Association of radiotherapy with favorable prognosis in daily clinical practice for treatment of locally advanced and metastatic pancreatic cancer

The survival impact of palliative radiotherapy on synchronous metastatic pancreatic ductal adenocarcinoma: metastatic site can serve for radiotherapy-decision

Background: The metastatic site seems to represent a malignancy with a different biological characteristic and is an important prognostic factor in metastatic pancreatic ductal adenocarcinoma (mPDAC). Palliative radiotherapy is a therapeutic option, and usually used for pain management in the treatment of mPDAC. The real-world effect of radiotherapy on the survival outcomes of mPDAC patients might do exist and is worth exploring.

Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) was extracted to identify mPDAC diagnosed in the periods of 2010-2016. The statistical methods included Pearson's chi-square test, Log-rank test, Cox regression model and propensity score matching (PSM).

Results: Radiotherapy was able to improve the overall survival of PDAC with liver metastasis (p<0.001), but not for PDAC patients with lung (p=0.130), bone (p=0.451) and brain metastasis (p=0.226) before PSM. Radiotherapy can only a prognostic factor for PDAC liver metastasis (p=0.001) in the cox regression analysis. The survival curves provided consistent results with cox regression analysis (PDAC with liver metastasis: p=0.023, PDAC with lung metastasis: p=0.528, PDAC with bone metastasis: p=0.210, PDAC with brain metastasis: p=0.106) after PSM. We continue to divided PDAC liver patients into PDAC-liver-metastasis with and without lung, bone, and/or brain (LBB) metastasis. Finally, radiotherapy can be used as a feasible treatment to prolong the overall survival of patients with PDAC liver metastasis without LBB metastasis.

Conclusions: Radiotherapy can be used as a feasible treatment to prolong the overall survival of patients with PDAC liver metastasis without LBB metastasis.

Downregulation of OIP5-AS1 affects proNGF-induced pancreatic cancer metastasis by inhibiting p75NTR levels

We aimed to explore the mechanism by which long non-coding RNA (lncRNA) OIP5-AS1 affects proNGF (precursor nerve growth factor)-induced pancreatic cancer metastasis by targeting the miR-186-5p/NGFR axis. Bioinformatics was used to analyse whether OIP5-AS1 targets miR-186-5p/NGFR and their expression characteristics in pancreatic cancer. OIP5-AS1 and NGFR were overexpressed in pancreatic cancer, and their levels showed a significant positive correlation. Clinical trials also demonstrated that high expression of OIP5-AS1 and NGFR and low expression of miR-186-5p played a pro-cancer role in pancreatic cancer. MiR-186-5p inhibited the migration and invasion of colon cancer cells by targeting NGFR-regulated p75NTR. OIP5-AS1 regulated the action of miR-186-5p on NGFR mRNA and p75NTR by targeting miR-186-5p. Downregulation of NGFR inhibited the expression of p75NTR protein and blocked the role of proNGF in promoting the migration and invasion of pancreatic cancer cells. Animal experiments also showed that the knockdown of miR-186-5p promoted cancer via the expression of NGFR mRNA and p75NTR protein, while the downregulation of proNGF blocked the effects. OIP5-AS1, as a ceRNA, promotes the progression of pancreatic cancer by targeting miR-186-5p/NGFR and affecting the prognosis of patients, which may be related to the action of proNGF.

Postoperative Imaging and Tumor Marker Surveillance in Resected Pancreatic Cancer

