The Role of Consolidation Chemoradiotherapy in Locally Advanced Pancreatic Cancer Receiving Chemotherapy: An Updated Systematic Review and Meta-Analysis

Effect of Radiotherapy in Neoadjuvant Treatment of Borderline Resectable and Locally Advanced Pancreatic Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Pancreatic cancer is a malignant tumor with poor prognosis and bad curative effect. Previous studies did not confirm the role of radiotherapy in neoadjuvant treatment of borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC). By reviewing new findings reported in recent years, we conducted this study to evaluate the survival impact by comparing chemoradiotherapy (CRT) with chemotherapy alone.

MATERIALS AND METHODS

PubMed, Embase, MEDLINE, Web of Science, Scopus, and Cochrane Library were searched for studies reporting median overall survival (OS) in patients with BRPC or LAPC treated with neoadjuvant treatment. Secondary outcomes included progression-free survival (PFS) or disease-free survival (DFS) or recurrence-free survival (RFS) and R0 resection rate.

RESULTS

A total of 18 studies were included in the meta-analysis. OS (hazard ratio [HR] = 0.76, 95% confidence interval [CI]: 0.64-0.91, I2 = 61.7%) and PFS/DFS/RFS (HR = 0.72, 95% CI: 0.58-0.91, I2 = 52.3%) are both favored CRT. Although R0 resection rate was increased in CRT group, significant survival benefit of radiotherapy was found in LAPC and low resection rate subgroup in stratification analysis. Regression analysis showed that only tumor resectability was associated with OS.

CONCLUSIONS

For patients with LAPC and who are unlikely to receive resection, neoadjuvant radiotherapy seems to improve OS and PFS/DFS/RFS.

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.

Predictors of Acute and Late Toxicity in Patients Receiving Chemoradiation for Unresectable Pancreatic Cancer

Purpose

Patients with pancreatic cancer undergoing chemoradiation therapy may experience acute and chronic side effects. We conducted an exploratory analysis of patients with locally advanced pancreatic cancer (LAPC) undergoing definitive chemoradiation to identify factors influencing the occurrence of gastrointestinal (GI) bleeding, short-term radiation side effects, patterns of failure, and survival.

Methods and Materials

Under an institutional review board-approved protocol, we retrospectively studied patients with LAPC treated with chemoradiation. Statistical models were used to test associations between clinical characteristics and outcomes, including upper GI bleeding, radiation treatment breaks, and weight loss during therapy.

Results

Between 1999 and 2012, 211 patients were treated with radiation for pancreatic cancer. All patients received concurrent chemotherapy with either gemcitabine (174) or 5-fluorouracil (27), and 67 received intensity modulated radiation therapy (IMRT). Overall, 18 patients experienced an upper GI bleed related to treatment, with 70% of bleeds occurring in the stomach or duodenum, and among those patients, 11 (61%) patients had a pancreatic head tumor and 17 (94%) patients had a metallic biliary stent. IMRT was associated with decreased risk of postradiation nausea (odds ratio, 0.27 [0.11, 0.67], P = .006) compared with 3-dimensional conformal radiation. Regarding long-term toxicities, patients with a metallic biliary stent at the time of radiation therapy were at a significantly higher risk of developing upper GI bleeding (unadjusted hazard ratio [HR], 15.41 [2.02, 117.42], P = .008), even after controlling for radiation treatment modality and prescribed radiation dose (adjusted HR, 17.38 [2.26, 133.58], P = .006). Furthermore, biliary stent placement was associated with a higher risk of death (HR, 1.99 [1.41, 2.83], P < .001) after adjusting for demographic, treatment-related, and patient-related variables.

Conclusions

Metallic biliary stents may be associated with an increased risk of upper GI bleeding and mortality. Furthermore, IMRT was associated with less nausea and short-term toxicity compared with 3-dimensional conformal therapy.

Can Concurrent Chemoradiotherapy Add Meaningful Benefit in Addition to Induction Chemotherapy in the Management of Borderline Resectable and Locally Advanced Pancreatic Cancer?: A Systematic Review

OBJECTIVES

The role of concomitant chemoradiotherapy or radiotherapy (RT) after induction chemotherapy (IC) in borderline resectable and locally advanced pancreatic ductal adenocarcinoma is debatable. This systematic review aimed to explore this.

METHODS

We searched PubMed, MEDLINE, EMBASE, and Cochrane database. Studies were selected reporting outcomes on resection rate, R0 resection, pathological response, radiological response, progression-free survival, overall survival, local control, morbidity, and mortality.

