R0 Versus R1 Resection Matters after Pancreaticoduodenectomy, and Less after Distal or Total Pancreatectomy for Pancreatic Cancer

Treatment of pancreatic cancer-neoadjuvant treatment in borderline resectable/locally advanced pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is currently ranked fourth place of cancer related mortality. Only a minority of 10-20% of patients with PDAC have a primarily resectable disease, while 50-60% of the patients are diagnosed with irresectable disease. A certain group of patients is defined as "borderline resectable", which is mainly relied to contact of the tumor to major abdominal vessels. For preoperative evaluation of resectability CT and MRI is commonly used. Although CT-scanning, which is the standard preoperative imaging modality, has striking limitations concerning evaluation of lymph node status as well as vessel involvement and approximately 20% of the patients are staged incorrectly. A central part of modern therapy of locally advanced or not primarily resectable PDAC is neoadjuvant therapy. Especially neoadjuvant chemotherapy according to the FOLFIRINOX protocol resulted in high resection rates of initially not resectable patients. Furthermore, treatment with FOLFIRINOX was shown to be an independent predictor of improved prognosis and resection after neoadjuvant treatment with FOLFIRINOX was associated with improved survival. Neoadjuvant treatment was able to increases the rates of R0 resection, which depicts an independent prognostic factor and FOLFIRINOX outmatched other treatment regimes (e.g., gemcitabine-based radio-chemotherapy) concerning achievement of a R0 resection. While most evidence of neoadjuvant treatment of PDAC is conferred by retrospective analysis, there is growing data from randomized controlled trials, confirming the beneficial effects of neoadjuvant therapy on the prognosis of PDAC. Thus, patients with borderline resectable and locally advanced PDAC should be evaluated for neoadjuvant treatment. If there is no progression of the disease during neoadjuvant treatment exploration with the goal of R0 resection should be performed. If possible, patients should be included in well-designed randomized controlled trials at specialized pancreatic centers.

MDCT findings predicting post-operative residual tumor and survival in patients with pancreatic cancer

OBJECTIVES

To predict residual tumor (R) classification and overall survival (OS) on preoperative MDCT in patients who underwent first-line surgery for pancreatic ductal adenocarcinoma (PDA).

METHODS

Three hundred sixteen patients with PDA who underwent MDCT and first-line surgery were included. Patients were divided into a test (n = 216) and a validation group (n = 100). The R classification was categorized into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). We assessed the correlation between the MDCT findings and the R classification. For survival analysis, we used the Kaplan-Meier estimation and Cox proportional hazard model to determine the prognostic factors for OS. Validation of the prediction models for the R classification and OS was performed using C statistics and calibration plot.

RESULTS

Peritumoral fat stranding (odds ratio (OR) 3.826), suspicious distant metastasis (OR 2.916), portal vein involvement (OR 2.795), and tumor size (OR 1.045) were independent predictors for residual tumor (p < .05). On survival analysis, common hepatic artery involvement (hazard ratio (HR) 5.656), R1/R2 stage (HR 2.476), and N1 stage (HR 1.745) were predictors of poor OS (p < .05). C statistics for prediction models for R classification and OS were 0.816 and 0.662, respectively. Calibration plots showed good predictive performance in a high probability of the R1/R2 stage or poor OS.

CONCLUSION

Preoperative MDCT is useful for predicting the R classification using the tumor size, peritumoral fat stranding, portal vein involvement, and suspicious distant metastasis, as well as for anticipating poor OS using the N1 stage, common hepatic artery involvement, and R1/R2 stage in patients with PDA.

KEY POINTS

• Thorough assessment of the involvement of common hepatic artery or portal vein and peritumoral fat stranding is warranted for predicting prognosis in patients with pancreatic ductal adenocarcinoma. • Not only encasement but also abutment of common hepatic artery or portal vein by tumor predicts poor prognosis after upfront surgery. • If residual tumor or poor overall survival is anticipated on preoperative MDCT, neoadjuvant treatment can be performed.

