Solid Pseudopapillary Tumor of the Pancreas: Is Enucleation Safe?

BACKGROUND

While solid pseudopapillary tumor (SPT) of the pancreas are oncologically low-risk tumors, their resection with pancreaticoduodenectomy (PD) or partial pancreatectomy (PP) carries a significant risk for morbidity. To balance the favorable prognosis with the surgical morbidity of pancreas resection, this study explores the oncologic safety of enucleation (EN).

PATIENTS AND METHODS

The National Cancer Database (NCDB) was queried for resected SPT from January 2004 through December 2020. Perioperative outcomes and survival were analyzed with Kruskal-Wallis tests, and Kaplan-Meier analysis (with log-rank test). Survival analysis was performed to compare patients with and without lymph node (LN) metastases and binary logistic regression for predictors of LN metastasis.

RESULTS

A total of 922 patients met inclusion criteria; 18 patients (2%) underwent EN, 550 (59.6%) underwent PP, and 354 (38.4%) underwent PD. Mean tumor size was 57.6 mm. Length of hospital stay was significantly shorter for EN compared with PP and PD groups (3.8 versus 6.2 versus 9.4 days, p < 0.001). There was a nonsignificant improvement in unplanned readmission [0% versus 8% versus 10.7% (p = 0.163)], 30-day mortality [0% versus 0.5% versus 0% (p = 0.359)], and 90-day mortality [0% versus 0.5% versus 0% (p = 0.363)] between EN, PP, and PD groups. Survival analyses showed no difference in OS when comparing EN versus PP (p = 0.443), and EN versus PD (p = 0317). Patients with LN metastases (p < 0.001) fared worse, and lymphovascular invasion, higher T category (T3-4) and M1 status were found as predictors for LN metastasis.

CONCLUSIONS

EN may be considered for select patients leading to favorable outcomes. Because survival was worse in the rare cohort of patients with LN metastases, the predictors for LN metastasis identified here may aid in stratifying patients to EN versus resection.

Metabolomics analysis of islet regeneration in partial pancreatectomy mice reveals increased levels of long-chain fatty acids and activated cAMP signaling pathway

Islet regeneration is a complex process involving multiple metabolic adaptions, but the specific characterization of the islet metabolome in relation to cell proliferation has not been established. This study aimed to investigate the metabolomic changes of regenerative islets from partial pancreatectomy (Ppx) mice and speculate underlying mechanisms. Islet samples were collected from C57/BL6 mice undergoing 70-80% Ppx or sham surgery, followed by analyses of glucose homeostasis, islet morphology, and untargeted metabolomics profiles using liquid chromatography-tandem mass spectrometry (LC-MS/MS). There is no difference in blood glucose and body weight between sham and Ppx mice. After surgery, the Ppx mice showed impaired glucose tolerance, increased Ki67 positive beta cells, and elevated beta-cell mass. LC-MS/MS analysis identified fourteen differentially changed metabolites in islets of Ppx mice, including long-chain fatty acids (e.g., docosahexaenoic acid) and amino acid derivatives (e.g., creatine). Pathway analysis based on the KEGG database revealed five significantly enriched signaling pathways including cAMP signaling pathway. Further immunostaining assay on pancreatic tissue sections showed the levels of p-CREB, a transcription factor downstream of cAMP, elevated in islets from Ppx mice. In conclusion, our results demonstrate that islet regeneration involves metabolic alterations in long-chain fatty acids and amino acid derivatives, as well as the activation of the cAMP signaling pathway.

Prevalence and Risk Factors for Pancreatic Insufficiency After Partial Pancreatectomy

BACKGROUND

This study aimed to determine the rate, timing, and predictors of diabetes and exocrine pancreatic insufficiency after pancreatectomy in order to inform preoperative patient counseling and risk management strategies.

METHODS

Using prescription claims as a surrogate for disease prevalence, IBM Watson Health MarketScan was queried for claims patterns pre- and post-pancreatectomy. Multivariable models explored associations between clinical characteristics and medication use within 2 years of surgery.

