Clinical Outcomes of Surgery After Neoadjuvant Chemotherapy in Locally Advanced Pancreatic Ductal Adenocarcinoma.

Purpose: Clinical outcomes of surgery after neoadjuvant chemotherapy have not been investigated for locally advanced pancreatic cancer (LAPC), despite well-established outcomes in borderline resectable pancreatic cancer (BRPC). This study aimed to investigate the clinical outcomes of patients with LAPC who underwent curative resection following neoadjuvant chemotherapy. Materials and Methods: We retrospectively reviewed the records of patients diagnosed with pancreatic adenocarcinoma between January 2017 and December 2020. Results: Among 1,358 patients, 260 underwent surgery following neoadjuvant chemotherapy. Among 356 LAPC patients, 98 (27.5%) and 147 (35.1%) of 418 BRPC patients underwent surgery after neoadjuvant chemotherapy. Compared to resectable pancreatic cancer (resectable PC) with upfront surgery, both LAPC and BRPC exhibited higher rates of venous resection (28.6% vs. 49.0% vs. 4.0%), arterial resection (30.6% vs. 6.8% vs. 0.5%) and greater estimated blood loss (260.5 vs. 213.1 vs. 70.4 mL). However, hospital stay, readmission rates and postoperative pancreatic fistula rates (Grade B or C) did not differ significantly between LAPC, BRPC, and resectable PC. Overall and relapse-free survival did not differ significantly between LAPC and BRPC patients. The median overall survival was 37.3 months for LAPC and 37.0 months for BRPC. The median relapse-free survival was 22.7 months for LAPC and 26.0 months for BRPC. Conclusion: Overall survival time and postoperative complications in LAPC patients who underwent curative resection following neoadjuvant chemotherapy showed similar results to those of BRPC patients. Further research is needed to identify specific sub-populations of LAPC patients who benefit most from conversion surgery and to minimize postoperative complications.

Adaptive MRI-guided stereotactic body radiation therapy for locally advanced pancreatic cancer - A phase II study.

PURPOSE: Stereotactic body radiotherapy (SBRT) has emerged as a promising new modality for locally advanced pancreatic cancer (LAPC). The current study evaluated the efficacy and toxicity of SBRT in patients with LAPC (NCT03648632). METHODS: This prospective single institution phase II study recruited patients with histologically or cytologically proven adenocarcinoma of the pancreas after more than two months of combination chemotherapy with no sign of progressive disease. Patients were prescribed 50-60 Gy in 5-8 fractions. Patients were initially treated on a standard linac (n = 4). Since 2019, patients were treated using online magnetic resonance (MR) image-guidance on a 1.5 T MRI-linac, where the treatment plan was adapted to the anatomy of the day. The primary endpoint was resection rate. RESULTS: Twenty-eight patients were enrolled between August 2018 and March 2022. All patients had non-resectable disease at time of diagnosis. Median follow-up from inclusion was 28.3 months (95 % CI 24.0-NR). Median progression-free and overall survival from inclusion were 7.8 months (95 % CI 5.0-14.8) and 16.5 months (95 % CI 10.7-22.6), respectively. Six patients experienced grade III treatment-related adverse events (jaundice, nausea, vomiting and/or constipation). One of the initial four patients receiving treatment on a standard linac experienced a grade IV perforation of the duodenum. Six patients (21 %) underwent resection. A further one patient was offered resection but declined. CONCLUSION: This study demonstrates that SBRT in patients with LAPC was associated with promising overall survival and resection rates. Furthermore, SBRT was safe and well tolerated, with limited severe toxicities.

Extracellular volume-based scoring system for tracking tumor progression in pancreatic cancer patients receiving intraoperative radiotherapy.