Systematic review of clinical prediction models for survival after surgery for resectable pancreatic cancer

BACKGROUND

As more therapeutic options for pancreatic cancer are becoming available, there is a need to improve outcome prediction to support shared decision-making. A systematic evaluation of prediction models in resectable pancreatic cancer is lacking.

METHODS

This systematic review followed the CHARMS and PRISMA guidelines. PubMed, Embase and Cochrane Library databases were searched up to 11 October 2017. Studies reporting development or validation of models predicting survival in resectable pancreatic cancer were included. Models without performance measures, reviews, abstracts or more than 10 per cent of patients not undergoing resection in postoperative models were excluded. Studies were appraised critically.

RESULTS

After screening 4403 studies, 22 (44 319 patients) were included. There were 19 model development/update studies and three validation studies, altogether concerning 21 individual models. Two studies were deemed at low risk of bias. Eight models were developed for the preoperative setting and 13 for the postoperative setting. Most frequently included parameters were differentiation grade (11 of 21 models), nodal status (8 of 21) and serum albumin (7 of 21). Treatment-related variables were included in three models. The C-statistic/area under the curve values ranged from 0·57 to 0·90. Based on study design, validation methods and the availability of web-based calculators, two models were identified as the most promising.

CONCLUSION

Although a large number of prediction models for resectable pancreatic cancer have been reported, most are at high risk of bias and have not been validated externally. This overview of prognostic factors provided practical recommendations that could help in designing easily applicable prediction models to support shared decision-making.

Correlation between appearance of the retroportal fat plane at preoperative CT and pathology findings in resected adenocarcinoma of the pancreatic head

AIM

To correlate the appearance of the retroportal fat plane at preoperative computed tomography (CT) and the pathology findings in resected adenocarcinoma of the pancreatic head (PDAC).

MATERIAL AND METHODS

Forty-eight patients with resected PDAC of the pancreatic head were included (24 men, 24 women, mean age 63 years, median BMI 24.1). All patients underwent CT <30 days before surgery. The state of the retroperitoneal resection margin and the presence of lymphatic or perineural invasion were obtained from pathology reports. CT images were reviewed independently by two radiologists for assessment of the retroportal fat plane and graded in two categories (clear/effaced). Inter-reader discrepancies were solved in consensus. Interobserver agreement was calculated and Fisher's test was used to assess the correlation between CT and pathology findings. Visceral fat areas were measured and correlated with CT findings.

RESULTS

A clear retroportal fat plane was significantly associated with a negative retroperitoneal margin at pathology with 100% specificity and PPV (p=0.0001). No association was observed between the appearance of the fat plane at CT and the presence of lymphatic or perineural invasion (p=ns). Interobserver agreement for retroportal fat plane evaluation was good (0.741). False-positive cases had a significantly lower visceral fat area than the correctly classified patients (p=0.0480).

CONCLUSIONS

A clear retroportal fat plane is significantly associated with negative retroperitoneal resection margins at pathology. The lack of visceral adipose tissue can lead to overestimation of retroportal fat plane involvement at preoperative CT.

Selecting chemotherapy for pancreatic cancer: Far away or so close?

Pancreatic cancer is a lethal disease with a very poor prognosis. In contrast to treatments for many other tumor types, cytotoxic agents are still the first-line drugs for pancreatic cancer in both the palliative and adjuvant settings. Some progress has been made in recent years, but most large phase 3 studies have not shown significant improvements in survival. Because the available drugs and regimens are limited in both type and effect, the selection of chemotherapy based on clinicopathologic characteristics may be consequential for pancreatic cancer. In the present report, we focused on 7 landmark clinical trials for pancreatic cancer. We observed that FOLFIRINOX (oxaliplatin, irinotecan, fluorouracil, and leucovorin) and NG (nab-paclitaxel and gemcitabine), 2 first-line regimens, exerted opposite effects on metastatic pancreatic cancer patients with different baseline carbohydrate antigen 19-9 (CA19-9) levels. This suggested that not only the performance status but possibly also CA19-9 levels should be considered when making a therapeutic choice for patients with advanced pancreatic cancer. Moreover, we found that patients with a diagnosis of pancreatic cancer who have undergone a surgical resection with a negative margin (R0) may benefit more from fluorouracil and/or oral prodrugs of fluorouracil-based adjuvant therapy than from gemcitabine. Conversely, gemcitabine or gemcitabine-based regimens may be more effective for patients with a positive resection margin (R1). Based on these findings, we propose flowcharts for selecting chemotherapy for both advanced and resected pancreatic cancer. Furthermore, we present possible mechanisms and interpretations underlying the selection of chemotherapy for pancreatic cancer and propose the tumor burden as a key variable in this process. Regardless of the possible bias and exact treatment selection process, this study offers an opportunity to improve patient outcomes by using agents currently used in the therapy of pancreatic cancer. Although these conclusions are based on indirect evidence, we provide insights and possibilities to drive the selection of chemotherapy for pancreatic cancer.

