The evolution of adjuvant and neoadjuvant chemotherapy and radiation for advanced pancreatic cancer: from 5-fluorouracil to GTX

Self-expanding metal stents (SEMS) for preoperative biliary decompression in patients with resectable and borderline-resectable pancreatic cancer: outcomes in 241 patients

BACKGROUND AND AIM

Obstructive jaundice caused by distal biliary obstruction can present in up to 70 % of patients with localized cancer of the head of the pancreas. The aim of this study was to report our experience in using self-expanding metal stents (SEMS) for preoperative biliary decompression in patients with resectable and borderline resectable carcinoma of the pancreatic head.

METHODS

We performed a retrospective study evaluating patients from two tertiary referral centers. Two-hundred and forty-one patients with resectable and borderline resectable pancreatic carcinoma underwent ERCP with metal biliary stent placement between September 2006 and August 2011. We assessed the effectiveness of SEMS to adequately decompress the biliary tree, procedural success, patient survival, stent patency, and stent-related complications.

RESULTS

Two-hundred and forty-one patients were evaluated [123 male, mean age (± SD) 67.4 ± 9.8 years; resectable 174, borderline resectable 67]. Patients with borderline-resectable cancer underwent neoadjuvant therapy and restaging before possible curative surgery. Successful placement of a metal biliary stent was achieved in all patients and improved jaundice. Patients were followed for mean duration of 6.3 months. The overall survival was 49 % at 27 months. Fourteen (5.8 %) patients experienced stent occlusion; the mean time to stent occlusion was 6.6 (range 1-20) months. Immediate complications included: post-ERCP pancreatitis (n = 14), stent migration (n = 3), and duodenal perforation (n = 3). Long-term complications included stent migration (n = 9) and hepatic abscess (n = 1). A total of 144/174 patients deemed to have resectable cancer at time of diagnosis underwent curative surgery. Due to disease progression or the discovery of metastasis after neoadjuvant therapy, only 22/67 patients with borderline-resectable cancer underwent curative surgery.

CONCLUSIONS

SEMS should be considered for patients with obstructive jaundice and resectable or borderline resectable pancreatic cancer, especially if surgery is not planned immediately as a result of preoperative chemoradiation. These stents appear to be safe and effective.

Advances in medical treatment of advanced pancreatic cancer

Chemotherapy is currently an important means of treating advanced pancreatic cancer. Gemcitabine is a chemotherapeutic agent for the first-line treatment of advanced pancreatic cancer. Some progress has been made to improve survival in patients with advanced pancreatic cancer with gemcitabine-based combination chemotherapy regimens. FOLFIRINOX is the first non-gemcitabine regimen whose efficacy has been demonstrated to be superior to gemcitabine in selected patients. In addition, the development of a variety of targeted drugs (including cytotoxic drugs and biological drugs) has brought a new prospect to the treatment of pancreatic cancer. In this article, we will review recent advances in chemotherapy and targeted therapy of pancreatic cancer.

Pancreatic proteolytic enzyme therapy compared with gemcitabine-based chemotherapy for the treatment of pancreatic cancer

PURPOSE Conventional medicine has had little to offer patients with inoperable pancreatic adenocarcinoma; thus, many patients seek alternative treatments. The National Cancer Institute, in 1998, sponsored a randomized, phase III, controlled trial of proteolytic enzyme therapy versus chemotherapy. Because most eligible patients refused random assignment, the trial was changed in 2001 to a controlled, observational study. METHODS All patients were seen by one of the investigators at Columbia University, and patients who received enzyme therapy were seen by the participating alternative practitioner. Of 55 patients who had inoperable pancreatic cancer, 23 elected gemcitabine-based chemotherapy, and 32 elected enzyme treatment, which included pancreatic enzymes, nutritional supplements, detoxification, and an organic diet. Primary and secondary outcomes were overall survival and quality of life, respectively. Results At enrollment, the treatment groups had no statistically significant differences in patient characteristics, pathology, quality of life, or clinically meaningful laboratory values. Kaplan-Meier analysis found a 9.7-month difference in median survival between the chemotherapy group (median survival, 14 months) and enzyme treatment groups (median survival, 4.3 months) and found an adjusted-mortality hazard ratio of the enzyme group compared with the chemotherapy group of 6.96 (P < .001). At 1 year, 56% of chemotherapy-group patients were alive, and 16% of enzyme-therapy patients were alive. The quality of life ratings were better in the chemotherapy group than in the enzyme-treated group (P < .01). CONCLUSION Among patients who have pancreatic cancer, those who chose gemcitabine-based chemotherapy survived more than three times as long (14.0 v 4.3 months) and had better quality of life than those who chose proteolytic enzyme treatment.

