Status of Neoadjuvant Therapy for Resectable Pancreatic Cancer

Cytological features contributing to the misclassification of pancreatic neuroendocrine tumors

INTRODUCTION

Pancreatic neuroendocrine tumors are a diverse group of malignant neoplasms of varying biological behavior, with outcomes predicted by tumor differentiation and grade. Initial diagnosis is often made by fine-needle aspiration cytology via endoscopic ultrasound of the pancreas primary. We retrospectively reviewed our institutional experience with pancreatic neuroendocrine cytology diagnosis and evaluated for tumor typing accuracy and causes of misdiagnosis.

MATERIALS AND METHODS

We searched our institutional database (1994-2012) for all pancreas fine-needle aspirations with corresponding pancreatic histology and a neuroendocrine diagnosis. Cases with discrepant cytology and histology diagnoses were reviewed for factors contributing to misclassification.

RESULTS

143 patients were identified with a neuroendocrine diagnosis either by cytology or histology. In the 129 cytology cases classified as positive/neoplastic/suspicious, tumor type was diagnosed correctly in 101 (78%) cases, incorrectly in 17 (13%), and unclassified (epithelioid neoplasm) in 11 (9%). The most common tumor classification error (7 cases) was misclassifying a neuroendocrine tumor as adenocarcinoma on cytology, which in one case led to inappropriate neoadjuvant chemotherapy. Features of neuroendocrine cytology misdiagnosed as adenocarcinoma included cell clustering and anisonucleosis. Features of non-neuroendocrine cytology misclassified as neuroendocrine included abundant acinar cells or problematic interpretation of immunohistochemical stains.

CONCLUSIONS

Cytology can accurately identify neuroendocrine differentiation in the majority of cases; nevertheless, there are potential serious pitfalls. Misclassification of a neuroendocrine tumor as adenocarcinoma or vice versa can have significant clinical impact. Clinical and radiological correlation is essential.

A single-arm, nonrandomized phase II trial of neoadjuvant gemcitabine and oxaliplatin in patients with resectable pancreas adenocarcinoma

BACKGROUND

The role for neoadjuvant systemic therapy in resectable pancreas adenocarcinoma remains undefined.

OBJECTIVE

We evaluated the efficacy of gemcitabine and oxaliplatin administered as preoperative therapy in patients with resectable pancreas adenocarcinoma.

METHODS

Eligible patients were screened using computed tomography-pancreas angiography, laparoscopy, endoscopic ultrasonography, and fine-needle aspiration cytology to identify 38 patients who received 4 cycles of neoadjuvant gemcitabine 1000 mg/m intravenously over 100 minutes and oxaliplatin 80 mg/m intravenously over 2 hours, every 2 weeks. Patients whose tumors remained resectable at restaging proceeded to operation and subsequently received 5 cycles of adjuvant gemcitabine (1000 mg/m intravenously over 30 minutes days 1, 8, and 15 every 4 weeks). The primary endpoint was 18-month overall survival and secondary endpoints included radiological, tumor marker and pathological response to neoadjuvant therapy, time to recurrence, patterns of failure, and feasibility of obtaining preoperative core biopsies.

RESULTS

Thirty-five of 38 patients (92%) completed neoadjuvant therapy. Twenty-seven patients underwent tumor resection (resectability rate 71%), of which 26 initiated adjuvant therapy for a total of 23 patients (60.5%) who completed all planned therapy. The 18-month survival was 63% (24 patients alive). The median overall survival for all 38 patients was 27.2 months (95% confidence interval: 17-NA) and the median disease-specific survival was 30.6 months (95% confidence interval: 19-NA).

CONCLUSIONS

This study met its endpoint and provided a signal suggesting that exploration of neoadjuvant systemic therapy is worthy of further investigation in resectable pancreas adenocarcinoma. Improved patient selection and more active systemic regimens are key. Clinical trials identification: NCT00536874.

Extended neoadjuvant chemotherapy for borderline resectable pancreatic cancer demonstrates promising postoperative outcomes and survival

BACKGROUND

The optimum approach to neoadjuvant therapy for patients with borderline resectable pancreatic cancer is undefined. Herein we report the outcomes of an extended neoadjuvant chemotherapy regimen in patients presenting with borderline resectable adenocarcinoma of the pancreatic head.

METHODS

Patients identified as having borderline resectable pancreatic head cancer by American Hepato-Pancreato-Biliary Association/Society of Surgical Oncology consensus criteria from 2008 to 2012 were tracked in a prospectively maintained registry. Included patients were initiated on a 24-week course of neoadjuvant chemotherapy. Medically fit patients who completed neoadjuvant treatment without radiographic progression were offered resection with curative intent. Clinicopathologic variables and surgical outcomes were collected retrospectively and analyzed.

