Comparison of neoadjuvant therapy and upfront surgery in resectable pancreatic cancer: a meta-analysis and systematic review

Comparison of the upfront surgery and neoadjuvant therapy in resectable and borderline resectable pancreatic cancer: an updated systematic review and meta-analysis

Pancreatic cancer is a malignant disease with a dismal prognosis. While neoadjuvant therapy has shown promise in the treatment of pancreatic cancer, its role remains a subject of controversy among physicians. We aimed to evaluate the benefits of neoadjuvant therapy in patients with resectable and borderline resectable pancreatic cancer. Eligible studies were identified from MEDLINE, Embase, Cochrane Library, and Web of Science. Studies comparing neoadjuvant therapy with upfront surgery (with or without adjuvant therapy) in resectable and borderline resectable pancreatic cancer were included. The primary endpoint assessed was overall survival. A total of 10,022 studies were identified, and the meta-analysis finally enrolled 50 revealed studies. The meta-analysis suggested that neoadjuvant therapy significantly improved the overall survival (HR 0.74, p < 0.001) and recurrence-free survival (HR 0.75, p = 0.006) compared to the upfront surgery approach. Furthermore, neoadjuvant therapy leads to favorable postoperative outcomes, with an enhanced R0 resection rate (OR 1.90, p < 0.001) and reduced lymph node metastasis (OR 0.36, p < 0.001) and perineural invasion (OR 0.42, p < 0.001), although it is associated with a reduced resection rate (OR 0.42, p < 0.001). In addition, patients treated with neoadjuvant therapy experience superior survival benefits compared to those undergoing adjuvant therapy (HR 0.87, p = 0.019). These results are further corroborated by the subgroup analysis of randomized controlled trials. Neoadjuvant therapy has the potential to provide survival benefits and improve postoperative long-term outcomes for patients with resectable and borderline resectable pancreatic cancer. However, to validate and reinforce these findings, further well-designed and large trials are required.

Preoperative frailty as a predictive factor for postoperative complications in patients with pancreatic cancer

Frailty is considered one of the most important indicators of a patient's general condition. However, only a few studies have investigated the association between preoperative frailty and postoperative complications in pancreatic cancer. Therefore, this study aimed to examine this association in patients with pancreatic cancer. We retrospectively reviewed 52 consecutive patients who underwent pancreatectomy for pancreatic cancer between July 2019 and March 2021. Patients were classified into two groups according to the presence of postoperative complications. Their characteristics and clinical parameters, including physical function, were analyzed. Patients with postoperative complications had a higher prevalence of frailty (58.8% vs 14.3%, p = 0.003) and a shorter 6-min walk distance (380 m vs 436 m, p = 0.020) than those without postoperative complications. Logistic regression analysis identified preoperative frailty as the only independent risk factor for complications after pancreatectomy (p = 0.002). Preoperative frailty is associated with postoperative complications of pancreatectomy. Since preoperative frailty can be easily evaluated, it is a useful predictor of postoperative complications after pancreatectomy.

Prognostic analysis of uveal melanoma based on the characteristic genes of M2-type macrophages in the tumor microenvironment

Uveal melanoma arises from stromal melanocytes and is the most prevalent primary intraocular tumor in adults. It poses a significant diagnostic and therapeutic challenge due to its high malignancy and early onset of metastases. In recent years, there has been a growing interest in the role of diverse immune cells in tumor cell development and metastasis. Using The Cancer Genome Atlas and the gene expression omnibus databases, and the CIBERSORT method, we investigated the topography of intra-tumor immune infiltration in uveal melanoma in this research. We evaluated the prognosis of uveal melanoma patients using the M2 macrophage immune cell infiltration score in conjunction with clinical tumor patient data. We built a prognostic model based on the distinctive genes of M2 macrophages and combined it with patients' clinical data in the database; we ran a survival prognostic analysis to authenticate the model's accuracy. The functional study revealed the importance of macrophage-associated genes in the development of uveal melanoma. Moreover, the reliability of our prediction model was verified by combining tumor mutational load, immune checkpoint, and drug sensitivity, respectively. Our study provides a reference for the follow-up study of uveal melanoma.

An integrative multi-omics analysis based on disulfidptosis-related prognostic signature and distinct subtypes of clear cell renal cell carcinoma

Background

The association between clear cell renal cell carcinoma (ccRCC) and disulfidoptosis remains to be thoroughly investigated.