Progress in the chemotherapy of pancreatic carcinoma

Pancreatic carcinoma is one of the most malignant tumors with characteristics of insidious onset, and low surgical curative rate, insensitivity to traditional chemoradiotherapy and poor prognosis. It is found that the adjuvant chemotherapy had held an edge over supporting therapy and the survival was extended. As a representative drug for adjuvant chemotherapy, gemcitabine shows favorable efficacy in comparison with traditional chemotherapy. With some further researches undergoing, a variety of targeted drugs (include cytotoxic drugs or bio-targeted drugs) have brought a new prospect for the adjuvant chemotherapy of pancreatic carcinoma.

Neoadjuvant chemotherapy and radiation for patients with locally unresectable pancreatic adenocarcinoma: feasibility, efficacy, and survival

BACKGROUND

We evaluated the feasibility and efficacy of neoadjuvant chemotherapy and radiation for patients with locally unresectable pancreatic cancer.

MATERIALS AND METHODS

From October 2000 to August 2006, 245 patients with pancreatic adenocarcinoma underwent surgical exploration at our institution. Of these, 78 patients (32%) had undergone neoadjuvant therapy for initially unresectable disease, whereas the remaining patients (serving as the control group) were explored at presentation (n=167). All neoadjuvant patients received gemcitabine-based chemotherapy, often in conjunction with docetaxal and capecitabine in a regimen called GTX (81%). Seventy-five percent of neoadjuvant patients also received preoperative abdominal radiation (5,040 rad).

RESULTS

Neoadjuvant patients were younger than control-group patients (60.8 vs 66.2 years, respectively, p<0.002). Seventy-six percent of neoadjuvant patients were resected as compared to 83% of control patients (NS). Concomitant vascular resection was required in 76% of neoadjuvant patients but only 20% of NS (p<0.01). Complications were more frequent in the neoadjuvant group (44.1 vs 30.9%, p<0.05), and mortality was higher (10.2 vs 2.9%, p<0.03). Among the neoadjuvant patients, all but one of the deaths were in patients that underwent arterial reconstruction. Mortality for patients undergoing a standard pancreatectomy without vascular resection was 0.8% in this series. Of patients resected, negative margins were achieved in 84.7% of neoadjuvant patients and 72.7% of NS. Within the cohort of neoadjuvant patients, radiation significantly increased the complication rate (13.3 vs 54.6%, p<0.006), but did not affect median survival (512 vs 729 days, NS). Median survival for patients who received neoadjuvant therapy (503 days) was longer than NS that were found to be unresectable at surgery (192 days, p<0.001) and equivalent to NS that were resected (498 days).

CONCLUSIONS

Resection rate, margin status, and median survivals were equivalent when neoadjuvant patients were compared to patients considered resectable by traditional criteria, demonstrating equal efficacy. Surgical resection with venous reconstruction following neoadjuvant therapy for patients with locally advanced pancreatic cancer can be performed with acceptable morbidity and mortality. This approach extended the boundaries of surgical resection and greatly increased median survival for the "inoperable" patient with advanced pancreatic cancer.

Neoadjuvant therapy in pancreatic cancer

Pancreatic cancer is the fourth leading cause of cancer deaths in the United States. Surgical resection offers the only hope of cure, though the addition of chemoradiation in the adjuvant setting has been shown to improve survival over surgery alone. Many patients are unable to receive adjuvant therapy due to prolonged postoperative recovery. For this reason, administration of chemoradiation preoperatively (neoadjuvant) has been proposed as an alternative to postoperative treatment. In patients with resectable disease, neoadjuvant therapy results in similar survivals compared to postoperative therapy, with a greater proportion of patients able to complete treatment. For selected patients with borderline or unresectable disease, neoadjuvant therapy offers the potential for tumor downstaging and increasing the likelihood of a margin-negative resection. This article reviews the use of neoadjuvant therapy in the treatment of pancreatic cancer.

The gemcitabine, docetaxel, and capecitabine (GTX) regimen for metastatic pancreatic cancer: a retrospective analysis

PURPOSE

We developed a laboratory based regimen called GTX which induces synergistic apoptosis in human pancreatic cancer cells. This retrospective review summarizes our clinical experience with GTX in an initial group of 35 patients; 66% untreated and 34% failed prior therapies.

METHODS

All patients treated with GTX for metastatic pancreatic cancer, prior to initiation of a prospective phase II trial of GTX were assessed and followed until death. GTX consisted of capecitabine (X), 750 mg/m(2) p.o. BID on days 1-14, gemcitabine (G) (750 mg/m(2)) over 75 min and docetaxel (T) (30 mg/m(2)) on days 4 and 11. Thus one cycle of GTX was 14 days with 7 days off for a 21 day cycle. Tumor assessments were repeated every 3 cycles.

