Minimally invasive pancreatic cancer surgery: What is the current evidence?

Revisiting the standards of cancer detection and therapy alongside their comparison to modern methods

In accordance with the World Health Organization data, cancer remains at the forefront of fatal diseases. An upward trend in cancer incidence and mortality has been observed globally, emphasizing that efforts in developing detection and treatment methods should continue. The diagnostic path typically begins with learning the medical history of a patient; this is followed by basic blood tests and imaging tests to indicate where cancer may be located to schedule a needle biopsy. Prompt initiation of diagnosis is crucial since delayed cancer detection entails higher costs of treatment and hospitalization. Thus, there is a need for novel cancer detection methods such as liquid biopsy, elastography, synthetic biosensors, fluorescence imaging, and reflectance confocal microscopy. Conventional therapeutic methods, although still common in clinical practice, pose many limitations and are unsatisfactory. Nowadays, there is a dynamic advancement of clinical research and the development of more precise and effective methods such as oncolytic virotherapy, exosome-based therapy, nanotechnology, dendritic cells, chimeric antigen receptors, immune checkpoint inhibitors, natural product-based therapy, tumor-treating fields, and photodynamic therapy. The present paper compares available data on conventional and modern methods of cancer detection and therapy to facilitate an understanding of this rapidly advancing field and its future directions. As evidenced, modern methods are not without drawbacks; there is still a need to develop new detection strategies and therapeutic approaches to improve sensitivity, specificity, safety, and efficacy. Nevertheless, an appropriate route has been taken, as confirmed by the approval of some modern methods by the Food and Drug Administration.

Estimation of the organ of origin of peri-ampullary malignancy by preoperative CT scan

BACKGROUND

Tumors occurring within the pancreatic head commonly arise from the pancreas, duodenal ampulla, distal bile duct, or duodenum. However, they are difficult to distinguish on standard preoperative imaging.

PURPOSE

To assess the ability of specialist reporting of preoperative computed tomography (CT) scans to determine the organ of origin of pancreatic cancer (PC).

MATERIAL AND METHODS

Blinded re-reporting of preoperative imaging from five hospitals was undertaken of a consecutive cohort of 411 patients undergoing surgery for PC between January 2006 and May 2014. Radiological identification of tumor site was determined by the presence of the main tumor bulk within the pancreatic head parenchyma and estimation of the pathological organ of origin of the PC was based on all the reported features.

RESULTS

Each pathological tumor type was noted to have distinct radiological features. Localization of a visible tumor within the pancreatic parenchyma was seen most commonly in PC (92%) than other tumor types (P < 0.0001). Local invasion into the duodenum was a characteristic feature seen in 79% of patients with ampullary tumors and isolated dilation of the bile duct without dilation of the pancreatic duct was seen most commonly in patients with ampullary or bile duct cancer. In the assessment of tumor origin, good agreement (kappa = 0.6, 0.51-0.68) was noted between the consensus radiology opinion and the final histology result. Overall accuracy was greatest for ampullary cancer (88.1%) and lowest for PC (83.2%).

CONCLUSION

Radiological assessment of preoperative imaging provides a high degree of accuracy in predicting the organ of origin of peri-ampullary cancer.

The net parenchymal thickness predicts pancreatic fistula after pancreaticoduodenectomy: a retrospective cohort study of objective data

BACKGROUND

The clinically relevant postoperative pancreatic fistula (CR-POPF) is still a challenging complication of pancreaticoduodenectomy (PD). This study aims to explore the predictors of CR-POPF after PD, including net parenchymal thickness (NPT) of pancreatic neck.

METHODS

The consecutive patients who underwent PD at a tertiary hospital were retrospectively reviewed. Univariate and multivariate analyses were conducted on the perioperative data, which was mainly extracted from the objective data, containing the results from the laboratory tests and the imaging examination. NPT refers to the total thickness of pancreatic gland excluding main pancreatic duct (MPD) at the CT film.

