Preoperative combined modality therapy for pancreatic cancer

Definition and Management of Borderline Resectable Pancreatic Cancer

Patients with localized pancreatic ductal adenocarcinoma seek potentially curative treatment, but this group represents a spectrum of disease. Patients with borderline resectable primary tumors are a unique subset whose successful therapy requires a care team with expertise in medical care, imaging, surgery, medical oncology, and radiation oncology. This team must identify patients with borderline tumors then carefully prescribe and execute a combined treatment strategy with the highest possibility of cure. This article addresses the issues of clinical evaluation, imaging techniques, and criteria, as well as multidisciplinary treatment of patients with borderline resectable pancreatic ductal adenocarcinoma.

Results of a phase I trial of 12 patients with locally advanced pancreatic carcinoma combining gefitinib, paclitaxel, and 3-dimensional conformal radiation: report of toxicity and evaluation of circulating K-ras as a potential biomarker of response to therapy

OBJECTIVE

To evaluate the toxicity of daily gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor, with concurrent chemoradiation (CRT) in patients with locally advanced pancreatic adenocarcinoma and prospectively evaluate plasma k-ras as a potential marker of response to gefitinib and CRT.

METHODS

Eleven of 12 eligible patients enrolled received a 7-day induction of gefitinib (250 mg PO) followed by daily gefitinib with concurrent CRT. Patients received 50.4 Gy/28 fractions of external beam radiation with weekly paclitaxel (40 mg/m IV) followed by maintenance on gefitinib. Plasma k-ras codon 12 mutations were detected using a two-stage restriction fragment length polymorphism-polymerase chain reaction assay on patients' plasma both before and after therapy. Mutations were confirmed by direct sequencing.

RESULTS

Common adverse events included grade 1 skin rash (63%), grade 1 to 2 gastrointestinal symptoms including anorexia, nausea, vomiting, and diarrhea occurred in 63% of patients, grade 3 nausea occurred in 45% of patients. Three patients did not complete therapy, only one was possibly associated with study drug. K-ras mutations were detected in the pre-gefitinib plasma of 5/11 patients and in the matched tumor tissue of 3/4 patients. In patients where k-ras mutations were undetectable post-treatment, survival times were favorable.

CONCLUSIONS

Combination of daily gefitinib with concurrent CRT in this locally advanced pancreatic cancer population was reasonably tolerated. Rapid changes in serum k-ras may provide critical information as to the efficacy of a novel agent and assist in tailoring treatment for cancers of the pancreas.

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.

A dosimetric analysis of dose escalation using two intensity-modulated radiation therapy techniques in locally advanced pancreatic carcinoma

PURPOSE

To perform an analysis of three-dimensional conformal radiation therapy (3D-CRT), sequential boost intensity-modulated radiation therapy (IMRTs), and integrated boost IMRT (IMRTi) for dose escalation in unresectable pancreatic carcinoma.

METHODS AND MATERIALS

Computed tomography images from 15 patients were used. Treatment plans were generated using 3D-CRT, IMRTs, and IMRTi for dose levels of 54, 59.4, and 64.8 Gy. Plans were analyzed for target coverage, doses to liver, kidneys, small bowel, and spinal cord.

RESULTS

Three-dimensional-CRT exceeded tolerance to small bowel in 1 of 15 (6.67%) patients at 54 Gy, and 4 of 15 (26.7%) patients at 59.4 and 64.8 Gy. 3D-CRT exceeded spinal cord tolerance in 1 of 15 patients (6.67%) at 59.4 Gy and liver constraints in 1 of 15 patients (6.67%) at 64.8 Gy; no IMRT plans exceeded tissue tolerance. Both IMRT techniques reduced the percentage of total kidney volume receiving 20 Gy (V20), the percentage of small bowel receiving 45 Gy (V45), and the percentage of liver receiving 35 Gy (V35). IMRTi appeared superior to IMRTs in reducing the total kidney V20 (p < 0.0001), right kidney V20 (p < 0.0001), and small bowel V45 (p = 0.02).

CONCLUSIONS

Sequential boost IMRT and IMRTi improved the ability to achieve normal tissue dose goals compared with 3D-CRT. IMRTi allowed dose escalation to 64.8 Gy with acceptable normal tissue doses and superior dosimetry compared with 3D-CRT and IMRTs.