Methods

We conducted multiple bioinformatics analyses, including prognostic analysis and cluster analysis, using R software. Additionally, we utilized Quantitative Real-time PCR to measure RNA levels of specific genes. The proliferation of ccRCC was assessed through CCK8 and colony formation assays, while the invasion and migration of ccRCC cells were evaluated using the transwell assay.

Results

In this study, utilizing data from multiple ccRCC cohorts, we identified molecules that contribute to disulfidoptosis. We conducted a comprehensive investigation into the prognostic and immunological roles of these molecules. Among the disulfidoptosis-related metabolism genes (DMGs), LRPPRC, OXSM, GYS1, and SLC7A11 exhibited significant correlations with ccRCC patient prognosis. Based on our signature, patients in different groups displayed varying levels of immune infiltration and different mutation profiles. Furthermore, we classified patients into two clusters and identified multiple functional pathways that play important roles in the occurrence and development of ccRCC. Given its critical role in disulfidoptosis, we conducted further analysis on SLC7A11. Our results demonstrated that ccRCC cells with high expression of SLC7A11 exhibited a malignant phenotype.

Conclusions

These findings enhanced our understanding of the underlying function of DMGs in ccRCC.

Prognostic role of E2F1 gene expression in human cancer: a meta-analysis

OBJECTIVE

E2F1 has been confirmed to be highly expressed in a variety of cancers. To better understand the prognostic value of E2F1 in cancer patients, this study was conducted to comprehensively evaluate the prognostic value of E2F1 in cancer according to published data.

METHOD

PubMed, Web of Science and CNKI database were searched until May 31^th, 2022 by using key words to retrieve the published essays on the role of E2F1 expression in the prognostic value of cancer. The essays were identified according to the inclusion and exclusion criteria. The pooled result of hazard ratio and 95% confidence interval was calculated with Stata17.0 software.

RESULT

A total of 17 articles were included in this study involved in 4481 cancer patients. The pooled results showed that higher E2F1 expression was significantly correlated with unfavorable overall survival (HR = 1.10, I² = 95.3%, *P_{Heterogeneity} = 0.000) and disease-free survival (HR = 1.41, I² = 95.2%, *P_{Heterogeneity} = 0.000) of cancer patients. Such a significant association of was maintained subgroup of sample size of patients (> 150: for OS, HR = 1.77, and for DFS, HR = 0.91; or < 150: for OS, HR = 1.93, and for DFS, HR = 4.39), ethnicity (Asian: for OS, HR = 1.65, and for DFS, HR = 1.08; or not Asian: HR = 3.55, and for DFS, HR = 2.87), the data from database (clinical: for OS, HR = 1.24, and for DFS, HR = 1.40; or database: for OS, HR = 2.29, and for DFS, HR = 3.09), paper published year (after 2014: for OS, HR = 1.90;and for DFS,HR = 1.87; or before 2014: for OS, HR = 1.40, and for DFS, HR = 1.22); cancer type (female specific cancer: for OS, HR = 1.41, and for DFS, HR = 0.64; or non-gender specific cancers: for OS, HR = 2.00, and for DFS, HR = 2.95). In addition, according to the database data, we also found that higher E2F1 expression level would lead to worse prognosis of patients, and the results were consistent with the statistical analysis results in the paper.

CONCLUSION

E2F1 could be served as a prognostic biomarker in cancer patients and higher levels of in cancer patients could predict shorter overall survival and disease-free survival.

Neoadjuvant Treatment Versus Upfront Surgery in Resectable Pancreatic Cancer: A Cost-Effectiveness Analysis

PURPOSE

Pancreatic cancer (PC) has an overall 5-year survival rate of 10%. The use of neoadjuvant chemoradiation is debated in resectable disease. The purpose of this study is to evaluate the cost-effectiveness of neoadjuvant chemoradiation followed by pancreaticoduodenectomy (NACRT) versus upfront pancreaticoduodenectomy and adjuvant chemotherapy (USR) in resectable PC.

METHODS

A decision tree model was used to estimate the cost-effectiveness of NACRT versus USR. Values from the published literature populate the tree: costs from Medicare (FY2021) reimbursements, and morbidity and survival data for quality-adjusted life-years (QALYs). Patients with resectable pancreatic adenocarcinoma who qualified for resection were included. The ICER was the primary outcome. The model was validated using one-way and two-way deterministic, as well as probabilistic sensitivity analyses.

