Mesopancreatic excision for pancreatic ductal adenocarcinoma improves local disease control and survival

[Relevance of frozen section diagnostics in pancreatic surgery]

Frozen sections are performed in pancreatic surgery for three reasons: histopathological confirmation of previously unclear space-occupying lesions, determination of the extent of surgical resection in an operative exploration and for possible follow-up resections after previously carried out surgical resections. Overall, in the literature there are heterogeneous data with respect to an improvement in the prognosis of a secondary R0 resection by a repeat resection in comparison to a R1 resection. Nowadays, extended pancreatic resections including vascular resections are technically feasible and safe. Nevertheless, with respect to the precise radicality in the surgical procedure, all patient characteristics should be taken into consideration in addition to the histopathological diagnosis of the frozen sections.

Most oncological pancreas resections must consider the mesopancreas

BACKGROUND

In preoperative staging for patients with a ductal adenocarcinoma of the pancreatic head (PDAC), resectability is anatomically characterized by the possible clearance of the medial vascular grove. Borderline resectable PDAC patients who retain an increased risk of infiltration to the portomesenteric system and/or arterial vasculate are candidates for neoadjuvant therapy. However, redefined pathological analysis revealed the dorsal resection margin to be similar at risk for R1 resection. Mesopancreatic excision (MPE) aims to secure the integrity of the dorsal and ventral resection margins. The existence of the mesopancreas (MP) is inevitable, since the pancreas is of a secondary retroperitoneal nature and the dorsal as well as ventral fascial coverings define the peripancreatic compartment anatomy. It remains unknown if the MP area is only infiltrated in high-risk PDAC patients or if MPE during pancreatoduodenectomy should be employed for localized PDAC patients as well.

METHODS

Patients who underwent upfront pancreatoduodenectomy were included. CRM evaluation and analysis of the MP was standardized in all patients. Patients were sub-grouped by the infiltration status of the vascular groove (localized disease: LOC). In LOC patients there was evidently no cancerous infiltration into the medial vascular groove (true + primary resectable).

RESULTS

Two hundred eighty-four consecutive patients who underwent pancreatoduodenectomy were included (169 LOC patients). In LOC patients the MP infiltration rate remained high but was significantly lower when compared to advanced PDAC patients (MP + 69.2% vs. 83.5%, p = 0.005). In LOC patients, CRM resection status of the dorsal resection status remained significantly affected by the MP infiltration status (R0CRM- 80.5% vs. 62.8%, p = 0.019).

CONCLUSION

These important findings clearly show underestimated tumor extensions into the mesopancreas even in localized, primary resectable PDAC patients who are currently amenable for upfront resection. Synergistically to total mesorectal or mesocolic excision, which is applied to all stages of colorectal disease, MPE is justified in primary resectable patients as well. Therefore, MPE should be employed in all PDAC patients. Since the infiltration status of the mesopancreas was a significant factor for incomplete resection in primary resectable PDAC patients, neoadjuvant treatment options for must be discussed.

Impact of overweight on patients undergoing laparoscopic pancreaticoduodenectomy: analysis of surgical outcomes in a high-volume center

BACKGROUND

The feasibility and safety of laparoscopic pancreaticoduodenectomy (LPD) in overweight patients is still controversial. This study was designed to analyze the impact of overweight on surgical outcomes in patients undergoing LPD.

METHODS

Data from patients who underwent LPD between January 2018 and July 2022 were analyzed retrospectively. A 1:1 propensity score-matching (PSM) analysis was performed to minimize bias between groups.

RESULTS

A total of 432 patients were enrolled, with a normal weight group (n = 241) and an overweight group (n = 191). After matching, 144 patients were enrolled in each group. The results showed that the incidence of clinically relevant postoperative pancreatic fistula (CR-POPF) and delayed gastric emptying (DGE) was significantly higher in the overweight group compared to the normal weight group (P = 0.036). However, there were no significant differences in perioperative mortality (1.4% vs. 2.1%, P = 0.652) and long-term survival outcomes between malignancy patients with different body mass index (BMI) before and after PSM (all P > 0.05).

CONCLUSIONS

It is safe and feasible for overweight patients to undergo LPD with mortality and long-term survival outcomes comparable to the normal weight group. High-quality prospective randomized controlled trials are still needed.