RESULTS

Univariate analyses showed that total serum bilirubin (TBiL) and albumin (ALB) levels, MPD size and NPT were significantly different between the patients with and without CR-POPF. The white blood cell count, the rate of intra-abdominal infection (IAI) and the postoperative length of hospital stay (LOS) were associated with the incidence of CR-POPF. The proportion of patients with pancreatic adenocarcinoma or chronic pancreatitis was significantly lower in the CR-POPF group than in the non-CR-POPF group. Multivariate analyses manifested that ALB ≤35 g/L and NPT >10 mm were two of the independent risk factors for CR-POPF.

CONCLUSION

Preoperative ALB ≤35 g/L and NPT > 10 mm were both the independent predictors of CR-POPF. CR-POPF was associated with the higher IAI rate and the extended LOS.

Use of a standardized reporting template: can we improve report quality in pancreatic and peri-ampullary malignancy?

BACKGROUND

Accurate pancreatic and periampullary cancer staging with resectability assessment is vital to optimize surgical management and improve patient outcomes. The aim of this study is to assess the usefulness of a standardized reporting template.

METHODS

Retrospective review of all surgically managed patients with pancreatic or periampullary malignancy between January 2018 and June 2019. Pre-operative CT imaging report was anonymised and audited against a modified NCCN reporting template. The same imaging studies were re-reported by two experienced GI radiologists using the same template.

RESULTS

Fifty-nine patients (37 male) with median age of 68 years (36-83) underwent surgery for suspected pancreatic/peri-ampullary malignancy. The median time between pre-operative CT scan and surgery was 56.5 days (14-225). The use of reporting template resulted in significant increase in number of reported key features (p < 0.005), interobserver agreed features (p < 0.005) and overall k-value assessed interobserver agreement (p < 0.005). Template reports correlated closely with key intraoperative findings whilst primary free text reports did not (k-value 0.85-0.96 versus 0.20-0.46, p < 0.05).

CONCLUSION

The use of a reporting template resulted in a more complete and accurate pancreatic/peri-ampullary tumour evaluation, improved inter-observer relatability and correlation with intraoperative findings.

Hypoxic pancreatic stellate cell-derived exosomal mirnas promote proliferation and invasion of pancreatic cancer through the PTEN/AKT pathway

Pancreatic stellate cells (PSCs) are important components of the tumor microenvironment in pancreatic cancer (PC) and contribute to its development and metastasis through mechanisms that remain incompletely characterized. Tumor hypoxia affects the function and behavior of PC and stromal cells, and can alter exosomal content to modify cell-cell communication. The present study explored the effects of exosomal miRNAs produced by hypoxia-preconditioned PSCs on the growth and metastatic potential of PC cells. Subcutaneous xenografts and liver metastasis mouse models revealed increased tumorigenic potential upon co-implantation of PC cells and PSCs as compared to PC cells alone. Screening miRNA profiles of mouse plasma exosomes and cultured PSCs, followed by miRNA overexpression and inhibition assays, enabled us to identify miR-4465 and miR-616-3p as prominent hypoxia-induced, PSC-derived, exosomal miRNAs promoting PC cell proliferation, migration, and invasion. Proteomics analysis of PC cells incubated with exosomes derived from hypoxic PSCs showed significant downregulation of PTEN. Dual-luciferase reporter assays and western blotting showed that both miR-4465 and miR-616-3p target PTEN and activate AKT signaling in PC cells. We conclude that hypoxia upregulates miR-4465 and miR-616-3p expression in PSC-derived exosomes. Following exosome uptake, these miRNAs promote PC progression and metastasis by suppressing the PTEN/AKT pathway.