RESULTS

The base case was modeled using a 65-year-old male. NACRT yielded 1.61 QALYs at $45,483.52 USD. USR yielded 1.47 QALYs at a discount of $6,840.96 USD. The ICER was $48,130 USD, which favors NACRT. One-way sensitivity analyses upheld these results except when ≤ 21.0% of NACRT patients proceeded to surgery and when ≤ 85.4% of NACRT patients were resectable at surgery. Two-way sensitivity analyses also favored NACRT except in cases when the proportion of resected disease after NACRT decreased. NACRT was favored in 94.3% of 100,000 random-sampling simulations.

CONCLUSION

It is more cost-effective to administer NACRT before surgery for patients with resectable PC. On the basis of sensitivity analyses, USR with adjuvant therapy is only favored if rates of resection and eligibility for resection after NACRT decrease. NACRT should be considered in all patients unless there is an absolute contraindication.

Efficacy and safety of laparoscopic radical resection following neoadjuvant therapy for pancreatic ductal adenocarcinoma: A retrospective study

BACKGROUND

Multiple studies have demonstrated that neoadjuvant chemotherapy (NACT) can prolong the overall survival of pancreatic ductal adenocarcinoma (PDAC) patients. However, most studies have focused on open surgery following NACT.

AIM

To investigate the efficacy and safety of laparoscopic radical resection following NACT for PDAC.

METHODS

We retrospectively analyzed the clinical data of 15 patients with pathologically confirmed PDAC who received NACT followed by laparoscopic radical surgery in our hospital from December 2019 to April 2022. All patients underwent abdominal contrast-enhanced computed tomography (CT) and positron emission tomography-CT before surgery to accurately assess tumor stage and exclude distant metastasis.

RESULTS

All 15 patients with pancreatic cancer were successfully converted to surgical resection after NACT, including 8 patients with pancreatic head cancer and 7 patients with pancreatic body and tail cancer. Among them, 13 patients received the nab-paclitaxel plus gemcitabine regimen (gemcitabine 1000 mg/m² plus nab-paclitaxel 125 mg/m² on days 1, 8, and 15 every 4 wk) and 2 patients received the modified FOLFIRINOX regimen (intravenous oxaliplatin 68 mg/m², irinotecan 135 mg/m², and leucovorin 400 mg/m² on day 1 and fluorouracil 400 mg/m² on day 1, followed by 46-h continuous infusion of fluorouracil 2400 mg/m²). After each treatment cycle, abdominal CT, tumor markers, and circulating tumor cell counts were reviewed to evaluate the treatment efficacy. All 15 patients achieved partial remission. The surgical procedures included laparoscopic pancreaticoduodenectomy (LPD, n = 8) and laparoscopic radical antegrade modular pancreatosplenectomy (L-RAMPS, n = 7). None of them were converted to a laparotomy. One patient with pancreatic head carcinoma was found to have portal vein involvement during the operation, and LPD combined with vascular resection and reconstruction was performed. The amount of blood loss and operation times of L-RAMPS vs LPD were 435.71 ± 32.37 mL vs 343.75 ± 145.01 mL and 272.52 ± 49.14 min vs 444.38 ± 68.63 min, respectively. The number of dissected lymph nodes was 16.87 ± 4.10, and 3 patients had positive lymph nodes. One patient developed grade B postoperative pancreatic fistula (POPF) after L-RAMPS, and one patient experienced jaundice after LPD. None of the patients died after surgery. As of April 2022, progressive disease was noted in 4 patients, 2 patients had liver metastasis, and one had both liver metastasis and lymph node metastasis and died during the follow-up period.

CONCLUSION

Laparoscopic radical resection of PDAC after NACT is safe and effective if it is performed by a surgeon with rich experience in LPD and in a large center of pancreatic surgery.

Neoadjuvant Therapy for Pancreatic Ductal Adenocarcinoma: Where Do We Go?

The incidence of pancreatic ductal adenocarcinoma (PDAC) has been on the rise in recent years; however, its clinical diagnosis and treatment remain challenging. Although surgical resection remains the only chance for long-term patient survival, the likelihood of initial resectability is no higher than 20%. Neoadjuvant therapy (NAT) in PDAC aims to transform the proportion of inoperable PDACs into operable cases and reduce the likelihood of recurrence to improve overall survival. Ongoing phase 3 clinical trial aims to validate the role of NAT in PDAC therapy, including prolongation of survival, increased R0 resection, and a higher proportion of negative lymph nodes. Controversies surrounding the role of NAT in PDAC treatment include applicability to different stages of PDAC, chemotherapy regimens, radiation, duration of treatment, and assessment of effect. This review aims to summarize the current progress and controversies of NAT in PDAC.