RESULTS

All 35 patients had metastatic pancreatic cancer (94% liver, 6% lung sites). Grade 3-4 hematological toxicities were: leukopenia and thrombocytopenia-both 14%, and anemia 9%, respectively. The overall response rate of all 35 patients treated with GTX (from 0.5 cycles onward) was 29% (CR/PR) by WHO criteria, and 31% had a minor response or stable disease (MR, SD). At the metastatic sites for the 35 patients, there were 9% complete (CR) and 31% partial (PR) responses (total 40%). For the 31 patients who had their primary tumor (4 patients had a prior Whipple resection), there were 13% CR and 19% PR for a response rate of 32% at the primary tumor site. Overall median progression free survival of responders was 6.3 months (95% C.I. 4.4-10.4 months) and median survival was 11.2 months (95% C.I. 8.1-15.1 months). Survival after initiation of GTX at 12, 18, 24 and 30 months was 43, 29, 20, and 11%, respectively.

CONCLUSION

Our retrospective review suggests that GTX has potential as a regimen for untreated and treated metastatic pancreatic cancer.

New and emerging radiosensitizers and radioprotectors

The combination of chemotherapy and radiation has led to clinical breakthroughs in several disease sites, and current work continues to define optimum combinations of proven chemotherapy as well as more recently available, noncytotoxic agents. Administration of systemic therapies allows modulation of radiation response to improve tumor control (radiosensitization) or to prevent normal tissue toxicity (radioprotection). Substantial progress has been made in identifying the targets of standard chemotherapeutic radiation sensitizers and protectors as well as in the introduction of a new generation of molecularly targeted therapies in combination with radiation. We have reviewed the most recent, predominantly early phase clinical trials combining systemic agents with radiation. Although the proof of an improved schedule ultimately needs to come from well-run Phase III trials, the search among schedules could be shortened by the use of surrogate endpoints such as presence of active drug metabolites in the tumor. This has been accomplished only in a few cases and needs to become a more standard part of radiation sensitizer and protector trials.

Cyclopamine increases the cytotoxic effects of paclitaxel and radiation but not cisplatin and gemcitabine in Hedgehog expressing pancreatic cancer cells

INTRODUCTION

The hedgehog signaling pathway (Hh) is frequently over expressed in pancreatic adenocarcinomas. We studied the potential cytotoxic interactions between cyclopamine, a Hh pathway inhibitor and paclitaxel, cisplatin, gemcitabine and ionizing radiation (IR).

METHODS

In vitro clonogenic survival analysis was performed with cyclopamine alone or cyclopamine in combination with paclitaxel, gemcitabine, cisplatin and IR in Hh expressing human pancreatic tumor cells and Hh non-expressing colon cancer cells. Relative cytotoxicity was assessed in combination treatment compared with exposure to single agents. Assays of apoptosis (annexin V) were performed in the presence of cyclopamine, chemotherapeutic agents, and IR.

RESULTS

We report that cyclopamine increased the cytotoxic effects of paclitaxel and IR in Hh expressing pancreatic carcinoma cells. These effects were not observed in Hh non-expressing cells. Cyclopamine did not significantly increase killing by cisplatin or gemcitabine in Hh expressing pancreatic cancer cells.

CONCLUSIONS

These data suggest strategies to combine Hh inhibitors with radiotherapy and chemotherapeutic agents, specifically paclitaxel and related compounds in the treatment of pancreatic cancer.

Neoadjuvant chemoradiation in patients with pancreatic adenocarcinoma

In spite of the high mortality in pancreatic cancer, significant progress is being made. This review discusses multimodality therapy for patients with pancreatic cancer. Surgical therapy currently offers the only potential monomodal cure for pancreatic adenocarcinoma. However, only 10-20% of patients present with tumors that are amenable to resection, and even after resection of localized cancers, long-term survival is rare. The addition of chemoradiation therapy significantly increases median survival. To achieve long-term success in treating this disease it is therefore increasingly important to identify effective neoadjuvant/adjuvant multimodality therapies. Preoperative chemoradiation for potentially resectable pancreatic cancer has the following advantages: (1) neoadjuvant treatment would eliminate the delay of adjuvant treatment due to postoperative complications; (2) neoadjuvant treatment could avoid unnecessary surgery for patients with metastatic disease evident on restaging after neoadjuvant therapy; (3) down-staging after neoadjuvant therapy may increase the likelihood of negative surgical margins; and (4) neoadjuvant treatment could prevent peritoneal tumor cell implantation and dissemination caused during surgery. This review systematically summarizes the current status, controversies, and prospects of neoadjuvant treatment of pancreatic cancer.

Current management of locally advanced pancreatic cancer

Almost 30% of patients with pancreatic cancer present with large, locally advanced tumors in the absence of distant metastases. Because surgical resection is frequently contraindicated by vascular invasion, locally advanced pancreatic cancer has a dismal prognosis with a 6-10-month median survival. Recent advances in the multimodality treatment of other gastrointestinal malignancies have not altered the management of patients with locally advanced pancreatic cancer, a clinical dilemma reflected by the number of nonrandomized trials and anecdotal reports addressing this difficult disease. Our review summarizes the current status of aggressive surgical resection and neoadjuvant chemoradiation for locally advanced pancreatic cancer and suggests a treatment algorithm for patients with this disease based upon published clinical evidence.