Pathologic response with neoadjuvant chemotherapy and stereotactic body radiotherapy for borderline resectable and locally-advanced pancreatic cancer

Stereotactic body radiotherapy in pancreatic adenocarcinoma

BACKGROUND

Stereotactic body radiotherapy (SBRT) in pancreatic cancer allows high delivery of radiation doses on tumors without affecting surrounding tissue. This review aimed at the SBRT application in the treatment of pancreatic cancer.

DATA SOURCES

We retrieved articles published in MEDLINE/PubMed from January 2017 to December 2022. Keywords used in the search included: "pancreatic adenocarcinoma" OR "pancreatic cancer" AND "stereotactic ablative radiotherapy (SABR)" OR "stereotactic body radiotherapy (SBRT)" OR "chemoradiotherapy (CRT)". English language articles with information on technical characteristics, doses and fractionation, indications, recurrence patterns, local control and toxicities of SBRT in pancreatic tumors were included. All articles were assessed for validity and relevant content.

RESULTS

Optimal doses and fractionation have not yet been defined. However, SBRT could be the standard treatment in patients with pancreatic adenocarcinoma in addition to CRT. Furthermore, the combination of SBRT with chemotherapy may have additive or synergic effect on pancreatic adenocarcinoma.

CONCLUSIONS

SBRT is an effective modality for patients with pancreatic cancer, supported by clinical practice guidelines as it has demonstrated good tolerance and good disease control. SBRT opens a possibility of improving outcomes for these patients, both in neoadjuvant treatment and with radical intent.

Safety and Efficacy of Neoadjuvant SABR in Pancreatic Cancer: Effect of Magnetic Resonance Imaging-Guided Respiratory-Gated Adaptive Radiation Therapy

Purpose

We aimed to evaluate the safety and efficacy of neoadjuvant SABR using magnetic resonance imaging-guided respiratory-gated adaptive radiation therapy (MRgRg-ART) in pancreatic cancer.

Methods and Materials

We performed a single-institution retrospective review in patients with pancreatic cancer who underwent neoadjuvant SABR followed by surgical resection. After neoadjuvant chemotherapy, those considered resectable by the multidisciplinary team received SABR over 5 consecutive days using MRgRg-ART. Factors associated with severe postoperative complications (Clavien-Dindo grade ≥III) and prognostic factors for overall survival were analyzed.

Results

Sixty-two patients were included in the analysis, with a median follow-up of 10.3 months. The median prescribed dose to the planning target volume was 50 Gy. Fifty-two (85.3%) patients underwent R0 resection, and 11 (18.0%) experienced severe postoperative complications. No factors were associated with the incidence of severe postoperative complications. There were 3 cases of locoregional recurrence, resulting in a 12-month local control rate of 93.1%. Elevated postoperative carbohydrate antigen 19-9 was significantly associated with poor overall survival in the multivariate analysis (P = .037).

Conclusions

Neoadjuvant SABR with 50 Gy using MRgRg-ART delivered to pancreatic cancer resulted in a notable survival outcome with acceptable toxicities. Further studies are warranted to investigate the long-term effects of this method.

Comparative Effectiveness of Chemotherapy Alone Versus Radiotherapy-Based Regimens in Locally Advanced Pancreatic Cancer: A Real-World Multicenter Analysis (PAULA-1)

Different options for locally advanced pancreatic cancer (LAPC) are available based on international guidelines: chemotherapy (CHT), chemoradiation (CRT), and stereotactic body radiotherapy (SBRT). However, the role of radiotherapy is debated in LAPC. We retrospectively compared CHT, CRT, and SBRT ± CHT in a real-world setting in terms of overall survival (OS), local control (LC), and distant metastasis-free survival (DMFS). LAPC patients from a multicentric retrospective database were included (2005-2018). Survival curves were calculated using the Kaplan-Meier method. Multivariable Cox analysis was performed to identify predictors of LC, OS, and DMFS. Of the 419 patients included, 71.1% were treated with CRT, 15.5% with CHT, and 13.4% with SBRT. Multivariable analysis showed higher LC rates for CRT (HR: 0.56, _95%CI 0.34-0.92, p = 0.022) or SBRT (HR: 0.27, _95%CI 0.13-0.54, p < 0.001), compared to CHT. CRT (HR: 0.44, _95%CI 0.28-0.70, p < 0.001) and SBRT (HR: 0.40, _95%CI 0.22-0.74, p = 0.003) were predictors of prolonged OS with respect to CHT. No significant differences were recorded in terms of DMFS. In selected patients, the addition of radiotherapy to CHT is still an option to be considered. In patients referred for radiotherapy, CRT can be replaced by SBRT considering its duration, higher LC rate, and OS rate, which are at least comparable to that of CRT.

Stereotactic Body Radiotherapy (SBRT) of Pancreatic Cancer-A Critical Review and Practical Consideration

Pancreatic cancer is the third leading cause of cancer death in the developed world and is predicted to become the second by 2030. A cure may be achieved only with surgical resection of an early diagnosed disease. Surgery for more advanced disease is challenging and can be contraindicated for many reasons. Neoadjuvant therapy may improve the probability of achieving R0 resection. It consists of systemic treatment followed by radiation therapy applied concurrently or sequentially with cytostatics. A novel approach to irradiation, stereotactic body radiotherapy (SBRT), has the potential to improve treatment results. SBRT can deliver higher doses of radiation to the tumor in only a few treatment fractions. It has attracted significant interest for pancreatic cancer patients, as it is completed quickly, requires less time away from full-dose chemotherapy, and is well-tolerated than conventional radiotherapy. In this review, we aim to provide the reader with a basic overview of current evidence for SBRT indications in the treatment of pancreatic tumors. In the second part of the review, we focus on practical information with respect to SBRT treatment plan preparation the performance of such therapy. Finally, we discuss future directions related to the use of magnetic resonance linear accelerators.

Neoadjuvant treatment of pancreatic adenocarcinoma: Chemoradiation or stereotactic body radiation therapy?

Despite recent advances, the prognosis of pancreatic adenocarcinomas remains poor, even for patients with resectable tumors. For these latter, new approaches based on neoadjuvant treatment have been developed. Two components are used: chemotherapy and radiation therapy (RT). Indeed, pre-operative RT has many advantages in terms of efficacy and tolerance. It increases notably the chances of subsequent complete tumor resection. Several prospective trials are currently ongoing to clarify its place in the therapeutic arsenal. Another crucial question is to know which is the best RT technique: conventional normofractionated chemoradiotherapy or hypofrationated stereotactic body RT?

Pathological complete response after neoadjuvant therapy for pancreatic ductal adenocarcinoma does not equal cure

BACKGROUND

There is a scarcity of data about patients with pancreatic ductal adenocarcinoma (PDAC) who received neoadjuvant therapy before radical resection and achieved a pathological complete response (pCR). The aim of this study was to describe the recurrence and survival in this subset of patients.