Chemoradiotherapy in gallbladder cancer

Gallbladder cancer (GC) is considered a rare disease associated with a poor prognosis. Unfortunately, the low number of cases makes the performance of trials addressing the role of adjuvant, neoadjuvant, and/or palliative therapy difficult. For a long time, the majority of trials were 5-fluorouracil (5 FU)-based, and results were uniformly poor. Since the introduction of Gemcitabine, response rates of approximately 30% have been observed through the use of this drug and new approaches have been tested. In this sense, drugs such as Cisplatin and Capecitabine have been employed concurrently with gemcitabine and/or radiation. Since a recurrence pattern is both distant and local, chernoradiation seems a logical option to deal with the disease. However, at the present time, the lack of valid and scientific evidence means that most of the recommendations originate from trials dealing with other tumors, such as pancreas cancer and biliary tract cancer (BTC). The aforementioned treatment alternatives warrant further evaluation focusing on GC.

Preoperative staging and evaluation of resectability in pancreatic ductal adenocarcinoma

BACKGROUND

Cancer of the pancreas is a common disease, but the large majority of patients have tumours that are irresectable at the time of diagnosis. Moreover, patients whose tumours are clearly beyond surgical cure are best treated non-operatively, if possible, by relief of biliary obstruction and percutaneous biopsy to confirm the diagnosis and then consideration of oncological treatment, notably chemotherapy. These facts underline the importance of a standard protocol for the preoperative determination of operability (is it worth operating?) and resectability (is there a chance that the tumour can be removed?). Recent years have seen the advent of many new techniques, both radiological and endoscopic, for the diagnosis and staging of pancreatic cancer. It would be impracticable in time and cost to submit every patient to every test. This review will evaluate the available techniques and offer a possible algorithm for use in routine clinical practice.

DISCUSSION

In deciding whether to operate with a view to resecting a pancreatic cancer, the surgeon must take into account factors related to the patient, the tumour and the institution and team entrusted with the patient's care. Patient-related factors include age, general health, pain and the presence or absence of malnutrition and an acute phase inflammatory response. Tumour-related factors include tumour size and evidence of spread, whether to adjacent organs (notably major blood vessels) or further afield. Hospital-related factors chiefly concern the volume of pancreatic cancer treated and thus the experience of the whole team. Determination of resectability is heavily dependent upon detailed imaging. Nowadays conventional ultrasonography can be supplemented by endoscopic, laparoscopic and intra-operative techniques. Computed tomography (CT) remains the single most useful staging modality, but MRI continues to improve. PET scanning may demonstrate unsuspected metastases and likewise laparoscopy. Diagnostic cholangiography can be performed more easily by MR techniques than by endoscopy, but ERCP is still valuable for preoperative biliary decompression in appropriate patients. The role of angiography has declined. Percutaneous biopsy and peritoneal cytology are not usually required in patients with an apparently resectable tumour. The prognostic value of tumour marker levels and bone marrow biopsy is yet to be established. Preoperative chemotherapy or chemoradiation may have a role in down-staging an irresectable tumour sufficiently to render it resectable. Selective use of diagnostic laparoscopy staging is potentially helpful in determination of resectability. Laparotomy remains the definitive method for determining the resectability of pancreatic cancer, with or without portal vein resection, and should be undertaken in suitable patients without clear-cut evidence of irresectability.

Surgical resection after preoperative chemoradiotherapy benefits selected patients with unresectable pancreatic cancer

Simultaneous chemoradiation is used in unresectable pancreatic cancer for palliation. It is not known if the use of adjuvant surgery will benefit this group of patients. From November 1991 to September 1998, 47 patients with unresectable pancreatic cancer were treated with simultaneous preoperative radiation therapy (45 Gy) and chemotherapy. Chemotherapy followed three different protocols: cisplatin, 5-fluorouracil +/- paclitaxel; cisplatin, 5-fluorouracil (protracted infusion); and docetaxel and gemcitabine. Whipple pancreatoduodenectomy was performed 1 month after the end of radiation in patients selected for resection. Twenty-three unresectable tumors after preoperative treatment (47%) received an additional dose (10-12 Gy) of radiotherapy using intraoperative or external radiation therapy. Twelve patients (26%) were considered to have clinically resectable tumors after the preoperative treatment. Nine patients had surgery (19% of the total number of patients), and 2 of them had complete pathologic response. After chemoradiation, two patients died of pneumonia and gastrointestinal bleeding, respectively, and another two patients died in the postoperative period. Local recurrence was observed in 22% of the patients and 57% had distant metastases. Three-year survival rates for patients with unresectable and resectable tumors was 0% (median survival 10 months) and 48% (median survival 23 months), respectively (p = 0.0004). Preoperative treatment with chemotherapy and radiotherapy in patients with unresectable pancreatic cancer is feasible. In some patients, the tumor can be resected, and in addition some cases of complete pathologic response were found. Long-term survivors were observed in the group of resected tumors. More effective chemotherapy regimens are needed because the majority of the patients died of metastatic disease.