Neoadjuvant Treatment for Resectable and Borderline Resectable Pancreatic Cancer: Chemotherapy or Chemoradiotherapy?

Worldwide, there is a shifting paradigm from immediate surgery with adjuvant treatment to a neoadjuvant approach for patients with resectable or borderline resectable pancreatic cancer (RPC or BRPC). Comparison of neoadjuvant and adjuvant studies is extremely difficult because of a great difference in patient selection. The evidence from randomized studies shows that overall survival by intention-to-treat improves after neoadjuvant gemcitabine-based chemoradiotherapy or chemotherapy (various regimens), as compared to immediate surgery followed by adjuvant chemotherapy. Radiotherapy appears to play an important role in mediating locoregional effects. Yet, since more effective chemotherapy regimens are currently available, in particular FOLFIRINOX and Gemcitabine/Nab-paclitaxel, these chemotherapy regimens should be investigated in future randomized trials combined with (stereotactic) radiotherapy to further improve outcomes of RPC and BRPC.

Neoadjuvant therapy vs. upfront surgery for resectable pancreatic cancer: An update on a systematic review and meta-analysis

The effectiveness of neoadjuvant therapy (NAT) remains controversial in the treatment of pancreatic cancer (PC). Therefore, this meta-analysis aimed to investigate the clinical differences between NAT and upfront surgery (US) in resectable pancreatic cancer (RPC). Eligible studies were retrieved from PubMed, Embase, and Cochrane Library. The endpoints assessed were R0 resection rate, pathological T stage < 2 rate, positive lymph node rate, and overall survival. A total of 4,588 potentially relevant studies were identified, and 13 studies were included in this study. In patients with RPC, this meta-analysis showed that NAT presented an increased R0 resection rate, pathological T stage < 2 rate, and a remarkably reduced positive lymph node rate compared to US. However, patients receiving NAT did not result in a significantly increased overall survival. These findings supported the application of NAT, especially as a patient selection strategy, in the management of RPC. Additional large clinical studies are needed to determine whether NAT is superior to US.

Disparities in the Use of Neoadjuvant Therapy for Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND

Current guidelines support either immediate surgical resection or neoadjuvant therapy (NT) for patients with resectable pancreatic ductal adenocarcinoma (PDAC). However, which patients are selected for NT and whether disparities exist in the use of NT for PDAC are not well understood.

METHODS

Using the National Cancer Database from 2004 through 2016, the clinical, demographic, socioeconomic, and hospital-related characteristics of patients with stage I/II PDAC who underwent immediate surgery versus NT followed by surgery were compared.

RESULTS

Among 58,124 patients who underwent pancreatectomy, 8,124 (14.0%) received NT whereas 50,000 (86.0%) did not. Use of NT increased significantly throughout the study period (from 3.5% in 2004 to 26.4% in 2016). Multivariable logistic regression analysis showed that travel distance, education level, hospital facility type, clinical T stage, tumor size, and year of diagnosis were associated with increased use of NT, whereas comorbidities, uninsured/Medicaid status, South/West geography, left-sided tumor location, and increasing age were associated with immediate surgery (all P<.001). Based on logistic regression-derived interaction factors, the association between NT use and median income, education level, Midwest location, clinical T stage, and clinical N stage significantly increased over time (all P<.01).

CONCLUSIONS

In addition to traditional clinicopathologic factors, several demographic, socioeconomic, and hospital-related factors are associated with use of NT for PDAC. Because NT is used increasingly for PDAC, efforts to reduce disparities will be critical in improving outcomes for all patients with pancreatic cancer.

Response to Neoadjuvant Therapy and Prognosis in Patients with Resectable Pancreatic Cancer: A Propensity Score Matching Analysis

Background/Aims

Controversy regarding the effectiveness of neoadjuvant therapy for resectable pancreatic ductal adenocarcinoma (PDAC) still exists. Here, we aimed to identify the potential benefits of neoadjuvant therapy followed by surgery for resectable PDAC.