METHODS

The Embase, Web of Science and PubMed databases were systematically searched for eligible studies published between January 2000 and August 2020. Clinicopathological data of individual patients with pCR after neoadjuvant therapy for PDAC were extracted, pooled and analysed.

RESULTS

A total of 87 patients were subject to analysis. The majority of patients were female (61.5%) with a median age of 64 (range 43-75) years. Among reported, 41.9% of patients received gemcitabine-based neoadjuvant chemotherapy, 33.7% received FOLFIRINOX (5-fluorouracil, oxaliplatin, irinotecan and leucovorin)-based regimen and 24.4% received fluoropyrimidine drugs-based regimen. Preoperative radiation was administered to 78.8% of the patients. Twenty-nine (33.3%) patients developed disease recurrence during a median follow-up period of 22.4 (range 2-194) months. The median, 1-, 3- and 5-year overall survival rates were 105 months, 93.6%, 70.3% and 70.3%, respectively.

CONCLUSION

Despite the excellent long-term outcomes, a pCR does not equal cure because this cohort of patients still has a significant risk of recurrence.

A phase II trial proposal of total neoadjuvant treatment with primary chemotherapy, stereotactic body radiation therapy, and intraoperative radiation therapy in borderline resectable pancreatic adenocarcinoma

BACKGROUND

The current management guidelines recommend that patients with borderline resectable pancreatic adenocarcinoma (BRPC) should initially receive neoadjuvant chemotherapy. The addition of advanced radiation therapy modalities, including stereotactic body radiation therapy (SBRT) and intraoperative radiation therapy (IORT), could result in a more effective neoadjuvant strategy, with higher rates of margin-free resections and improved survival outcomes.

METHODS/DESIGN

In this single-center, single-arm, intention-to-treat, phase II trial newly diagnosed BRPC will receive a "total neoadjuvant" therapy with FOLFIRINOX (5-fluorouracil, irinotecan and oxaliplatin) and hypofractionated SBRT (5 fractions, total dose of 30 Gy with simultaneous integrated boost of 50 Gy on tumor-vessel interface). Following surgical exploration or resection, IORT will be also delivered (10 Gy). The primary endpoint is 3-year survival. Secondary endpoints include completion of neoadjuvant treatment, resection rate, acute and late toxicities, and progression-free survival. In the subset of patients undergoing resection, per-protocol analysis of disease-free and disease-specific survival will be performed. The estimated sample size is 100 patients over a 36-month period. The trial is currently recruiting.

TRIAL REGISTRATION

NCT04090463 at clinicaltrials.gov.

SPARC, a phase-I trial of pre-operative, margin intensified, stereotactic body radiation therapy for pancreatic cancer

BACKGROUND AND PURPOSE

Following resection of pancreatic cancer, risk of positive margins and local recurrence remain high, especially for borderline-resectable pancreatic cancer (BRPC). We aimed to establish the maximum tolerated dose of a margin-intensified five-fraction stereotactic body radiotherapy (SBRT) regimen designed to treat the region at risk.

MATERIALS AND METHODS

We conducted a prospective multicentre phase-1 rolling-six dose-escalation study. BRPC patients received pre-operative SBRT, with one dose to the primary tumour and an integrated boost to the region where tumour was in contact with vasculature. Four dose-levels were proposed, with starting dose 30 Gy to primary PTV and 45 Gy to boost volume (PTV_R), in five daily fractions. Primary endpoint was maximum tolerated dose (MTD), defined as highest dose where zero of three or one of six patients experienced dose-limiting toxicity (DLT).

RESULTS

Twelve patients were registered, eleven received SBRT. Radiotherapy was well tolerated with all treatment completed as scheduled. Dose was escalated one level up from starting dose without encountering any DLT (prescribed 32.5 Gy PTV, 47.5 Gy PTV_R). Nine serious adverse reactions or events occurred (seven CTCAE Grade 3, two Grade 4). Two patients went on to have surgical resection. Median overall survival for SBRT patients was 8.1 months. The study closed early when it was unable to recruit to schedule.

CONCLUSION

Toxicity of SBRT was low for the two dose-levels that were tested, but MTD was not established. Few patients subsequently underwent resection of pancreatic tumour after SBRT, and it is difficult to draw conclusions regarding the safety or toxicity of these therapies in combination.

Maximizing Tumor Control and Limiting Complications With Stereotactic Body Radiation Therapy for Pancreatic Cancer

PURPOSE

Stereotactic body radiation therapy (SBRT) and stereotactic ablative body radiation therapy is being increasingly used for pancreatic cancer (PCa), particularly in patients with locally advanced and borderline resectable disease. A wide variety of dose fractionation schemes have been reported in the literature. This HyTEC review uses tumor control probability models to evaluate the comparative effectiveness of the various SBRT treatment regimens used in the treatment of patients with localized PCa.

METHODS AND MATERIALS

A PubMed search was performed to review the published literature on the use of hypofractionated SBRT (usually in 1-5 fractions) for PCa in various clinical scenarios (eg, preoperative [neoadjuvant], borderline resectable, and locally advanced PCa). The linear quadratic model with α/β= 10 Gy was used to address differences in fractionation. Logistic tumor control probability models were generated using maximum likelihood parameter fitting.

RESULTS

After converting to 3-fraction equivalent doses, the pooled reported data and associated models suggests that 1-year local control (LC) without surgery is ≈79% to 86% after the equivalent of 30 to 36 Gy in 3 fractions, showing a dose response in the range of 25 to 36 Gy, and decreasing to less than 70% 1-year LC at doses below 24 Gy in 3 fractions. The 33 Gy in 5 fraction regimen (Alliance A021501) corresponds to 28.2 Gy in 3 fractions, for which the HyTEC pooled model had 77% 1-year LC without surgery. Above an equivalent dose of 28 Gy in 3 fractions, with margin-negative resection the 1-year LC exceeded 90%.

CONCLUSIONS

Pooled analyses of reported tumor control probabilities for commonly used SBRT dose-fractionation schedules for PCa suggests a dose response. These findings should be viewed with caution given the challenges and limitations of this review. Additional data are needed to better understand the dose or fractionation-response of SBRT for PCa.

Dosimetric Feasibility Study of Dose Escalated Stereotactic Body Radiation Therapy (SBRT) in Locally Advanced Pancreatic Cancer (LAPC) Patients: It Is Time to Raise the Bar

Background and Objective

To assess the dosimetric feasibility of a stereotactic body radiotherapy (SBRT) dose escalated protocol, with a simultaneous integrated boost (SIB) and a simultaneous integrated protection (SIP) approach, in patients with locally advanced pancreatic cancer (LAPC).