OBJECTIVES: To investigate the value of extracellular volume (ECV) derived from portal-venous phase (PVP) in predicting prognosis in locally advanced pancreatic cancer (LAPC) patients receiving intraoperative radiotherapy (IORT) with initial stable disease (SD) and to construct a risk-scoring system based on ECV and clinical-radiological features. MATERIALS AND METHODS: One hundred and three patients with LAPC who received IORT demonstrating SD were enrolled and underwent multiphasic contrast-enhanced CT (CECT) before and after IORT. ECV maps were generated from unenhanced and PVP CT images. Clinical and CT imaging features were analyzed. The independent predictors of progression-free survival (PFS) determined by multivariate Cox regression model were used to construct the risk-scoring system. Time-dependent receiver operating characteristic (ROC) curve analysis and the Kaplan-Meier method were used to evaluate the predictive performance of the scoring system. RESULTS: Multivariable analysis revealed that ECV, rim-enhancement, peripancreatic fat infiltration, and carbohydrate antigen 19-9 (CA19-9) response were significant predictors of PFS (all p < 0.05). Time-dependent ROC of the risk-scoring system showed a satisfactory predictive performance for disease progression with area under the curve (AUC) all above 0.70. High-risk patients (risk score ≥ 2) progress significantly faster than low-risk patients (risk score < 2) (p < 0.001). CONCLUSION: ECV derived from PVP of conventional CECT was an independent predictor for progression in LAPC patients assessed as SD after IORT. The scoring system integrating ECV, radiological features, and CA19-9 response can be used as a practical tool for stratifying prognosis in these patients, assisting clinicians in developing an appropriate treatment approach. CRITICAL RELEVANCE STATEMENT: The scoring system integrating ECV fraction, radiological features, and CA19-9 response can track tumor progression in patients with LAPC receiving IORT, aiding clinicians in choosing individual treatment strategies and improving their prognosis. KEY POINTS: Predicting the progression of LAPC in patients receiving IORT is important. Our ECV-based scoring system can risk stratifying patients with initial SD. Appropriate prognostication can assist clinicians in developing appropriate treatment approaches.

REDISCOVER guidelines for borderline-resectable and locally advanced pancreatic cancer: management algorithm, unanswered questions, and future perspectives.

The REDISCOVER guidelines present 34 recommendations for the selection and perioperative care of borderline-resectable (BR-PDAC) and locally advanced ductal adenocarcinoma of the pancreas (LA-PDAC). These guidelines represent a significant shift from previous approaches, prioritizing tumor biology over anatomical features as the primary indication for resection. Condensed herein, they provide a practical management algorithm for clinical practice. However, the guidelines also highlight the need to redefine LA-PDAC to align with modern treatment strategies and to solve some contradictions within the current definition, such as grouping "difficult" and "impossible" to resect tumors together. Furthermore, the REDISCOVER guidelines highlight several areas requiring urgent research. These include the resection of the superior mesenteric artery, the management strategies for patients with LA-PDAC who are fit for surgery but unable to receive multi-agent neoadjuvant chemotherapy, the approach to patients with LA-PDAC who are fit for surgery but demonstrate high serum Ca 19.9 levels even after neoadjuvant treatment, and the optimal timing and number of chemotherapy cycles prior to surgery. Additionally, the role of primary chemoradiotherapy versus chemotherapy alone in LA-PDAC, the timing of surgical resection post-neoadjuvant/primary chemoradiotherapy, the efficacy of ablation therapies, and the management of oligometastasis in patients with LA-PDAC warrant investigation. Given the limited evidence for many issues, refining existing management strategies is imperative. The establishment of the REDISCOVER registry ( https://rediscover.unipi.it/ ) offers promise of a unified research platform to advance understanding and improve the management of BR-PDAC and LA-PDAC.

A 15-Year Single-Institution Retrospective Study of Primary Pancreatic Cancer Treated with Non-Ablative Palliative Radiotherapy.

