Combination of intraoperative radiation with resection of cancer of the pancreas

Achieving 'Marginal Gains' to Optimise Outcomes in Resectable Pancreatic Cancer

Simple Summary

Improving outcomes in pancreatic cancer is achievable through the accumulation of marginal gains. There exists evidence of variation and undertreatment in many areas of the care pathway. By fully realising the existing opportunities, there is the potential for immediate improvements in outcomes and quality of life.

Abstract

Improving outcomes among patients with resectable pancreatic cancer is one of the greatest challenges of modern medicine. Major improvements in survival will result from the development of novel therapies. However, optimising existing pathways, so that patients realise benefits of already proven treatments, presents a clear opportunity to improve outcomes in the short term. This narrative review will focus on treatments and interventions where there is a clear evidence base to improve outcomes in pancreatic cancer, and where there is also evidence of variation and under-treatment. Avoidance of preoperative biliary drainage, treatment of pancreatic exocrine insufficiency, prehabiliation and enhanced recovery after surgery, reducing perioperative complications, optimising opportunities for elderly patients to receive therapy, optimising adjuvant chemotherapy and regular surveillance after surgery are some of the strategies discussed. Each treatment or pathway change represents an opportunity for marginal gain. Accumulation of marginal gains can result in considerable benefit to patients. Given that these interventions already have evidence base, they can be realised quickly and economically.

ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in borderline-resected pancreatic cancer

•

Radiation dose-escalation with intraoperative electron beam radiation therapy to the posterior resection margin and/or to residual disease is feasible with limited toxicity.

•

Preoperative therapy prolongs the interval to surgery and IOERT, allowing an improved selection of patients who are candidates for local treatment intensification.

•

Primary systemic therapy combined with chemoradiation allows to boost with IOERT in over 70% of patients with R0 surgical tumour beds.

•

Median survival time ranges from 19 to 35 months in electron boosted patients.

•

Overall survival at 5 years of over 30% is reported by contemporary expert IOERT institutions.

Radiation therapy (RT) is a valuable component of multimodal treatment for localized pancreatic cancer. Intraoperative radiation therapy (IORT) is a very precise RT modality to intensify the irradiation effect for cancer involving upper abdominal structures and organs, generally delivered with electrons (IOERT). Unresectable, borderline and resectable disease categories benefit from dose-escalated chemoradiation strategies in the context of active systemic therapy and potential radical surgery. Prolonged preoperative treatment may act as a filter for selecting patients with occult resistant metastatic disease. Encouraging survival rates have been documented in patients treated with preoperative chemoradiation followed by radical surgery and IOERT (>20 months median survival, >35% survival at 3 years). Intensive preoperative treatment, including induction chemotherapy followed by chemoradiation and an IOERT boost, appears to prolong long-term survival within the subset of patients who remain relapse-free for>2 years (>30 months median survival; >40% survival at 3 years). Improvement of local control through higher RT doses has an impact on the survival of patients with a lower tendency towards disease spread. IOERT is a well-accepted approach in the clinical scenario (maturity and reproducibility of results), and extremely accurate in terms of dose-deposition characteristics and normal tissue sparing. The technique can be adapted to systemic therapy and surgical progress. International guidelines (National Comprehensive Cancer Network or NCCN guidelines) currently recommend use of IOERT in cases of close surgical margins and residual disease. We hereby report the ESTRO/ACROP recommendations for performing IOERT in borderline-resectable pancreatic cancer.

Pancreatic Cancer: 80 Years of Surgery-Percentage and Repetitions

Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and projected to become the second and third leading causes of cancer-related deaths by 2030. The mean costs in 2015 may be assumed to be $79,800 per patient and for each resection $164,100. Attempt is made to evaluate the results over the last 80 years, the number of survivors, and the overall survival percentage. Methods. Altogether 1230 papers have been found which deal with resections and reveal survival information. Only 621 of these report 5-year survivors. Reservation about surgery was first expressed in 1964 and five-year survival of nonresected survivors is well documented. Results. The survival percentage depends not only on the number of survivors but also on the subset from which it is calculated. Since the 1980s the papers have mainly reported the number of resections and survival as actuarial percentages, with or without the actual number of survivors being reported. The actuarial percentage is on average 2.75 higher. Detailed information on the original group (TN), number of resections, and actual number of survivors is reported in only 10.6% of the papers. Repetition occurs when the patients from a certain year are reported several times from the same institution or include survivors from many institutions or countries. Each 5-year survivor may be reported several times. Conclusion. Assuming a 10% resection rate and correcting for repetitions and the life table percentage the overall actual survival rate is hardly more than 0.3%.

