[Current status and prospects of neoadjuvant therapy for resectable pancreatic cancer]

Pancreatic cancer is a highly malignant tumor. About 75% of patients with pancreatic cancer who underwent radical surgical resection will still experience postoperative recurrence. Neoadjuvant therapy could improve outcomes in patients with borderline resectable pancreatic cancer,has become a consensus;however it is still controversial in resectable pancreatic cancer. Limited high-quality randomized controlled trial studies support the routine initiation of neoadjuvant therapy in resectable pancreatic cancer. With the development of new technologies, such as next-generation sequencing, liquid biopsy, imaging omics, and organoids, patients are expected to benefit from the precision screening of potential candidates for neoadjuvant therapy and individualized treatment strategy.

[The comparison of prognosis and risk factors after radical resection for pancreatic ductal adenocarcinoma between China Pancreas Data Center and SEER]

Objectives: To compare the prognosis of patients underwent radical resection for pancreatic ductal adenocarcinoma(PDAC) in Surveillance, Epidemiology, and End Results(SEER) and China Pancreas Data Center(CPDC), and to compare the prognostic factors for PDAC in both databases. Methods: The data of patients underwent radical resection for PDAC in CPDC database from January 2016 to December 2017 and SEER database from January 2014 to December 2015 were retrospectively analyzed. The prognosis of patients in both databases was analyzed by the Kaplan-Meier method, Log-rank method, and propensity score matching, and the Cox proportional hazard regression was used to analyze the independent prognosis factors for PDAC. Results: There were 1 977 cases and 2 220 cases of pancreatic cancer that underwent radical resection from CPDC and SEER, respectively. There were more male patients(60.90%,1 204/1 977) than female patients(39.10%,773/1 977) in CPDC, while nearly 1∶1 ratio(male:1 112 cases,female:1108)was observed between male and female in SEER(χ²=48.977,P<0.01). The proportion of patients under 45 years old was the smallest in both databases, and the age group with the most significant proportion was 60 to 74 years old. The ratio of patients over 75 years old in the SEER(24.28%,539/2 220) was higher than that of CPDC(7.89%,156/1 977)(χ²=202.090,P<0.01), while the proportion of patients between 45 and 59 years old in CPDC(33.69%,666/1 977) was higher than that in SEER(19.77%,439/2 220)(χ²=103.640,P<0.01). There were more pancreatic head cancers than body and tail cancers in both databases, and no statistical difference was found in tumor size between the two databases (W=2 181 502,P=0.740). More positive and examined lymph nodes were found in SEER patients (W=3 265 131,W=2 954 363,all P<0.01); and the proportion of patients who had at least 15 lymph nodes dissected was higher in SEER(63.24%,1 404/2 220)(χ²=532.130,P<0.01). There were more patients without neoadjuvant or adjuvant therapy in CPDC(57.16%,1 130/1 977) than that in SEER(24.91%,553/2 220)(χ²=451.390,P<0.01). After propensity score matching, the overall survival for CPDC was better than that for SEER(Log-rank test:χ²=4.500,P=0.034), and the median overall survival was 24 months and 23 months respectively. Cox regressional analysis showed the common independent prognosis factors in both databases were ≥75 years old, pancreatic head cancer, poorly differentiated and undifferentiated tumors, T stage, N stage(All P<0.05). Neoadjuvant or adjuvant therapy was a protective factor in both databases(CPDC:Wald=27.082;SEER:Wald=212.285, all P<0.01) and 45 to 59 years old was protective factor in the SEER database(Wald=5.212,P=0.020). Conclusions: The data in both databases have a good consistency. However, in terms of data quality, examined lymph nodes count, and neoadjuvant/adjuvant therapy rate, the CPDC differs greatly from the SEER.

[Implementation and controversies of enhanced recovery after surgery in pancreaticoduodenectomy]

The concept of enhanced recovery after surgery(ERAS) has been widely accepted and applied in clinical practice.However,as one of the most complex surgical procedures in abdominal surgery,pancreaticoduodenectomy is characterized by long operation time,high incidence rate of postoperative complications and delayed recovery,there still remain some controversies about application of ERAS approaches in perioperative managements of pancreaticoduodenectomy.Although more and more studies has revealed the safety and efficacy of ERAS approaches in pancreaticoduodenectomy,the implementation of ERAS approaches should be still individualized in clinical practice to ensure safety of the patients.

[Circulating tumor cells in pancreatic cancer patients: progression in the detection methods and clinical application]

Circulating tumor cells (CTC) disseminate from primary tumors by undergoing epithelial mesenchymal transition that allow their entry into the circulation to drive metastatic formation in pancreatic cancer patients.Technological advances in detection and characterization of CTC are conducive to the early diagnosis, differential diagnosis, monitoring disease progression and predicating the probability of canceration or the chemotherapeutic efficacy. Nowadays, detection methods of CTC can be based on immunomagnetic beads technique, cell filtration or microfluidic chips technology, but there are great differences in the sample throughput, CTC recovery rate, purity, and CTC viability among them.Owing to the dilemma in detection methods, the intrinsic relevance between the biological characteristics of CTC and clinical manifestations is still not exactly elucidated. By the improved methodology, next generation sequencing technology and exploring the technique for culturing CTC in vitro and establishing xenotransplanted tumor model in nude mice, more and more biological information will be revealed, and finally, individualized treatment is achieved.

[Diagnosis and treatment of pancreatic neuroendocrine neoplasmas in Von Hippel-Lindau syndrome]

Von Hippel-Lindau(VHL) syndrome is a rare autosomal dominant hereditary disease, and pancreas is one of the frequently involved intra-abdominal organs, including simple pancreatic cysts, pancreatic serous cystadenomas and neuroendocrine neoplasmas. Most of the VHL-related pancreatic neuroendocrine neoplasmas (VHL-pNEN)were non-functional, but they still have a tendency to be malignant. Treatment options for VHL-pNEN include regular follow-up, surgical resection, and medication therapy. When compared with sporadic pNEN, the malignant degree of VHL-pNEN is lower, with a better prognosis, so the surgical treatment should be carefully considered. The indications of surgery for VHL-pNEN include big primary lesions (≥3 cm), fast tumor doubling time (<500 days), VHL gene mutation on exon 3, malignant manifestations on imaging findings, and functional pNEN lesions. The function-preserving approach should be performed to keep the functional pancreatic parenchyma as much as possible. Even for patients with a late stage malignancy that cannot be radically resected, active medication therapy may still lead to a long-term survival.

[Surgical treatment of pancreatic cystic neoplasms: follow-up or surgical intervention]

Pancreatic cystic neoplasm(PCN) are common and increasingly detected in recent years including serous cystic neoplasms, mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, solid pseudopapillary neoplasms and cystic pancreatic neuroendocrine tumors.Some of PCN have a low risk of malignancy while others have a high risk and need interventions, even in the same type of cystic neoplasms. The management of PCN requires risk stratification for malignant potential, and clinicians should have a systematic approach for establishing a diagnosis and determining which patients require surgical treatment. Under the guidance of minimally invasive surgery, some organ preserving procedures including tumor enucleation, segmental pancreatic resection, duodenum-preserving total or subtotal pancreatic head resection, and spleen-preserving pancreatic body and tail resection are recommended for treatment of PCN. The indications for follow-up or surgical intervention for treatment of PCN patients should be mastered strictly to avoid either insufficient- or over-treatment.