Current approaches to novel therapeutics in pancreatic cancer

Pancreatic cancer is one of the most refractory neoplasms to medical treatment. Until now there has been only modest improvement in the treatment of this disease. Standards of care for combined-modality treatment of resectable as well as locally advanced, unresectable disease have not been uniformly accepted to date because of an equivocal or conflicting data. The inception of gemcitabine introduced the new era in the management of metastatic pancreatic cancer, however, new therapeutic approaches still need to be defined. The article discusses the current knowledge of the biology of this lethal disease, its impact on treatment options, and explores novel therapeutic modalities that are likely to improve outcomes and survival for patients in the future.

Gemcitabine, paclitaxel, and radiation for locally advanced pancreatic cancer: a Phase I trial

PURPOSE

To determine the maximum tolerated dose (MTD) and dose-limiting toxicities of gemcitabine, paclitaxel, and concurrent radiation for pancreatic cancer.

METHODS AND MATERIALS

Twenty patients with locally unresectable pancreatic cancer were studied. The initial dose level was gemcitabine 75 mg/m(2) and paclitaxel 40 mg/m(2) weekly for 6 weeks. Concurrent radiation to 50.4 Gy was delivered in 1.8 Gy fractions. The radiation fields included the primary tumor, plus the regional peripancreatic, celiac, and porta hepatis lymph nodes.

RESULTS

Dose-limiting toxicities of diarrhea, dehydration, nausea, and anorexia occurred in 3 of 3 patients at the second dose level of gemcitabine, 150 mg/m(2)/week. An intermediate dose level of gemcitabine, 110 mg/m(2)/week, was added, but gastrointestinal toxicity and pulmonary pneumonitis were encountered. The MTD therefore was gemcitabine 75 mg/m(2)/week with paclitaxel 40 mg/m(2)/week and concurrent radiation. Two of 11 patients treated at the MTD had Grade 3/4 toxicity. Four of 10 assessable patients treated at the MTD responded (40%), including one pathologic complete response.

CONCLUSION

The maximum tolerated dosage of gemcitabine is 75 mg/m(2)/week with paclitaxel 40 mg/m(2)/week and conventional 50.4 Gy radiation fields. A Phase II Radiation Therapy Oncology Group study is under way.

A phase II single institutional experience with preoperative radiochemotherapy in pancreatic adenocarcinoma

BACKGROUND

Resection of pancreatic adenocarcinoma has a limited impact on survival. We hypothesized that delivering preoperative radiochemotherapy (RTCT) might enhance local control of the cancer and improve survival.

METHODS

Nineteen patients with localized pancreatic cancer (14 head and 5 body) were treated during the past 4 years with an intramural protocol consisting of continuous infusion of fluorouracile (5-FU: 650 mg/m(2)/D1-D5 and D21-D25 and Cisplatin 80 mg/m(2)/bolus D2 and D22 with preoperative external beam radiotherapy (RT) (30Gy split course RT or 45 Gy standard fractionation RT).

RESULTS

Four patients did not have surgical resection: Three patients were noted to have liver metastases and 1 patient developed peritoneal carcinomatosis. The remaining 15 patients had potentially curative resection (12 Whipple procedure and 3 distal subtotal pancreatectomy). There was no postoperative death. Pathologic findings showed five major responses including 2 patients with complete pathologic response. The overall median survival for the 19 study patients was 20 months. The median disease free and 2-year overall survival for the group with resection were 30 months and 52.3%.

CONCLUSIONS

Preoperative RTCT followed by resection is well-tolerated and safe for patients with localized pancreatic cancer. Major histological response occurred for 25% of patients. This approach could offer improvement in patient survival.