Methods

We reviewed radiologically resectable PDAC patients who received resection with curative intent at a tertiary hospital in South Korea between January 2012 and August 2019. A total of 202 patients underwent curative resection for resectable PDAC 167 underwent surgical resection first during this period, and 35 received neoadjuvant chemotherapy/chemoradiation therapy followed by surgery. Resectable PDAC patients were subdivided, and 13 propensity score matching (PSM) was performed to reduce selection bias.

Results

Compared with the group that received surgery first, the group that received neoadjuvant treatment followed by surgery had significantly smaller tumors (22.0 mm vs 27.0 mm, p=0.004), a smaller proportion of patients with postoperative pathologic T stage (p=0.026), a smaller proportion of patients with lymphovascular invasion (20.0% vs 40.7%, p=0.022), and a larger proportion of patients with negative resection margins (74.3% vs 51.5%, p=0.049). After PSM, the group that received neoadjuvant therapy had a significantly longer progression-free survival than those in the group that underwent surgery first (29.6 months vs 15.1 months, p=0.002). Overall survival was not significantly different between the two groups after PSM analysis.

Conclusions

We observed significantly better surgical outcomes and progression-free survival with the addition of neoadjuvant therapy to the management of resectable PDAC. However, despite PSM, there was still selection bias due to the use of different regimens between the groups receiving surgery first and neoadjuvant therapy. Large homogeneous samples are needed in the future prospective studies.

Head-to-head comparison between FOLFIRINOX and gemcitabine plus nab-paclitaxel in the neoadjuvant chemotherapy of localized pancreatic cancer: a systematic review and meta-analysis

Background

The benefits of neoadjuvant chemotherapy (NCT) in pancreatic cancer (PC) have been realized and gradually accepted. FOLFIRINOX and gemcitabine and nab-paclitaxel (GA) are the two most widely used regimens for PC NCT.

Methods

The literature was systematically reviewed by searching MEDLINE, EMBASE, Web of Science and the Cochrane Library for studies published until September 2020.

Results

Eight studies were eligible for the meta-analysis. Compared to GA, neoadjuvant FOLFIRINOX significantly prolonged overall survival [hazard ratio (HR) =0.65, 95% confidence interval (95% CI): 0.55-0.77; P<0.001]. FOLFIRINOX provided better survival benefits in the first three years after surgery; however, the 4- and 5-year survival probabilities of the two strategies were similar based on a conservative estimation in the random effect model. The perioperative parameters analysed included perineural invasion (PNI), lymphovascular invasion (LVSI), R0 status, postoperative complications and resection rate. The PNI rate was marginally elevated in the GA group compared with the FOLFIRINOX cohort [79.8% vs. 70.5%, odds ratio (OR) =0.70, 95% CI: 0.47-1.06, P=0.09], which may account for the potential survival benefits of FOLFIRINOX.

Conclusions

The results of our meta-analysis suggest that FOLFIRINOX is non-inferior to GA in patients who are FOLFIRINOCX capable.

Therapeutic response assessment in pancreatic ductal adenocarcinoma: society of abdominal radiology review paper on the role of morphological and functional imaging techniques

Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related death in the United States and is projected to be the second by 2030. Systemic combination chemotherapy is considered an essential first-line treatment for the majority of patients with PDA, in both the neoadjuvant and palliative settings. In addition, a number of novel therapies are being tested in clinical trials for patients with advanced PDA. In all cases, accurate and timely assessment of treatment response is critical to guide therapy, reduce drug toxicities and cost from a failing therapy, and aid adaptive clinical trials. Conventional morphological imaging has significant limitations, especially in the context of determining primary tumor response and resectability following neoadjuvant therapies. In this article, we provide an overview of current therapy options for PDA, highlight several morphological imaging findings that may be helpful to reduce over-staging following neoadjuvant therapy, and discuss a number of emerging imaging, and non-imaging, tools that have shown promise in providing a more precise quantification of disease burden and treatment response in PDA.

Neoadjuvant therapy versus upfront surgery for early-stage left-sided pancreatic adenocarcinoma: A propensity-matched analysis from a national cohort of distal pancreatectomies

BACKGROUND

There are limited data on the efficacy of neoadjuvant therapy (NAT) for early-stage distal pancreas adenocarcinoma (PDAC). Previous studies focused on adenocarcinoma of the head of the pancreas or dealt with borderline and locally advanced tumors of the body and tail.

METHODS

This is a retrospective study of the National Cancer Database between 2006 and 2015. A propensity-matched analysis was performed to compare overall survival estimates between NAT and upfront resection (UR) groups.

