Phase II study of induction gemcitabine and S-1 followed by chemoradiotherapy and systemic chemotherapy using S-1 for locally advanced pancreatic cancer

Total Neoadjuvant Therapy in Localized Pancreatic Cancer: Is More Better?

Pancreatic ductal adenocarcinoma (PDAC) poses a significant challenge in oncology due to its advanced stage upon diagnosis and limited treatment options. Surgical resection, the primary curative approach, often results in poor long-term survival rates, leading to the exploration of alternative strategies like neoadjuvant therapy (NAT) and total neoadjuvant therapy (TNT). While NAT aims to enhance resectability and overall survival, there appears to be potential for improvement, prompting consideration of alternative neoadjuvant strategies integrating full-dose chemotherapy (CT) and radiotherapy (RT) in TNT approaches. TNT integrates chemotherapy and radiotherapy prior to surgery, potentially improving margin-negative resection rates and enabling curative resection for locally advanced cases. The lingering question: is more always better? This article categorizes TNT strategies into six main groups based on radiotherapy (RT) techniques: (1) conventional chemoradiotherapy (CRT), (2) the Dutch PREOPANC approach, (3) hypofractionated ablative intensity-modulated radiotherapy (HFA-IMRT), and stereotactic body radiotherapy (SBRT) techniques, which further divide into (4) non-ablative SBRT, (5) nearly ablative SBRT, and (6) adaptive ablative SBRT. A comprehensive analysis of the literature on TNT is provided for both borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC), with detailed sections for each.

Normo- or Hypo-Fractionated Photon or Proton Radiotherapy in the Management of Locally Advanced Unresectable Pancreatic Cancer: A Systematic Review

LAPC is associated with a poor prognosis and requires a multimodal treatment approach. However, the role of radiation therapy in LAPC treatment remains controversial. This systematic review aimed to explore the role of proton and photon therapy, with varying radiation techniques and fractionation, in treatment outcomes and their respective toxicity profiles.

METHODS

Clinical studies published from 2012 to 2022 were systematically reviewed using PubMed, MEDLINE (via PubMed) and Cochrane databases. Different radiotherapy-related data were extracted and analyzed.

RESULTS

A total of 31 studies matched the inclusion criteria. Acute toxicity was less remarkable in stereotactic body radiotherapy (SBRT) compared to conventionally fractionated radiotherapy (CFRT), while in proton beam therapy (PBT) grade 3 or higher acute toxicity was observed more commonly with doses of 67.5 Gy (RBE) or higher. Late toxicity was not reported in most studies; therefore, comparison between groups was not possible. The range of median overall survival (OS) for the CFRT and SBRT groups was 9.3-22.9 months and 8.5-20 months, respectively. For the PBT group, the range of median OS was 18.4-22.3 months.

CONCLUSION

CFRT and SBRT showed comparable survival outcomes with a more favorable acute toxicity profile for SBRT. PBT is a promising new treatment modality; however, additional clinical studies are needed to support its efficacy and safety.

S-1 Maintenance Therapy After First-Line Treatment With Nab-Paclitaxel Plus S-1 for Advanced Pancreatic Adenocarcinoma: A Real-World Study

Background

In our previous phase II study, nab-paclitaxel plus S-1 (NPS) showed encouraging objective response rate (ORR) as first-line treatment for advanced pancreatic adenocarcinoma (APAC). This study aimed to evaluate the effectiveness and safety of S-1 maintenance after NPS in APAC and to explore factors predicting survival benefits when using S-1 maintenance.

Methods

Between 2014 and 2018 a total of 182 patients with APAC, who were primarily treated with NPS, were included. For patients without progression or with treatment discontinuation due to any reasons within 4 months during NPS treatment, S-1 monotherapy was administrable as maintenance therapy at the physicians’ discretion based on the patients’ preference and performance status. Efficacy and safety of S-1 maintenance were investigated.

