I trial, we evaluated the safety of S-1, a novel oral fluoropyrimidine anticancer agent, combined with external-beam radiotherapy (EBRT) to determine the maximum-tolerated dose and dose-limiting toxicity (DLT) in unresectable pancreatic cancer patients. Patients had histologically proven unresectable locally advanced or metastatic pancreatic cancer. S-1 was administered orally twice daily. External-beam radiotherapy was delivered in fractions of 1.25 Gy × 2 per day, totalling 50 Gy per 40 fractions for 4 weeks. S-1 was given at five dose levels: 60 mg m^–2 day^–1 on days 1–7 and 15–21 (level 1), 1–14 (level 2), and 1–21 (level 3a) and 80 mg m^–2 day^–1 on days 1–21 (level 3b) and 1–28 (level 4). We studied 17 patients: dose levels 1 (four patients), 2 (four patients), 3a (three patients), 3b (three patients), and 4 (three patients). One patient in level 1 (grade 3 vomiting) and two patients in level 4 (grade 4 neutropenia and grade 3 anorexia) showed DLT. No DLT was seen for levels 2, 3a, and 3b. Clinical effects by computed tomography included 5 partial responses (35%), 11 cases of stable disease, and one case of progressive disease. CA19–9 levels of less than half the starting values were observed in 8 of 16 (50%) patients. S-1 at a dose of 80 mg m^–2 day^–1 given on days 1–21 is safe and recommended for phase-II study in patients with locally advanced and unresectable pancreatic cancer when given with EBRT.

Full-dose gemcitabine and concurrent radiotherapy for unresectable pancreatic cancer

PURPOSE

Full-dose gemcitabine and concurrent radiotherapy is a promising treatment approach in unresectable pancreatic cancer. This study was conducted to assess the pattern of failure and toxicity associated with the use of conformal treatment volumes, omitting prophylactic lymph node irradiation.

METHODS AND MATERIALS

Seventy-four patients with locally advanced pancreatic cancer were treated between 1997 and 2005 with full-dose (1000 mg/m(2), Days 1, 8, and 15) gemcitabine and concurrent radiotherapy (36 Gy [median] in 15 daily fractions). The planning target volume (PTV) was limited to the gross tumor volume (GTV) plus 1-cm margin. Patient computed tomography (CT) scans were systematically reviewed to determine the pattern of failure. Kaplan-Meier and Cox-regression models were used to analyze freedom from local progression (FFLP), distant failure, overall survival (OS), and toxicity.

RESULTS

With a median follow-up of 10.6 months (20.6 months in living patients), the 1-year and 2-year FFLP rates were 64% and 38%, respectively. Four patients (5%) failed in the peripancreatic lymph nodes (3 in-field and 1 marginal failure). Median OS was 11.2 months. Analyzed as a time-dependent covariate, local failure was a significant predictor of OS (p = 0.0074). Sixteen patients (22%) had significant gastrointestinal (GI) toxicity (> or = Grade 3). PTV correlated with significant GI toxicity (p = 0.007).

CONCLUSIONS

Freedom from local progression in unresectable pancreatic cancer is suboptimal. In conjunction with full-dose gemcitabine, the use of conformal fields encompassing only the GTV helps reduce toxicity and does not result in marginal failures. Our findings provide rationale for intensification of local therapy in conjunction with more effective systemic therapy.

Concurrent gemcitabine and radiotherapy with and without neoadjuvant gemcitabine for locally advanced unresectable or resected pancreatic cancer: A phase I-II study

PURPOSE

To determine the safety, efficacy, and tolerability of biweekly gemcitabine with concurrent radiotherapy (RT) for resected and locally advanced (LA) pancreatic cancer.

METHODS AND MATERIALS

Eligible patients had either LA or resected pancreatic cancer. Between March 1999 and July 2001, 63 patients (31 with LA and 32 with resected disease) were treated. Of the 63 patients, 28 were enrolled in a Phase I study of increasing radiation doses (35 Gy [n = 7], 43.75 Gy [n = 11], and 52.5 Gy [n = 10] given within 4, 5, or 6 weeks, respectively, in 1.75-Gy fractions) concurrently with 40 mg/m(2) gemcitabine biweekly. Subsequently, 35 were enrolled in a Phase II study with the addition of induction gemcitabine 1000 mg/m(2) within 7 or 8 weeks to concurrent biweekly gemcitabine (40 mg/m(2)) and 52.5 Gy RT within 6 weeks.