Material and Methods

Twenty LAPC lesions, previously treated with SBRT at our Institution, were re-planned. The original prescribed and administered dose was 50/30/25 Gy in five fractions to PTV_sib (tumor-vessel interface [TVI])/PTV_t (tumor volume)/PTV_sip (overlap area between PTV_t and planning organs at risk volume [PRV_oars]), respectively. At re-planning, the prescribed dose was escalated up to 60/40/33 Gy in five fractions to PTV_sib/PTV_t/PTV_sip, respectively. All plans were performed using an inspiration breath hold (IBH) technique and generated with volumetric modulated arc therapy (VMAT). Well-established and accepted OAR dose constraints were used (D_0.5cc < 33 Gy for luminal OARs and D_0.5cc < 38 Gy for corresponding PRV_oars). The primary end-point was to achieve a median dose equal to the prescription dose for the PTV_sib with D₉₈≥ 95% (95% of prescription dose is the minimum dose), and a coverage for PTV_t and PTV_sip of D₉₅≥95%, with minor deviations in OAR dose constraints in < 10% of the plans.

Results

PTV_sib median (± SD) dose/D₉₅/conformity index (CI) were 60.54 (± 0.85) Gy/58.96 (± 0.86) Gy/0.99 (± 0.01), respectively; whilst PTV_t median (± SD) dose/D₉₅ were 44.51 (± 2.69) Gy/38.44 (± 0.82) Gy, and PTV_sip median (± SD) dose/D₉₅ were 35.18 (± 1.42) Gy/33.01 (± 0.84) Gy, respectively. With regard to OARs, median (± SD) maximum dose (D_0.5cc) to duodenum/stomach/bowel was 29.31 (± 5.72) Gy/25.29 (± 6.90) Gy/27.03 (± 5.67) Gy, respectively. A minor acceptable deviation was found for a single plan (bowel and duodenum D_0.5cc=34.8 Gy). V38 < 0.5 cc was achieved for all PRV luminal OARs.

Conclusions

In LAPC patients SBRT, with a SIB/SIP dose escalation approach up to 60/40/33 Gy in five fractions to PTV_sib/PTV_t/PTV_sip, respectively, is dosimetrically feasible with adequate PTVs coverage and respect for OAR dose constraints.

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.

Basics and Frontiers on Pancreatic Cancer for Radiation Oncology: Target Delineation, SBRT, SIB technique, MRgRT, Particle Therapy, Immunotherapy and Clinical Guidelines

Pancreatic cancer represents a modern oncological urgency. Its management is aimed to both distal and local disease control. Resectability is the cornerstone of treatment aim. It influences the clinical presentation’s definitions as up-front resectable, borderline resectable and locally advanced (unresectable). The main treatment categories are neoadjuvant (preoperative), definitive and adjuvant (postoperative). This review will focus on (i) the current indications by the available national and international guidelines; (ii) the current standard indications for target volume delineation in radiotherapy (RT); (iii) the emerging modern technologies (including particle therapy and Magnetic Resonance [MR]-guided-RT); (iv) stereotactic body radiotherapy (SBRT), as the most promising technical delivery application of RT in this framework; (v) a particularly promising dose delivery technique called simultaneous integrated boost (SIB); and (vi) a multimodal integration opportunity: the combination of RT with immunotherapy.

Impact of Neoadjuvant Chemoradiation on Pathologic Response in Patients With Localized Pancreatic Cancer

Introduction/Background: Multimodal neoadjuvant therapy has resulted in increased rates of histologic response in pancreatic tumors and adjacent lymph nodes. The biologic significance of the collective response in the primary tumor and lymph nodes is not understood.

Methods: Patients with localized PC who received neoadjuvant therapy and surgery with histologic assessment of the primary tumor and local-regional lymph nodes were included. Histopathologic response was classified using the modified Ryan score as follows: no viable cancer cells (CR), rare groups of cancer cells (nCR), residual cancer with evident tumor regression (PR), and extensive residual cancer with no evident tumor regression (NR). Nodal status was defined by number of lymph nodes (LN) with tumor metastases: N0 (0 LN), N1 (1–3), N2 (≥4).

Results: Of 341 patients with localized PC who received neoadjuvant therapy and surgery, 107 (31%) received chemoradiation alone, 44 (13%) received chemotherapy alone, and 190 (56%) received chemotherapy and chemoradiation. Histopathologic response consisted of 15 (4%) CRs, 59 (17%) nCRs, 188 (55%) PRs, and 79 (23%) NRs. Patients who received chemotherapy alone had the worst responses (n = 21 for NR, 48%) as compared to patients who received chemoradiation alone (n = 25 for NR, 24%) or patients who received both therapies (n = 33 for NR, 17%) (Table 1; p = 0.001). Median overall survival for all 341 patients was 39 months; OS by histopathologic subtype was not reached (CR), 49 months (nCR), 38 months (PR), and 34 months (NR), respectively (p = 0.004). Of the 341 patients, 208 (61%) had N0 disease, 97 (28%) had N1 disease, and 36 (11%) had N2 disease. In an adjusted hazards model, modified Ryan score of PR or NR (HR: 1.71; 95% CI: 1.15–2.54; p = 0.008) and N1 (HR: 1.42; 95% CI: 1.1.02–2.01; p = 0.04), or N2 disease (HR: 2.54, 95% CI: 1.64–3.93; p < 0.001) were associated with increased risk of death.

Conclusions: Neoadjuvant chemotherapy alone is associated with lower rates of pathologic response. Patients with CR or nCR have a significantly improved OS as compared to patients with PR or NR. Nodal status is the most important pathologic prognostic factor. Neoadjuvant chemoradiation may be an important driver of pathologic response.

Measuring the Integration of Stereotactic Ablative Radiotherapy Plus Surgery for Early-Stage Non-Small Cell Lung Cancer: A Phase 2 Clinical Trial

Importance

Stereotactic ablative radiotherapy (SABR) is a standard treatment option in patients with medically inoperable early-stage non-small cell lung cancer (NSCLC), yet the pathologic complete response (pCR) rate after SABR is unknown. Neoadjuvant SABR in patients with cancer who are fit for resection has been hypothesized to improve local control and induce antitumor immune activity, potentially leading to better outcomes.

Objectives

To determine the pCR rate after SABR and to assess oncologic and toxicity outcomes after a combined approach of neoadjuvant SABR followed by surgery.

Design, Setting, and Participants

A phase 2, single-arm trial, with patient accrual from September 30, 2014, to August 15, 2017 (median follow-up, 19 months), was performed at a tertiary academic cancer center. Patients 18 years or older with T1T2N0M0 NSCLC and good performance status, with adequate pulmonary reserve to undergo surgical resection, were studied.

Interventions

Patients underwent neoadjuvant SABR using a risk-adapted fractionation scheme followed by surgery 10 weeks later.

Main Outcomes and Measures

The pCR rate as determined by hematoxylin-eosin staining.