We studied the use of palliative radiotherapy (RT) among patients with primary, non-curable, locally advanced pancreatic cancer. In this subset of patients, with very poor survival, various palliative RT dose fractionation schemes are used; but, in the absence of a guideline, practice patterns vary, and dose choice is mainly based on the physician's intuition. We divided the patients into three groups, according to the dose fractionation schedules received: low (A), intermediate (B), and high (C) dose groups, to study the potential differences in outcome between the different dose prescriptions. Cohort: n = 184. Median age: 69 years. Male: n = 105 (57%), female: n = 79 (43%). Stage IV: n = 117 (64%). T4: n = 127 (69%). Tumor location: head: n = 109 (59%), body: n = 37 (20%), tail: n = 25 (14%), neck: n = 11 (6%), and uncinate: n = 2 (1%). Prior systemic therapy: n = 66 (36%). Most common dose fractionations received: 20 Gy in five fractions n = 67 (36%), 30 Gy in 10 fractions n = 49 (27%), and 8 Gy in one fraction n = 23 (13%). Group A: n = 33 (18%), median overall survival (OS) 19 days (95% CI 4-33). Group B: n = 84 (46%), median OS 52 days (95% CI 43-60). Group C: n = 67 (36%), median OS 126 days (95% CI 77-174). Median days to in-field progression: Group A 59 days (range 7-109), Group B 96 days (range 19-173), and Group C 97 days (range 13-475). To our knowledge, this is the largest reported retrospective cohort of patients receiving non-ablative palliative RT to treat their primary pancreatic tumors. Most patients had metastatic disease, T4 tumors of the pancreatic head and had not received prior systemic therapy. A significant survival benefit was seen favoring the high dose/longer RT fractionation group, presumably due to appropriate patient selection rather than an RT effect. Despite the relatively short median overall survival, one fifth of the patients were found to experience an in-field progression following RT.

Locally advanced pancreatic cancer: Is surgical palliation associated with improved clinical outcome relative to medical palliation?

BACKGROUND: The value of palliative surgery in pancreatic cancer is not well-defined. METHODS: We queried the National Cancer Database for patients undergoing curative-intent resection, palliative surgery or medical palliation for clinical stage cT4N0-2M0 pancreatic cancer. Cohorts were 1:1:1 propensity-score-matched for comorbidities and stage. Kaplan-Meier method was used to compare overall survival for matched cohorts. RESULTS: 9,107 patients met inclusion criteria: 3,567 (39 â€‹%) underwent curative intent surgery, 1608 (18 â€‹%) surgical palliation, 3932 (43 â€‹%) medical palliation. Patients undergoing resection and surgical palliation had significant hospitalizations (11.0 â€‹± â€‹0.4 vs. 10.0 â€‹± â€‹0.3 days; p â€‹= â€‹0.821) and rates of readmission (8.1 â€‹% vs. 2.0 â€‹%; p â€‹< â€‹0.001). Patients undergoing surgical palliation demonstrated marginal increases in survival relative to those undergoing medical palliation (8.54 vs. 7.36 months; p â€‹< â€‹0.0001). CONCLUSION: In patients undergoing care for locally advanced pancreatic cancer, palliative surgery is associated with marginal improvement in survival but significant lengths of hospitalization and risk of readmission.

Local ablative therapies and the effect on antitumor immune responses in pancreatic cancer - A review.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease, projected to rank as the second most prevalent cause of cancer-related mortality by 2030. Despite significant progress in advances in surgical techniques and chemotherapy protocols, the overall survival (OS) remains to be less than 10 % for all stages combined. In recent years, local ablative techniques have been introduced and utilized as additional therapeutic approaches for locally advanced pancreatic cancer (LAPC), with promising results with respect to local tumor control and OS. In addition to successful cytoreduction, there is emerging evidence that local ablation induces antitumor immune activity that could prevent or even treat distant metastatic tumors. The enhancement of antitumor immune responses could potentially make ablative therapy a therapeutic option for the treatment of metastatic PDAC. In this review, we summarize current ablative techniques used in the management of LAPC and their impact on systemic immune responses.

Performance and safety of diagnostic EUS FNA/FNB and therapeutic ERCP in patients with borderline resectable and locally advanced pancreatic cancer - results from a population-based, prospective cohort study.