Background: Pancreatic cancer is a catastrophic disease with high recurrence and death rates, even in early stages. Early detection and early treatment improve survival in many cancer types but have not yet been clearly documented to do so in pancreatic cancer. In this study, we assessed the benefit on survival resulting from different patterns of surveillance in daily practice after curative surgery of early pancreatic cancer. Methods: Patients with pancreatic ductal adenocarcinoma who had received curative surgery between January 2000 and December 2013 at our institute were retrospectively reviewed. Patients were classified into one of four groups, based on surveillance strategy: the symptom group, the imaging group, the marker group (carbohydrate antigen 19-9 and/or carcinoembryonic antigen), and the intense group (both imaging and tumor marker assessment). Overall survival (OS), relapse-free survival (RFS), and post-recurrence overall survival (PROS) were evaluated. Results: One hundred and eighty-one patients with documented recurrence or metastasis were included in our analysis. The median OS for patients in the symptom group, imaging group, marker group, and intense group were 21.4 months, 13.9 months, 20.5 months, and 16.5 months, respectively (p = 0.670). Surveillance with imaging, tumor markers, or both was not an independent risk factor for OS in univariate and multivariate analyses. There was no significant difference in median RFS (symptom group, 11.7 months; imaging group, 6.3 months; marker group, 9.3 months; intense group, 6.9 months; p = 0.259) or median PROS (symptom group, 6.9 months; imaging group, 7.5 months; marker group, 5.0 months; intense group, 7.8 months; p = 0.953) between the four groups. Multivariate analyses identified poor Eastern Cooperative Oncology Group Performance Status (ECOG PS) (≥1), primary tumor site (tail), and tumor grade (poor differentiation) were poor prognostic factors for OS. Conclusions: Surveillance with regular imaging, tumor marker, or both was not an independent risk factor for OS of pancreatic cancer patients who undergo curative tumor resection.

Prognostic value of PD-L1 overexpression for pancreatic cancer: evidence from a meta-analysis

Programmed death-ligand 1 (PD-L1) is an immune checkpoint that is often activated in cancer and plays a pivotal role in the initiation and progression of cancer. However, the clinicopathologic significance and prognostic value of PD-L1 in pancreatic cancer (PC) remains controversial. In this study, we conducted a meta-analysis to retrospectively evaluate the relationship between PD-L1 and PC. PubMed and other databases were searched for the clinical studies published up to March 21, 2017, to be included in the meta-analysis. Hazard ratios and their 95% CIs were calculated. Risk ratios (RRs) were extracted to assess the correlations between the clinicopathologic parameters and PD-L1 expression. Ten studies including 1,058 patients were included in the meta-analysis. The pooled results indicated that positive PD-L1 expression was correlated with a poor overall survival outcome in PC patients (hazard ratio =1.76, 95% CI: 1.43–2.17, P<0.00001). Interestingly, high PD-L1 expression was correlated with poor pathologic differentiation (RR =1.57, 95% CI: 1.25–1.98, P=0.0001) and neural invasion (RR =1.30, 95% CI: 1.03–1.64, P=0.03). However, there were no significant correlations between PD-L1 expression and other clinicopathologic characteristics. In summary, our meta-analysis implied that PD-L1 could serve as a negative predictor for the overall survival of PC patients, and high expression of PD-L1 was correlated with poor differentiation and neural invasion, indicating that anti-PD-L1 treatments should be evaluated in PC patients, especially in those who exhibit these two characteristics.

Association of MDM2 expression with shorter progression-free survival and overall survival in patients with advanced pancreatic cancer treated with gemcitabine-based chemotherapy

This study evaluated the prognostic roles of murine double minute 2 (MDM2) and p53 in pancreatic cancer patients treated with gemcitabine-based chemotherapy. A total of 137 advanced or recurrent adenocarcinoma patients who were treated with gemcitabine-based palliative chemotherapy were reviewed, selected from 957 patients with pancreatic malignancy between 2008 and 2013 at our hospital. Immunohistochemical staining for MDM2 and p53 with formalin-fixed, paraffin-embedded tumor tissues was independently reviewed. Nuclear or cytoplasmic expression of MDM2 and p53 was found in tumor cells of 30 (21.9%) and 71 (51.8%) patients, respectively. Patients with MDM2 expression had shorter median overall survival (OS) (3.7 vs 5.8 mo; P = .048) and median progression-free survival (PFS) (1.5 vs 2.5 mo; P < .001); by contrast, p53 expression was not correlated with OS or PFS. In the multivariate analysis, MDM2 expression (hazard ratio = 1.731; P = .025) was an independent and unfavorable prognostic factor of OS. Additionally, MDM2 expression was significantly associated with progressive disease (PD) and death (P = .015) following first-line gemcitabine-based therapy. In advanced pancreatic cancer patients, MDM2 expression is associated with shorter OS and PFS after gemcitabine-based chemotherapy.