Results

In 123 patients without progression within 4 months during NPS treatment, 74 received S-1 maintenance and had median progression-free survival of 9.6 months and median overall survival of 16.7 months. Multivariable analysis showed that in patients receiving S-1 maintenance after first-line NPS therapy, an Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0, non-metastatic disease, and complete or partial response as best response to NPS chemotherapy were independently associated with better survival. The most common all-grade hematological and non-hematological adverse events were neutropenia (82.4%) and peripheral neurotoxicity (66.2%), respectively, and the most common ≥Grade 3 hematological and non-hematological adverse events were neutropenia (40.5%) and peripheral neurotoxicity (6.8%), respectively in patients who received S-1 maintenance.

Conclusions

Our real-world study showed that S-1 maintenance after tumor response or stable disease induced by first-line NPS treatment was effective and well-tolerated for some patients with APAC, which offers a promising alternative treatment strategy with encouraging survival for APAC.

Efficacy and safety of gemcitabine-capecitabine combination therapy for pancreatic cancer: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Recent randomized controlled trials revealed the combination of gemcitabine and capecitabine (GemCap) regime shows promising efficacy in pancreatic cancer patients. Here, we conducted a meta-analysis to compare the efficacy and safety of gemcitabine (Gem) with GemCap for pancreatic cancer.

METHODS

The database of MEDLINE (PubMed), EMBASE, Cochrane Central Controster of Controlled Trials, Web of Science was searched for relevant randomized controlled trials before 8 April, 2020. The outcomes were overall survival (OS), 12-month survival rate, progress free survival (PFS), partial response rate (PRR), objective response rate (ORR), and Grade 3/4 toxicities.

RESULTS

Five randomized controlled trials involving 1879 patients were included in this study. The results showed that GemCap significantly improves the OS (hazard ratio = 1.15, 95% CI: 1.037-1.276, P = .008), PFS (hazard ratio = 1.211, 95% CI 1.09-1.344, P = 0), PRR (relative risk (RR) = 0.649, 95% CI 0.488-0.862, P = .003), ORR (RR = 0.605, 95% CI 0.458-0.799, P = 0), and the overall toxicity (RR = 0.708, 95% CI 0.620-0.808, P = .000) compared to Gem alone. However, no significant difference was found in 12-month survival.

CONCLUSIONS

Despite a higher incidence of Grade 3/4 toxicity, GemCap was associated with better outcomes of OS, PFS, PRR, ORR, as compared with Gem, which is likely to become a promising therapy for pancreatic cancer.

Total neoadjuvant therapy for initially inoperable pancreatic cancer: A systematic review of phase 2-3 studies

INTRODUCTION

Patients with initially inoperable non-metastatic pancreatic cancer (PC) have a poor prognosis, often similar to those with metastatic disease. Neoadjuvant chemotherapy (CT) plus concomitant or sequential radiotherapy (RT) may cause tumor shrinkage and allow for radical surgery. We pooled data of studies in which patients with locally advanced (unresectable) or borderline resectable PC were treated with a course of induction (or consolidation) CT followed or preceded by neoadjuvant CTRT regimen.

MATERIALS AND METHODS

We searched articles, including phase 2 or 3 studies, published in English from 2010 up to December 2020 in PubMed, SCOPUS, the Cochrane Library, and EMBASE. The primary outcomes were the pooled radical and R0 resection rates, median PFS and OS of included patients (those included in the intent to treat analysis).

RESULTS

A total of 28 studies were finally considered eligible for inclusion in quantitative analysis for a total of 2446 patients with locally advanced/borderline resectable PC. Overall the pooled rate of resection was 29.7% (95%CI 26.7-32.8%). In patients who completed the CT + CTRT program, the overall resection rate was 31.8% (95% 28.4-35.4%). After exclusion of studies that included resectable PCs, the overall resection rate was 19.9% (95%CI 17.3-22.7%). In studies were all patients had unresectable PC (n = 20 studies), the resection rate was 12.1% (95%CI 10-14.5%). In two studies that enrolled all borderline resectable PCs the resection rate was 59.2% (95%CI 48.9-68.8%). The pooled R0 resection rate was 68.7% (95%CI 64.7-72.3%). The median pooled OS was 15.7 months (95%CI 14-17.2 months) and the median pooled PFS was 10.7 (95%CI 9.3-12.1 months).

