Combining gemcitabine with radiation in pancreatic cancer: understanding important variables influencing the therapeutic index

Phase II Trial of Postoperative Adjuvant Gemcitabine and Cisplatin Chemotherapy Followed by Chemoradiotherapy with Gemcitabine in Patients with Resected Pancreatic Cancer

Purpose

Despite curative resection, the 5-year survival for patients with resectable pancreatic cancer is less than 20%. Recurrence occurs both locally and at distant sites and effective multimodality adjuvant treatment is needed.

Materials and Methods

Patients with curatively resected stage IB-IIB pancreatic adenocarcinoma were eligible. Treatment consisted of chemotherapy with gemcitabine 1,000 mg/m² on days 1 and 8 and cisplatin 60 mg/m² on day 1 every 3 weeks for two cycles, followed by chemoradiotherapy (50.4 Gy/28 fx) with weekly gemcitabine (300 mg/m²/wk), and then gemcitabine 1,000 mg/m² on days 1 and 8 every 3 weeks for four cycles. The primary endpoint was 1-year disease-free survival rate. The secondary endpoints were disease-free survival, overall survival, and safety.

Results

Seventy-four patients were enrolled. One-year disease-free survival rate was 57.9%. Median disease-free and overall survival were 15.0 months (95% confidence interval [CI], 11.6 to 18.4) and 33.0 months (95% CI, 21.8 to 44.2), respectively. At the median follow-up of 32 months, 57 patients (77.0%) had recurrence including 11 patients whose recurrence was during the adjuvant treatment. Most of the recurrences were systemic (52 patients). Stage at the time of diagnosis (70.0% in IIA, 51.2% in IIB, p=0.006) were significantly related with 1-year disease-free survival rate. Toxicities were generally tolerable, with 53 events of grade 3 or 4 hematologic toxicity and four patients with febrile neutropenia.

Conclusion

Adjuvant gemcitabine and cisplatin chemotherapy followed by chemoradiotherapy with gemcitabine and maintenance gemcitabine showed efficacy and good tolerability in curatively resected pancreatic cancer.

Comparison of neoadjuvant therapy and upfront surgery in resectable pancreatic cancer: a meta-analysis and systematic review

Objective

The role of neoadjuvant therapy (NAT) in resectable pancreatic cancer (RPC) remains controversial. Therefore, this meta-analysis was performed to compare the clinical differences between NAT and upfront surgery in RPC.

Materials and methods

A systematic literature search was performed in PubMed, Embase, Web of Science, and the Cochrane Register of Controlled Trials databases. Only patients with RPC who underwent tumor resection and received adjuvant or neoadjuvant treatment were enrolled. The OR or HR and 95% CIs were calculated employing fixed-effects or random-effects models. The HR and its 95% CI were extracted from each article that provided survival curve. Publication bias was estimated using funnel plots and Egger’s regression test.

Results

In total, eleven studies were included with 9,386 patients. Of these patients, 2,508 (26.7%) received NAT. For patients with RPC, NAT resulted in an increased R0 resection rate (OR=1.89; 95% CI=1.26–2.83) and a reduced positive lymph node rate (OR=0.34; 95% CI=0.31–0.37) compared with upfront surgery. Nevertheless, patients receiving NAT did not exhibit a significantly increased overall survival (OS) time (HR=0.91; 95% CI=0.79–1.05).

Conclusion

In patients with RPC, R0 resection rate and positive lymph node rate after NAT were superior to those of patients with upfront surgery. The NAT group exhibited no significant effect on OS time when compared with the upfront surgery group. However, this conclusion requires more clinical evidence to improve its credibility.

Interventional Oncology Service Development

Interventional oncology is rapidly expanding its suite of oncologic therapies, providing unique proven therapeutic benefits. To grow a practice alongside other oncology specialties, knowledge of cancer fundamentals is required. Areas of interest include methods to assess disease stage, treatment toxicity, and response. Additionally, techniques to leverage opportunities and resources available at one's institution toward practice development and efficiency will be reviewed.

Neoadjuvant chemoradiation therapy with gemcitabine/cisplatin and surgery versus immediate surgery in resectable pancreatic cancer: results of the first prospective randomized phase II trial

Background

In nonrandomized trials, neoadjuvant treatment was reported to prolong survival in patients with pancreatic cancer. As neoadjuvant chemoradiation is established for the treatment of rectal cancer we examined the value of neoadjuvant chemoradiotherapy in pancreatic cancer in a randomized phase II trial. Radiological staging defining resectability was basic information prior to randomization in contrast to adjuvant therapy trials resting on pathological staging.

Patients and methods

Patients with resectable adenocarcinoma of the pancreatic head were randomized to primary surgery (Arm A) or neoadjuvant chemoradiotherapy followed by surgery (Arm B), which was followed by adjuvant chemotherapy in both arms. A total of 254 patients were required to detect a 4.33-month improvement in median overall survival (mOS).

Results

The trial was stopped after 73 patients; 66 patients were eligible for analysis. Twenty nine of 33 allocated patients received chemoradiotherapy. Radiotherapy was completed in all patients. Chemotherapy was changed in 3 patients due to toxicity. Tumor resection was performed in 23 vs. 19 patients (A vs. B). The R0 resection rate was 48 % (A) and 52 % (B, P = 0.81) and (y)pN0 was 30 % (A) vs. 39 % (B, P = 0.44), respectively. Postoperative complications were comparable in both groups. mOS was 14.4 vs. 17.4 months (A vs. B; intention-to-treat analysis; P = 0.96). After tumor resection, mOS was 18.9 vs. 25.0 months (A vs. B; P = 0.79).

Conclusion

This worldwide first randomized trial for neoadjuvant chemoradiotherapy in pancreatic cancer showed that neoadjuvant chemoradiation is safe with respect to toxicity, perioperative morbidity, and mortality. Nevertheless, the trial was terminated early due to slow recruiting and the results were not significant. ISRCTN78805636; NCT00335543.