The effect of therapeutic irradiation on LactoSorb absorbable copolymer

Bioabsorbable implants continue to gain popularity in providing temporary internal fixation due to their many advantages over metallic internal fixation. Coincident with the presence of internal fixation devices, it may be necessary to use radiotherapy to treat tumors. While metal implants can alter the distribution of the radiotherapy beam, bioabsorbable polymer implants are, essentially, tissue equivalent. This ionizing irradiation, in sufficiently high dose, can affect polymers through chain scission and cross-linking and accelerate the hydrolysis of absorbable polymers. However, little is known about the effects of therapeutic doses on such materials. This study exposed LactoSorb (Biomet, Inc., Warsaw, IN) absorbable copolymer to doses of x-ray irradiation in a clinically relevant manner, in vitro, with individual doses of 2 Gy administered five days per week for up to eight weeks, yielding a total cumulative dose of up to 80 Gy. Specimens were tested both mechanically and for inherent viscosity. Overall, the LactoSorb specimens withstood exposure to the irradiation exceedingly well, providing empirical evidence of the suitability of this material for temporary internal fixation when subsequent radiotherapy in the region is probable.

A pilot study of chronomodulated infusional 5-fluorouracil chemoradiation for pancreatic cancer

BACKGROUND

Dose limiting acute toxicity from chemoradiation for pancreatic cancer occurs in 15% -20% of patients treated with post-operative adjuvant therapy. Reported here is a pilot study using chronomodulated infusional 5-fluorouracil (5-FU) chemoradiation (CIC) for pancreatic cancer, a treatment designed to reduce normal tissue toxicity and maintain efficacy, with specific evaluation of acute and late morbidity, patterns of disease progression, and survival.

PATIENTS AND METHODS

Twenty-three patients with adenocarcinoma of the pancreas were treated with 5-FU CIC between January 1997 and September 1999. The median age was 64, and there were 9 males and 14 females. Six patients were considered unresectable and seventeen others were treated post-operatively. The median external beam irradiation dose was 50.4 Gy. 5-FU infusion was given five days per week (300 mg/m2/d) and the median total dose was 8.4 g/m2. The chronomodulated 5-FU infusion consists of a low basal infusion rate for 16 hours followed by an eight-hour escalating-deescalating infusion peaking at 10 p.m. All patients were followed from the time of initial diagnosis until last follow-up or death; the median follow-up was 16 months.

RESULTS

No RTOG grade 3 or 4 hematologic toxicity occurred. Twelve of seventeen patients treated postoperatively have been controlled locally, and seven patients have no evidence of disease. The median survival is 28 months and one-year actuarial survival is 88% in the group of resected patients. The 6 patients treated for unresectable disease have a median survival of 13 months.

CONCLUSIONS

Acute toxicity of 5-FU CIC appears to be less frequent and less severe than that reported with flat infusional or bolus 5-FU based chemoradiation used for adjuvant post-operative therapy for pancreatic cancer. This method may warrant further examination, as it may be attractive for the elderly or those who cannot tolerate the toxicity associated with standard post-operative treatment protocols.

UFT plus oral leucovorin calcium (Orzel) and radiation in combined modality therapy: a comprehensive review

5-fluorouracil (5-FU) has become the most commonly used drug in combination with radiation therapy. The recent availability of oral formulations of 5-FU in conjunction with the ability to modulate the anabolic and catabolic metabolism of 5-FU with leucovorin and dihydropyrimidine dehydrogenase (DPD) inhibitors, respectively, may provide a substantial improvement in the ease of administration and the efficacy of fluoropyrimidine therapy. Several oral fluoropyrimidines are under investigation. UFT (uracil:tegafur) plus oral leucovorin (Orzel) is the first oral DPD-inhibitory fluoropyrimidine. With daily administration, Orzel achieves similar concentrations of 5-FU obtained with continuous-infusion 5-FU. This paper summarizes the therapeutic rationale for Orzel and reviews the clinical experience with UFT and UFT/LV in combined modality therapy regimens.