Pancreatic cancer: A review of clinical diagnosis, epidemiology, treatment and outcomes

This review aims to outline the most up-to-date knowledge of pancreatic adenocarcinoma risk, diagnostics, treatment and outcomes, while identifying gaps that aim to stimulate further research in this understudied malignancy. Pancreatic adenocarcinoma is a lethal condition with a rising incidence, predicted to become the second leading cause of cancer death in some regions. It often presents at an advanced stage, which contributes to poor five-year survival rates of 2%-9%, ranking firmly last amongst all cancer sites in terms of prognostic outcomes for patients. Better understanding of the risk factors and symptoms associated with this disease is essential to inform both health professionals and the general population of potential preventive and/or early detection measures. The identification of high-risk patients who could benefit from screening to detect pre-malignant conditions such as pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasms and mucinous cystic neoplasms is urgently required, however an acceptable screening test has yet to be identified. The management of pancreatic adenocarcinoma is evolving, with the introduction of new surgical techniques and medical therapies such as laparoscopic techniques and neo-adjuvant chemoradiotherapy, however this has only led to modest improvements in outcomes. The identification of novel biomarkers is desirable to move towards a precision medicine era, where pancreatic cancer therapy can be tailored to the individual patient, while unnecessary treatments that have negative consequences on quality of life could be prevented for others. Research efforts must also focus on the development of new agents and delivery systems. Overall, considerable progress is required to reduce the burden associated with pancreatic cancer. Recent, renewed efforts to fund large consortia and research into pancreatic adenocarcinoma are welcomed, but further streams will be necessary to facilitate the momentum needed to bring breakthroughs seen for other cancer sites.

Tumour origin and R1 rates in pancreatic resections: towards consilience in pathology reporting

To evaluate differences in the R1 rates of ampullary (AC), pancreatic (PC), and distal bile duct (DBD) cancers in pancreatoduodenectomies (PD) using standardised pathology assessment. Data of PD (2010-2011) analysed in accordance with the Royal College of Pathologists (UK) protocol, were retrieved. Clinicopathologic features, including frequency, topography, and mode of margin involvement in AC (n = 87), PC (n = 18), and DBD (n = 5) cancers were evaluated. The R1 rate was 7%, 67%, and 20% in the AC, PC, and DBD cancers (p < 0.001). Within the PC cohort, R1 rate was heterogeneous (chemo-naïve, 77%; post-neoadjuvant, 40%). Commonest involved margins were as follows: posterior in overall PD (35%), AC (43%), overall PC (33%), and post-neoadjuvant PC (100%); superior mesenteric artery margin in chemo-naïve PC (38%) and common bile duct margin in DBD (100%) cancers. In AC, majority (66%) of R1 were signet ring cell type. Indirect margin involvement due to tumour within lymph node, perineural sheath or lymphovascular space was observed in 26% cases, and altered R1 rate in AC, PC, and DBD cohorts by 1%, 12%, and 0%, respectively. Although not statistically significant, patients with R1 had lower disease-free survival than those with R0 (mean, 25.4 months versus 44.4 months). Tumour origin impacts R1 data in PD necessitating its accurate classification by pathologists. Indirect involvement, histology, and neoadjuvant therapy influence the R1 rate, albeit in a minority of cases. Generating cogent R1 data based on standardised pathology reporting is the foremost need of the hour.