Electronic supplementary material

The online version of this article (doi: 10.1007/s00066-014-0737-7) contains supplementary material, which is available to authorized users.

Phase I study evaluating the treatment of patients with locally advanced pancreatic cancer with carbon ion radiotherapy: the PHOENIX-01 trial

Background

Treatment options for patients with locally advanced pancreatic cancer include surgery, chemotherapy as well as radiotherapy. In many cases, surgical resection is not possible, and therefore treatment alternatives have to be performed. Chemoradiation has been established as a convincing treatment alternative for locally advanced pancreatic cancer. Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE), which can be calculated between 1.16 and 2.46 depending on the pancreatic cancer cell line as well as the endpoint analyzed. Japanese Data on the evaluation of carbon ion radiation therapy showed promising results for patients with pancreatic cancer.

Methods and design

The present PHOENIX-01 trial evaluates carbon ion radiotherapy using the active rasterscanning technique in patients with advanced pancreatic cancer in combination with weekly gemcitabine and adjuvant gemcitabine. Primary endpoint is toxicity, secondary endpoints are overall survival, progression-free survival and response.

Discussion

The physical and biological properties of the carbon ion beam promise to improve the therapeutic ratio in patients with pancreatic cancer: Due to the inverted dose profile dose deposition in the entry channel of the beam leads to sparing of normal tissue; the Bragg peak can be directed into the defined target volume, and the sharp dose fall-off thereafter again spares normal tissue behind the target volume. The higher RBE of carbon ions, which has been shown also for pancreatic cancer cell lines in the preclinical setting, is likely to contribute to an increase in local control, and perhaps in OS. Early data from Japanese centers have shown promising results. In conclusion, this is the first trial to evaluate actively delivered carbon ion beams in patients with locally advanced pancreatic cancer within a dose-escalation strategy.

Trial registration

NCT01795274

Intensity modulated radiotherapy as neoadjuvant chemoradiation for the treatment of patients with locally advanced pancreatic cancer. Outcome analysis and comparison with a 3D-treated patient cohort

BACKGROUND

To evaluate outcome after intensity modulated radiotherapy (IMRT) compared to 3D conformal radiotherapy (3D-RT) as neoadjuvant treatment in patients with locally advanced pancreatic cancer (LAPC).

MATERIALS AND METHODS

In total, 57 patients with LAPC were treated with IMRT and chemotherapy. A median total dose of 45 Gy to the PTV_baseplan and 54 Gy to the PTV_boost in single doses of 1.8 Gy for the PTV_baseplan and median single doses of 2.2 Gy in the PTV_boost were applied. Outcomes were evaluated and compared to a large cohort of patients treated with 3D-RT.

RESULTS

Overall treatment was well tolerated in all patients and IMRT could be completed without interruptions. Median overall survival was 11 months (range 5-37.5 months). Actuarial overall survival at 12 and 24 months was 36 % and 8 %, respectively. A significant impact on overall survival could only be observed for a decrease in CA 19-9 during treatment, patients with less pre-treatment CA 19-9 than the median, as well as weight loss during treatment. Local progression-free survival was 79 % after 6 months, 39 % after 12 months, and 13 % after 24 months. No factors significantly influencing local progression-free survival could be identified. There was no difference in overall and progression-free survival between 3D-RT and IMRT. Secondary resectability was similar in both groups (26 % vs. 28 %). Toxicity was comparable and consisted mainly of hematological toxicity due to chemotherapy.

CONCLUSION

IMRT leads to a comparable outcome compared to 3D-RT in patients with LAPC. In the future, the improved dose distribution, as well as advances in image-guided radiotherapy (IGRT) techniques, may improve the use of IMRT in local dose escalation strategies to potentially improve outcome.

Advanced-stage pancreatic cancer: therapy options

Pancreatic ductal adenocarcinoma is one of the most aggressive cancers, and surgical resection is a requirement for a potential cure. However, the majority of patients are diagnosed with advanced-stage disease, either metastatic (50%) or locally advanced cancer (30%). Although palliative chemotherapy is the standard of care for patients with metastatic disease, management of locally advanced adenocarcinoma is controversial. Several treatment options, including extended surgical resections, neoadjuvant therapy with subsequent resections, as well as palliative radiotherapy and/or chemotherapy, should be considered. However, there is little evidence available to support treatment options for locally advanced disease. As valid predictive biomarkers for stratification of therapy are not available today, future trials need to define the role of the different treatment options. This Review summarizes the current evidence and discusses available treatment options for both locally advanced and metastatic pancreatic adenocarcinoma.

Comparison of four target volume definitions for pancreatic cancer. Guidelines for treatment of the lymphatics and the primary tumor

BACKGROUND AND PURPOSE

Target volume definitions for radiotherapy in pancreatic ductal adenocarcinoma (PDAC) vary substantially. Some groups aim to treat the primary tumor only, whereas others include elective lymph nodes (eLNs). eLNs close to the primary tumor are often included unintentionally within the treatment volume, depending on the respective treatment philosophies. We aimed to measure the percentages of anatomical coverage of eLNs by comparing four different contouring guidelines.

PATIENTS AND METHODS

Planning target volumes (PTVs) were contoured using planning computed tomography (CT) scans of 11 patients with PDAC based on the Oxford, RTOG (Radiation Therapy Oncology Group), Michigan, and SCALOP (Selective Chemoradiation in Advanced Localised Pancreatic Cancer trial) guidelines. Clinical target volumes (CTVs) included the peripancreatic, para-aortic, paracaval, celiac trunk, superior mesenteric, and portal vein lymph node areas. Volumetric comparisons of the coverage of all eLN regions were conducted to illustrate the differences between the four contouring strategies.

RESULTS

The PTV sizes of the RTOG and Oxford guidelines were comparable. The SCALOP and Michigan PTV sizes were similar to each other and significantly smaller than the RTOG and Oxford PTVs. A large variability of eLN coverage was found for the various subregions according to the respective contouring strategies.