Prognostic value of the CRM-status in pancreatic ductal adenocarcinoma - data from a regional cancer registry

BACKGROUND

Ductal pancreatic adenocarcinoma (PDAC) still has a dismal prognosis even when deemed resectable. A cancer free resection margin (R0) is associated with a more favourable prognosis than the presence of tumour cells at resection margin (R1). However, the precise definition of the R0 status is still a matter of debate in PDAC. For a more accurate determination of R0 in PDAC the concept of circumferential resection margins (CRM) has been established and has been incorporated into the German national S3 guideline on exocrine pancreatic cancer. However, an international standardized nomenclature of CRM is still missing, and the clinical value of the CRM concept is not yet fully established. Here we evaluate whether the CRM status as defined in the national German S3 guideline corresponds with overall and progression free survival in PDAC using data from the regional cancer registry of the State of Baden Württemberg in Germany.

METHODS

Data from the cancer registry of the State of Baden-Württemberg, Germany, were used to assess the relationship between CRM-status and progression free survival (PFS) as well as 3-year overall survival (OS) using documented patients diagnosed with resectable ductal adenocarcinoma of the pancreas between 2015 and 2020. Patients were residents of the State of Baden-Württemberg and underwent surgery for PDAC. The R-status was assessed according to the national German S3 guideline with R0 wide/CRM- when CRM is > 1 mm from the tumour, R0 narrow/CRM + when CRM is ≤ 1 mm from the tumour and R1 when tumour cells are found at the resection margin.

RESULTS

In total we identified 1098 cases surgically treated for pancreatic cancer and fulfilling the inclusion criteria. 340 patients had an R0 wide/CRM- resection, 410 patients an R0 narrow/CRM + resection, and 348 patients an R1 resection. The R0 wide/CRM- status was associated with a significantly increased median OS rate compared to the other two groups (51,5%, 37,4% and 26,7% for R0 wide/CRM-, R0 narrow/CRM + and R1, respectively). mPFS was also longer in the R0 wide/CRM- group. These findings were robust with regards to grading and tumour location.

CONCLUSIONS

CRM is prognostic for patients with resectable PDAC making the pathological assessment of the R-status according to the CRM concept worthwhile.

Comparative study of short-and long-term results in patients with perihilar cholangiocarcinoma undergoing surgical resection: does the extent and side of resection really affect outcome?

BACKGROUND

The surgical management of perihilar carcinoma (pCCA) is still subject of ongoing debate. To provide more clarity, this study was conducted to evaluate outcomes related to the side and extent of heatectomy in patients with pCAA.

METHODS

A total of 32 patients with curative resection for pCCA were identified from our prospective database. Short-and long-term clinical outcome data and histopathological results were compared between right-sided (R-H) and left-sided (L-H) hepatectomy.

RESULTS

Nine patients (28.13%) underwent left-sided hepatectomy while a right-sided hepatectomy was accomplished in 23 patients (71.87%). In the R-H group hepatic conditioning of the future liver remnant (FLR) prior to extended resection was necessary in 13 cases (56.52%), and simultaneous pancreaticoduodenectomy was performed in 5 patients (21.74%). The arterial and portal venous reconstruction rates were 17.39% and 11.11% (P=1.00), and 60.87% and 33.33% (P=0.243) in the R-H and L-H groups, respectively. No statistically significant differences in short-term morbidity and mortality between both groups were observed. The rate of R0 resections was comparable (R-H: 78.26% versus L-H: 66.67%; P=0.654) resulting in similar long-term overall and disease-free survival rates after right-and left hepatectomy.

CONCLUSIONS

In patients with pCCA, both right- and left-sided resections appear to be safe and feasible options with similar postoperative morbidity and oncologic outcomes. Consecutively, the ideal surgical approach should be patient-tailored based on anatomical considerations and the functional future liver capacity.

Defining distal splenopancreatectomy by the mesopancreas

BACKGROUND

The implementation of the pathologic CRM (circumferential resection margin) staging system for pancreatic head ductal adenocarcinomas (hPDAC) resulted in a dramatic increase of R1 resections at the dorsal resection margin, presumably because of the high rate of mesopancreatic fat (MP) infiltration. Therefore, mesopancreatic excision (MPE) during pancreatoduodenectomy has recently been promoted and has demonstrated better local disease control, fueling the discussion of neoadjuvant downsizing regimes in MP + patients. However, it is unknown to what extent the MP is infiltrated in patients with distal pancreatic (tail/body) carcinomas (dPDAC). It is also unknown if the MP infiltration status affects surgical margin control in distal pancreatectomy (DP). The aim of our study was to histopathologically analyze MP infiltration and elucidate the influence of resection margin clearance on recurrence and survival in patients with dPDAC. Furthermore, the results were compared to a collective receiving MPE for hPDAC.