Results

Forty patients (mean [SD] age, 68 [8] years; 23 [58%] female) were enrolled. Thirty-five patients underwent surgery and were evaluable for the primary end point. The pCR rate was 60% (95% CI, 44%-76%). The 30- and 90-day postoperative mortality rates were both 0%. Grade 3 or 4 toxic effects occurred in 7 patients (18%). In patients receiving surgery, 2-year overall survival was 77% (95% CI, 48%-91%), local control was 100% (95% CI, not defined), regional control was 53% (95% CI, 22%-76%), and distant control was 76% (95% CI, 45%-91%). Quality of life did not decline after treatment, with no significant changes in mean Functional Assessment of Cancer Therapy for Lung-Trial Outcome Index score during the first year of follow-up.

Conclusions and Relevance

The pCR rate after SABR for early-stage NSCLC was 60%, lower than hypothesized. The combined approach had toxic effects comparable to series of surgery alone, and there was no perioperative mortality. Further studies are needed to evaluate this combined approach compared with surgical resection alone.

Trial Registration

ClinicalTrials.gov identifier: NCT02136355.

[Stereotactic body radiotherapy: Passing fad or revolution?]

Stereotactic body radiotherapy (SBRT) is a young technology that can deliver a high dose of radiation to the target, utilizing either a single dose or a small number of fractions with a high degree of precision within the body. Various technical solutions co-exist nowadays, with particular features, possibilities and limitations. Health care authorities have currently validated SBRT in a very limited number of locations, but many indications are still under investigation. It is therefore challenging to accurately appreciate the SBRT therapeutic index, its place and its role within the anticancer therapeutic arsenal. The aim of the present review is to provide SBRT definitions, current indications, and summarize the future ways of research. There are three validated indications for SBRT: un-resecable T1-T2 non small cell lung cancer, <3 slow-growing pulmonary metastases secondary to a stabilized primary, and the tumours located close to the medulla. In other situations, the benefit of SBRT is still to be demonstrated. One of the most promising way of research is the ablative treatment of oligo metastatic cancers, with recent studies suggesting a survival benefit. Furthermore, the most recent data suggest that SBRT is safe. Finally, the SBRT combined with immune therapies is promising, since it could theoretically trigger the adaptative anticancer response.

The Evolving Field of Stereotactic Body Radiation Therapy in Pancreatic Cancer

Pancreatic cancer remains a devastating disease with dismal outcomes despite the development of novel chemotherapeutic regimens and radiation techniques. Stereotactic body radiation therapy (SBRT) offers an advantage both in image guidance and radiation dose delivery to direct ablative doses to tumors with acceptable toxicity compared to conventional techniques. Recent literature is clustered with data pertaining to SBRT in patients with resectable, borderline resectable and locally advanced pancreatic tumors. We here present a summary of the current data and highlight the limitations and potential for future growth. Further clinical study in the form of multi-institutional trials is warranted to establish the role of SBRT in combination with new chemo- therapeutic agents as well as a non-invasive alternative to surgery.

Is a Pathological Complete Response Following Neoadjuvant Chemoradiation Associated With Prolonged Survival in Patients With Pancreatic Cancer?

OBJECTIVES

To describe the survival outcome of patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma (BR/LA-PDAC) who have a pathologic complete response (pCR) following neoadjuvant chemoradiation.

BACKGROUND

Patients with BR/LA-PDAC are often treated with neoadjuvant chemoradiation in an attempt to downstage the tumor. Uncommonly, a pCR may result.

METHODS

A retrospective review of a prospectively maintained database was performed at a single institution. pCR was defined as no viable tumor identified in the pancreas or lymph nodes by pathology. A near complete response (nCR) was defined as a primary tumor less than 1 cm, without nodal metastasis. Overall survival (OS) and disease-free survival (DFS) were reported.

RESULTS

One hundred eighty-six patients with BR/LA-PDAC underwent neoadjuvant chemoradiation and subsequent pancreatectomy. Nineteen patients (10%) had a pCR, 29 (16%) had an nCR, and the remaining 138 (74%) had a limited response. Median DFS was 26 months in patients with pCR, which was superior to nCR (12 months, P = 0.019) and limited response (12 months, P < 0.001). The median OS of nCR (27 months, P = 0.003) or limited response (26 months, P = 0.001) was less than that of pCR (more than 60 months). In multivariable analyses pCR was an independent prognostic factor for DFS (HR = 0.45; 0.22-0.93, P = 0.030) and OS (HR=0.41; 0.17-0.97, P = 0.044). Neoadjuvant FOLFIRINOX (HR=0.47; 0.26-0.87, P = 0.015) and negative lymph node status (HR=0.57; 0.36-0.90, P = 0.018) were also associated with improved survival.

CONCLUSIONS

Patients with BR/LA-PDAC who had a pCR after neoadjuvant chemoradiation had a significantly prolonged survival compared with those who had nCR or a limited response.

Current and emerging radiotherapy strategies for pancreatic adenocarcinoma: stereotactic, intensity modulated and particle radiotherapy

The role of radiotherapy for locally advanced pancreatic cancer (LAPC) is unclear based on studies that used conventional doses and fractionation schedules. Modern radiotherapy techniques have not been studied in depth, however. We reviewed the literature on emerging methods of delivering higher doses of conformal radiotherapy using stereotactic body radiation, intensity modulated radiation, and particle beam radiation, highlighting clinical outcomes and toxicities. The literature review suggests low rates of acute and late toxicities when higher doses of radiation are given with careful attention to normal tissue dose constraints, including for stereotactic body radiotherapy (SBRT), escalated doses with intensity modulated radiation therapy (IMRT), and particle-based therapy. Retrospective evidence suggests prolonged survival for patients who receive biological equivalent doses above 70 Gy. Prospective trials that evaluate modern radiotherapy techniques are warranted for LAPC.

Resectable pancreatic adenocarcinoma neo-adjuvant FOLF(IRIN)OX-based chemotherapy - a multicenter, non-comparative, randomized, phase II trial (PANACHE01-PRODIGE48 study)

BACKGROUND

At time of diagnosis, less than 10% of patients with pancreatic adenocarcinomas (PDAC) are considered to be immediately operable (i.e. resectable). Considering their poor overall survival (OS), only tumours without vascular invasion (NCCN 2017) should be considered for resection, i.e. those for which resection with disease-free margins (R0) is theoretically possible in absence of presurgery treatment. With regard to high R1 rates and undetectable locoregional and/or metastatic spreading prior to surgery explain (at least in part) the observed 1-year relapse and mortality rates of 50 and 25%, respectively. Today, upfront surgery followed by adjuvant chemotherapy is the reference treatment in Europe. The main limitation of the adjuvant approach is the low rate of completion of the full therapeutic sequence. Indeed, only 47 to 60% patients received any adjuvant therapy after resection compared to more than 75% for neoadjuvant therapy. No previous prospective study has compared this approach to a neoadjuvant FOLFIRINOX or FOLFOX chemotherapy for resectable PDAC.