Objective: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS FNA/FNB) and potential endoscopic retrograde cholangiopancreatography (ERCP) for biliary decompression are indicated in patients with pancreatic cancer before initation of primary chemotherapy. This study aims to investigate the performance and safety of these two procedures in patients with borderline resectable (BRPC) or locally advanced pancreatic cancer (LAPC). Methods: Endoscopy and pathology reports, and hospital records of consecutive patients with a radiological diagnosis of BRPC/LAPC included in a population based, protocol-driven study (NORPACT-2) were reviewed. Results: Of 251 patients, 223 (88.9%) underwent EUS-FNA/FNB, and 133 (53%) underwent ERCP. Repeated EUS attempts were performed in 33 (14.8%), eight (3.6%), and four (1.8%) patients. FNA was performed in 155 procedures, FNB in 30, and combined EUS-FNA/FNB in 83. Diagnostic accuracy was 86.1% for first EUS-FNA/FNB. The cumulative diagnostic accuracy for all attempts was 96%. False positive rate for malignancy was 0.9%. Of a total of 149 ERCP procedures, 122 (81.9%) were successful, and 27 (18.1%) were unsuccessful. Success rate of first ERCP attempt was 80.5% (107/133). Sixteen patients (12%) underwent a second attempt with a success rate of 93.8% (15 of 16). Combined EUS and ERCP was performed in 41 patients. Complications occurred in eight procedures (3%) after EUS-FNA/FNB, 23 procedures (15.3%) after ERCP, and four (9.8%) patients after combined EUS-FNA/FNB and ERCP. Conclusion: EUS-FNA/FNB and ERCP with biliary stenting in patients with BRPC/LAPC demonstrated acceptable performance and safety. Repeat procedures were performed with high success rates. Same session EUS-FNA/FNB and ERCP for biliary decompression is safe.

Sequential Irreversible Electroporation for Locally Advanced Pancreatic Cancer.

Pancreatic cancer is a lethal disease, with locally advanced pancreatic cancer (LAPC) having a dismal prognosis. For patients with LAPC, gemcitabine-based regimens, with or without radiation, have long been the standard of care. Irreversible electroporation (IRE), a non-thermal ablative technique, may potentially prolong the survival of patients with LAPC. In this article, the authors present a case of LAPC of the uncinate process (biopsy proven pancreatic neuroendocrine carcinoma) with duodenal invasion. The patient had a combination of chemotherapy and radiation therapy but was found to have stable disease. He then underwent intra-operative IRE with cholecystectomy, Roux-en-Y gastrojejunostomy and hepaticojejunostomy. He subsequently underwent percutaneous IRE 13 months post open IRE. The patient also completed peptide receptor radionuclide therapy and has been started on Lanreotide. Following combination therapy, the pancreatic tumor showed significant reduction in size, with patient survival at 53 months post-diagnosis at the time of writing.

Accuracy analysis of different dose calculation algorithms for locally advanced pancreatic cancer stereotactic body radiotherapy.

Background: The dose distribution in different optimization algorithm plans of stereotactic radiotherapy (SBRT) for locally advanced pancreatic cancer (LAPC) were compared and analyzed using monte carlo dose calculate algorithm (MC). Methods: A retrospective study analyzed 26 LAPC patients treated with SBRT. The SBRT plans were designed by raytracing (RT) and fine size pencil beam (FSPB) algorithms in the CyberKnife (CK) precision system, all of which met the requirements of clinical target dose and organ at risk (OAR). Keeping the original optimization parameters unchanged, the RT and FSPB algorithm plans were recalculated by MC algorithm. The accuracy of different algorithm plnas were compared and analyzed by using planning parameters and dose distribution. Results: There was no significant differences in the coverage and conformal index (CI) of the planned target volume (PTV) between RT and FSPB algorithm plans, but dose distribution of organ at risk (OAR) and the maximum dose outside the PTV boundary of 2 cm (D2cm) were lower in FSPB plans compared to RT plans, and this difference was statistically significant with p-values < 0.05. Compared to the MC algorithm, both RT algorithm and FSPB algorithm overestimated dose of the PTV and OAR. The RT algorithm was more consistent with the MC algorithm than the FSPB algorithm. The relative error of PTV coverage within the RT algorithm was 8.02% ± 1.53%, and the relative error range of OAR dose parameters was 3.32% -12.73%. Conclusion: Although the FSPB algorithm could achieve rapid dose drop-off around the PTV and lower dose distribution in the OAR for pancreatic cancer SBRT plans, the algorithm error were higher than the RT algorithm. RT and FSPB algorithm overestimated the dose in the target and OAR. That was important to evaluate the clinical plans.