CONCLUSION

This is the first study to directly compare the percentage of anatomical coverage of eLNs according to four PTVs in the same patient cohort. Potential practical consequences are discussed in detail.

Pancreatic cancer tumor size on CT scan versus pathologic specimen: implications for radiation treatment planning

PURPOSE

Pancreatic cancer primary tumor size measurements are often discordant between computed tomography (CT) and pathologic specimen after resection. Dimensions of the primary tumor are increasingly relevant in an era of highly conformal radiotherapy.

METHODS AND MATERIALS

We retrospectively evaluated 97 consecutive patients with resected pancreatic cancer at two Boston hospitals. All patients had CT scans before surgical resection. Primary endpoints were maximum dimension (in millimeters) of the primary tumor in any direction as reported by the radiologist on CT and by the pathologist for the resected gross fresh specimen. Endoscopic ultrasound (EUS) findings were analyzed if available.

RESULTS

Of the patients, 87 (90%) had preoperative CT scans available for review and 46 (47%) had EUS. Among proximal tumors (n = 69), 40 (58%) had pathologic duodenal invasion, which was seen on CT in only 3 cases. The pathologic tumor size was a median of 7 mm larger compared with CT size for the same patient (range, -15 to 43 mm; p < 0.0001), with 73 patients (84%) having a primary tumor larger on pathology than CT. Endoscopic ultrasound was somewhat more accurate, with pathologic tumor size being a median of only 5 mm larger compared with EUS size (range, -15 to 35 mm; p = 0.0003).

CONCLUSIONS

Computed tomography scans significantly under-represent pancreatic cancer tumor size compared with pathologic specimens in resectable cases. We propose a clinical target volume expansion formula for the primary tumor based on our data. The high rate of pathologic duodenal invasion suggests a risk of duodenal under-coverage with highly conformal radiotherapy.

Gemcitabine/cisplatin versus 5-fluorouracil/mitomycin C chemoradiotherapy in locally advanced pancreatic cancer: a retrospective analysis of 93 patients

Background

Despite of a growing number of gemcitabine based chemoradiotherapy studies in locally advanced pancreatic cancer (LAPC), 5-fluorouracil based regimens are still regarded to be standard and the debate of superiority between the two drugs is going on. The aim of this retrospective analysis was to evaluate the effect of two concurrent chemoradiotherapy regimens using 5-fluorouracil or gemcitabine to compare their effect and tolerance.

Methods

We have performed a single centre retrospective analysis of 93 patients treated with conventionally fractionated radiotherapy of 55.8 Gray using either concurrent 5-fluorouracil, 1 g/m² on days 1-5 and 29-33 of radiotherapy and 10 mg/m² of mitomycin C on day 1, 29 of radiotherapy (FM group, 35 patients) versus gemcitabine (300 mg/m²) and cisplatin, (30 mg/m²) on days 1, 8, 22, and 29 (GC group, 58 patients). Primary endpoint was the median overall survival (OS) rate.

Results

The median OS rate was 12.7 months in the GC group and 9.7 months in the FM group. The 1-year OS rate was 53% versus 40%, respectively (p = 0.009). GC led to more grade 3 leukocytopenia and thrombocytopenia than FM, but not to more grade 4 myelosuppression. Thrombocytopenia was the most frequently observed grade 4 toxicity in both groups (11% after FM versus 12% after GC). No grade 3/4 febrile neutropenia was observed. Grade 3 nausea was more common in the FM group (20% versus 9%) and grade 4 nausea was observed in one patient per group only.

Conclusions

GC was superior to FM for overall survival and both regimens were similar in terms of tolerance. We conclude that GC leads to encouraging results and that the use of FM for chemoradiotherapy in LAPC cannot be recommended without concerns.

Gemcitabine-mediated radiosensitization of human soft tissue sarcoma

BACKGROUND/PURPOSE

Local and systemic control of soft tissue sarcoma (STS) remains a clinical challenge, particularly for retroperitoneal, deep truncal, or advanced extremity disease. 2',2'-Difluoro-2'-deoxycytidine (gemcitabine) is a potent radiosensitizer in many tumor types, but it has not been studied in human STS. The purpose of this study was to determine the radiosensitizing potential of gemcitabine in preclinical models of human STS.

MATERIALS AND METHODS

The in vitro radiosensitizing activity of gemcitabine was assessed with clonogenic survival assay on three human STS cell lines: SK-LMS-1 (leiomyosarcoma), SW-872 (liposarcoma), and HT-1080 (fibrosarcoma). Cell cycle distribution was determined using dual-channel flow cytometry. The in vivo radiosensitizing activity of gemcitabine was assessed with subcutaneous SK-LMS-1 nude mice xenografts. Tumor-bearing mice were treated with concurrent weekly gemcitabine and fractionated daily radiotherapy (RT) (2 Gy daily) for 3 weeks (a total dose of 30 Gy).

RESULTS

The 50% inhibitory concentration (IC(50)) of gemcitabine for the human STS cell lines ranged from 10 to 1000 nM. Significant in vitro radiosensitization was demonstrated in all three human STS cell lines using gemcitabine concentrations at and below the IC(50). Maximal radiosensitization was associated with accumulation of cells in early S-phase. SK-LMS-1 xenografts displayed significant tumor growth delay with combined gemcitabine and RT compared to either treatment alone. Treatment related toxicity was greatest in the gemcitabine plus RT arm, but remained at an acceptable level.

CONCLUSIONS

Gemcitabine is a potent radiosensitizer in preclinical models of human STS. Clinical trials combining gemcitabine and RT in human STS are warranted.