RESULTS

The search resulted in 6635 articles. After 2 rounds of screening, 34 publications were selected. We found 3 randomized controlled studies and 1 prospective cohort study, and the rest were retrospective studies. There is consistent evidence that addition of concomitant chemoradiotherapy or RT after IC improves pathological response and local control. There are conflicting results in terms of other outcomes.

CONCLUSIONS

Concomitant chemoradiotherapy or RT after IC improves local control and pathological response in borderline resectable and locally advanced pancreatic ductal adenocarcinoma. The role of modern RT in improving other outcome requires further research.

A phase II randomised trial of induction chemotherapy followed by concurrent chemoradiotherapy in locally advanced pancreatic cancer: the Taiwan Cooperative Oncology Group T2212 study

BACKGROUND

The objective of this study was to evaluate the efficacy and safety of induction chemotherapy (ICT), GOFL (gemcitabine, oxaliplatin plus fluorouracil (5-FU)/leucovorin) versus modified FOLFIRINOX (irinotecan, oxaliplatin plus 5-FU/leucovorin), followed by concurrent chemoradiotherapy (CCRT) in locally advanced pancreatic adenocarcinoma (LAPC).

METHODS

Chemo-naive patients with measurable LAPC were eligible and randomly assigned to receive biweekly ICT with either mFOLFIRINOX or GOFL for 3 months. Patients without systemic progression would have 5-FU- or gemcitabine-based CCRT (5040 cGy/28 fractions) and were then subjected to surgery or continuation of chemotherapy until treatment failure. The primary endpoint was 9-month progression-free survival (PFS) rate.

RESULTS

Between July 2013 and January 2019, 55 patients were enrolled. After ICT, 21 (77.8%) of 27 patients who received mFOLFIRINOX and 17 (60.7%) of 28 patients who received GOFL completed CCRT. Of them, one and five had per-protocol R0/R1 resection. On intent-to-treat analysis, the 9-month PFS rate, median PFS and overall survival in mFOLFIRINOX and GOFL arms were 30.5% versus 35.9%, 6.6 (95% confidence interval: 5.9-12.5) versus 7.6 months (3.9-12.3) and 19.6 (13.4-22.9) versus 17.9 months (13.4-23.9), respectively. Grade 3-4 neutropenia and diarrhoea during induction mFOLFIRINOX and GOFL were 37.0% versus 21.4% and 14.8% versus 3.6%, respectively.

CONCLUSION

Induction GOFL and mFOLFIRINOX followed by CCRT provided similar clinical outcomes in LAPC patients.

CLINICALTRIAL

GOV IDENTIFIER

NCT01867892.

Results of a single-arm pilot study of 32P microparticles in unresectable locally advanced pancreatic adenocarcinoma with gemcitabine/nab-paclitaxel or FOLFIRINOX chemotherapy

BACKGROUND

Unresectable locally advanced pancreatic cancer (LAPC) is generally managed with chemotherapy or chemoradiotherapy, but prognosis is poor with a median survival of ∼13 months (or up to 19 months in some studies). We assessed a novel brachytherapy device, using phosphorous-32 (32P) microparticles, combined with standard-of-care chemotherapy.

PATIENTS AND METHODS

In this international, multicentre, single-arm, open-label pilot study, adult patients with histologically or cytologically proven unresectable LAPC received 32P microparticles, via endoscopic ultrasound-guided fine-needle implantation, planned for week 4 of 5-fluorouracil, leucovorin, irinotecan and oxaliplatin (FOLFIRINOX) or gemcitabine/nab-paclitaxel chemotherapy, per investigator's choice. The primary endpoint was safety and tolerability measured using Common Terminology Criteria for Adverse Events version 4.0. The lead efficacy endpoint was local disease control rate at 16 weeks.

RESULTS

Fifty patients were enrolled and received chemotherapy [intention-to-treat (ITT) population]. Forty-two patients received 32P microparticle implantation [per protocol (PP) population]. A total of 1102 treatment-emergent adverse events (TEAEs) were reported in the ITT/safety population (956 PP), of which 167 (139 PP) were grade ≥3. In the PP population, 41 TEAEs in 16 (38.1%) patients were possibly or probably related to 32P microparticles or implantation procedure, including 8 grade ≥3 in 3 (7.1%) patients, compared with 609 TEAEs in 42 (100%) patients attributed to chemotherapy, including 67 grade ≥3 in 28 patients (66.7%). The local disease control rate at 16 weeks was 82.0% (95% confidence interval: 68.6% to 90.9%) (ITT) and 90.5% (95% confidence interval: 77.4% to 97.3%) (PP). Tumour volume, carbohydrate antigen 19-9 levels, and metabolic tumour response at week 12 improved significantly. Ten patients (20.0% ITT; 23.8% PP) had surgical resection and median overall survival was 15.2 and 15.5 months for ITT and PP populations, respectively.