RESULTS

In total, 18.96% of 2,848 pancreaticoduodenectomy (PD) patients and 18.95% of 1,858 distal pancreatectomy (DP) patients had preoperative diabetic medication prescription claims. Fewer (6.6% and 3.88%, respectively) had pancreatic enzyme replacement therapy (PERT) claims. Diabetic medication claims increased to 28.69% after PD and 38.59% after DP [adjusted relative risk (aRR) = 1.36 (95% CI 1.27, 1.46)]. Other associated factors included age > 45, medical comorbidity, and obesity. The incidence of new diabetic medication claims among medication naïve patients was 13.78% for PD and 24.7% for DP (p < 0.001) with a median 4.7 and 4.9 months post-operatively. The prevalence of PERT claims was 55.97% after PD and 17.06% after DP [aRR = 0.32 (0.29, 0.36)]. The incidence of postoperative PERT claims 53.98% (PD) and 14.84% (DP) (p < 0.0001). The median time to new PERT claim was 3.0 (PD) and 3.2 (DP) months, respectively. Claims for both diabetic medications and PERT rose sharply after surgery and plateaued within 6 months.

CONCLUSIONS

This study defines prevalence, timing, and predictors for post-pancreatectomy insufficiency to inform preoperative counseling, risk modification strategies, and interventions related to quality of life.

Mesenchymal stem cells promote pancreatic β-cell regeneration through downregulation of FoxO1 pathway

Background

Mesenchymal stem cells (MSC) are non-haematopoietic, fibroblast-like multipotent stromal cells. In the injured pancreas, these cells are assumed to secrete growth factors and immunomodulatory molecules, which facilitate the regeneration of pre-existing β-cells. However, when MSC are delivered intravenously, their majority is entrapped in the lungs and does not reach the pancreas. Therefore, the aim of this investigation was to compare the regenerative support of hTERT-MSC (human telomerase reverse transcriptase mesenchymal stem cells) via intrapancreatic (IPR) and intravenous route (IVR).

Methods

hTERT-MSC were administered by IPR and IVR to 50% pancreatectomized NMRI nude mice. After eight days, blood glucose level, body weight, and residual pancreatic weight were measured. Proliferating pancreatic β-cells were labelled and identified with bromodeoxyuridine (BrdU) in vivo. The number of residual islets and the frequency of proliferating β-cells were compared in different groups with sequential pancreatic sections. The pancreatic insulin content was evaluated by enzyme-linked immunosorbent assay (ELISA) and the presence of hTERT-MSC with human Alu sequence. Murine gene expression of growth factors, β-cell specific molecules and proinflammatory cytokines were inspected by real-time polymerase chain reaction (RT-PCR) and Western blot.

Results

This study evaluated the regenerative potential of the murine pancreas post-hTERT-MSC administration through the intrapancreatic (IPR) and intravenous route (IVR). Both routes of hTERT-MSC transplantation (IVR and IPR) increased the incorporation of BrdU by pancreatic β-cells compared to control. MSC induced epidermal growth factor (EGF) expression and inhibited proinflammatory cytokines (IFN-γ and TNF-α). FOXA2 and PDX-1 characteristics for pancreatic progenitor cells were activated via AKT/ PDX-1/ FoxO1 signalling pathway.

Conclusion

The infusion of hTERT-MSC after partial pancreatectomy (Px) through the IVR and IPR facilitated the proliferation of autochthonous pancreatic β-cells and provided evidence for a regenerative influence of MSC on the endocrine pancreas. Moderate benefit of IPR over IVR was observed which could be a new treatment option for preventing diabetes mellitus after pancreas surgery.

Supplementary information

The online version contains supplementary material available at at 10.1186/s13287-020-02007-9.

Characteristics of patients who developed glucose intolerance in the early period after partial pancreatectomy

Background

New-onset diabetes mellitus (DM) often develops after partial pancreatectomy. Little is known regarding how soon patients develop glucose intolerance after partial pancreatectomy. We investigated the incidence of and factors contributing to the development of glucose intolerance during hospitalization after partial pancreatectomy.