METHOD

Clinicopathological and survival parameters of 295 consecutive patients who underwent surgery for PDAC (n = 63 dPDAC and n = 232 hPDAC) were evaluated. The CRM evaluation was performed in a standardized fashion and the specimens were examined according to the Leeds pathology protocol (LEEPP). The MP area was histopathologically evaluated for cancerous infiltration.

RESULTS

In 75.4% of dPDAC patients the MP fat was infiltrated by vital tumor cells. The rates of MP infiltration and R0CRM- resections were similar between dPDAC and hPDAC patients (p = 0.497 and 0.453 respectively). MP- infiltration status did not correlate with CRM implemented resection status in dPDAC patients (p = 0.348). In overall survival analysis, resection status and MP status remained prognostic factors for survival. In follow up analysis. surgical margin clearance in dPDAC patients was associated with a significant improvement in local recurrence rates (5.2% in R0CRM- resected vs. 33.3 in R1/R0CRM + resected, p = 0.002).

CONCLUSION

While resection margin status was not affected by the MP status in dPDAC patients, the high MP infiltration rate, as well as improved survival in MP- dPDAC patients after R0CRM- resection, justify mesopancreatic excision during splenopancreatectomy. Larger scale studies are urgently needed to validate our results and to study the effect on neoadjuvant treatment in dPDAC patients.

Undifferentiated sarcomatoid carcinoma of the pancreas-a single-institution experience with 23 cases

BACKGROUND

The clinical course and surgical outcomes of undifferentiated sarcomatoid carcinoma of the pancreas (USCP) remain poorly characterized owing to its rarity. This study aimed to describe the histology, clinicopathologic features, perioperative outcomes, and overall survival (OS) of 23 resected USCP patients.

METHODS

We retrospectively described the histology, clinicopathologic features, perioperative outcomes and OS of patients who underwent pancreatectomy with a final diagnosis of USCP in a single institution.

RESULTS

A total of 23 patients were included in this study. Twelve patients were male, the median age at diagnosis was 61.5 ± 13.0 years (range: 35-89). Patients with USCP had no specific symptoms and characteristic imaging findings. The R0 resection was achieved in 21 cases. The En bloc resection and reconstruction of mesenteric-portal axis was undertaken in 9 patients. There were no deaths attributed to perioperative complications in this study. The intraoperative tumor-draining lymph nodes (TDLNs) dissection was undergone in 14 patients. The 1-, 3- and 5-year survival rates were 43.5%, 4.8% and 4.8% in the whole study, the median survival was 9.0 months. Only 1 patient had survived more than 5 years and was still alive at last follow-up. The presence of distant metastasis (p = 0.004) and the presence of pathologically confirmed mesenteric-portal axis invasion (p = 0.007) was independently associated with poor OS.

CONCLUSIONS

USCP was a rare subgroup of pancreatic malignancies with a bleak prognosis. To make a diagnose of USCP by imaging was quite difficult because of the absence of specific manifestations. Accurate diagnosis depended on pathological biopsy, and the IHC profile of USCP was mainly characterized by co-expression of epithelial and mesenchymal markers. A large proportion of patients have an early demise, especially for patients with distant metastasis and pathologically confirmed mesenteric-portal axis invasion. Long-term survival after radical resection of USCPs remains rare.

[Histopathologic diagnosis of solid and cystic pancreatic lesions with a focus on ductal adenocarcinoma : A vademecum for daily practice]

Pancreas pathology is constantly evolving and can present various challenges for pathologists. This paper is focused on providing helpful hints for daily routine diagnostics. During histopathological analysis of pancreas biopsies, pancreatic ductal adenocarcinoma must be distinguished not only from other solid neoplasms, but especially from its mimicker, autoimmune pancreatitis. This can be achieved by a systematic workup following clear diagnostic criteria. When analyzing samples from cystic pancreatic lesions, mucin-producing neoplasms must be detected due to their role as pancreatic cancer precursors; molecular analyses can help considerably with their detection and distinction. During frozen section examination, evaluation of the pancreatic neck margin and analysis of unclear lesions of the liver are two important tasks, which are explained further in this article. A special challenge is the evaluation of neoadjuvant treated pancreatic cancer, which requires a detailed macroscopic and microscopic workup. Finally, current advances in precision oncology and emerging approaches for pancreatic cancer within this field are discussed. With the advancement of technical possibilities and their increasingly broad implementation, the classification systems in pancreatic pathology will continue to gain in complexity, but also in accuracy.