The role of radiotherapy in multimodal treatment of pancreatic carcinoma

Pancreatic ductal carcinoma is one of the most lethal malignancies, but in recent years a number of positive developments have occurred in the management of pancreatic carcinoma. This article aims to give an overview of the current knowledge regarding the role of radiotherapy in the treatment of pancreatic ductal adenocarcinoma (PDAC). The results of meta-analyses, phase III-studies, and phase II-studies using chemoradiotherapy and chemotherapy for resectable and non-resectable PDAC were reviewed. The use of radiotherapy is discussed in the neoadjuvant and adjuvant settings as well as in the locally advanced situation. Whenever possible, radiotherapy should be performed as simultaneous chemoradiotherapy. Patients with PDAC should be offered entry into clinical trials to identify optimal treatment results.

Proposing the lymphatic target volume for elective radiation therapy for pancreatic cancer: a pooled analysis of clinical evidence

Background

Radiation therapy is an important cancer treatment modality in both adjuvant and definitive setting, however, the use of radiation therapy for elective treatment of regional lymph nodes is controversial for pancreatic cancer. No consensus on proper selection and delineation of subclinical lymph nodal areas in adjuvant or definitive radiation therapy has been suggested either conclusively or proposed for further investigation. This analysis aims to study the pattern of lymph node metastasis through a pooled analysis of published results after radical tumor and lymph nodal resection with histological study in pancreatic cancer.

Methods

Literature search using electronic databases including MEDLINE, EMBASE, and CANCERLIT from January 1970 to June 2009 was performed, supplemented by review of references. Eighteen original researches and a total of 5954 pancreatic cancer patients underwent radical surgical resection were included in this analysis. The probability of metastasis in regional lymph nodal stations (using Japan Pancreas Society [JPS] Classification) was calculated and analyzed based on the location and other characteristics of the primary disease.

Results

Commonly involved nodal regions in patients with pancreatic head tumor include lymph nodes around the common hepatic artery (Group 8, 9.79%), posterior pancreaticoduodenal lymph nodes (Group 13, 32.31%), lymph nodes around the superior mesenteric artery (Group 14, 15.85%), paraaortic lymph nodes (Group 16, 10.92%), and anterior pancreaticoduodenal lymph nodes (Group 17, 19.78%); The probability of metastasis in other lymph nodal regions were <9%.

Commonly involved nodal regions in patients with pancreatic body/tail tumor include lymph nodes around the common hepatic artery (Group 8, 15.07%), lymph nodes around the celiac trunk (Group 9, 9.59%), lymph nodes along the splenic artery (Group 11, 35.62%), lymph nodes around the superior mesenteric artery (Group 14, 9.59%), paraaortic lymph nodes (Group 16, 16.44%), and inferior body lymph nodes (Group 18, 24.66%). The probability of metastasis in other lymph nodal regions were <9%.

Conclusions

Pancreatic cancer has a high propensity of regional lymphatic metastases; however, clear patterns including the site and probability of metastasis can be identified and used as a guide of treatment in patients with resectable pancreatic cancer. Further clinical investigation is needed to study the efficacy of elective treatment to CTV defined based on these patterns using high-dose conformal or intensity-modulated radiation therapy.

Pretargeted radioimmunotherapy of pancreatic cancer xenografts: TF10-90Y-IMP-288 alone and combined with gemcitabine

Pancreatic cancer is a silent disease that most commonly presents in an already metastatic form. Current treatment options provide little survival benefit. Radiolabeled PAM4 IgG, a monoclonal antibody that recognizes a unique epitope associated with a mucin found almost exclusively in pancreatic cancer, has shown encouraging therapeutic effects in animal models and in early clinical testing ((90)Y-humanized PAM4 IgG, (90)Y-clivatuzumab tetraxetan). The studies reported herein examine a new pretargeting procedure for delivering therapeutic radionuclides.

METHODS

We prepared a humanized, recombinant tri-Fab bispecific monoclonal antibody (bsmAb) (TF10) using specificity for targeting pancreatic cancer of PAM4 and another Fab binding to a hapten (histamine-succinyl-glycine [HSG]) and tested this in a pretargeting setting with a (90)Y-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-di-HSG-peptide (pretargeted radioimmunotherapy [PT-RAIT]). Nude mice bearing established Capan-1 human pancreatic cancer xenografts were given TF10 and then received the (90)Y peptide as a single bolus dose 19 h later, or the therapy cycle was fractionated weekly. Other studies examined different combinations with gemcitabine.

RESULTS

PT-RAIT of 18.5 MBq ( approximately 50% of its maximum tolerated dose [MTD]) was as effective as the MTD of (90)Y-PAM4 IgG (5.55 MBq). Three monthly doses of 9.25 MBq of PT-RAIT combined with a monthly cycle of gemcitabine (3 weekly, 6-mg doses) significantly enhanced survival, compared with PT-RAIT alone. Adding gemcitabine as a radiosensitizer to 9.25 MBq of PT-RAIT enhanced objective responses. Weekly fractionation of the PT-RAIT, as compared with a single treatment, improved responses.

CONCLUSION

PAM4-based PT-RAIT with (90)Y hapten peptide is an effective treatment for pancreatic cancer, with less toxicity than (90)Y-PAM4 IgG, in this model. Combinations with gemcitabine and dose fractionation of the PT-RAIT enhanced therapeutic responses.

Downstaging of pancreatic carcinoma after neoadjuvant chemoradiation

BACKGROUND AND PURPOSE

Neoadjuvant chemoradiation could improve survival in patients with pancreatic cancer because of a higher rate of R0 resections, lower rate of nodal metastasis (ypN) and of local recurrence. This approach was tested in a cohort to estimate its effect on survival.

PATIENTS AND METHODS

Three-dimensional, conformal radiation to the primary tumor (55.8 Gy) and the lymphatics (50.4 Gy) was combined with chemotherapy. Resection was performed 6 weeks after completion of chemoradiation.