Expanding laparoscopic pancreaticoduodenectomy to pancreatic-head and periampullary malignancy: major findings based on systematic review and meta-analysis

BACKGROUND

Laparoscopic pancreaticoduodenectomy (LPD) remains to be established as a safe and effective alternative to open pancreaticoduodenectomy (OPD) for pancreatic-head and periampullary malignancy. The purpose of this meta-analysis was to compare LPD with OPD for these malignancies regarding short-term surgical and long-term survival outcomes.

METHODS

A literature search was conducted before March 2018 to identify comparative studies in regard to outcomes of both LPD and OPD for the treatment of pancreatic-head and periampullary malignancies. Morbidity, postoperative pancreatic fistula (POPF), mortality, operative time, estimated blood loss, hospitalization, retrieved lymph nodes, and survival outcomes were compared.

RESULTS

Among eleven identified studies, 1196 underwent LPD, and 8247 were operated through OPD. The pooled data showed that LPD was associated with less morbidity (OR = 0.57, 95%CI: 0.41~ 0.78, P < 0.01), less blood loss (WMD = - 372.96 ml, 95% CI, - 507.83~ - 238.09 ml, P < 0.01), shorter hospital stays (WMD = - 197.49 ml, 95% CI, - 304.62~ - 90.37 ml, P < 0.01), and comparable POPF (OR = 0.85, 95%CI: 0.59~ 1.24, P = 0.40), and overall survival (HR = 1.03, 95%CI: 0.93~ 1.14, P = 0.54) compared to OPD. Operative time was longer in LPD (WMD = 87.68 min; 95%CI: 27.05~ 148.32, P < 0.01), whereas R0 rate tended to be higher in LPD (OR = 1.17; 95%CI: 1.00~ 1.37, P = 0.05) and there tended to be more retrieved lymph nodes in LPD (WMD = 1.15, 95%CI: -0.16~ 2.47, P = 0.08), but these differences failed to reach statistical significance.

CONCLUSIONS

LPD can be performed as safe and effective as OPD for pancreatic-head and periampullary malignancy with respect to both surgical and oncological outcomes. LPD is associated with less intraoperative blood loss and postoperative morbidity and may serve as a promising alternative to OPD in selected individuals in the future.

Surgical Outcomes of Pancreaticoduodenectomy for Pancreatic Cancer with Proximal Dorsal Jejunal Vein Involvement

BACKGROUND/PURPOSE

The proximal jejunal vein which branches from the dorsal side of the superior mesenteric vein (SMV) usually drains the inferior pancreatoduodenal veins (IPDVs) and contacts the uncinate process of the pancreas. We focused on this vein, termed the proximal dorsal jejunal vein (PDJV), and evaluated the anatomical classification of the PDJV and surgical outcomes in patients with pancreatic ductal adenocarcinoma (PDAC) with PDJV involvement (PDJVI).

METHODS

The jejunal veins that branch from the dorsal side of the SMV above the inferior border of the duodenum are defined as PDJVs. We investigated 121 patients who underwent upfront pancreaticoduodenectomy for PDAC between 2011 and 2017; PDJVs were resected in all patients. The anatomical classification of PDJV was evaluated using multidetector computed tomography. Surgical and prognostic outcomes of pancreticoduodenectomy for PDAC with PDJVI were evaluated.

RESULTS

The PDJVs were classified into seven types depending on the position of the first and second jejunal veins relative to the superior mesenteric artery. In all patients, the morbidity and mortality rates were 15.7 and 0.8%, respectively. The rates for parameters including SMV resection, presence of pathological T3-4, R0 resection, and 3-year survival were 46.2, 92.3, 92.3, and 61.1%, respectively, when there was PDJVI (n = 13). When there was no PDJVI (n = 108), the rates were 60.2, 93.5, 86.1, and 58.3%, respectively. Overall, there were no significant differences.

CONCLUSIONS

Pancreaticoduodenectomy with PDJV resection is feasible for PDAC with PDJVI and satisfactory overall survival rates are achievable. It may be necessary to reconsider the resectability of PDAC with PDJVI.