A comparative study of the "superior mesenteric artery first" approach versus the conventional approach in short-term and long-term outcomes in patients with pancreatic ductal adenocarcinoma undergoing laparoscopic pancreaticoduodenectomy

BACKGROUND

The use of laparoscopic pancreaticoduodenectomy (LPD) in pancreatic head cancer remains controversial, and an appropriate surgical approach can help improve perioperative safety and oncological outcomes. This study aimed to assess the short-term outcomes and long-term survival of the superior mesenteric artery first (SMA-first) approach in patients with pancreatic ductal adenocarcinoma (PDAC) undergoing LPD.

METHODS

The data of 91 consecutive PDAC patients who underwent LPD from June 2014 to June 2021 were retrospectively analyzed. Patients were divided into two groups, the modified SMA-first approach group, using a combined posterior and anterior approach, and the conventional approach group. Perioperative outcomes, pathologic results, and overall survival (OS) were compared between groups, and propensity score-matched (PSM) analysis was performed.

RESULTS

The number of lymph nodes harvested was greater in the SMA-first approach group (19 vs. 15, P = 0.021), as did the results in the matched cohort (21 vs. 15, P = 0.046). No significant difference was observed in the R0 resection rate (93.3% vs. 82.6%, P = 0.197), but the involvement of the SMA margin was indeed lower in the SMA-first approach group (0 vs. 13%). There were no obvious variances between the two groups in terms of intraoperative bleeding, operative time, overall and major postoperative complication rates, and mortality in either the original cohort or matched cohort. The median OS was 21.8 months in the SMA-first group, whereas it was 19.8 months in the conventional group (P = 0.900). Survival also did not differ in the matched cohort (P = 0.558). TNM stage, resection margin, overall complications, and adjuvant therapy were independent risk factors affecting OS.

CONCLUSION

The modified SMA-first approach is safe and feasible for PDAC patients undergoing LPD. It had a slight advantage in specimen quality, but OS was not significantly prolonged.

A neoadjuvant therapy compatible prognostic staging for resected pancreatic ductal adenocarcinoma

OBJECTIVE

To improve prediction, the AJCC staging system was revised to be consistent with upfront surgery (UFS) and neoadjuvant therapy (NAT) for PDAC.

BACKGROUND

The AJCC staging system was designed for patients who have had UFS for PDAC, and it has limited predictive power for patients receiving NAT.

METHODS

We examined 146 PDAC patients who had resection after NAT and 1771 who had UFS at Changhai Hospital between 2012 and 2021. The clinicopathological factors were identified using Cox proportional regression analysis, and the Neoadjuvant Therapy Compatible Prognostic (NATCP) staging was developed based on these variables. Validation was carried out in the prospective NAT cohort and the SEER database. The staging approach was compared to the AJCC staging system regarding predictive accuracy.

RESULTS

The NAT cohort's multivariate analysis showed that tumor differentiation and the number of positive lymph nodes independently predicted OS. The NATCP staging simplified the AJCC stages, added tumor differentiation, and restaged the disease based on the Kaplan-Meier curve survival differences. The median OS for NATCP stages IA, IB, II, and III was 31.7 months, 25.0 months, and 15.8 months in the NAT cohort and 30.1 months, 22.8 months, 18.3 months, and 14.1 months in the UFS cohort. Compared to the AJCC staging method, the NATCP staging system performed better and was verified in the validation cohort.

CONCLUSIONS

Regardless of the use of NAT, NATCP staging demonstrated greater predictive abilities than the existing AJCC staging approach for resected PDAC and may facilitate clinical decision-making based on accurate prediction of patients' OS.

Patients with Chronic Liver Disease under Surveillance for Hepatocellular Carcinoma Have a Favorable Long-Term Outcome for Pancreatic Cancer Due to Early Diagnosis and High Resection Rate

Patients with viral hepatitis-related chronic liver disease (CLD) under surveillance for hepatocellular carcinoma (HCC) are often diagnosed with pancreatic cancer (PC) at an early stage. However, the long-term outcomes of these patients are unclear. We aimed to clarify the long-term outcomes of patients with PC with viral hepatitis-related CLD using a chart review. Data collection included the Union for International Cancer Control (UICC) stage at PC diagnosis, hepatitis B virus and hepatitis C virus status, and long-term outcomes. The distribution of the entire cohort (N = 552) was as follows: early stage (UICC 0-IB; n = 52, 9.5%) and non-early stages (UICC IIA-IV; n = 500, 90.5%). At diagnosis, the HCC surveillance group (n = 18) had more patients in the early stages than the non-surveillance group (n = 534) (50% vs. 8.0%), leading to a higher indication rate for surgical resection (72.2% vs. 29.8%) and a longer median survival time (19.0 months vs. 9.9 months). We confirmed that patients with viral hepatitis-related CLD under HCC surveillance were diagnosed with PC at an early stage. Because of the higher indication rate for surgical resection in these patients, they had favorable long-term outcomes for PC.