Pancreatoduodenectomy for pancreatic head tumors in the elderly - Systematic review and meta-analysis

The age at which patients are undergoing pancreatoduodenectomy is increasing worldwide. The data on the outcome of this surgical procedure in the elderly is constantly expanding. This meta-analysis aims to assess the safety of pancreatoduodenectomy in elderly population, primarily focusing on morbidity and mortality. We searched the Medline, Embase and Cochrane databases to identify eligible studies. The most recent search was performed on 10th April 2017. Inclusion criteria were: (1) comparison of the characteristics and perioperative outcomes of older patients versus younger patients undergoing pancreatoduodenectomy; (2) objective evaluation of mortality or overall morbidity; and (3), publication in English. Exclusion criteria were: (1) a lack of comparative data; (2) a lack of primary outcomes or insufficient data to analyze; (3) a focus on procedures other than pancreatoduodenectomy; or (4), the impossibility of extraction of data specifically concerning pancreatoduodenectomy. Primary outcomes were overall morbidity and mortality. Secondary outcomes analyzed postoperative complications, R0 rate and length of hospital stay. 45 eligible studies were chosen, with a combined total of 21,295 patients. Older patients compared to younger patients had a higher risk of death (2.26% vs. 4.54%; RR: 2.23; 95% CI 1.74-2.87) and a higher complication rate (47.23% vs. 39.35%; RR: 1.17; 95% CI 1.12-1.24). There were no differences in pancreatic fistula occurrence (p = 0.27), bile leakage (p = 0.81), postoperative hemorrhage (p = 0.08), or R0 rate (p = 0.92). Our review confirms, that in the case of pancreatoduodenectomy, advanced age is a risk factor for increased non-surgical morbidity and, by extension, higher mortality.

Current status of enhanced recovery after surgery (ERAS) protocol in gastrointestinal surgery

Enhanced Recovery After Surgery (ERAS) is an evidence-based paradigm shift in perioperative care, proven to lower both recovery time and postoperative complication rates. The role of ERAS in several surgical disciplines was reviewed. In colorectal surgery, ERAS protocol is currently well established as the best care. In gastric surgery, 2014 saw an establishment of ERAS protocol for gastrectomies with resulting meta-analysis showing ERAS effectiveness. ERAS has also been shown to be beneficial in liver surgery with many centers starting implementation. The advantages of ERAS in pancreatic surgery have been strongly established, but there is still a need for large-scale, multicenter randomized trials. Barriers to implementation were analyzed, with recent studies concluding that successful implementation requires a multidisciplinary team, a willingness to change and a clear understanding of the protocol. Additionally, the difficulty in accomplishing necessary compliance to all protocol items calls for new implementation strategies. ERAS success in different patient populations was analyzed, and it was found that in the elderly population, ERAS shortened the length of hospitalization and did not lead to a higher risk of postoperative complications or readmissions. ERAS utilization in the emergency setting is possible and effective; however, certain changes to the protocol may need to be adapted. Therefore, further research is needed. There remains insufficient evidence on whether ERAS actually improves patients’ course in the long term. However, since most centers started to implement ERAS protocol less than 5 years ago, more data are expected.

PPoma Review: Epidemiology, Aetiopathogenesis, Prognosis and Treatment

Generally, pancreatic polypeptide-secreting tumor of the distal pancreas (PPoma) is classified as a rare tumor, and may occur sporadically or be associated in families or with multiple endocrine neoplasia type 1 (NEM 1). It grows slowly, reaching large dimensions at the time of diagnosis and the symptomatology is fundamentally due to the mass effect, causing either non-specific abdominal pain or symptoms suggestive of obstruction of the pancreatic or biliary duct. Therefore, when detected, they are usually malignant, with metastases mainly in the liver. The combination of serum analysis of increased levels of chromogranin A and pancreatic polypeptide and pancreastatin is very useful with a sensitivity of up to 95%. However, in addition, scintigraphicexams with somatostatin analogues should be performed to better clarify the diagnosis. Surgical resection is the treatment of choice, despite surgical difficulty and because they are generally palliative due to the metastases. Surgeries for tumor volume reduction are also performed to relieve symptoms. Chemotherapy commonly uses streptozotocin and somatostatin analogues to treat residual disease. Unfortunately, the survival rates are still very low, less than 10%, and if metastases already exist, this percentage drops to 3%.