RESULTS

38 of 120 patients with locally advanced cancer underwent tumor resection thereafter. Three patients (8%) had pathologic complete response. Median tumor-specific survival was 29 months and overall survival 25 months. Patients with clear margins (35/38; 89%) had a 3-year disease-specific survival rate of 51% versus 0% with positive margins (p = 0.008). Nodal disease rate decreased from 50% at pretherapeutic imaging to 32% at resection. Patients with ypN0 status (n = 26/38) had a 3-year tumor-specific survival rate of 50% compared to 31% in patients with ypN1 status. At multivariate analysis, resection status and nodal spread significantly predicted tumor-specific survival. Chemoradiation was generally well tolerated.

CONCLUSION

The current results support randomized testing of neoadjuvant chemoradiation to prove survival prolongation. Compared to the literature this approach seems to reduce the number of positive nodes.

Vitamin D for the prevention and treatment of pancreatic cancer

Pancreatic cancer is ranked fifth among cancer-related deaths worldwide with a 5-year survival rate of less than 5%. Currently, surgery is the only effective therapy. However, most patients are diagnosed in the late stage and are not suitable for receiving curative surgery. Moreover, pancreatic cancer doesn’t respond well to traditional chemotherapy and radiotherapy, leaving little effective treatment for advanced pancreatic cancer cases. 1α,25-dihydroxyvitamin D₃ [1α,25(OH)₂D₃], the biologically active form of vitamin D₃, was originally identified during studies of calcium and bone metabolism, though it is now recognized that it exerts biological effects in almost every tissue in the body. Abundant evidence has shown that 1α,25(OH)₂D₃ has antiproliferative, apoptotic, pro-differentiation and antiangiogensis effects in many types of cancer cells in vivo and in vitro, including breast, prostate, and colon. Similarly, the antitumor growth effect of 1α,25(OH)₂D₃ on pancreatic cells has been demonstrated. The clinical use of 1α,25(OH)₂D₃ is impeded by the lethal side effects of hypercalcemia and hypercalciuria. Therefore, 1α,25(OH)₂D₃ analogs, which are either equipotent or more potent than 1α,25(OH)₂D₃ in inhibiting tumor cell growth but with fewer hypercalcemic and hypercalciuric side effects, have been developed for the treatment of different cancers. Recently, a pre-clinical study demonstrated that a less calcemic analog of 1α,25(OH)₂D₃, 19-nor-1α,25(OH)₂D₂ (Paricalcitol), is effective in inhibiting tumor growth in vitro and in vivo, via upregulation of p21 and p27 tumor suppressor genes. Studies on the anti-tumor effects of a more potent analog of Paricalcitol are underway. 1α,25(OH)₂D₃ and its analogs are potentially attractive novel therapies for pancreatic cancer.

The integration of chemoradiation in the care of patient with localized pancreatic cancer

The use of chemoradiation for patients with localized pancreatic cancer is controversial. Although some randomized trials have indicated that chemoradiation improves the median survival of patients with locally advanced as well as resected pancreatic cancer, other more recent trials have called into question the role of chemoradiation and have supported the use of chemotherapy. In the adjuvant setting, the high local tumor recurrence/persistence rate in all trials probably reflects the inclusion of patients with incompletely resected tumors, whose prognosis is similar to the prognosis of patients with locally advanced who do not undergo resection, making these trials difficult to interpret. More precise clinical staging and selection of patients appropriate for surgical resection is an important goal. The keys to the successful integration of radiotherapy in the care of patients with localized pancreatic cancer are selection, sequencing and smaller treatment volumes. A strategy of initial chemotherapy followed by consolidation with a well-tolerated chemoradiation regimen both in the adjuvant and locally advanced settings maximizes benefits of both treatment options, which are in fact complementary. Herein, we discuss the rationale for this approach as well as the ongoing investigation of novel radiation approaches designed to enhance outcome through the molecular and physical targeting of disease as well as the investigation of neoadjuvant chemoradiation in radiographically resectable and borderline resectable pancreatic cancer.

Preoperative gemcitabine-based chemoradiation for patients with resectable adenocarcinoma of the pancreatic head

PURPOSE

We conducted a phase II trial to assess the outcomes of patients who received preoperative gemcitabine-based chemoradiation and pancreaticoduodenectomy (PD) for stage I/II pancreatic adenocarcinoma.

PATIENTS AND METHODS

Eligible patients with pancreatic head/uncinate process adenocarcinoma and radiographically defined potentially resectable disease received chemoradiation with 7 weekly intravenous (IV) infusions of gemcitabine (400 mg/m(2) IV over 30 minutes) plus radiation therapy (30 Gy in 10 fractions over 2 weeks). Patients underwent restaging 4 to 6 weeks after completion of chemoradiation and, in the absence of disease progression, were taken to surgery.

RESULTS

The study enrolled 86 patients. At the time of restaging, disease progression or a decline in performance status precluded 13 patients from surgery. Seventy-three (85%) of 86 patients were taken to surgery, extrapancreatic disease was found in nine, and 64 (74%) of 86 underwent a successful PD. Median overall survival (86 patients) was 22.7 months with a 27% 5-year survival. Median survival was 34 months for the 64 patients who underwent PD and 7 months for the 22 unresected patients (P < .001). The 5-year survival for those who did and did not undergo PD was 36% and 0%, respectively.

CONCLUSION

Preoperative gemcitabine-based chemoradiation followed by restaging and evaluation for surgery separated the study population into two different subsets: patients likely to benefit from PD (n = 64) and those in whom surgery would be unlikely to provide clinical benefit (n = 22). Furthermore, the encouraging overall survival observed in this large trial supports the continued investigation of gemcitabine-based preoperative therapy in resectable pancreatic cancer.