Stage II Pancreatic Adenocarcinoma after Endovascular Repair of Abdominal Aortic Aneurysm: A Case Report and Literature Review

BACKGROUNDS

Concomitant abdominal aortic aneurysms (AAA) and gastrointestinal malignancies are uncommon. Endovascular repair (EVAR) is widely used to treat AAA. However, no consensus exists on the optimal strategy for treating AAA when associated with pancreatic adenocarcinoma. In addition, only few reports of pancreaticoduodenectomy (PD) after EVAR exist.

PRESENTATION OF CASE

A pancreatic tumor was detected during follow-up after EVAR for AAA in an 83-year-old female patient. The diagnosis was high-grade intraepithelial neoplasia. Modified pylorus-preserving pancreaticoduodenectomy was safely performed. The patient recovered moderately and was discharged two weeks after surgery. The pathological diagnosis was middle-grade pancreatic ductal adenocarcinoma. The patient survived for 24 months with no recurrence or cardiovascular complications.

CONCLUSIONS

Conducting periodic follow-ups after AAA surgery is helpful for the early discovery of gastrointestinal tumors. EVAR surgery is safe and feasible and thus recommended for AAA patients with pancreatic cancer, although it may increase the risk of cancer. The stage of malignancy and post-EVAR medical history can be valuable in evaluating the benefits of pancreatic surgery for such cases.

Combined CT and serum CA19-9 for stratifying risk for progression in patients with locally advanced pancreatic cancer receiving intraoperative radiotherapy

Background and purpose

The aim of this study was to evaluate the significance of baseline computed tomography (CT) imaging features and carbohydrate antigen 19-9 (CA19-9) in predicting prognosis of locally advanced pancreatic cancer (LAPC) receiving intraoperative radiotherapy (IORT) and to establish a progression risk nomogram that helps to identify the potential beneficiary of IORT.

Methods

A total of 88 LAPC patients with IORT as their initial treatment were enrolled retrospectively. Clinical data and CT imaging features were analyzed. Cox regression analyses were performed to identify the independent risk factors for progression-free survival (PFS) and to establish a nomogram. A risk-score was calculated by the coefficients of the regression model to stratify the risk of progression.

Results

Multivariate analyses revealed that relative enhanced value in portal-venous phase (REV-PVP), peripancreatic fat infiltration, necrosis, and CA19-9 were significantly associated with PFS (all p < 0.05). The nomogram was constructed according to the above variables and showed a good performance in predicting the risk of progression with a concordance index (C-index) of 0.779. Our nomogram stratified patients with LAPC into low- and high-risk groups with distinct differences in progression after IORT (p < 0.001).

Conclusion

The integrated nomogram would help clinicians to identify appropriate patients who might benefit from IORT before treatment and to adapt an individualized treatment strategy.

Long-Term Outcomes of Venous Resections in Pancreatic Ductal Adenocarcinoma Patients: A Nationwide Cohort Study

To investigate whether pancreatic resections (PR) for pancreatic ductal adenocarcinoma (PDAC) is associated with worse survival when resection of the superior mesenteric vein/portal vein (SMV/PV) is required.

Background

PR for PDAC with resection of the superior mesenteric vein/portal vein (SMV/PV, PR+V resection) may be associated with inferior overall survival (OS) compared with PR without the need for SMV/PV resection (PR-V). We hypothesized that PR+V results in lower OS compared with PR-V.

Method

Retrospective study using data from the nationwide Danish Pancreatic Cancer Database from 2011 to 2020. Data on patients who underwent PR for PDAC were extracted. A group of PR patients found nonresectable on exploratory laparotomy (EXP) was also included. OS was assessed using Kaplan-Meier and Cox proportional hazards models adjusting for confounders (age, sex, R-resection level, chemotherapy, comorbidities, histology T and N classification, procedure subtype as well as tumor distance to the SMV/PV).

Results

Overall, 2403 patients were identified. Six hundred two underwent exploration only (EXP group), whereas 412 underwent pancreatic resection with (PR+V group) and 1389 (PR-V) without SMV/PV resection. Five-year OS for the PR+V group was lower (20% vs 30%) compared with PR-V, although multivariate Cox proportional hazards modeling could not associate PR+V status with OS (Hazard ratio 1.11, P = 0.408).