Chemoradiation for pancreatic and biliary cancer: current status of RTOG studies

Chemoradiation for gastrointestinal cancers is actively under study in the Radiation Therapy Oncology Group (RTOG) and consists of external irradiation combined with simultaneously administered chemotherapy given to provide radiation sensitization and to attack micro metastatic disease. Two national protocols for the treatment of patients with pancreatic and biliary cancers are now active. RTOG 97-04 is a phase III post-operative combined modality program for patients with resected pancreatic cancer. All patients receive protracted infusional 5-fluorouracil (5-FU) combined with 50.4 Gy given in 28 fractions. Prior to and after chemoradiation all patients are randomized to receive multiple cycles of either infusional 5-FU or Gemcitabine to determine the effect on survival. In the other study (RTOG 98-12) patients with unresectable pancreatic cancer are given 50.4 Gy combined with weekly Paclitaxel (50 mg/m2) to examine the efficacy of this active combination in a phase II trial in a multi-institutional setting. Both of these trials have recently been opened to accrual. A third RTOG study for patients with biliary cancer will examine the efficacy of giving pre-operative chronomodulated infusional 5-FU chemoradiation. The background and the rationale for these studies is based on the long history of 5-FU radiation sensitization in the treatment of cancers of these anatomic sites and will be summarized. A brief review of recently published trials using chemoradiation in conjunction with new irradiation treatment techniques "3D" conformal therapy for these diseases will be discussed.

Preoperative chemoradiation for patients with locally advanced adenocarcinoma of the pancreas

BACKGROUND

Improved resectability is a major theoretical benefit of preoperative chemoradiation for pancreatic cancer. Since 1994, patients at Duke University Medical Center with locally advanced pancreatic cancer have been treated with multimodality preoperative therapy. The purpose of this study was to review our experience with preoperative therapy for locally advanced pancreatic cancer and determine if an aggressive neoadjuvant regimen would not only downstage these tumors pathologically but also improve the odds of complete surgical resection.

METHODS

The charts of 25 patients treated with neoadjuvant chemoradiation at Duke University Medical Center with biopsy-proven, locally advanced adenocarcinoma of the pancreas were reviewed. Tumors were defined as locally advanced based on radiographic or intraoperative evidence of disease that abuts the superior mesenteric artery or vein (n = 22) or involves lymph nodes that are within the proposed radiation field (n = 3). All 25 patients received external beam radiotherapy (median dose 4500 cGy) in daily fractions of 180 cGy over 5 weeks. All patients concurrently received 5-fluorouracil (FU), and many also received mitomycin C or cisplatin, or both. Patients were given a 3- to 4-week break before a restaging computed tomographic (CT) scan was performed. Three patients were not restaged: one died from metastatic disease; one was reclassified as having a neuroendocrine tumor; and one was lost to follow-up.

RESULTS

On restaging after neoadjuvant therapy, 64% of patients had stable or decreased primary tumor size. Radiographically, two patients appeared potentially resectable, and seven others developed evidence of metastatic disease. Eight patients underwent exploration, but only five could be resected. Of the five patients resected, only one had negative margins and negative lymph nodes. This patient had significant pancreatitis on initial exploration. After neoadjuvant therapy, he had a complete response radiographically, and there was no residual cancer in his resection specimen. Pathologic examination of the other resection specimens suggested that despite significant tumor fibrosis, malignant cells persist even at the periphery of the lesions.

CONCLUSION

Although neoadjuvant chemoradiation has many theoretical advantages in managing pancreatic malignancy, true pathologic downstaging of locally advanced lesions into tumors that can be removed with negative nodes and margins appears to be a rare event with currently used therapeutic regimens.

Progress report. A randomized multicenter European study comparing adjuvant radiotherapy, 6-mo chemotherapy, and combination therapy vs no-adjuvant treatment in resectable pancreatic cancer (ESPAC-1)

CONCLUSION

The ESPAC-1 trial is the largest study of its kind in pancreatic cancer and should definitively address the question of the role of conventional methods of adjuvant treatment in pancreatic cancer.

BACKGROUND

At the joint International Association of Pancreatology and the European Pancreatic Club meeting in Mannheim, Germany (June 12-15, 1996) a satellite meeting of the European Study Group for Pancreatic Cancer (ESPAC) met to discuss the progress of the ESPAC-1 trial.

METHODS

A randomized multicenter study to address which, if any, of the following adjuvant treatments are of benefit in patients with resectable pancreatic cancer: radiotherapy (40 Gy with 5-FU as a sensitizing agent), 6 mo of chemotherapy (5-FU and folinic acid), or a combination of these treatments.

RESULTS

From February 1994 to June 1996 (the time of the Mannheim meeting) 221 patients so far have been recruited into the three treatment arms and one control arm.