CONCLUSIONS

Surgery is a treatment option in about one third of patients with initially inoperable PC, following total neoadjuvant therapy. In unresectable cases the resection rate was 12%. Median OS and PFS rates were comparable with historical data of advanced PCs. Optimal integration and sequence of chemo- and radiotherapy in unresectable PC must still be defined.

Intraoperative radiotherapy vs concurrent chemoradiotherapy in the treatment of patients with locally advanced pancreatic cancer

PURPOSE

The purpose of the multi-institutional retrospective study was to evaluate whether intraoperative radiotherapy (IORT) has advantages in the treatment of patients with locally advanced pancreatic cancer (LAPC) compared with concurrent chemoradiotherapy (CCRT).

PATIENTS AND METHODS

A total of 103 patients with LAPC whom was treated with IORT (Arm A; n = 50) or CCRT (Arm B; n = 53) from 2015.6 to 2016.7 were retrospectively identified. Data on feasibility, toxicity, and overall survival (OS) were evaluated.

RESULTS

Most factors of the two cohorts were similar. The severe adverse events (grade 3 and 4) patients in Arm B were higher than patients in Arm A (34% vs 0%). Disease progression was noted in 38 patients (76%) in Arm A and 37 patients (69.8%) in Arm B. The median survival of patients in Arm A and B were 15.3 months (95% CI, 13.0-17.6 months) and 13.8 months (95% CI, 11.0-16.6 months), respectively. The 1-year survival rate were 66.3% in Arm A (95% CI, 52.3%-80.2%) and 60.9% in Arm B (95% CI, 46.4%-75.4%). There was no significant difference in OS between patients treated with IORT and with CCRT (p = 0.458).

CONCLUSION

Our results demonstrated that patients with LAPC treated with IORT showed fewer adverse events, less treatment time, and high feasibility compared to CCRT. Although, IORT has no advantages in survival and tumor control compared with CCRT.

Novel strategies using modern radiotherapy to improve pancreatic cancer outcomes: toward a new standard?

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive solid tumours with an estimated 5-year overall survival rate of 7% for all stages combined. In this highly resistant disease that is located in the vicinity of many radiosensitive organs, the role of radiotherapy (RT) and indications for its use in this setting have been debated for a long time and are still under investigation. Although a survival benefit has yet to be clearly demonstrated for RT, it is the only technique, other than surgery, that has been demonstrated to lead to local control improvement. The adjuvant approach is now strongly challenged by neoadjuvant treatments that could spare patients with rapidly progressive systemic disease from unnecessary surgery and may increase free margin (R0) resection rates for those eligible for surgery. Recently developed dose-escalated RT treatments, designed either to maintain full-dose chemotherapy or to deliver a high biologically effective dose, particularly to areas of contact between the tumour and blood vessels, such as hypofractionated ablative RT (HFA-RT) or stereotactic body RT (SBRT), are progressively changing the treatment landscape. These modern strategies are currently being tested in prospective clinical trials with encouraging preliminary results, paving the way for more effective treatment combinations using novel targeted therapies. This review summarizes the current literature regarding the use of RT for the treatment of primary PDAC, describes the limitations of conventional RT, and discusses the emerging role of dose-escalated RT and heavy-particle RT.

Gemcitabine plus nab-paclitaxel for locally advanced or borderline resectable pancreatic cancer

Overall survival in a phase III study for metastatic pancreatic cancer has significantly improved with gemcitabine (GEM) plus nab-paclitaxel. However, to date, there is limited data on the efficacy and safety of its use for patients with locally advanced (LA) or borderline resectable pancreatic cancer (BRPC). Here, we investigated the efficacy and safety of first-line GEM plus nab-paclitaxel for LA or BRPC. We retrospectively analysed consecutive patients with pathologically confirmed, untreated LA or BRPC who started receiving first-line GEM plus nab-paclitaxel. A total of 30 patients (LA, n = 22; BRPC, n = 8) were analysed. Twelve patients (40%) without distant metastasis received additional chemoradiotherapy using S-1. Laparotomy was performed on 8 patients and 6 (20%; LA, n = 3; BR, n = 3) achieved R0 resection. Objective response rate was 44.8%. For all patients, median progression-free survival and overall survival were 14.8 and 29.9 months, respectively. Median overall survival for LA was 24.1 months with a 2-year survival rate of 50.8%. The most frequently observed grade 3 or 4 toxicities were neutropenia (73%) and biliary infection (13%). First-line GEM plus nab-paclitaxel was well-tolerated and feasible with an encouraging survival for LA or BRPC.