Patients and methods

We retrospectively analyzed the cases of 38 patients with normal glucose tolerance pre-surgery who underwent a partial pancreatectomy (pancreaticoduodenectomy, n = 23; distal pancreatectomy, n = 15). The patients' glucose tolerance and insulin secretory/sensitivity values were determined by a normal meal tolerance test (NMTT) within 2 months post-surgery during their hospitalization.

Results

The post-surgery NMTT values revealed that 11 (28.9%) patients developed new-onset impaired glucose tolerance (the IGT group); the other 27 (71.1%) patients maintained normal glucose tolerance (the NGT group). The pre-operative hemoglobin A1c (HbA1c) levels were significantly higher in the IGT group (5.84%) versus the NGT group (5.58%, p = 0.034). There were no significant between-group differences in age, sex ratio, body mass index, the ratio of operative procedure (either pancreaticoduodenectomy or distal pancreatectomy), or post-operative insulin secretory values including the fasting/postprandial C-peptide index. The IGT group showed significantly higher insulin resistance assessed by the homeostasis model assessment of insulin resistance (HOMA-IR) versus the NGT group (1.52 ± 0.67 vs. 0.65 ± 0.42, p < 0.001).

Conclusion

After undergoing a partial pancreatectomy, approximately 30% of the patients developed glucose intolerance during the hospitalized period. Our findings indicate that pre-operative HbA1c and post-operative HOMA-IR values can be associated with developing glucose intolerance just after partial pancreatectomy.

Nationwide Outcome of Gastrectomy with En-Bloc Partial Pancreatectomy for Gastric Cancer

BACKGROUND

Radical gastrectomy is the cornerstone of the treatment of gastric cancer. For tumors invading the pancreas, en-bloc partial pancreatectomy may be needed for a radical resection. The aim of this study was to evaluate the outcome of gastrectomies with partial pancreatectomy for gastric cancer.

METHODS

Patients who underwent gastrectomy with or without partial pancreatectomy for gastric or gastro-oesophageal junction cancer between 2011 and 2015 were selected from the Dutch Upper GI Cancer Audit (DUCA). Outcomes were resection margin (pR0) and Clavien-Dindo grade ≥ III postoperative complications and survival. The association between partial pancreatectomy and postoperative complications was analyzed with multivariable logistic regression. Overall survival of patients with partial pancreatectomy was estimated using the Kaplan-Meier method.

RESULTS

Of 1966 patients that underwent gastrectomy, 55 patients (2.8%) underwent en-bloc partial pancreatectomy. A pR0 resection was achieved in 45 of 55 patients (82% versus 85% in the group without additional resection, P = 0.82). Clavien-Dindo grade ≥ III complications occurred in 21 of 55 patients (38% versus 17%, P < 0.001). Median overall survival [95% confidence interval] was 15 [6.8-23.2] months. For patients with and without perioperative systemic therapy, median survival was 20 [12.3-27.7] and 10 [5.7-14.3] months, and for patients with pR0 and pR1 resection, it was 20 [11.8-28.3] and 5 [2.4-7.6] months, respectively.

CONCLUSIONS

Gastrectomy with partial pancreatectomy is not only associated with a pR0 resection rate of 82% but also with increased postoperative morbidity. It should only be performed if a pR0 resection is feasible.

Pancreatic desmoid tumor: A rare case with radiologic-pathologic correlation

A 39-year-old female patient was referred to our tertiary oncologic center for additional investigations relating to a suspect pancreatic tail lesion. An abdominal computed tomography scan and magnetic resonance imaging scan showed a solid lesion demonstrating progressive enhancement. Complete resection was obtained and the final diagnosis was that of a desmoid tumor of the pancreas, an exceptionally rare tumor demonstrating overlap with other solid and cystic lesions of the pancreas [1]. Therefore, it is important to recognize the essential role of pathology, particularly immunohistochemistry, in identifying this tumor. The high rate of postsurgical recurrence should prompt repeated follow-ups considering the potential aggressive nature of desmoid tumors.