The multidisciplinary management of gastrointestinal cancer. Pancreatic cancer: from pathogenesis to cure

Pancreatic cancer is the fourth leading cause of cancer-related death in the USA. The disease has a high mortality rate and the 5-year survival rate is estimated to be 4%. Currently, surgical resection is only possible in 20% of patients; even then, the overall 5-year survival rate is only 25%. As such, surgical therapy alone is not sufficient for pancreatic carcinoma, and prospective investigation of additional modalities is crucial. Numerous negative trials have shown that chemotherapy alone is the standard of care after resection of pancreatic carcinoma. However, results remain poor and progress with new drugs is needed in this setting. For locally advanced disease, the situation is more complicated; the ideal chemoradiation schedule has not been clearly defined, and improvements could come in the near future from the use of new radiotherapy tools and targeted therapies. For advanced disease, chemotherapy alone has given very disappointing results. A multidisciplinary approach combining biological assessment of targets with clinical trials to evaluate new targeted drugs should be considered.

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.

Future chemoradiation strategies in pancreatic cancer

Although not universally accepted, 5-fluorouracil (5-FU)-based chemoradiation is considered a standard treatment for patients with localized pancreatic cancer. Randomized trials have indicated that chemoradiation improves median survival of both locally advanced and resected pancreatic cancer. While the use of adjuvant chemoradiation in pancreatic cancer has been called into question since the publication of the European Study Group for Pancreatic Cancer (ESPAC)-1 trial, this study has not changed standard practice in the United States. All randomized trials investigating adjuvant chemoradiation have reported significant local as well as distant disease control limitations, making the study of novel chemoradiation and adjuvant chemotherapy important. Selected centers are investigating neoadjuvant chemoradiation in radiographically resectable patients. Advantages of neoadjuvant chemoradiation compared to postoperative therapy include increased local control, increased access to therapy, addressing the systemic disease recurrence risk without delay, and optimal patient selection for pancreaticoduodenectomy through exclusion of patients with rapidly progressive metastatic disease. In the years since it was approved for use in pancreatic cancer, gemcitabine has stood the test of time as a systemic agent but has not been widely adopted as a radiosensitzer in pancreatic cancer. Single-arm clinical trials that initially explored gemcitabine as a radiosensitzer in locally advanced pancreatic cancer demonstrated the potential for significant toxicity without dramatic improvements in efficacy. Recent strategies for improving the efficacy of chemoradiation include improved chemoradiation sensitization through the concurrent incorporation of molecular targeted agents, and the use of new radiation technology such as intensity-modulated radiotherapy (IMRT) and stereotactic radiotherapy. Herein, we discuss the relative merits of strategies that seek to improve outcome through these novel means and present recent data from novel strategies that will provide the background for future trials.

Large topographic variability of upper abdominal lymphatics and the consequences for radiation treatment planning

BACKGROUND AND PURPOSE

Inclusion of regional lymph nodes usually is indicated when treating upper gastrointestinal malignancies. Lymphatics follow the large vessels of this region. Vascular variability with consequences for planning treatment volume (PTV) was studied.

MATERIALS AND METHODS

Upper abdominal metric relationship of the vascular origins was analysed in CT scans in 104 patients to estimate its influence on PTV variability. PTV volumes were calculated based on these. Additionally, the PTV size of 3D plans of 34 patients with pancreatic adenocarcinoma (PDAC) was analysed depending on different PTV definitions.

RESULTS

Vascular origin varied most for the inferior mesenteric artery (IMA) with substantial PTV size differences. Volumetric variability was analysed for PDAC (IMA versus renal hilum as caudal margin). Additional PTV for IMA was < 100 cc (median) but ranged up to 350 cc in CT (100-199 ml in 14/34 and > 200 ml in 3/34 patients). Data from treatment planning confirmed this observation.

CONCLUSIONS

Considerable vascular and lymphatic variability obliges to base PTV on the individual vascular anatomy. For most patients the caudal PTV margin for PDAC can safely be set at the IMA. But PTV should be restricted when the additional volume would lead to a significant increase to avoid haematotoxicity from concomitant gemcitabine which is proportional with PTV size. The risk of kidney toxicity is also subject to PTV expansion in the caudal direction.

The argument for pre-operative chemoradiation for localized, radiographically resectable pancreatic cancer

Although not universally accepted, chemoradiation is considered a standard adjuvant treatment for patients with resected pancreatic cancer. Theoretical advantages of reduced toxicity and increased efficacy with the use of pre-operative chemoradiation compared to post-operative adjuvant chemoradiation have recently been validated with the publication of a phase III trial in the adjuvant treatment of rectal cancer. Additional advantages of pre-operative chemoradiation that apply specifically to pancreatic cancer include increased access to therapy in patients treated before surgery, addressing the systemic disease recurrence risk without delay, and optimal patient selection for pancreaticoduodenectomy through exclusion of patients with rapidly progressive metastatic disease. Critical components of a pre-operative treatment strategy for pancreatic cancer include adherence to a strict definition of resectability, accurate radiographic staging capable of identifying patients with potentially resectable disease, and a safe and efficient means of obtaining a tissue diagnosis and relieving biliary obstruction. Herein, we discuss the rationale for the use of pre-operative chemoradiation in pancreatic cancer, the results of treatment, and future strategies to address the pattern of disease recurrence.

Tumor radiosensitizers--current status of development of various approaches: report of an International Atomic Energy Agency meeting

PURPOSE

The International Atomic Energy Agency (IAEA) held a Technical Meeting of Consultants to (1) discuss a selection of relatively new agents, not those well-established in clinical practice, that operated through a variety of mechanisms to sensitize tumors to radiation and (2) to compare and contrast their tumor efficacy, normal tissue toxicity, and status of development regarding clinical application. The aim was to advise the IAEA as to which developing agent or class of agents would be worth promoting further, by supporting additional laboratory research or clinical trials, with the eventual goal of improving cancer control rates using radiotherapy, in developing countries in particular.

RESULTS

The agents under discussion included a wide, but not complete, range of different types of drugs, and antibodies that interfered with molecules in cell signaling pathways. These were contrasted with new molecular antisense and gene therapy strategies. All the drugs discussed have previously been shown to act as tumor cell radiosensitizers or to kill hypoxic cells present in tumors.