CONCLUSIONS

Endoscopic ultrasound-guided 32P microparticle implantation has an acceptable safety profile. This study also suggests clinically relevant benefits of combining 32P microparticles with standard-of-care systemic chemotherapy for patients with unresectable LAPC.

Current status of non-surgical treatment of locally advanced pancreatic cancer

Pancreatic cancer is the 7th leading cause of death due to cancer in industrialized countries and the 11th most common cancer globally, with 458918 new cases (2.5% of all cancers) and 432242 deaths (4.5% of all cancer deaths) in 2018. Unfortunately, 80% to 90% of the patients present with unresectable disease, and the reported 5-year survival rate range between 10% and 25%, even after successful resection with tumor-free margins. Systemic chemotherapy, radiotherapy, and minimally invasive image-guided procedures that have emerged over the past years, are used for the management of non-operable PC. This review focuses on currently available non-surgical options of locally advanced pancreatic cancer.

Korean clinical practice guideline for pancreatic cancer 2021: A summary of evidence-based, multi-disciplinary diagnostic and therapeutic approaches

Pancreatic cancer is the eighth most common cancer and the fifth most common cause of cancer-related death in Korea. To enable standardization of management and facilitate improvements in outcome, a total of 53 multi-disciplinary experts in gastroenterology, surgery, medical oncology, radiation oncology, radiology, nuclear medicine, and pathology in Korea developed new recommendations that integrate the most up-to-date, evidence-based research findings and expert opinions. Recommendations were made on imaging diagnosis, endoscopic management, surgery, radiotherapy, palliative chemotherapy, and specific management procedures, including neoadjuvant treatment or adjuvant treatment for patients with resectable, borderline resectable, and locally advanced unresectable pancreatic cancer. This is the English version of the Korean clinical practice guideline for pancreatic cancer 2021. This guideline includes 20 clinical questions and 32 statements. This guideline represents the most standard guideline for the diagnosis and treatment of patients with pancreatic ductal adenocarcinoma in adults at this time in Korea. The authors believe that this guideline will provide useful and informative advice.

Photon versus carbon ion irradiation: immunomodulatory effects exerted on murine tumor cell lines

While for photon radiation hypofractionation has been reported to induce enhanced immunomodulatory effects, little is known about the immunomodulatory potential of carbon ion radiotherapy (CIRT). We thus compared the radio-immunogenic effects of photon and carbon ion irradiation on two murine cancer cell lines of different tumor entities. We first calculated the biological equivalent doses of carbon ions corresponding to photon doses of 1, 3, 5, and 10 Gy of the murine breast cancer cell line EO771 and the OVA-expressing pancreatic cancer cell line PDA30364/OVA by clonogenic survival assays. We compared the potential of photon and carbon ion radiation to induce cell cycle arrest, altered surface expression of immunomodulatory molecules and changes in the susceptibility of cancer cells to cytotoxic T cell (CTL) mediated killing. Irradiation induced a dose-dependent G2/M arrest in both cell lines irrespective from the irradiation source applied. Likewise, surface expression of the immunomodulatory molecules PD-L1, CD73, H2-Db and H2-Kb was increased in a dose-dependent manner. Both radiation modalities enhanced the susceptibility of tumor cells to CTL lysis, which was more pronounced in EO771/Luci/OVA cells than in PDA30364/OVA cells. Overall, compared to photon radiation, the effects of carbon ion radiation appeared to be enhanced at higher dose range for EO771 cells and extenuated at lower dose range for PDA30364/OVA cells. Our data show for the first time that equivalent doses of carbon ion and photon irradiation exert similar immunomodulating effects on the cell lines of both tumor entities, highlighted by an enhanced susceptibility to CTL mediated cytolysis in vitro.

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.

ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in unresected pancreatic cancer

Radiation therapy (RT) is a valuable component of multimodal treatment for localized pancreatic cancer. Intraoperative radiation therapy (IORT) is a very precise sub-component of RT that can intensify the irradiation effect for cancer involving an anatomically well-defined volume, generally delivered with electrons (IOERT). Unresectable disease categories benefit from dose-escalated chemoradiation strategies in the context of active systemic therapy and potential radical surgery. Prolonged preoperative treatment may act as a filter for selecting patients with occult resistant metastatic disease. Long-term survivors were observed among unresected patients treated with external beam RT and an IOERT boost (OS 6% at 3 years; 3% >5 years). Improvement of local control through higher RT doses has an impact on the survival of patients with a lower tendency towards disease spread. IOERT is a well-accepted asset in the clinical scenario (maturity and reproducibility of results, albeit of low official level of evidence) and extremely accurate in terms of dose-deposit characteristics and normal tissue sparing. It is a technique that can be integrated with systemic therapy and surgical progress. International guidelines (National Comprehensive Cancer Network or NCCN guidelines) currently recommend the use of IOERT in cases of close surgical margins and residual disease. We report the ESTRO/ACROP recommendations for performing IOERT in unresected pancreatic cancer.

Current Clinical Strategies of Pancreatic Cancer Treatment and Open Molecular Questions

Pancreatic cancer is one of the most lethal malignancies and is associated with a poor prognosis. Surgery is considered the only potential curative treatment for pancreatic cancer, followed by adjuvant chemotherapy, but surgery is reserved for the minority of patients with non-metastatic resectable tumors. In the future, neoadjuvant treatment strategies based on molecular testing of tumor biopsies may increase the amount of patients becoming eligible for surgery. In the context of non-metastatic disease, patients with resectable or borderline resectable pancreatic carcinoma might benefit from neoadjuvant chemo- or chemoradiotherapy followed by surgeryPatients with locally advanced or (oligo-/poly-)metastatic tumors presenting significant response to (neoadjuvant) chemotherapy should undergo surgery if R0 resection seems to be achievable. New immunotherapeutic strategies to induce potent immune response to the tumors and investigation in molecular mechanisms driving tumorigenesis of pancreatic cancer may provide novel therapeutic opportunities in patients with pancreatic carcinoma and help patient selection for optimal treatment.

Characterization of Oncolytic Vaccinia Virus Harboring the Human IFNB1 and CES2 Transgenes

Purpose

The purpose of this study was to assess characteristics of SJ-815, a novel oncolytic vaccinia virus lacking a functional thymidine kinase-encoding TK gene, and instead, having two human transgenes: the IFNB1 that encodes interferon β1, and the CES2 that encodes carboxylesterase 2, which metabolizes the prodrug, irinotecan, into cytotoxic SN-38.

Materials and Methods

Viral replication and dissemination of SJ-815 were measured by plaque assay and comet assay, respectively, and compared to the backbone of SJ-815, a modified Western Reserve virus named WI. Tumor cytotoxicity of SJ-815 (or mSJ-815, which has the murine IFNB1 transgene for mouse cancers) was evaluated using human and mouse cancer cells. Antitumor effects of SJ-815, with/without irinotecan, were evaluated using a human pancreatic cancer-bearing mouse model and a syngeneic melanoma-bearing mouse model. The SN-38/irinotecan ratios in mouse melanoma tissue 4 days post irinotecan treatment were compared between groups with and without SJ-815 intravenous injection.

Results

SJ-815 demonstrated significantly lower viral replication and dissemination, but considerably stronger in vitro tumor cytotoxicity than WI. The combination use of SJ-815 plus irinotecan generated substantial tumor regression in the human pancreatic cancer model, and significantly prolonged survival in the melanoma model (hazard ratio, 0.11; 95% confidence interval, 0.02 to 0.50; p=0.013). The tumor SN-38/irinotecan ratios were over 3-fold higher in the group with SJ-815 than those without (p < 0.001).

Conclusion

SJ-815 demonstrates distinct characteristics gained from the inserted IFNB1 and CES2 transgenes. The potent antitumor effects of SJ-815, particularly when combined with irinotecan, against multiple solid tumors make SJ-815 an attractive candidate for further preclinical and clinical studies.

Duration of chemotherapy prior to chemoradiation affects survival outcomes for resected stage I-II or unresected stage III pancreatic cancer

BACKGROUND

For resected early stage pancreatic cancer, RTOG 9704 evaluated the outcome of 3 weeks of postoperative chemotherapy (C) followed by chemoradiation (CRT) and further C. For unresectable locally advanced pancreatic cancer, a recent literature review of prospective studies showed that the duration of induction C prior to CRT can impact survival. However, the ideal duration of C prior to CRT remains unclear for these patient cohorts. This National Cancer Database (NCDB) study was performed to compare the outcome of various durations of C prior to CRT.