RESULTS

In the LA population, the best response observed was a complete response in 1, partial response in 3, stable disease in 10, and progressive disease in 17. In the phase II trial, gemcitabine plus RT was not delivered to 8 patients because of progression with induction gemcitabine alone (n = 5) or by patient request (n = 3). On intent-to-treat analysis, the median survival in the LA patients was 13.9 months and the 2-year survival rate was 16.1%. In the resected population, the median progression-free survival was 8.3 months, the median survival was 18.4 months, and the 2- and 5-year survival rate was 36% and 19.4%, respectively. The treatment was well tolerated; the median gemcitabine dose intensity was 96% of the planned dose in the neoadjuvant and concurrent portions of the Phase II study. No treatment-related deaths occurred.

CONCLUSION

Biweekly gemcitabine (40 mg/m(2)) concurrently with RT (52.5 Gy in 30 fractions of 1.75 Gy) with or without induction gemcitabine is safe and tolerable and shows efficacy in patients with LA and resected pancreatic cancer.

Prognostic implication of para-aortic lymph node metastasis in resectable pancreatic cancer

BACKGROUND

The survival curve of patients who undergo surgical resection of pancreatic cancer displays a steep decline within 1 year and a relatively slow decline thereafter. The patients with a short survival time may have identifiable clinicopathologic factors that lead to rapid relapse.

STUDY DESIGN

We analyzed clinicopathologic factors in 133 patients who underwent margin-negative pancreatoduodenectomy with extended radical lymphadenectomy for invasive ductal carcinoma of the pancreas to detect factors that could be responsible for the short survival.

RESULTS

Tumor size, invasion of the anterior pancreatic capsule, retroperitoneal invasion, portal venous invasion, major arterial invasion, and metastasis to the para-aortic lymph nodes were variables associated with survival time in univariate analysis. Metastasis to the para-aortic lymph nodes was the single independent factor with a significant association with mortality in multivariate analysis. Some 84% of the patients who had positive para-aortic lymph nodes died within 1 year, versus 46% of the patients with negative nodes.

CONCLUSIONS

Although tumors that involve the para-aortic lymph nodes may technically be resectable, the expected postoperative survival time for most patients is less than 1 year. If para-aortic nodal metastasis is detected, alternative treatment strategies should be considered.

Rationale and appropriate use of chemotherapy and radiotherapy for pancreatic ductal adenocarcinoma

The emergence of effective systemic chemotherapy, along with the parallel development of new targeted cell signal inhibitors for pancreatic cancer treatment, has provided impetus for a re-examination of the appropriate use of chemotherapy and radiation therapy in this malignancy. In addition to exciting developments in the treatment of locally advanced and metastatic disease, new data have emerged regarding the efficacy of adjuvant and neoadjuvant therapy when combined with traditional surgical approaches such as a Whipple procedure. This review summarizes the sentinel clinical trials and discoveries that have influenced the development and deployment of scientifically based multidisciplinary care for today's patients, with a particular focus on modern radiation and chemotherapy.

The relation between deoxycytidine kinase activity and the radiosensitising effect of gemcitabine in eight different human tumour cell lines

Background

Gemcitabine (dFdC) is an active antitumour agent with radiosensitising properties, shown both in preclinical and clinical studies. In the present study, the relation between deoxycytidine kinase (dCK) activity and the radiosensitising effect of gemcitabine was investigated in eight different human tumour cell lines.

Methods

Tumour cells were treated with dFdC (0–100 nM) for 24 h prior to radiotherapy (RT) (γ-Co⁶⁰, 0–6 Gy, room temperature). Cell survival was determined 7, 8, or 9 days after RT by the sulforhodamine B test. dCK activity of the cells was determined by an enzyme activity assay.