CONCLUSION

Specific recommendations were made for more preclinical studies with certain of the agents and for clinical trials that would be suitable for industrialized countries, as well as trials that were considered more appropriate for developing countries.

Definition of elective lymphatic target volume in ductal carcinoma of the pancreatic head based on histopathologic analysis

PURPOSE

In chemoradiation for pancreatic carcinoma three-dimensional target volume definitions could maximize tolerability and therapeutic effect at the same time because toxicity correlates with treatment volume. We aimed to define guidelines for elective treatment of nodal areas based on pathologic nodal involvement to optimize treatment volume for this tumor.

METHODS AND MATERIALS

Pathologic patterns of regional nodal spread in 175 patients who underwent primary pancreatoduodenectomy with > or =10 assessed nodes and literature data on para-aortic spread were the base of the definition of the target volume. Significant correlations between spread to lymphatic areas and tumor characteristics were determined using Fisher's exact test. Computed tomography scans and a Pinnacle3 (Philips, Best, The Netherlands) system were used for treatment planning.

RESULTS

Among 175 resected tumors without pretreatment, 76% had regional nodal metastasis and 22% had spread to distant nodes. High-risk lymphatic areas were identified and selected for elective treatment. A standardized planning procedure was derived and tested under treatment conditions.

CONCLUSIONS

Histopathologic data allowed us to develop recommendations for standardized treatment planning for ductal carcinoma of the pancreatic head. These are proposed for quality assurance in multicenter studies and routine use.

Concurrent chemoradiotherapy treatment of locally advanced pancreatic cancer: gemcitabine versus 5-fluorouracil, a randomized controlled study

PURPOSE

To determine the efficacy and tolerability of gemcitabine (GEM)-concurrent chemoradiotherapy (CCRT) vs. 5-fluorouracil (5-FU) CCRT for locally advanced pancreatic cancer.

METHODS AND MATERIALS

Thirty-four patients with locally advanced pancreatic cancer were studied. Eighteen patients were randomized to receive GEM CCRT (600 mg/m(2)/wk for 6 weeks) and 16 patients to receive bolus 5-FU CCRT (500 mg/m(2)/d for 3 days repeated every 2 weeks for 6 weeks). All patients were to receive 3D-CRT 50.4-61.2 Gy at 1.8-Gy/d fractions and GEM (1000 mg/m(2) weekly for 3 weeks repeated every 4 weeks) after RT.

RESULTS

The median survival and median time to progression were 14.5 months and 7.1 months for the GEM CCRT group and 6.7 months and 2.7 months for the 5-FU CCRT group (p = 0.027 and p = 0.019, respectively). The quality-adjusted life month survival time was 11.2 +/- 0.5 months for GEM CCRT and 6.0 +/- 0.3 months for 5-FU CCRT patients (p <0.001). The response rate was 50% (four complete responses and five partial responses) for GEM CCRT and 13% (two partial responses) for 5-FU CCRT (p = 0.005). Pain control was 39% for GEM CCRT and 6% for 5-FU CCRT (p = 0.043). Grade 3-4 neutropenia (34% vs. 19%), thrombocytopenia (0% vs. 7%), nausea (33% vs. 31%), vomiting (17% vs. 19%), hospitalization days per month of survival (7.4 +/- 1.7 days vs. 8.0 +/- 1.3 days), and full dose of RT received (78% vs. 75%) were not significantly different between the GEM CCRT and 5-FU CCRT patients.

CONCLUSION

GEM CCRT appears more effective than 5-FU CCRT for locally advanced pancreatic cancer and has comparable tolerability.

A phase I study of radiation therapy and twice-weekly gemcitabine and cisplatin in patients with locally advanced pancreatic cancer

PURPOSE

In vitro studies suggest that low-dose gemcitabine sensitizes cells to radiation therapy and that this effect persists for 48 h after drug exposure. Cisplatin is a radiation sensitizer and is also synergistic with gemcitabine in some in vitro tumor systems. Gemcitabine's radiosensitizing properties can theoretically be exploited by twice-weekly administration. This study assessed toxicity in patients with pancreatic cancer treated with radiation therapy, gemcitabine, and cisplatin.

METHODS AND MATERIALS

Patients with locally advanced pancreatic or gastric cancer were eligible. Gemcitabine and cisplatin were given twice weekly for 3 weeks during radiation therapy (50.4 Gy in 28 fractions). The starting dose of gemcitabine was 5 mg/m(2) i.v. The starting dose for cisplatin was 5 mg/m(2). Chemotherapy doses escalated every 3 to 6 patients according to a standard Phase I study design.

RESULTS

Twenty-four evaluable patients, all with pancreatic cancer, were treated on this protocol. Grade 3 neutropenia occurred in 2 patients, Grade 3 thrombocytopenia occurred in 2, and Grade 4 lymphopenia occurred in 1. There was no clear relationship between chemotherapy dose and hematologic toxicity. The most common Grade 3-4 nonhematologic toxic responses were vomiting (7 patients) and nausea (7 patients). Dose-limiting toxicity consisting of Grade 4 nausea and vomiting occurred in 2 of 3 patients at dose Level 6 (gemcitabine 45 mg/m(2) i.v. and cisplatin 10 mg/m(2) i.v.). Six patients were treated at dose Level 5 (gemcitabine 30 mg/m(2) i.v. and cisplatin 10 mg/m(2) i.v.) without dose-limiting toxicity.

CONCLUSION

Gemcitabine 30 mg/m(2) i.v. twice weekly and cisplatin 10 mg/m(2) i.v. twice weekly may be given concurrently with radiation therapy (50.4 Gy in 28 fractions) with acceptable toxicity.

Phase I trial of strictly time-scheduled gemcitabine and cisplatin with concurrent radiotherapy in patients with locally advanced pancreatic cancer

PURPOSE

Maximal therapeutic gain in xenograft sarcoma and toxicity for jejunal mucosa is time dependent for concurrent gemcitabine and radiotherapy (RT). We used a time-dependent schedule to determine the maximal-tolerated dose and dose-limiting toxicities (DLTs; Grade 4 hematologic or Grade 3 other toxicity).