Currently available first-line drug therapies for treating pancreatic cancer

INTRODUCTION

Pancreatic adenocarcinoma is the 9th most common cancer in the United States and the 4th most common cause of cancer-related death given its poor prognosis.

AREAS COVERED

The authors have performed a literature search for pertinent published clinical trials, ongoing Phase 3 clinical trials, and current treatment guidelines using PubMed, Clinicaltrials.gov, and NCCN, ASCO, ESMO, and JPS websites. The review itself discusses landmark studies and ongoing research into the chemotherapy regimens recommended by each oncologic society. The authors also examine drugs that were promising but failed in Phase 3 trials and those currently being investigated. Finally, the authors provide their expert opinion on the subject and provide their future perspectives.

EXPERT OPINION

While advances in chemotherapy for pancreatic cancer have been limited in comparison to other cancers, there have been improvements in survival. Combination therapy and a goal of R0 resection are key elements to extend life. Novel agents directed at the unique properties of pancreatic cancer are promising.

A single institutional experience of combined carbon-ion radiotherapy and chemotherapy for unresectable locally advanced pancreatic cancer

PURPOSE

The aim of this study was to evaluate the efficacy and safety of carbon-ion radiotherapy (C-ion RT) for unresectable locally advanced pancreatic cancer (LAPC).

METHODS AND MATERIALS

Patients with LAPC treated with definitive C-ion RT between April 2014 and July 2017 were analyzed retrospectively. The prescribed dose was 55.2 Gy (relative biological effectiveness [RBE] weighted absorbed dose) in 12 fractions. Overall survival (OS), local control (LC), progression free survival (PFS), and toxicity were evaluated.

RESULTS

Sixty-four patients were enrolled. All patients completed planned course of C-ion RT. The median follow-up time for survivors from the initiation of C-ion RT was 24.4 months (range, 5.1-46.1 months). Median survival time was 25.1 months. Two-year OS, LC, and PFS were 53% (95% confidence interval [CI], 39%-66%), 82% (95% CI, 66%-91%), and 23% (95% CI, 14%-36%), respectively. Four patients experienced acute grade 3 toxicities including 3 gastrointestinal (GI) toxicities. There was no grade 3 or more late toxicity.

CONCLUSIONS

The clinical results of C-ion RT for LAPC at our institution were comparable to those of a recent multi-institutional analysis.

Survival benefit of conversion surgery for patients with initially unresectable pancreatic cancer who responded favorably to nonsurgical treatment

BACKGROUND

Conversion surgery (CS) is expected as a new therapeutic strategy for patients with unresectable pancreatic cancer (UR-PC). We analyzed outcomes of CS for patients with UR-PC and evaluated the survival benefit of CS.

METHODS

Thirty-four patients diagnosed with UR-PC according to the National Comprehensive Cancer Network guideline underwent CS in our hospital. Resectability was considered by multimodal images in patients who underwent nonsurgical treatment (NST) for more than 6 months. CS was performed only in patients who were judged to be able to undergo R0 resection.

RESULTS

Twenty-six patients had locally advanced PC, and eight had distant metastases. The median duration of NST was 9 (range 5-44) months. R0 resection was achieved in 30 patients (88.2%). Six patients (17.6%) showed Evans grade ≥III. Three- and 5-year overall survival (OS) rates from initial treatment were 74% and 56.9%, respectively, with median survival time (MST) of 5.3 years. The actual 5-year OS rate in 19 patients was 47.4% with an MST of 4.0 years. Patients with Evans grade ≥III had a better prognosis than those with Evans grade <III (P = 0.0092, log-rank test).

CONCLUSIONS

Conversion surgery might have survival benefits to patients with UR-PC who responded favorably to NST.