Role of radiation therapy in the management of pancreatic cancer

Local failure remains a major issue for patients with both resectable and locally advanced pancreatic cancer. The role of radiation therapy in the management of this disease is less clear and represents an area of some controversy. The objective of this review is to present the rationale for radiation therapy in pancreatic cancer, as well as to discuss the potential limitations and caveats of the currently available studies.

Adjuvant therapy for pancreatic cancer

Pancreatic cancer is a challenging malignancy to treat, as less than one-fifth of diagnosed cases are resectable, surgery is complex and postoperative recovery slow, treated patients tend to relapse and overall survival rates are low. It is one of the leading causes of cancer-related mortality. Adjuvant therapy has been employed in resectable disease, to target micrometastases and improve prognosis. Chemotherapy, chemoradiotherapy (chemoRT) and chemoradiotherapy (chemoRT) followed on by chemotherapy have been evaluated in randomised controlled trials. The European Study Group for Pancreatic Cancer (ESPAC)-1 and CONKO-001 trials clearly established the survival advantage of adjuvant chemotherapy with 5 fluorouracil (5FU) plus folinic acid and gemcitabine respectively over no chemotherapy. The ESPAC-3 (version 2) trial demonstrated equivalence between 5FU plus folinic acid and gemcitabine in terms of survival parameters, though gemcitabine had a better toxicity profile. The results of these key studies, together with smaller ones have been subjected to meta-analyses, with confirmation of improved survival with adjuvant systemic chemotherapy. The EORTC-40891 and ESPAC-1 trials found no survival advantage with adjuvant chemoRT compared to observation, and this has been reflected in a subsequent meta-analysis. The popularisation of chemoRT, with follow on chemotherapy (versus observation) was based on the small underpowered GITSG trial. The ESPAC-1 trial was unable to find a survival benefit for chemoRT, with follow on chemotherapy compared to observation. The RTOG-9704 trial assessed chemoRT with follow on chemotherapy in both arms and found no difference between survival in the gemcitabine and 5FU arms. There has never been a published head-to-head randomised comparison of adjuvant chemotherapy to chemoRT, with follow on chemotherapy. Ongoing randomised trials are looking into adjuvant combination chemotherapy, chemotherapy with follow on chemoRT, and neoadjuvant therapy. Novel agents continue to be assessed in early phase trials with a major emphasis on predictive and prognostic biomarkers. Based on the available evidence, adjuvant chemotherapy with gemcitabine or 5FU/folinic acid is the current recommended gold standard in the management of resected pancreatic cancer.

Perioperative intra-arterial and systemic chemotherapy for pancreatic cancer

BACKGROUND

Even after curative resection of pancreatic cancer, there is a high probability of systemic recurrence. This indicates that subclinical metastases are already present at the time of operation. The purpose of this study was to assess the feasibility and outcomes of patients who received a novel multimodality therapy combining pancreatic resection and intraoperative radiation therapy (IORT) with pre- and postoperative chemotherapy for pancreatic cancer.

METHODS

For eligible patients with pancreatic cancer, 5-FU was administered at a dose of 125 mg/m(2)/day on days 1-5 every week as a continuous pancreatic and hepatic arterial infusion, and gemcitabine was infused intravenously at a dose of 800 mg/m(2) per day once per week for 2 weeks for preoperative chemotherapy. Pancreatic resection combined with IORT was performed 1 week after preoperative chemotherapy. Postoperative chemotherapy was performed in the same way as preoperative chemotherapy. We performed an intention-to-treat analysis for all enrolled patients.

RESULTS

This study enrolled 44 patients. The most common toxicities were hematological and gastrointestinal events. Grade 3/4 hematological toxicities were observed during preoperative chemotherapy, although there were no grade 3/4 nonhematological events. Postoperative chemotherapy-related toxicities were more critical and frequent than preoperative ones. There were no pre- or postoperative chemotherapy-associated deaths. Median overall survival was 36.5 months with 30.5% overall 5-year survival.

CONCLUSIONS

This multimodality therapy is feasible and promises to contribute to survival. It should be evaluated in a phase III setting.

Long-term outcomes of extended radical resection combined with intraoperative radiation therapy for pancreatic cancer

BACKGROUND/PURPOSE

Systemic and/or local recurrence often occurs even after curative resection for pancreatic cancer (PC). To prevent local relapse we adopted an extended radical resection combined with intraoperative radiation therapy in patients with PC, and all the patients were followed for more than 5 years.

METHODS

We assessed the long-term outcomes of 41 patients who underwent this combined therapy. The cumulative survival curve in this series was depicted using the Kaplan-Meier method. Statistical analyses were performed using the log-rank test.

RESULTS

The actual 5-year survival rate was 14.6%, with a median survival time of 17.6 months. Six patients have been 5-year survivors. Local recurrence occurred in only 2 patients (5.0%). Cancer-related death occurred in 32 patients, 18 of whom had liver metastases. The patients with liver metastases had a significantly shorter survival time than those with other cancer-related causes of death. Patients with n3 lymph node involvement, extrapancreatic nerve plexus invasion, and stage IV disease had significantly poorer prognoses than patients without these characteristics.