METHODS AND MATERIALS

Patients with pancreatic cancer (n = 33), periampullary carcinoma (n = 1), or bile duct cancer (n = 2) were treated with 3-day conformal RT with 50.4 Gy (tumor, lymphatics) plus a 5.4-Gy boost. Concurrent cisplatin (20 mg/m(2)/d on Days 1-5 and 29-33) and gemcitabine (initially 600 mg/m(2), weekly on Fridays 68 h before RT) were administered. Because of DLT, the doses were reduced to 500 mg/m(2) weekly and then 500, 400, or 300 mg/m(2) on Days 2, 5, 26, 33.

RESULTS

DLT occurred at all dose levels of gemcitabine >300 mg/m(2). Fourteen patients were treated at the recommended Phase II dose of gemcitabine (300 mg/m(2)) without DLT. The response to chemoradiation allowed 10 of 30 initially unresectable patients with primary pancreatic carcinoma to undergo radical surgery, including a complete response in 2 cases.

CONCLUSIONS

At the recommended Phase II dose, chemoradiation with gemcitabine and cisplatin can be administered safely in pancreatic carcinoma. However, at higher dose levels, toxicity is severe and frequent. Patients with a chance for conversion to resection could benefit from this schedule.

Novel techniques in the delivery of radiation in pediatric oncology

The field of radiation oncology continues to develop at a rapid pace, due to concurrent progress in high speed computing, improved sensitivity in diagnostic imaging (both anatomic and physiologic), and the introduction of rational new therapeutics built on solid radiobiologic principles. These innovations will become critically important in the field of pediatric oncology, as they will allow for an increased therapeutic ratio in the developing child. Maximizing the benefit of lower dose radiation through the use of radiation modifiers (hypoxic cell sensitizers, signal transduction pathway inhibitors, concurrent chemotherapy), increasing the tolerance of normal tissues (radioprotectors) and tailoring the target area more closely to the desired critical tissues (IMRT, functional simulation with PET and MRS, radiolabeled monoclonal antibodies) will lessen the short and long term toxicity of radiation and increase its effectiveness.

Is the therapeutic index better with gemcitabine-based chemoradiation than with 5-fluorouracil-based chemoradiation in locally advanced pancreatic cancer?

PURPOSE

To retrospectively compare the toxicity and efficacy of concurrent gemcitabine-based chemoradiation with that of concurrent 5-fluorouracil (5-FU)-based chemoradiation in patients with unresectable pancreatic cancer.

PATIENTS AND METHODS

Between September 1996 and May 2000, 114 patients with localized unresectable adenocarcinoma of the pancreas were treated with concurrent chemoradiation. Locally advanced unresectable disease was defined as low-density tumor in contact with the superior mesenteric artery (SMA) or celiac artery, or occlusion of the superior mesenteric-portal venous confluence. Fifty-three patients were selected to receive gemcitabine in 7 weekly cycles (250-500 mg/m(2)) with concurrent radiotherapy (median dose 30 Gy, range 30-33 Gy in 10-11 fractions). The remaining 61 patients received continuous-infusion 5-FU (200-300 mg/m(2)) with concurrent radiotherapy (30 Gy in 10 fractions). Radiotherapy was delivered to the primary tumor and regional lymphatics. Patients receiving gemcitabine and those receiving 5-FU had a similar mean Karnofsky performance status (KPS, 89% vs. 86%), distribution of tumor grade (43% vs. 33% poorly differentiated), and percent weight loss (all p = NS). However, patients treated with gemcitabine had a significantly larger median maximum cross-sectional tumor area (TA, 8.8 cm(2) vs. 5.7 cm(2), p = 0.046) and were significantly younger (median age 60 vs. 68 years, p <0.001). Severe acute toxicity (ST) was defined as toxicity requiring a hospital stay of more than 5 days, mucosal ulceration with bleeding, more than 3 dose deletions of gemcitabine or discontinuation of 5-FU, or toxicity resulting in surgical intervention or death. Kaplan-Meier analysis was used to calculate the actuarial rate of local progression on imaging (LP), the rate of distant metastasis (DM), and the overall survival (OS) rate. The imaging was reviewed in resected patients.

RESULTS

Patients receiving gemcitabine developed significantly more ST during treatment (23% vs. 2%, p < 0.0001) than did those receiving 5-FU. Patients treated with gemcitabine had a similar 10-month LP rate (62% vs. 61%), 10-month DM rate (55% vs. 47%), 1-year OS rate (42% vs. 28%), and median OS duration (11 months vs. 9 months) to patients treated with 5 FU (all p = NS). Five patients who received gemcitabine and 1 patient who received 5-FU underwent margin-negative pancreaticoduodenectomy after chemoradiation. Three patients had a short segment (<or= 1 cm in length) of low-density tumor abutting the SMA, 1 had involvement of the common hepatic artery, and 1 had a short-segment occlusion of the superior mesenteric vein, amenable to venous resection and reconstruction. The other patient was thought to have inflammatory changes discontiguous with the tumor surrounding the SMA, which resolved after therapy. TA >10 cm(2) (p = 0.03) and poor differentiation (p = 0.07) were associated with a worse survival duration; however, other factors, such as KPS and weight loss >10% and age did not influence OS.

CONCLUSION

Despite the selection of healthier patients to receive gemcitabine, there was a significantly higher severe toxicity rate than with 5-FU. The median and 1-year survivals were not significantly different with the use of concurrent gemcitabine; however, the tumors treated were significantly larger. Additionally, a small number of patients with minimal arterial involvement whose disease met our radiographic definition of unresectable disease had margin-negative resections after treatment with gemcitabine-based chemoradiation. These possible benefits and the high rate of severe toxicity define a very narrow therapeutic index for concurrent gemcitabine-based chemoradiation given by this schedule of administration.