METHODS

PANACHE01-PRODIGE48 is a prospective multicentre controlled randomized non comparative Phase II trial, evaluating the safety and efficacy of two regimens of neo-adjuvant chemotherapy (4 cycles of mFOLFIRINOX or FOLFOX) relative to the current reference treatment (surgery and then adjuvant chemotherapy) in patients with resectable PDAC. The main co-primary endpoints are OS rate at 12 months and the rate of patients undergoing the full therapeutic sequence.

DISCUSSION

The "ideal" cancer treatment for resectable PDAC would have the following characteristics: administration to the highest possible proportion of patients, ability to identify fast-progressing patients (i.e. poor candidates for surgery), a low rate of R1 resections (through optimisation of local disease control), and an acceptable toxicity profile. The neoadjuvant approach may meet all these criteria. With respect to published data on the efficacy of FOLFOX and mFOLFIRINOX, these two regimens are potential candidates for neoadjuvant use in the aim to optimising oncological outcomes in resectable PDAC.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02959879 . Trial registration date: November 9, 2016.

Management of Borderline Resectable Pancreatic Cancer

With the rapid development of imaging modalities and surgical techniques, the clinical entity representing tumors that are intermediate between resectable and unresectable pancreatic adenocarcinoma has been identified has been termed "borderline resectable" (BR). These tumors are generally amenable for resection but portend an increased risk for positive margins after surgery and commonly necessitate vascular resection and reconstruction. Although there is a lack of consensus regarding the appropriate definition of what constitutes a BR pancreatic tumor, it has been demonstrated that this intermediate category carries a particular prognosis that is in between resectable and unresectable disease. In order to downstage the tumor and increase the probability of clear surgical margins, neoadjuvant therapy is being increasingly utilized and studied. There is a lack of high-level evidence to establish the optimal treatment regimen for BR tumors. When resection with negative margins is achieved after neoadjuvant therapy, the prognosis for BR tumors approaches and even exceeds that for resectable disease. This review presents the current definitions, different treatment approaches, and the clinical outcomes of BR pancreatic cancer.

Postoperative complications after resection of borderline resectable and locally advanced pancreatic cancer: The impact of neoadjuvant chemotherapy with conventional radiation or stereotactic body radiation therapy

BACKGROUND

The impact of neoadjuvant stereotactic body radiation therapy on postoperative complications for patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma remains unclear. Limited studies have compared neoadjuvant stereotactic body radiation therapy versus conventional chemoradiation therapy. A retrospective study was performed to determine if perioperative complications were different among patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma receiving neoadjuvant stereotactic body radiation therapy or chemoradiation therapy.

METHODS

Patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma who underwent neoadjuvant chemotherapy with stereotactic body radiation therapy or chemoradiation therapy followed by pancreatectomy at the Johns Hopkins Hospital between 2008 and 2015 were included. Predictive factors for severe complications (Clavien grade ≥ III) were assessed by univariate and multivariate analyses.

RESULTS

A total of 168 patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma underwent neoadjuvant chemotherapy and RT followed by pancreatectomy. Sixty-one (36%) patients underwent stereotactic body radiation therapy and 107 (64%) patients received chemoradiation therapy. Compared with the chemoradiation therapy cohort, the neoadjuvant stereotactic body radiation therapy cohort was more likely to have locally advanced pancreatic ductal adenocarcinoma (62% vs 43% P = .017) and require a vascular resection (54% vs 37%, P = .027). Multiagent chemotherapy was used more commonly in the stereotactic body radiation therapy cohort (97% vs 75%, P < .001). Postoperative complications (Clavien grade ≥ III 23% vs 28%, P = .471) were similar between stereotactic body radiation therapy and chemoradiation therapy cohort. No significant difference in postoperative bleeding or infection was noted in either group.

CONCLUSION

Compared with chemoradiation therapy, neoadjuvant stereotactic body radiation therapy appears to offer equivalent rates of perioperative complications in patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma despite a greater percentage of locally advanced disease and more complex operative treatment.

Perioperative and Survival Outcomes Following Neoadjuvant FOLFIRINOX versus Gemcitabine Abraxane in Patients with Pancreatic Adenocarcinoma

CONTEXT

Neoadjuvant chemotherapy is increasingly used in borderline resectable and locally advanced pancreatic cancer to facilitate surgical resection.

OBJECTIVE

To compare progression free survival and overall survival in patients receiving neoadjuvant FOLFIRINOX with those receiving gemcitabine/abraxane.

DESIGN

Retrospective cohort study.

SETTING

University of Colorado Hospital from 2012-2016.

PARTICIPANTS

Patients with pancreatic adenocarcinoma.

INTERVENTIONS

Neoadjuvant FOLFIRINOX or gemcitabine/abraxane.

OUTCOME MEASURES

Perioperative outcomes, progression free survival, and overall survival were compared between groups. A multivariate Cox proportional hazard model was applied to evaluate survival outcomes.

RESULTS

We identified 120 patients: 83 (69.2%) FOLFIRINOX and 37 (30.8%) gemcitabine/abraxane. The FOLIFRINOX group was younger and had a lower ECOG performance status (p<0.05). Patients in the FOLFIRINOX group were more likely to undergo surgical resection compared to gemcitabine/abraxane (66.3% vs. 32.4%, p=0.002). Among all patients, median follow up was 16.9 months and FOLFIRINOX was associated with improved PFS (15.3 vs. 8.2 months, p=0.006), but not overall survival (23.5 vs. 18.7 months, p=0.228). In these patients, insulin-dependent diabetes was associated with a worse progression free survival and overall survival and surgical resection was protective. Among surgically resected patients, median follow up was 21.1 months and there was no difference in progression free survival (19.5 vs. 15.1 months) or overall survival (27.4 vs. 19.8 months) between the FOLFIRINOX and gemcitabine/abraxane groups, respectively (p>0.05). Insulin-dependent diabetes and a poor-to-moderate pathologic response was associated with worse progression free survival and overall survival.

CONCLUSION

Neoadjuvant FOLFIRINOX may improve progression free survival by increasing the proportion of patients undergoing surgical resection. Improved understanding of the role for selection bias and longer follow up are needed to better define the impact of neoadjuvant FOLFIRINOX on overall survival.

Stereotactic Body Radiation Therapy in the Management of Upper GI Malignancies

The role of external beam radiation therapy (EBRT) in the management of upper gastrointestinal malignancies is constantly evolving. As radiation therapy techniques improve and are able to deliver more ablative doses of radiotherapy while sparing healthy tissue, radiation can be applied to a wider range of clinical scenarios. Stereotactic body radiation therapy (SBRT) allows a high dose of radiation to be delivered to a highly conformal treatment volume in a short amount of time. Another potential advantage of SBRT is its ability to increase tumor immunogenicity, while also having less of an immunosuppressive effect on the patient, as compared to conventionally fractionated radiation therapy. In so doing, SBRT may potentiate the effects of immune therapy when the two treatments are combined, thus improving therapeutic outcomes. This article provides an overview of the role of SBRT in the management of upper gastrointestinal GI malignancies and the emerging data on immune biomarkers and SBRT, with a focus on pancreatic and liver cancer.