RESULTS

Sixty-four patients with borderline resectable pancreatic cancer started neoadjuvant therapy. Thirty-nine (61 %) met resection criteria and underwent operative exploration with curative intent, and 31 (48 %) were resected. Of the resected patients, 18 (58 %) had positive lymph nodes, 15 (48 %) required en-bloc venous resection, 27 (87 %) had a R0 resection, and 3 (10 %) had a complete pathologic response. There were no postoperative deaths at 90 days, 16 % of patients had a severe complication, and the 30-day readmission rate was 10 %. The median overall survival of all 64 patients was 23.6 months, whereas that of unresectable patients was 15.4 months. Twenty-five of the resected patients (81 %) are still alive at a median follow-up of 21.6 months.

CONCLUSIONS

Extended neoadjuvant chemotherapy is well tolerated by patients with borderline resectable pancreatic head adenocarcinoma, selects a subset of patients for curative surgery with low perioperative morbidity, and is associated with favorable survival.

A systematic review and meta-analysis of survival and surgical outcomes following neoadjuvant chemoradiotherapy for pancreatic cancer

INTRODUCTION

This systematic review and meta-analysis aims to characterize the surgically important benefits and complications associated with the use of neoadjuvant chemoradiotherapy for the treatment of both resectable and initially unresectable pancreatic cancer. Studies were identified through a systematic literature search and analyzed by two independent reviewers. Survival, peri-operative complications, death rate, pancreatic fistula rate, and the incidence of involved surgical margins were analyzed and subject to meta-analysis.

METHODS

Nineteen studies, involving 2,148 patients were identified. Only cohort studies were included.

RESULTS

The meta-analysis found that patients with unresectable pancreatic cancer who underwent neoadjuvant chemoradiotherapy achieved similar survival outcomes to patients with resectable disease, even though only 40% were ultimately resected. Neoadjuvant chemoradiotherapy was not associated with a statistically significant increase in the rate of pancreatic fistula formation or total complications.

CONCLUSION

Patients receiving neoadjuvant chemoradiotherapy were less likely to have a positive resection margin, although there was an increase in the risk of peri-operative death.

A systematic review and meta-analysis of survival and surgical outcomes following neoadjuvant chemoradiotherapy for pancreatic cancer

INTRODUCTION

This systematic review and meta-analysis aims to characterize the surgically important benefits and complications associated with the use of neoadjuvant chemoradiotherapy for the treatment of both resectable and initially unresectable pancreatic cancer. Studies were identified through a systematic literature search and analyzed by two independent reviewers. Survival, peri-operative complications, death rate, pancreatic fistula rate, and the incidence of involved surgical margins were analyzed and subject to meta-analysis.

METHODS

Nineteen studies, involving 2,148 patients were identified. Only cohort studies were included.

RESULTS

The meta-analysis found that patients with unresectable pancreatic cancer who underwent neoadjuvant chemoradiotherapy achieved similar survival outcomes to patients with resectable disease, even though only 40% were ultimately resected. Neoadjuvant chemoradiotherapy was not associated with a statistically significant increase in the rate of pancreatic fistula formation or total complications.

CONCLUSION

Patients receiving neoadjuvant chemoradiotherapy were less likely to have a positive resection margin, although there was an increase in the risk of peri-operative death.

Neoadjuvant/preoperative gemcitabine for patients with localized pancreatic cancer: a meta-analysis of prospective studies

BACKGROUND

Long-term prognosis for localized pancreatic cancer remains poor. We sought to assess the benefit of neoadjuvant/preoperative chemotherapy with or without radiotherapy.

METHODS

Prospective studies where gemcitabine with or without radiotherapy was provided before surgery in patients with initially resectable or unresectable disease were reviewed by meta-analysis. Primary outcome was survival, and secondary outcomes were tumor response after therapy, toxicity, surgical exploration, and resection rates.

RESULTS

Twenty independent studies with 707 participants were included, 366 with resectable lesions and 341 with unresectable lesions. Seven studies were phase I/II trials, 10 phase II, and 3 prospective cohort studies. Estimated 1- and 2-year survival probabilities after resection were 91.7% (95% confidence interval [CI] 75-100) and 67.2% (95% CI 38-87) for initially resectable patients, and 86.3% (95% CI 78-100) and 54.2% (95% CI 25-100) for initially unresectable patients. The complete/partial response rate was 12% (95% CI 4-23) and 27% (95% CI 18-38) in resectable and unresectable lesions, respectively. The rate of treatment-related grade 3-4 toxicity was 31% (95% CI 21-42). Of resectable patients evaluable after restaging, 91% (95% CI 83-97) underwent surgery, and 82% (95% CI 65-95) of explored patients underwent resection. R0 resections amounted to 89% (95% CI 83-94). Of unresectable patients evaluable after restaging, 39% (95% CI 28-50) underwent surgery, and 68% (95% CI 53-82) of explored patients were resected, with 60% (95% CI 50-71) R0 resections.

CONCLUSIONS

Current analysis provides marginal support to the assumed benefits of neoadjuvant therapies for patients with resectable cancer, and indicates a potential advantage only for a minority of those with unresectable lesions.