Analysis of the cost-effectiveness of proton beam therapy for unresectable pancreatic cancer in Japan.

BACKGROUND: Proton beam therapy (PBT) has recently been included in Japan's social health insurance benefits package. This study aimed to determine the cost-effectiveness of PBT for unresectable, locally advanced pancreatic cancer (LAPC) as a replacement for conventional photon radiotherapy (RT). METHODS: We estimated the incremental cost-effectiveness ratio (ICER) of PBT as a replacement for three-dimensional conformal RT (3DCRT), a conventional photon RT, using clinical evidence in the literature and expense complemented by expert opinions. We used a decision tree and an economic and Markov model to illustrate the disease courses followed by LAPC patients. Effectiveness was estimated as quality-adjusted life years (QALY) using utility weights for the health state. Social insurance fees were calculated as the costs. The stability of the ICER against the assumptions made was appraised using sensitivity analyses. RESULTS: The effectiveness of PBT and 3DCRT was 1.67610615 and 0.97181271 QALY, respectively. The ICER was estimated to be ¥5,376,915 (US$46,756) per QALY. According to the suggested threshold for anti-cancer therapy from the Japanese authority of ¥7,500,000 (US$65,217) per QALY gain, such a replacement would be considered cost-effective. The one-way and probabilistic sensitivity analyses demonstrated stability of the base-case ICER. CONCLUSION: PBT, as a replacement for conventional photon radiotherapy, is cost-effective and justifiable as an efficient use of finite healthcare resources. Making it a standard treatment option and available to every patient in Japan is socially acceptable from the perspective of health economics.

Assessment of the level III of Inoue by preoperative endoscopic ultrasound and elastography: a novel approach to predict a periarterial divestment technique in borderline resectable (BR) or locally advanced (LA) pancreatic adenocarcinoma-How I do it.

BACKGROUND: Periarterial divestment is a surgical technique to approach borderline resectable (BR) or locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC) with arterial involvement. There are no reports in the literature regarding the role of endoscopic ultrasound and elastography (EUS-EG) in exploring the integrity of Inoue's level III and its correlation with the periarterial divestment technique feasibility. Our research is aimed at exploring the role of EUS-EG in this scenario. METHODS: We describe our approach to Inoue's level II by EUS-EG in patients with BR and LA pancreatic cancer patients after neoadjuvant chemotherapy. RESULTS: Between June 2019 and December 2020, four patients out of 25 were eligible to perform a preoperative EUS-EG. In all cases, Inoue's level III integrity was corroborated by EUS-EG and confirmed posteriorly in the surgical scenario where a periarterial divestment technique was feasible. Vein resections were necessary in all cases, with no need for arterial resection. An R0 (> 1 mm) margin was achieved in all patients, and the histopathological assessment showed the presence of neurovascular tissue at the peripheral arterial margin. CONCLUSION: Preoperatively, EUS-EG is a novel approach to explore the integrity of Inoue's level III and could be helpful to preclude a periarterial divestment technique in borderline resectable or locally advanced pancreatic adenocarcinoma with arterial involvement.

Predictive factors for survival in borderline resectable and locally advanced pancreatic cancer: are these really two different entities?