Neoadjuvant treatment of pancreatic adenocarcinoma: a systematic review and meta-analysis of 5520 patients

BACKGROUND

Recent years have seen standardization of the anatomic definitions of pancreatic adenocarcinoma, and increasing utilization of neoadjuvant therapy (NAT). The aim of the current review was to summarize the evidence for NAT in pancreatic adenocarcinoma since 2009, when consensus criteria for resectable (R), borderline resectable (BR), and locally advanced (LA) disease were endorsed.

METHODS

PubMed search was undertaken along with extensive backward search of the references of published articles to identify studies utilizing NAT for pancreatic adenocarcinoma. Abstracts from ASCO-GI 2014 and 2015 were also searched.

RESULTS

A total of 96 studies including 5520 patients were included in the final quantitative synthesis. Pooled estimates revealed 36% grade ≥ 3 toxicities, 5% biliary complications, 21% hospitalization rate and low mortality (0%, range 0-16%) during NAT. The majority of patients (59%) had stable disease. On an intention-to-treat basis, R0-resection rates varied from 63% among R patients to 23% among LA patients. R0 rates were > 80% among all patients who were resected after NAT. Among R and BR patients who underwent resection after NAT, median OS was 30 and 27.4 months, respectively.

CONCLUSIONS

The current study summarizes the recent literature for NAT in pancreatic adenocarcinoma and demonstrates improving outcomes after NAT compared to those historically associated with a surgery-first approach for pancreatic adenocarcinoma.

Neoadjuvant Therapy for Pancreatic Cancer: Systematic Review of Postoperative Morbidity, Mortality, and Complications

The purpose of this review was to assess whether neoadjuvant chemotherapy and chemoradiotherapy (CRT) result in differential postoperative morbidity and mortality as compared with pancreatic tumor resection surgery alone. Using PRISMA guidelines and the PubMed search engine, we reviewed all prospective phase II trials of neoadjuvant chemotherapy and CRT for pancreatic cancer that examined postoperative morbidities and mortalities. A total of 30 articles were identified, collated, and analyzed. Risks of postoperative complications vary based on trial. With surgery alone, the most common postoperative complications included delayed gastric emptying (DGE) (17% to 24%), pancreatic fistula (10% to 20%), anastomotic leaks (0% to 15%), postoperative bleeding (2% to 13%), and infections/sepsis (17% to 20%). With surgery alone, the mortality was <5%. Neoadjuvant chemotherapy showed comparable fistula rates (3% to 4%), leaks (3% to 11%), infection (3% to 7%), with mortality 0% to 4% in all but 1 study. CRT for resectable/borderline resectable patients also showed comparable complication rates: DGE (6% to 15%), fistulas (2% to 3%), leaks (3% to 7%), bleeding/hemorrhage (2% to 13%), infections/sepsis (3% to 19%), with 9/13 studies showing a mortality of ≤4%. As compared with initially borderline/resectable tumors, CRT for initially unresectable tumors (despite less data) showed higher complication rates: DGE (13% to 33%), fistulas (3% to 25%), infections/sepsis (3% to 16%). However, the confounding factor of the potentially higher tumor burden as an associative agent remains. The only parameters slightly higher than historical surgery-only complication rates were leaks and bleeding/hemorrhage (13% to 20%). Mortality rates in these patients were consistently 0%, with 2 outliers. Hence, neoadjuvant chemotherapy/CRT is safe from a postoperative complication standpoint, without significant increases in complication rates compared with surgery alone. Resectable and borderline resectable patients have fewer complications as compared with unresectable patients, although data for the latter are lacking.

Neoadjuvant chemotherapy in borderline resectable pancreatic cancer: A case report

Pancreatic cancer is the fourth leading cause of cancer mortality and is associated with a poor overall survival even when diagnosed early and considered resectable. Complete surgical removal with negative histological margins is an independent predictor of survival and remains the only potential curative treatment. In borderline resectable pancreatic adenocarcinoma (BRPAC), preoperative systemic therapy may increase resectability and margin-negative resection rate. There is no current consensus on the optimal chemotherapy regimen for BRPAC. The present case describes a patient with BRPAC who achieved a pathological complete response to neoadjuvant FOLFIRINOX (folinic acid, fluorouracil, irinotecan and oxaliplatin), but early relapse following a pancreaticoduodenectomy without vascular resection, with an uneventful postoperative course, except for a pulmonary embolism.

Integration of Stereotactic Body Radiation Therapy into the Multidisciplinary Management of Pancreatic Cancer

Although most patients with pancreatic cancer die of metastatic disease, an autopsy study showed that up to one-third of patients die of predominantly local disease. This patient population stands to benefit the most from radiation, surgery, or both. Unfortunately, however, single-agent chemotherapy has had minimal benefit in pancreatic cancer, and most patients progress distantly before receiving radiation therapy (RT). With the addition of multiagent chemotherapy, patients are living longer, and RT has emerged as an important modality in preventing local progression. Standard chemoradiation delivered over 5-6 weeks has been shown to improve local control, but this approach delays full-dose systemic therapy and increases toxicity when compared to chemotherapy alone. Stereotactic body RT (SBRT) delivered in 3-5 fractions can be used to accurately target the pancreatic tumor with small margins and limited acute treatment-related toxicity. Given the favorable toxicity profile, SBRT can easily be integrated with other therapies in all stages of pancreatic cancer. However, future studies are necessary to determine optimal dose or fractionation regimens and sequencing with targeted therapies and immunotherapy. The purpose of this review is to discuss our current understanding of SBRT in the multidisciplinary management of patients with pancreatic cancer and future implications.

Stereotactic Body Radiation Therapy for Locally Advanced Pancreatic Cancer: A Systematic Review and Pooled Analysis of 19 Trials

PURPOSE

Although surgery is the standard of care for resectable pancreatic cancer (PC), standard-dose chemoradiation therapy and chemotherapy alone are suitable for patients with unresectable disease. Stereotactic body radiation therapy (SBRT) is an alternative, focused local therapy that delivers high radiation doses within a few fractions to the cancer, sparing the surrounding critical tissue. We performed a systematic review and pooled analysis of published trials to evaluate the efficacy and safety of this emerging treatment modality.

METHODS AND MATERIALS

We searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, SCOPUS, the Web of Science, and CINAHL for publications regarding SBRT for locally advanced PC. The 1-year overall survival (OS) rate was the primary endpoint, and the median OS, 2-year OS rate, 1-year locoregional control (LRC) rate, and grade 3 to 4 toxicities were the secondary endpoints. A multivariate random-effects meta-analysis was performed to calculate the aggregated OS rates at 1 and 2 years and the 1-year LRC rate.