CONCLUSIONS

Our combined therapy for patients with PC contributed to local control; however, it provided no survival benefit, because of liver metastases.

Adjuvant therapy for pancreatic cancer: a review

Pancreatic cancer is uniformly fatal unless it can be surgically resected. Survival rates for the 15% to 20% of patients who have resectable disease, however, are a disappointing 10% to 30%, depending on the status of margins and surrounding lymph nodes. In the mid-1980s, a landmark study by the Gastrointestinal Tumor Study Group was the first to demonstrate a survival benefit from adjuvant therapy in the form of chemoradiation. Since then, several studies in both North America and Europe have tested the role of adjuvant chemotherapy or chemoradiation in pancreatic cancer, and the results have stirred great controversy. For this review, the evidence for adjuvant therapy in pancreatic cancer was examined, and the significant practice differences that exist between North American and European oncologists were highlighted. The authors investigated the results from the European Study Group for Pancreatic Cancer-1 trial and the reasons why that study has served to reinforce rather than resolve these trans-Atlantic differences. They also reviewed preliminary data from more recent adjuvant trials and explored the possible benefits of a neoadjuvant approach.

Extended radical operation of pancreatic head cancer: Appraisal of its clinical significance

AIM: To evaluate the significance of extended radical operation and its indications.

METHODS: Between January 1995 and December 1998, 56 inpatients with pancreatic head cancer received operation. Among them 35 patients (group 1) experienced the Whipple operation, and 21 patients (group 2) received the extended radical operation. The 1-, 2-, 3-year cumulative survival rates were used to evaluate the efficacy of the two operative procedures. Clinical stage (CS) was assessed retrospectively with the help of CT. The indications for extended radical operation were discussed.

RESULTS: There was no difference in hospital mortality and morbidity rates. Whereas the 1-, 2-, 3-year cumulative survival rates were 84.8%, 62.8%, 39.9% in the extended radical operation group, and were 70.8%, 47.6%, 17.2% in the Whipple operation group, there was a significant difference between the two groups (P<0.001, P<0.001, P<0.001, respectively). Most of the deaths within 3 years after operation were due to recurrence in the two groups. However, the 1-, 2-, 3-year cumulative rates of death due to local recurrence were decreased from 37.4% in patients that received the Whipple procedure to 23.8% in those who received by extended radical operation. Patients who survived for more than 3 years were only noted in those with CS1 in the Whipple procedure group and were founded in cases with CS1, CS2 and part of CS3 in the extended radical operation group.

CONCLUSION: The extended radical operation appears to benefit patients with pancreatic head carcinoma which was indicated in CS1, CS2 and part of CS3 without severe invasion.

Recurrence after resection for ductal adenocarcinoma of the pancreas

We analyzed the pattern of failure and clinicopathologic factors influencing the disease-free survival of 78 patients who died after macroscopic curative resection for pancreatic cancer. Local recurrence was a component of failure in 56 patients (71.8%) and hepatic recurrence in 48 (61.5%), both accounting for 97% of the total recurrence rate. About 95% of recurrences occurred by 24 months after operation. Median disease-free survival time was 8 months, and cumulative 1-, 3-, and 5-year actuarial disease-free survival rates were 66%, 7%, and 3%, respectively. Multivariate analysis showed that tumor grade (p = 0.04), microscopic radicality of resection (p = 0.04), lymph node status (p = 0.01), and size of the tumor (p = 0.005) were independent predictors of disease-free survival. Patterns of failure and disease-free survival were not statistically influenced by the type of surgical procedure performed. Median survival time from the detection of recurrence until death was 7 months for local recurrence versus 3 months for hepatic or local plus hepatic recurrence (p < 0.05). From our experience and the data collected from the literature, it appears that surgery alone is an inadequate treatment for cure in patients with pancreatic carcinoma. Effective adjuvant therapies are needed to improve locoregional control of pancreatic cancer after surgical resection.

Surgical concepts for therapy of pancreatic neoplasms

Surgical treatment of pancreatic malignomas has improved dramatically over the past decades, which is illustrated by the decrease in perioperative mortality to 1%-2%. This has made it possible to widen the indication for pancreatic resection and the extent of the surgical intervention. Experience with pancreatic resection for neoplasms at our center using standard surgical techniques during the last decade is reviewed, with special focus on the cases with partial resection of the portal vein. Perioperative morbidity has decreased below 5% and 5-year survival rates reach 60% for stage I tumors and 15%-25% for stage II and III tumors. The authors conclude that surgical therapy for pancreatic neoplasms is safe and yields a considerably higher quality of life for the patient and therefore should be considered in all patients with this disease entity.