BACKGROUND: The treatment of borderline resectable (BR) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC) has evolved with a wider application of neoadjuvant chemotherapy (NACHT). The aim of this study was to identify predictive factors for survival in BR and LA PDAC. METHODS: Clinicopathologic data of patients with BR and LA PDAC who underwent surgical exploration between January 2011 and June 2021 were retrospectively collected. Survival from the date of surgery was estimated using the Kaplan-Meier method. Simple and multiple Cox proportional hazards models were fitted to identify factors associated with survival. Surgical resection was analyzed in combination with the involvement of lymph nodes as this last was only known after a formal resection. RESULTS: Ninety patients were surgically explored (BR: 45, LA: 45), of which 51 (57%) were resected (BR: 31, LA: 20). NACHT was administered to 43 patients with FOLFIRINOX being the most frequent regimen applied (33/43, 77%). Major complications (Clavien-Dindo grade III and IV) occurred in 7.8% of patients and 90-day mortality rate was 3.3%. The median overall survival since surgery was 16 months (95% CI 12-20) in the group which underwent surgical resection and 10 months (95% CI 7-13) in the group with an unresectable tumor (p=0.001). Cox proportional hazards models showed significantly lower mortality hazard for surgical resection compared to no surgical resection, even after adjusting for National Comprehensive Cancer Network  (NCCN) classification and administration of NACHT [surgical resection with involved lymph nodes vs no surgical resection (cHR 0.49; 95% CI 0.29-0.82; p=0.007)]. There was no significant difference in survival between patients with BR and LA disease (cHR= 1.01; 95% CI 0.63-1.62; p=0.98). CONCLUSIONS: Surgical resection is the only predictor of survival in patients with BR and LA PDAC, regardless of their initial classification as BR or LA. Our results suggest that surgery should not be denied to patients with LA PDAC a priori. Prospective studies including patients from the moment of diagnosis are required to identify biologic and molecular markers which may allow a better selection of patients who will benefit from surgery.

Irreversible electroporation combined with chemotherapy and PD-1/PD-L1 blockade enhanced antitumor immunity for locally advanced pancreatic cancer.

Background: Irreversible electroporation (IRE) is a novel local tumor ablation approach with the potential to stimulate an antitumor immune response. However, it is not effective in preventing distant metastasis in isolation. This study aimed to compare the potential of augmenting the antitumor immune response in patients with locally advanced pancreatic cancer (LAPC) who underwent IRE combined with chemotherapy and PD-1/PD-L1 blockade with those who underwent IRE combined with chemotherapy. Methods: A retrospective review was conducted on LAPC patients treated either with IRE in combination with chemotherapy and PD-1/PD-L1 blockade (group A) or with IRE with chemotherapy alone (group B) from July 2015 to June 2021. The primary outcomes were overall survival (OS) and progression-free survival (PFS), with immune responses and adverse events serving as secondary endpoints. Risk factors for OS and PFS were identified using univariate and multivariate analyses. Results: A total of 103 patients were included in the final analysis, comprising 25 in group A and 78 in group B. The median duration of follow-up was 18.2 months (3.0-38.6 months). Group A patients demonstrated improved survival compared to group B (median OS: 23.6 vs. 19.4 months, p = 0.001; median PFS: 18.2 vs. 14.7 months, p = 0.022). The data suggest a robust immune response in group A, while adverse events related to the treatment were similar in both groups. The multivariate analysis identified the combination of IRE, chemotherapy, and PD-1/PD-L1 blockade as an independent prognostic factor for OS and PFS. Conclusion: The addition of PD-1/PD-L1 blockade to the regimen of IRE combined with chemotherapy enhanced antitumor immunity and extended survival in LAPC patients.

Developments and challenges in neoadjuvant therapy for locally advanced pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) remains a significant public health challenge and is currently the fourth leading cause of cancer-related mortality in developed countries. Despite advances in cancer treatment, the 5-year survival rate for patients with PDAC remains less than 5%. In recent years, neoadjuvant therapy (NAT) has emerged as a promising treatment option for many cancer types, including locally advanced PDAC, with the potential to improve patient outcomes. To analyze the role of NAT in the setting of locally advanced PDAC over the past decade, a systematic literature search was conducted using PubMed and Web of Science. The results suggest that NAT may reduce the local mass size, promote tumor downstaging, and increase the likelihood of resection. These findings are supported by the latest evidence-based medical literature and the clinical experience of our center. Despite the potential benefits of NAT, there are still challenges that need to be addressed. One such challenge is the lack of consensus on the optimal timing and duration of NAT. Improved criteria for patient selection are needed to further identify PDAC patients likely to respond to NAT. In conclusion, NAT has emerged as a promising treatment option for locally advanced PDAC. However, further research is needed to optimize its use and to better understand the role of NAT in the management of this challenging disease. With continued advances in cancer treatment, there is hope of improving the outcomes of patients with PDAC in the future.