RESULTS

A total of 19 studies, encompassing 1009 patients, were included in the present analysis. The pooled 1-year OS was 51.6% in 13 trials with data available. The median OS ranged from 5.7 to 47 months (median 17). The LRC rate at 1 year was 72.3%. Overall, the occurrence of severe adverse events did not exceed 10%. LRC appeared to correlate with the total SBRT dose and the number of fractions.

CONCLUSIONS

The advantages of SBRT in terms of treatment time, satisfactory OS, and LRC indicate that it is an effective option for inoperable PC. However, a definitive validation of this treatment modality in large randomized studies is required, owing to the nonrandomized nature of the included studies and the limitations of small single-center series that include mixed populations.

A current perspective on stereotactic body radiation therapy for pancreatic cancer

Pancreatic cancer is a formidable malignancy with poor outcomes. The majority of patients are unable to undergo resection, which remains the only potentially curative treatment option. The management of locally advanced (unresectable) pancreatic cancer is controversial; however, treatment with either chemotherapy or chemoradiation is associated with high rates of local tumor progression and metastases development, resulting in low survival rates. An emerging local modality is stereotactic body radiation therapy (SBRT), which uses image-guided, conformal, high-dose radiation. SBRT has demonstrated promising local control rates and resultant quality of life with acceptable rates of toxicity. Over the past decade, increasing clinical experience and data have supported SBRT as a local treatment modality. Nevertheless, additional research is required to further evaluate the role of SBRT and improve upon the persistently poor outcomes associated with pancreatic cancer. This review discusses the existing clinical experience and technical implementation of SBRT for pancreatic cancer and highlights the directions for ongoing and future studies.

Stereotactic body radiotherapy for renal cell cancer and pancreatic cancer : Literature review and practice recommendations of the DEGRO Working Group on Stereotactic Radiotherapy

PURPOSE

This report of the Working Group on Stereotactic Radiotherapy of the German Society of Radiation Oncology (DEGRO) aims to provide a literature review and practice recommendations for stereotactic body radiotherapy (SBRT) of primary renal cell cancer and primary pancreatic cancer.

METHODS

A literature search on SBRT for both renal cancer and pancreatic cancer was performed with focus on prospective trials and technical aspects for clinical implementation.

RESULTS

Data on renal and pancreatic SBRT are limited, but show promising rates of local control for both treatment sites. For pancreatic cancer, fractionated SBRT should be preferred to single-dose treatment to reduce the risk of gastrointestinal toxicity. Motion-compensation strategies and image guidance are paramount for safe SBRT delivery in both tumor entities.

CONCLUSION

SBRT for renal cancer and pancreatic cancer have been successfully evaluated in phase I and phase II trials. Pancreatic SBRT should be practiced carefully and only within prospective protocols due to the risk of severe gastrointestinal toxicity. SBRT for primary renal cell cancer appears a viable option for medically inoperable patients but future research needs to better define patient selection criteria and the detailed practice of SBRT.

Complete pathological response following neoadjuvant FOLFIRINOX in borderline resectable pancreatic cancer - a case report and review

BACKGROUND

Pancreatic cancer is among the top 5 most common cancers worldwide, but is particularly devastating due to its insidious nature. Complete surgical resection remains the only potential curative treatment, although only 20 % of patients present with a resectable tumor. Patients may alternatively present with borderline resectable pancreatic cancer or locally advanced pancreatic cancer and can be offered treatment with neoadjuvant intent. The effectiveness of these treatments is unclear and there is a paucity of data to suggest one optimal treatment approach.

CASE PRESENTATION

We describe a 61-year-old female who presented with a two-week history of obstructive jaundice in the context of vague abdominal pain that had been ongoing for years prior to her visit. CT scan of the abdomen confirmed a hypovascular mass in the uncinate process consistent with borderline resectable pancreatic cancer. Pancreatic adenocarcinoma was confirmed with endoscopic ultrasound guided fine-needle aspiration cytology. Following multidisciplinary discussion, it was recommended that she undergo treatment with FOLFIRINOX. After a total of 13 cycles, follow up CT revealed that the lesion had decreased in size and she was offered resection as a potentially curative treatment. She underwent pancreaticoduodenectomy. Final pathology report revealed no evidence of residual adenocarcinoma (ypT0 ypN0 (0/23)). The patient remains disease-free 15 months following surgery.

CONCLUSION

To date, there have been very few reports of a complete pathological response following neoadjuvant therapy in borderline resectable or locally advanced pancreatic cancer. This report describes a unique case of a complete pathological remission in a patient with borderline resectable pancreatic cancer following FOLFIRINOX therapy alone and adds to the growing base of evidence meriting the initiation of clinical trials to assess the efficacy of FOLFIRINOX in these subsets of pancreatic cancer.

Regression grading in neoadjuvant treated pancreatic cancer: an interobserver study

AIM

Several regression grading systems have been proposed for neoadjuvant chemoradiation-treated pancreatic ductal adenocarcinoma (PDAC). This study aimed to examine the utility, reproducibility and level of concordance of three most frequently used grading systems.

METHODS

Four gastrointestinal pathologists used the College of American Pathologists (CAP), Evans, MD Anderson Cancer Centre (MDA) regression grading systems to grade 14 selected cases (7-20 slides from each case) of neoadjuvant chemoradiation-treated PDAC. A postscoring discussion with each pathologist was conducted. The results were entered into a standardised data collection form and statistical analyses were performed.

RESULTS

There was little concordance across the three systems. The Kendall coefficient of concordance agreement scores were: CAP: 2-poor, 2-fair; Evans: 1-fair, 1-moderate, 2-good; MDA: 1-poor, 2-moderate, 1-good. Interpretation in all three grades in the CAP grading system was a source of discrepancy. Furthermore, using fibrosis as a criterion to assess regression was contentious. In the Evans system, quantifying tumour destruction using arbitrary percentage cut-offs (ie, 9% vs 10%; 50% vs 51%, etc) was imprecise and subjective. Although the MDA system generated greatest concordance, this was due to 'oversimplification' surrounding wide, arbitrarily assigned thresholds of </> 5% of tumour.

CONCLUSIONS

All systems lacked precision and clarity for accurate regression grading. Presently the clinical utility and impact of histological regression grading in patient management is questionable. There is a need to re-evaluate regression grading in the pancreas and establish a reproducible, clinically relevant grading system.

A phase-I trial of pre-operative, margin intensive, stereotactic body radiation therapy for pancreatic cancer: the 'SPARC' trial protocol

BACKGROUND

Standard therapy for borderline-resectable pancreatic cancer in the UK is surgery with adjuvant chemotherapy, but rates of resection with clear margins are unsatisfactory and overall survival remains poor. Meta-analysis of single-arm studies shows the potential of neo-adjuvant chemo-radiotherapy but the relative radio-resistance of pancreatic cancer means the efficacy of conventional dose schedules is limited. Stereotactic radiotherapy achieves sufficient accuracy and precision to enable pre-operative margin-intensive dose escalation with the goal of increasing rates of clear resection margins and local disease control.