RESULTS

A total of 5003 distal pancreatectomies for PDAC were identified, of whom 408 (9%) received NAT. After 1:1 matching, 353 NAT patients were compared with 353 UR patients. NAT was associated with lower 90-day mortality. There were no differences in the number of lymph nodes retrieved, or length of stay. With matching, the NAT group had higher median overall survival compared with UR (33.0 vs. 27.0 months; p = 0.009) and adjusted overall survival (hazard ratio = 0.63, 95% confidence interval = 0.51-0.77; p < 0.001).

CONCLUSION

The receipt of NAT followed by distal pancreatectomy for early-stage distal PDAC is associated with improved overall survival compared with UR. This study supports the use of NAT in the multimodal therapy paradigm of early-stage adenocarcinoma of the body and tail of the pancreas.

Open and Minimal Approaches to Pancreatic Adenocarcinoma

Surgical options and approaches to pancreatic cancer are changing in the current era. Neoadjuvant treatment strategies for pancreatic cancer combined with the increased use of minimal access surgical techniques mean that the modern pancreatic surgeon requires mastering a number of surgical approaches with to optimally manage patients. Whilst traditional open surgery remains the most frequent approach for surgery, the specific steps during surgery may need to be modified in light of the aforementioned neoadjuvant treatments. Robotic and laparoscopic approaches to pancreatic resection are feasible, but these surgical methods remain in their infancy. In this review article, we summarise the current surgical approaches to pancreatic cancer and how these are adapted to the minimal access setting with discussion of the patient outcome data.

Effect of neoadjuvant radiotherapy on survival of non-metastatic pancreatic ductal adenocarcinoma: a SEER database analysis

BACKGROUND

Neoadjuvant radiotherapy has been shown to improve marginal negative resection and local control of Pancreatic Ductal Adenocarcinoma (PDAC). However, whether it improves overall survival (OS) in patients with non-metastatic PDAC remains controversial. Therefore, the purpose of this study was to analyze the benefits of only surgery, neoadjuvant radiotherapy, adjuvant radiotherapy, and surgery plus chemotherapy for OS in patients with non-metastatic PDAC.

METHODS

PDAC diagnosed by surgical histopathology in the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2016 was selected. Kaplan-Meier analysis was used to compare the prognosis of patients with different treatments. Cox proportional risk model was used to analyze independent predictors of OS. Propensity score matching (PSM) was used to analyze the tumor prognosis of different treatment methods.

RESULTS

Before PSM analysis, the OS of surgery plus chemotherapy (HRs = 0.896, 95%CIs, 0.827-0.970; P = 0.007) were significantly better than the other three treatments for stage T1-3N0M0 PDAC patients. For stage T1-3N + M0 patients, adjuvant radiotherapy (HRs = 0.613, 95% CIs, 0.579-0.649; P < 0.001) had significantly better OS than surgery plus chemotherapy and neoadjuvant radiotherapy. For stage T4N0M0 patients, neoadjuvant radiotherapy (HRs = 0.482, 95% CIs, 0.347-0.670; P < 0.001) had significantly better OS than surgery plus chemotherapy and adjuvant radiotherapy. For stage T4N + M0 patients, neoadjuvant radiotherapy (HRs = 0.338, 95% CIs, 0.215-0.532; P < 0.001) had significantly longer OS than adjuvant radiotherapy and surgery plus chemotherapy. Even after PSM, Chemotherapy plus surgery was still the best treatment for T1-3N0M0 patients. Postoperative adjuvant radiotherapy had the best prognosis among T1-3N + M0 patients, and neoadjuvant radiotherapy was the best treatment for T4 patients.

CONCLUSIONS

For patients with non-metastatic PDAC, neoadjuvant radiotherapy, adjuvant radiotherapy and surgery plus chemotherapy were superior to only surgery in OS. For patients with stage T4 non-metastatic PDAC, neoadjuvant radiotherapy had the potential to be strongly recommended over adjuvant radiotherapy and surgery plus chemotherapy. However, neoadjuvant radiotherapy failed to benefit the survival of T1-3N0M0 stage patients, and surgery plus chemotherapy was preferred. For T1-3N + M0, neoadjuvant radiotherapy had no obvious advantage over adjuvant radiotherapy or surgery plus chemotherapy in OS, and adjuvant radiotherapy was more recommended.