Conclusion

When correcting for confounders, PR+V was not associated with lower OS compared with PR-V.

Clinicopathological and Prognostic Value of Survivin Expression in Surgically Resected Pancreatic Ductal Adenocarcinoma

Background: Survival after surgery for pancreatic ductal adenocarcinoma (PDAC) remains poor. Thus, novel therapeutic concepts focus on the development of targeted therapies. In this context, inhibitor of apoptosis protein (IAP) survivin is regarded as a promising oncotherapeutic target. However, its expression and prognostic value in different tumour compartments of PDAC have not been studied. Methods: Immunohistochemical analysis of survivin in different PDAC tumour compartments from 236 consecutive patients was correlated with clinicopathological variables and survival. Results: In comparison to healthy pancreatic tissue high nuclear (p < 0.001) and high cytoplasmic (p < 0.01) survivin expression became evident in the tumour centre, along the invasion front and in lymph node metastases. Cytoplasmic overexpression of survivin in tumour centres was related to the presence of distant metastasis (p = 0.016) and UICC III/IV stages (p = 0.009), while high cytoplasmic expression at the invasion front grouped with venous infiltration (p = 0.022). Increased nuclear survivin along the invasion front correlated with perineural invasion (p = 0.035). High nuclear survivin in tumour centres represented an independent prognostic factor for overall survival of pancreatic tail carcinomas (HR 13.5 95%CI (1.4−129.7)) and correlated with a limited disease-free survival in PDAC (HR 1.80 95%CI (1.04−3.12)). Conclusion: Survivin is associated with advanced disease stages and poor prognosis. Therefore, survivin will help to identify patients with aggressive tumour phenotypes that could benefit from the inclusion in clinical trials incorporating survivin inhibitors in PDAC.

Genetic Alterations Predict Long-Term Survival in Ductal Adenocarcinoma of the Pancreatic Head

Simple Summary

Pancreatic cancer is notorious for its poor prognosis. However, rare long-term survivors of pancreatic cancer exist. The aim of this study was to characterize the molecular profile of pancreatic cancer long-term survivors, to improve the stratification and management of pancreatic cancer patients in the future. Thirty-nine pancreatic cancer patients including short-term and long-term survivors were evaluated thoroughly. Their molecular profile was analyzed using panel next generation sequencing. As a result, patients with mutations commonly found in pancreatic cancer (KRAS G12D mutations and/or TP53 nonsense and splice site mutations) showed significantly worse survival. In contrast, long-term survivors of pancreatic cancer did not show the above-mentioned mutations but did show rare mutations of KRAS (Q61H/D57N). In conclusion, long-term survivors of pancreatic cancer do have a distinct molecular profile. Further studies using larger patient cohorts are warranted to confirm these results and possibly unravel rare potential targets for targeted therapy in pancreatic cancer.

Abstract

Background: Survival of patients with adenocarcinoma of the pancreas (PDAC) is poor and has remained almost unchanged over the past decades. The genomic landscape of PDAC has been characterized in recent years. The aim of this study was to identify a genetic profile as a possible predictor of prolonged survival in order to tailor therapy for PDAC patients. Methods: Panel next generation sequencing (NGS) and immunohistochemistry (IHC) were performed on paraffin-embedded tumor tissues from curatively treated PDAC patients. Tumor slides were re-evaluated with a focus on the histomorphology. Patients were subgrouped according to short and long overall (<4 years/>4 years) and disease-free (<2 years/>2 years) survival. Results: Thirty-nine patients were included in the study. Clinicopathological staging variables as well as the histomorphological subgroups were homogenously distributed between short- and long-term overall and disease-free survivors. In survival analysis, patients with the KRAS G12D mutation and patients with TP53 nonsense and splice-site mutations had a significantly worse overall survival (OS) and disease-free survival (DFS). Patients with long-term OS and DFS showed no KRAS G12D, no TP53 nonsense or splice-site mutations. Rare Q61H/D57N KRAS mutations were only found in long-term survivors. The allele frequency rate of KRAS and TP53 mutations in tumor cells was significantly higher in short-term disease-free survivors and overall survivors, respectively. Conclusions: NGS of PDAC revealed significant differences in survival outcome in a patient collective with homogenously distributed clinicopathological variables. Further multi-institutional studies are warranted to identify more long-term survivors to detect genetic differences suitable for targeted therapy.