Preoperative Therapy for Unresectable Locally Advanced Pancreatic Cancer for ≥6 Months Improves Prognosis After Pancreatectomy.

BACKGROUND/AIM: This study aimed to identify the optimal duration of pretreatment for unresectable locally advanced (UR-LA) pancreatic cancer and analyze its effect on the prognosis. PATIENTS AND METHODS: This retrospective study included 39 patients with UR-LA pancreatic cancer after pancreatectomy. The cutoff period of preoperative therapy was determined using a receiver operating characteristic curve. We investigated the relationship between preoperative and intraoperative clinical variables and overall survival (OS) in univariate and multivariate analyses. The relationship between the preoperative therapy duration and the clinicopathological variables was investigated. OS was compared according to preoperative therapy duration and the presence or absence of adjuvant surgery. RESULTS: After pretreatment, 15 patients underwent adjuvant surgery and 24 patients continued on chemotherapy without surgery. The multivariate analysis demonstrated preoperative therapy duration ≥6 months was an independent prognostic factor [hazard ratio (HR)=0.10, p=0.04]. No significant difference in the clinicopathological variables was observed between the two groups according to preoperative therapy duration. The OS was significantly better in patients who underwent adjuvant surgery after preoperative therapy duration ≥6 months than in those after preoperative therapy duration <6 months and in those without adjuvant surgery (5-year OS rates: 80% vs. 0%; p=0.01 and 5-year OS rates: 80% vs. 0%; p=0.004, respectively). The OS was not significantly better in patients with adjuvant surgery after preoperative therapy duration <6 months than in those without adjuvant surgery (2-year OS rates: 45.7% vs. 38.1%; p=0.98). CONCLUSION: Preoperative therapy for UR-LA pancreatic cancer for ≥6 months is necessary to improve prognosis after adjuvant surgery.

Proton radiotherapy as a treatment strategy to increase survival in locally advanced pancreatic cancer in the body and tail: a retrospective study.

BACKGROUND: Long-term outcomes and prognostic factors of proton radiotherapy for locally advanced pancreatic cancer (LAPC) in the body and tail are still unknown. The aim of this study was to determine the prognostic factors after proton radiotherapy in a large group of patients with LAPC in the body and tail. METHODS: The medical records of 200 patients with LAPC in the body and tail who underwent proton radiotherapy between February 2009 and January 2021 at the Hyogo Ion Beam Medical Center were retrospectively reviewed to identify prognostic factors that contribute to long-term survival. RESULTS: The overall survival rate at 1- and 2-year after PT was 69.6% and 35.4% with a median overall survival of 18.4 months. The 1- and 2-year local progression-free, and progression-free survival rates were 84.3% and 68.0%, and 44.3% and 19.4%, respectively. In multivariate analysis, superior mesenteric artery (SMA) invasion (SMA only invasion vs. celiac artery only invasion; P = 0.049: SMA and celiac artery invasion vs. celiac artery only invasion; P = 0.017), carbohydrate antigen 19-9 (CA 19-9) level ≥ 231.9 U/mL (P = 0.001), anterior peripancreatic invasion (P = 0.006), and incomplete scheduled concurrent chemotherapy (P = 0.009) were statistically significant prognostic factors for overall survival. There was no significant difference in local progression-free survival; however, distant metastasis-free survival was statistically worse in patients with prognostic factors than in those without. CONCLUSIONS: Proton radiotherapy for LAPC in the body and tail may be a valuable multidisciplinary treatment option. Patients with SMA invasion, higher pre-proton radiotherapy serum CA 19-9 level, anterior peripancreatic invasion, or incomplete scheduled concurrent chemotherapy had worse overall survival because of worse distant metastasis-free survival, suggesting that distant metastases have a significant impact on overall survival in such patients. TRIAL REGISTRATION: Retrospectively registered.