Results

A clear concentration-dependent radiosensitising effect of dFdC was observed in all cell lines. The degree of radiosensitisation was also cell line dependent and seemed to correlate with the sensitivity of the cell line to the cytotoxic effect of dFdC. The dCK activity of our cell lines varied considerably and differed up to three fold from 5 to 15 pmol/h/mg protein between the tested cell lines. In this range dCK activity was only weakly related to radiosensitisation (correlation coefficient 0.62, p = 0.11).

Conclusion

Gemcitabine needs to be metabolised to the active nucleotide in order to radiosensitise the cells. Since dFdCTP accumulation and incorporation into DNA are concentration dependent, the degree of radiosensitisation seems to be related to the extent of dFdCTP incorporated into DNA required to inhibit DNA repair. The activity of dCK does not seem to be the most important factor, but is clearly a major factor. Other partners of the intracellular metabolism of gemcitabine in relation to the cell cycle effects and DNA repair could be more responsible for the radiosensitising effect than dCK activity.

Concurrent cisplatin/gemcitabine chemotherapy along with radiotherapy in locally advanced cervical carcinoma: A phase II trial

OBJECTIVE

To evaluate the efficacy and safety of a concurrent regimen of gemcitabine/cisplatin and radiotherapy in women with locally advanced cervical carcinoma (LACC).

METHODS

From April 2001 to June 2002, we enrolled women diagnosed with histologically proven LACC (FIGO stages IIA through IIIB), for treatment with concurrent regimen of chemo-radiotherapy. The treatment consisted of: cisplatin 40 mg/m(2), followed by gemcitabine 125 mg/m(2), once weekly, given about 1 to 2 h before radiotherapy. External beam radiation was delivered 5 days/week to entire pelvic radiation field for a total of 50 Gy in 25 fractions over 5 weeks. After completion of external radiation, patients received brachytherapy with cesium-137 via standard Fletcher-suit applicators delivering 30 Gy to point A.

RESULTS

Of the 23 enrolled patients (mean age 47 years), 20 completed the treatment and were evaluable for response and safety. The complete response rate was 90% (18/20), and partial response rate was 10% (2 patients with persistent disease after therapy). Toxicity was moderate: 2 patients required blood transfusions; 5% patients had grade 2 leukopenia or thrombocytopenia; 40% had grade 1-2 nausea-vomiting, and 50% had grade 1 diarrhea. At a median follow-up of 12 months, all patients are alive, and 16/20 (80%) are disease-free.

CONCLUSIONS

The gemcitabine/cisplatin combination administered concurrently with radiotherapy is highly active in locally advanced cervical carcinoma. The tolerable toxicity and synergistic activity of this concurrent chemoradiation regimen are consistent with prior reports. Definitive results are awaited from an on-going large, randomized trial comparing this regimen with standard treatment.

Unraveling the mechanism of radiosensitization by gemcitabine: the role of TP53

Gemcitabine has excellent radiosensitizing properties, as shown in both preclinical and clinical studies. Radiosensitization correlated with the early S-phase block of gemcitabine. In the present study, we investigated the role of TP53 in the radiosensitizing effect of gemcitabine. Isogenic A549 cells differing in TP53 status were treated with gemcitabine during the 24 h prior to irradiation. Cell survival was determined 7 days after irradiation by the sulforhodamine B test. In addition, cell cycle perturbation was determined by flow cytometry and TP53 expression by Western blot analysis. Gemcitabine caused a concentration-dependent radiosensitizing effect in all cell lines. Transformed A549 cells were less sensitive to the cytotoxic effect of gemcitabine. The cell cycle arrest early in the S phase was dependent on the drug dose but was comparable in the different cell lines and was not related to functional TP53. Using isogenic cell lines, we have shown that neither TP53 status nor the transfection procedure influenced the radiosensitizing effect of gemcitabine. Since both the radiosensitizing effect at equitoxic concentrations and the cell cycle effect of gemcitabine were independent of TP53 expression, it is likely that TP53 protein does not play a crucial role in the radiosensitizing mechanism of gemcitabine.