Neoadjuvant Treatment Lowers the Risk of Mesopancreatic Fat Infiltration and Local Recurrence in Patients with Pancreatic Cancer

Simple Summary

After the implementation of an in-depth histopathological pancreas protocol, curative resection rates for pancreatic head cancers have drastically dropped. Standardized extended resections using embryo-anatomic landmarks (MPE), have recently been prooved to increase margin-negative resection rates. The mesopancreatic fat, excised during these extended resections, was infiltrated in the majority of the patients. Neoadjuvant treatment is an emerging topic of interest for pancreatic cancer patients. It remains unclear if these extended resections are still warranted in patients after neoadjuvant treatment. Neoadjuvant treatment lowered the risk for mesopancreatic fat infiltration and patients were less prone to local recurrence and margin positive resections when compared to patients after upfront surgery. However, the majority of the patients are yet diagnosed with mesopancreatic fat infiltration, justifying this extended approach synergistically with the treatment strategies for colorectal cancer.

Abstract

Background: Survival following surgical treatment of ductal adenocarcinoma of the pancreas (PDAC) remains poor. The recent implementation of the circumferential resection margin (CRM) into standard histopathological evaluation lead to a significant reduction in R0 rates. Mesopancreatic fat infiltration is present in ~80% of PDAC patients at the time of primary surgery and recently, mesopancreatic excision (MPE) was correlated to complete resection. To attain an even higher rate of R0(CRM−) resections in the future, neoadjuvant therapy in patients with a progressive disease seems a promising tool. We analyzed radiographic and histopathological treatment response and mesopancreatic tumor infiltration in patients who received neoadjuvant therapy prior to MPE. The aim of our study was to evaluate the need for MPE following neoadjuvant therapy and if multi-detector computed tomographically (MDCT) evaluated treatment response correlates with mesopancreatic (MP) infiltration. Method: Radiographic, clinicopathological and survival parameters of 27 consecutive patients who underwent neoadjuvant therapy prior to MPE were evaluated. The mesopancreatic fat tissue was histopathologically analyzed and the 1 mm-rule (CRM) was applied. Results: In the study collective, both the rate of R0 resection R0(CRM−) and the rate of mesopancreatic fat infiltration was 62.9%. Patients with MP infiltration showed a lower tumor response. Surgical resection status was dependent on MP infiltration and tumor response status. Patients with MDCT-predicted tumor response were less prone to MP infiltration. When compared to patients after upfront surgery, MP infiltration and local recurrence rate was significantly lower after neoadjuvant treatment. Conclusion: MPE remains warranted after neoadjuvant therapy. Mesopancreatic fat invasion was still evident in the majority of our patients following neoadjuvant treatment. MDCT-predicted tumor response did not exclude mesopancreatic fat infiltration.

Advances in Pancreatic Ductal Adenocarcinoma Treatment

Pancreatic Ductal Adenocarcinoma (PDAC) is one of the deadliest malignancies among all cancers. Despite curative intent, surgery and the use of standard cytotoxic chemotherapy and radiation therapy, PDAC remains treatment-resistant. In recent years, more contemporary treatment modalities such as immunotherapy via checkpoint inhibition have shown some promise in many other malignancies, yet PDAC still eludes an effective curative treatment. In investigating these phenomena, research has suggested that the significant desmoplastic and adaptive tumor microenvironment (TME) of PDAC promote the proliferation of immunosuppressive cells and act as major obstacles to treatment efficacy. In this review, we explore challenges associated with the treatment of PDAC, including its unique immunosuppressive TME. This review examines the role of surgery in PDAC, recent advances in surgical approaches and surgical optimization. We further focus on advances in immunotherapeutic approaches, including checkpoint inhibition, CD40 agonists, and discuss promising immune-based future strategies, such as therapeutic neoantigen cancer vaccines as means of overcoming the resistance mechanisms which underly the dense stroma and immune milieu of PDAC. We also explore unique signaling, TME and stromal targeting via novel small molecule inhibitors, which target KRAS, FAK, CCR2/CCR5, CXCR4, PARP and cancer-associated fibroblasts. This review also explores the most promising strategy for advancement in treatment of pancreatic cancer by reviewing contemporary combinatorial approaches in efforts to overcome the treatment refractory nature of PDAC.

Pre-Operative MDCT Staging Predicts Mesopancreatic Fat Infiltration-A Novel Marker for Neoadjuvant Treatment?