Can STEreotactic Body Radiation Therapy (SBRT) Improve the Prognosis of Unresectable Locally Advanced Pancreatic Cancer? Long-Term Clinical Outcomes, Toxicity and Prognostic Factors on 142 Patients (STEP Study).

AIM: The gold standard of care for pancreatic adenocarcinoma is the integrated treatment of surgery and chemotherapy (ChT), but about 50% of patients present with unresectable disease. Our study evaluated the efficacy in terms of local control, survival and safety of stereotactic body radiation therapy (SBRT) in locally advanced pancreatic cancer (LAPC). METHODS: A retrospective study (STEP study) analyzed patients with LAPC treated with a dose of 45 Gy in 6 fractions. Local control (LC), distant progression free survival (DPFS), overall survival (OS) and toxicity were analyzed according to the Kaplan-Meier method. RESULTS: A total of 142 patients were evaluated. Seventy-six patients (53.5%) received induction ChT before SBRT. The median follow-up was 11 months. One-, 2- and 3-year LC rate was 81.9%, 69.1% and 58.5%. Median DPFS was 6.03 months; 1- and 2-year DPFS rate was 19.9% and 4.5%. Median OS was 11.6 months and 1-, 2- and 3-year OS rates were 45.4%, 16.1%, and 9.8%. At univariate analysis, performed by the log-rank test, age < 70 years (p = 0.037), pre-SBRT ChT (p = 0.004) and post-SBRT ChT (p = 0.019) were associated with better OS. No patients experienced G3 toxicity. CONCLUSION: SBRT represents an effective and safe therapeutic option in the multimodal treatment of patients with LAPC in terms of increased LC. When SBRT was sequentially integrated with ChT, the treatment proved to be promising in terms of OS as well.

Machine learning-based prediction of surgical benefit in borderline resectable and locally advanced pancreatic cancer.

INTRODUCTION: Surgery represents a primary therapeutic approach for borderline resectable and locally advanced pancreatic cancer (BR/LAPC). However, BR/LAPC lesions exhibit high heterogeneity and not all BR/LAPC patients who undergo surgery can derive beneficial outcomes. The present study aims to employ machine learning (ML) algorithms to identify those who would obtain benefits from the primary tumor surgery. METHODS: We retrieved clinical data of patients with BR/LAPC from the Surveillance, Epidemiology, and End Results (SEER) database and classified them into surgery and non-surgery groups based on primary tumor surgery status. To eliminate confounding factors, propensity score matching (PSM) was employed. We hypothesized that patients who underwent surgery and had a longer median cancer-specific survival (CSS) than those who did not undergo surgery would certainly benefit from surgical intervention. Clinical and pathological features were utilized to construct six ML models, and model effectiveness was compared through measures such as the area under curve (AUC), calibration plots, and decision curve analysis (DCA). We selected the best-performing algorithm (i.e., XGBoost) to predict postoperative benefits. The SHapley Additive exPlanations (SHAP) approach was used to interpret the XGBoost model. Additionally, data from 53 Chinese patients prospectively collected was used for external validation of the model. RESULTS: According to the results of the tenfold cross-validation in the training cohort, the XGBoost model yielded the best performance (AUC = 0.823, 95%CI 0.707-0.938). The internal (74.3% accuracy) and external (84.3% accuracy) validation demonstrated the generalizability of the model. The SHAP analysis provided explanations independent of the model, highlighting important factors related to postoperative survival benefits in BR/LAPC, with age, chemotherapy, and radiation therapy being the top three important factors. CONCLUSION: By integrating of ML algorithms and clinical data, we have established a highly efficient model to facilitate clinical decision-making and assist clinicians in selecting the population that would benefit from surgery.