The radiosensitising effect of difluorodeoxyuridine, a metabolite of gemcitabine, in vitro

PURPOSE

Gemcitabine is an active antitumour agent with radiosensitising properties. Gemcitabine is rapidly metabolised, intracellularly as well as extracellularly, by deoxycytidine deaminase to difluorodeoxyuridine (dFdU), a compound with little antitumour activity. However, plasma concentrations are maintained for a prolonged period (>24 h) at levels known to cause growth inhibition. This is the first study that investigates the radiosensitising potential of dFdU in vitro.

METHODS

ECV304 and H292, human cancer cells, were treated with different concentrations dFdU (0-100 microM) during 24 h before radiation treatment (RT). The schedule dependency of the radiosensitising effect was studied by varying the interval between dFdU and radiation treatment. In addition, the cell cycle effect of dFdU was investigated with flow cytometry, and the induction of apoptosis under radiosensitising conditions was determined by Annexin V staining and caspase 3 cleavage.

RESULTS

dFdU caused a clear concentration-dependent radiosensitising effect in both ECV304 and H292 cells. Dose enhancement factor (DEF) increased with an increasing concentration of dFdU: DEFs were 1.10, 1.60 and 2.17 after treatment with 10, 25 and 50 microM dFdU, respectively, in ECV304 cells and 1.08, 1.31 and 1.60 after treatment with 25, 50 and 100 microM, respectively, in H292 cells. DEFs decreased with an increasing interval of 0-24 h between dFdU treatment and radiation. Under radiosensitising conditions, the combination dFdU and radiation resulted in an increased induction of apoptosis. In addition, the cell cycle effect of dFdU, an arrest at the early S phase, is comparable with the cell cycle effect of gemcitabine.

CONCLUSIONS

dFdU, the main metabolite of gemcitabine, causes a concentration- and schedule- dependent radiosensitising effect in vitro. Since the metabolite is present in plasma for a long period (>24 h) after treatment with gemcitabine, it might be partly responsible for the interaction between radiotherapy and gemcitabine. This observation might have important consequences for the optimal schedules of the combination gemcitabine and radiation therapy.

Chemoradiotherapy in patients with pancreatic carcinoma: phase-I study with a fixed radiation dose and escalating doses of weekly gemcitabine

AIM

The aim of this phase-I study is to determine the maximum tolerated dose (MTD) of weekly gemcitabine in concurrent combination with a total radiation dose of 54 Gy in patients with pancreatic cancer.

METHODS

In all patients, a total dose of 54 Gy was delivered in 30 fractions of 1.8 Gy/day. Gross tumor volume and regional lymph nodes were included in the irradiated volume with a 1- to 1.5-cm margin. The doses of weekly gemcitabine were escalated from 100 mg/m2 by increments of 50 mg/m2. Dose-limiting toxicity (DLT) was defined as hematologic toxicity, prolonged grade-3 non-hematologic toxicity, and incompletion of the planned treatment.

RESULTS

Twenty-six patients entered the trial. From level 1 (100 mg/m2) to level 4 (250 mg/m2), no patient experienced DLT except for 1 patient at level 1. At level 5 (300 mg/m2), 3 of the 5 patients met the DLT criteria. One patient developed severe pulmonary abscess, and the other 2 patients had hematologic DLT. The overall partial response rate was 29%, and the median survival time was 13.7 months. The first relapse occurred at the in-field primary site in 6 patients and at distant organs in 13 patients.

CONCLUSION

The MTD of weekly gemcitabine was 250 mg/m2 in the present chemoradiotherapy setting. The efficacy of this chemoradiotherapy regimen is currently being evaluated in the phase-II setting.

Combined Modality Therapy of Gemcitabine and Radiation

The combination of gemcitabine and radiotherapy is a promising combined modality therapy. However, the clinical application of this combination has to be implemented carefully because of an increased toxicity to normal tissues. A body of experimental evidence shows that gemcitabine is a potent radiosensitizer in vitro and in vivo. The observations so far indicate that various mechanisms are responsible for the radiosensitizing effect. Although it is often difficult to transfer experimental data to the clinic, these studies offer the possibility to develop an improved schedule of administration for patient treatment, based on rational evidence in tumor biology. In the current review, the preclinical data that support the use of gemcitabine as a radiosensitizing agent and the clinical trials that have been conducted to date are summarized.