The rates of microscopic incomplete resections (R1/R0CRM+) in patients receiving standard pancreaticoduodenectomy for PDAC remain very high. One reason may be the reported high rates of mesopancreatic fat infiltration. In this large cohort study, we used available histopathological specimens of the retropancreatic fat and correlated high resolution CT-scans with the microscopic tumor infiltration of this area. We found that preoperative MDCT scans are suitable to detect cancerous infiltration of this mesopancreatic tissue and this, in turn, was a significant indicator for both incomplete surgical resection (R1/R0CRM+) and worse overall survival. These findings indicate that a neoadjuvant treatment in PDAC patients with CT-morphologically positive infiltration of the mesopancreas may result in better local control and thus improved resection rates. Mesopancreatic fat stranding should thus be considered in the decision for neoadjuvant therapy. Background: Due to the persistently high rates of R1 resections, neoadjuvant treatment and mesopancreatic excision (MPE) for ductal adenocarcinoma of the pancreatic head (hPDAC) have recently become a topic of interest. While radiographic cut-off for borderline resectability has been described, the necessary extent of surgery has not been established. It has not yet been elucidated whether pre-operative multi-detector computed tomography (MDCT) staging reliably predicts local mesopancreatic (MP) fat infiltration and tumor extension. Methods: Two hundred and forty two hPDAC patients that underwent MPE were analyzed. Radiographic re-evaluation was performed on (1) mesopancreatic fat stranding (MPS) and stranding to peripancreatic vessels, as well as (2) tumor diameter and anatomy, including contact to peripancreatic vessels (SMA, GDA, CHA, PV, SMV). Routinely resected mesopancreatic and perivascular (SMA and PV/SMV) tissue was histopathologically re-analyzed and histopathology correlated with radiographic findings. A logistic regression of survival was performed. Results: MDCT-predicted tumor diameter correlated with pathological T-stage, whereas presumed tumor contact and fat stranding to SMA and PV/SMV predicted and correlated with histological cancerous infiltration. Importantly, mesopancreatic fat stranding predicted MP cancerous infiltration. Positive MP infiltration was evident in over 78%. MPS and higher CT-predicted tumor diameter correlated with higher R1 resection rates. Patients with positive MP stranding had a significantly worse overall survival (p = 0.023). Conclusions: A detailed preoperative radiographic assessment can predict mesopancreatic infiltration and tumor morphology and should influence the decision for primary surgery, as well as the extent of surgery. To increase the rate of R0CRM- resections, MPS should be considered in the decision for neoadjuvant therapy.

Para-aortic lymph nodes and ductal adenocarcinoma of the pancreas: Distant neighbors?

BACKGROUND

Para-aortic lymph nodes in the ductal adenocarcinoma of the pancreatic head are regarded as distant metastases. Chemotherapy is considered the only treatment option if para-aortic lymph nodes metastases are detected preoperatively or intraoperatively. The role of standardized para-aortic lymph node lymphadenectomy during pancreaticoduodenectomy remains controversial. The aim of this study was to evaluate complication profiles and survival.

METHODS

All cases of ductal adenocarcinoma of the pancreatic head were evaluated from a prospectively maintained database (n = 289). Para-aortic lymph node lymphadenectomy was routinely performed in all patients with suspected ductal adenocarcinoma of the pancreatic head. Subgroup analysis was performed between patients with histologically positive (+) and negative (-) para-aortic lymph nodes. Patients receiving pancreaticoduodenectomy without para-aortic lymph node lymphadenectomy for other causes served as a control group.

RESULTS

A total of 192 patients received para-aortic lymph node lymphadenectomy, of which 41 were positive for para-aortic lymph node metastases. In 97 patients with ductal adenocarcinoma of the pancreatic head, no para-aortic lymph node lymphadenectomy was performed owing to postoperative pancreatic ductal adenocarcinoma diagnosis. Clinicopathologic data were homogenously distributed. Hospital stay and postoperative morbidity demonstrated no significant difference between the 3 subgroups. The median overall survival of 19.63 months (95% confidence interval: 14.57-24.79 months) in para-aortic lymph node- patients was not statistically different when compared with the median overall survival of 18.22 months (95% confidence interval: 12.68-23.75 months) in para-aortic lymph node + patients (log-rank test P = .223). Preoperative computed tomography was a poor predictor for para-aortic lymph node status (sensitivity = 10.3%, specificity = 97.8%).

CONCLUSION

This study represents the largest cohort receiving routine para-aortic lymph node lymphadenectomy. Extended lymphadenectomy can be performed safely and, although disease-free survival of para-aortic lymph node+ patients was significantly shorter, overall survival and postrelapse survival were on par with that of para-aortic lymph node- patients. Preoperative computed tomography indicating para-aortic lymph node metastasis should not preclude curative resection.