METHODS

The NCDB was queried for resected primary stage I-II, cT1-3N0-1M0, and unresected stage III, cT4N0-1M0 pancreatic adenocarcinoma treated with C + CRT (2004-2015). Cohorts I-II and III included stage I-II and stage III cases, respectively. Patients were stratified by short (short C) and long duration (long C) of chemotherapy based on their median durations. Baseline patient, tumor, and treatment characteristics were examined. The primary endpoint was overall survival (OS). Kaplan-Meier analysis, multivariable Cox proportional hazards method, and propensity score matching were used.

RESULTS

Among 1577 patients, cohort I-II had 839 patients and cohort III had 738 patients. The longer duration of chemotherapy prior to CRT showed improved OS in the multivariate analysis in both cohort I-II (hazards ratio [HR] 0.72, P < 0.001) and cohort III (HR 0.83, P = 0.03). Using 1:1 propensity score matching, 610 patients for cohort I-II and 542 patients for cohort III were matched. After matching, long C remained statistically significant for improved OS compared with short C in both cohort I-II (median OS 26.1 vs 21.9 months; P = 0.003) and cohort III (median OS 16.7 vs 14.2; P = 0.02).

CONCLUSION

Our NCDB study using propensity score-matched analysis showed a survival benefit for using the longer duration of chemotherapy compared to the shorter duration for both resected stage I-II and unresected stage III pancreatic cancer.

Contemporary management of borderline resectable pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive tumors, with a low rate of survival, likely due to the tendency of the tumor for early local and distant spread. Pancreatic cancer accounts for about 3% of all cancers in the US and about 7% of all cancer deaths. Surgical resection still represents the best curative treatment for PDAC, although only 10–20% of patients are upfront resectable at diagnosis, 50% has metastatic disease and 35% locally advanced cancer. The 5-year overall survival (OS) after curative resection is limited to 20%. Moreover among patients who undergo surgery, 30% develop early recurrence while most of them will eventually relapse. The risk of early failure after surgery could be associated with inadequate preoperative radiological staging, lack of radical surgery and differences in tumor aggressiveness. In recent years, more accurate patient categorization due to sophisticated imaging tools and techniques increase the survival rate while neoadjuvant treatment can help surgeons select patients who will benefit most from surgery. Neoadjuvant therapy includes chemotherapy alone, chemoradiotherapy, chemotherapy with chemoradiation and targeted therapies. The aim of this review is to present the available data concerning the management of patients with borderline PDAC.

Large database utilization in health outcomes research in pancreatic cancer: an update

We sought to review published aggregate dataset studies on pancreatic cancer in the national and international settings, discuss the advantages and disadvantages these datasets possess, and possible future directions. A combination of Google Scholar, PubMed, and MEDLINE were used with search terms "pancreatic cancer" + "resectable" + "national cancer database", "pancreatic cancer" + "unresectable" + "national cancer database" and more broadly "borderline resectable pancreatic cancer", "locally advanced pancreatic cancer", "unresectable pancreatic cancer", and "resectable pancreatic cancer". Original articles and abstracts from this search were included, including data from the Surveillance, Epidemiology, and End Results (SEER) database, National Cancer Database (NCDB), and SEER-Medicare within the United States (US), as well as international database studies. Multiple database studies have been published regarding the role for radiotherapy in resected pancreatic cancer (n=6), the timing of additional therapy in resectable pancreatic cancer (n=4), and the role for radiotherapy and resection in locally advanced pancreatic cancer (LAPC) (n=4). Studies from both SEER and NCDB found a survival benefit to post-operative radiotherapy. In resectable pancreatic cancer, neoadjuvant treatment was found to be superior to adjuvant (NCDB). Chemoradiotherapy was found to be more beneficial than chemotherapy alone in LAPC, and patients who received highly-conformal or stereotactic body radiotherapy (SBRT) had improved survival compared to either conformal radiotherapy or chemotherapy alone. These studies also found that up to 10% of patients underwent resection, with a 90% margin-negative rate, and either one-half to one-third the risk of death of non-surgical patients. Criticism of large datasets includes lack of granularity of performance status, diagnosis, treatment, and outcomes-related data compared to properly administered prospective trials, as well as cross-over between treatment arms that cannot be accounted for, and concerns over quality of data represented. The US has witnessed a growing number of comparative effectiveness studies in pancreatic cancer. When taken together, certain themes emerge that are consistent with both single-institution data and clinical trials. These studies have also provided insight into questions not readily answerable by clinical trials. However, they require caution in interpretation.