Curative treatment for pancreatic neoplasms. Radical resection

The available data suggest that lymph node involvement is an important prognostic factor in patients with carcinoma of the head of the pancreas. Lymph node metastases occur in as many as 50% of the cases of even the smallest pancreatic cancers now being diagnosed and resected (i.e., those < 2 cm in diameter). There is some evidence, especially from clinical experience in Japan, that wider lymphatic dissections (i.e., wider than those commonly done with the standard Whipple resection) may prolong survival. Unfortunately, many of the available data around the world are retrospective and are not randomized between the standard and the radical operation. Moreover, the pathologic material has not been staged uniformly according to accepted criteria. Thus the various series are not comparable. Comparisons between series require standardization with respect to stage of disease, pathologic classification, and treatment protocols. Before any modification of the standard pancreaticoduodenectomy is adopted, an appropriately designed study should be performed to test its efficacy. This study would also require a more comprehensive analysis of the pathologic material than is commonly performed today in the United States and Europe.

Aggressive surgery for pancreatic duct cell cancer: feasibility, validity, limitations

Pancreatic duct cell cancer is characterized by a low resectability rate and a low long-term survival rate. Between September 1974 and December 1992 in our institution, 149 (59%) of the 253 patients with this cancer underwent resection. The operative procedures were pancreatoduodenectomy in 105 patients, total pancreatectomy in 36, and distal pancreatectomy in 8. The tumor was extirpated with extensive dissection of the lymph nodes and excision of the nerve plexus in the retroperitoneum. Of the 149 patients, 79 (53%) underwent combined resection of the pancreas and the portal vein; 16 of the 79 patients also underwent resection of the adjacent arteries. Three patients died within 30 days after surgery, and 17 other patients succumbed within 2 to 7 months. The mortality among patients undergoing pancreatectomy and resection of the portal vein (9.5%) was similar to that of patients with pancreatectomy alone (10%). Curative resection was necessary for long-term survival. The 5-year survival rate in 61 patients with the curative resection was 15%. Ten patients lived more than 5 years. Even patients with lymph node metastases and cancer invasion of the portal vein had a prolonged survival. Intraoperative irradiation was carried out in 35 patients to improve the survival rate, but without success. Infusion chemotherapy with 5-fluorouracil via the portal vein was tried in 25 patients, resulting in a decrease in liver metastasis. We have made some progress in the first step toward improving treatment, although we are far from the goal and it is necessary to conduct additional trials.

Intraoperative radiation therapy following pancreaticoduodenectomy

OBJECTIVE

To determine the morbidity and mortality of pancreaticoduodenectomy followed by electron-beam intraoperative radiation therapy (EB-IORT).

SUMMARY BACKGROUND DATA

Local recurrence following pancreaticoduodenectomy occurs in 50% to 90% of patients who undergo a potentially curative surgical resection for adenocarcinoma of the pancreatic head. To improve local disease control, a more aggressive retroperitoneal dissection has been combined with adjuvant EB-IORT.

METHODS

Forty-one patients with malignant neoplasms of the periampullary region underwent pancreaticoduodenectomy followed by EB-IORT between January 1989 and May 1992. EB-IORT was delivered in a dedicated operative suite, eliminating the need for patient relocation. Electron-beam energies of 6 to 12 MeV were used to deliver 10 to 20 Gy to the treatment field following resection but before pancreatic, biliary, and gastrointestinal reconstruction.

RESULTS

Median operative time was 9 hours, blood loss was 1 L, perioperative transfusion requirement was 2 units, and hospital stay was 20 days. One patient died of a postoperative myocardial infarction, and four patients required reoperation, one for an anastomotic leak. No patient failed to receive EB-IORT because of operative complications during the time period of this study.

CONCLUSION

Adjuvant EB-IORT after pancreaticoduodenectomy can be delivered safely, with low mortality and acceptable morbidity.

Intraoperative electron beam radiation therapy (IOEBRT) for carcinoma of the exocrine pancreas

The abdominal cavities of 50 patients were explored in a specially constructed intraoperative radiotherapy operating amphitheater at the Medical College of Ohio. Twenty-six patients were treated with intraoperative and postoperative precision high dose external beam therapy, 12 with intraoperative irradiation but no external beam therapy, and 12 with palliative surgery alone. All but two patients completed the postoperative external beam radiation therapy as initially prescribed. The median survival time for patients treated with palliative surgery alone was 4 months, and that for patients treated with intraoperative radiotherapy without external beam therapy was 3.5 months. Patients undergoing intraoperative irradiation and external beam radiation therapy had a median survival time of 10.5 months. Four patients died within 30 days of surgery and two patients died of gastrointestinal hemorrhage 5 months posttreatment.