METHODS/DESIGN

SPARC is a "rolling-six" design single-arm study to establish the maximum tolerated dose for margin-intensive stereotactic radiotherapy before resection of pancreatic cancer at high risk of positive resection margins. Eligible patients will have histologically or cytologically proven pancreatic cancer defined as borderline-resectable per National Comprehensive Cancer Network criteria or operable tumour in contact with vessels increasing the risk of positive margin. Up to 24 patients will be recruited from up to 5 treating centres and a 'rolling-six' design is utilised to minimise delays and facilitate ongoing recruitment during dose-escalation. Radiotherapy will be delivered in 5 daily fractions and surgery, if appropriate, will take place 5-6 weeks after radiotherapy. The margin-intense radiotherapy concept includes a systematic method to define the target volume for a simultaneous integrated boost in the region of tumour-vessel infiltration, and up to 4 radiotherapy dose levels will be investigated. Maximum tolerated dose is defined as the highest dose at which no more than 1 of 6 patients or 0 of 3 patients experience a dose limiting toxicity. Secondary endpoints include resection rate, resection margin status, response rate, overall survival and progression free survival at 12 and 24 months. Translational work will involve exploratory analyses of the cytological and humoral immunological responses to stereotactic radiotherapy in pancreatic cancer. Radiotherapy quality assurance of target definition and radiotherapy planning is enforced with pre-trial test cases and on-trial review. Recruitment began in April 2015.

DISCUSSION

This prospective multi-centre study aims to establish the maximum tolerated dose of pre-operative margin-intensified stereotactic radiotherapy in pancreatic cancer at high risk of positive resection margins with a view to subsequent definitive comparison with other neoadjuvant treatment options.

TRIAL REGISTRATION

ISRCTN14138956 . Funded by CRUK.

Favorable perioperative outcomes after resection of borderline resectable pancreatic cancer treated with neoadjuvant stereotactic radiation and chemotherapy compared with upfront pancreatectomy for resectable cancer

BACKGROUND

Neoadjuvant multi-agent chemotherapy and stereotactic body radiation therapy (SBRT) are utilized to increase margin negative (R0) resection rates in borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) patients. Concerns persist that these neoadjuvant therapies may worsen perioperative morbidities and mortality.

METHODS

Upfront resection patients (n=241) underwent resection without neoadjuvant treatment for resectable disease. They were compared to BRPC or LAPC patients (n=61) who underwent resection after chemotherapy and 5 fraction SBRT. Group comparisons were performed by Mann-Whitney U or Fisher's exact test. Overall Survival (OS) was estimated by Kaplan-Meier and compared by log-rank methods.

RESULTS

In the neoadjuvant therapy group, there was significantly higher T classification, N classification, and vascular resection/repair rate. Surgical positive margin rate was lower after neoadjuvant therapy (3.3% vs. 16.2%, P=0.006). Post-operative morbidities (39.3% vs. 31.1%, P=0.226) and 90-day mortality (2% vs. 4%, P=0.693) were similar between the groups. Median OS was 33.5 months in the neoadjuvant therapy group compared to 23.1 months in upfront resection patients who received adjuvant treatment (P=0.057).

CONCLUSIONS

Patients with BRPC or LAPC and sufficient response to neoadjuvant multi-agent chemotherapy and SBRT have similar or improved peri-operative and long-term survival outcomes compared to upfront resection patients.

A Phase 1 Study of Stereotactic Body Radiation Therapy Dose Escalation for Borderline Resectable Pancreatic Cancer After Modified FOLFIRINOX (NCT01446458)

PURPOSE

A challenge in borderline resectable pancreatic cancer (BRPC) management is the high rate of positive posterior margins (PM). Stereotactic body radiation therapy (SBRT) allows for higher radiation delivery dose with conformity. This study evaluated the maximal tolerated dose with a dose escalation plan level up to 45 Gy using SBRT in BRPC.

METHODS AND MATERIALS

A single-institution, 3 + 3 phase 1 clinical trial design was used to evaluate 4 dose levels of SBRT delivered in 3 fractions to the planning target volume (PTV) with a simultaneous in-field boost (SIB) to the PM. Dose level (DL) 1 was 30 Gy to the PTV, and for dose levels 2 through 4 (DL2-DL4) the dose was 36 Gy. The SIB dose to the PM was 6, 6, 7.5, and 9 Gy for DL-1, DL-2, DL-3, and DL-4, respectively. All patients received 4 treatments of modified FOLFIRINOX (fluorouracil, leucovorin, irinotecan, oxaliplatin) before SBRT.

RESULTS

Thirteen patients with a median age of 64 years were enrolled. The median follow-up time was 18 months. The locations of the cancer were head (n=12) and uncinate/neck (n=1). One patient did not undergo SBRT. There were no grade 3 or 4 toxicities. Five patients did not undergo resection because of disease progression (1 local, 4 distant); 8 had R0 resection in the PM, and 5 of 8 had vessel reconstruction. Two patients had disease downstaged to T1 and T2 from T3 disease. Four patients are still alive, and 3 are disease free. The median overall survival for resected patients was not reached (9.3: not reached).

CONCLUSION

The SBRT dose of 36 Gy with a 9-Gy SIB to the PM (total 45 Gy) delivered in 3 fractions is safe and well tolerated. The dose-limiting toxicity for a 45-Gy dose was not reached, and further dose escalations are needed in future trials.

Stereotactic body radiotherapy for pancreatic cancer: recent progress and future directions

Despite advances in surgical, medical, and radiation therapy for pancreatic cancer, the prognosis remains poor. At this time, the only chance for long-term survival is surgical resection. More challenging is the optimal management of unresectable locally advanced pancreatic cancer, which has historically been treated with concurrent chemoradiation or chemotherapy alone. However, the survival and local control benefit of conventional radiotherapy in addition to chemotherapy was unclear. More recently, stereotactic body radiotherapy (SBRT) is emerging as a viable approach to maximizing local tumor control with a tolerable side effect profile. SBRT achieves sharp dose fall-off facilitating safe delivery of highly focused radiation to the tumor over 1-5 days. Although the optimal regimen of pancreas SBRT has not yet been established, its short treatment course limits the delay of additional. Future directions involve prospective study of pancreas SBRT and exploration of biomarkers and imaging technology in order to adopt a personalized management paradigm.

Histopathologic tumor response after induction chemotherapy and stereotactic body radiation therapy for borderline resectable pancreatic cancer

BACKGROUND

While clinical outcomes following induction chemotherapy and stereotactic body radiation therapy (SBRT) have been reported for borderline resectable pancreatic cancer (BRPC) patients, pathologic response has not previously been described.

METHODS

This single-institution retrospective review evaluated BRPC patients who completed induction gemcitabine-based chemotherapy followed by SBRT and surgical resection. Each surgical specimen was assigned two tumor regression grades (TRG), one using the College of American Pathologists (CAP) criteria and one using the MD Anderson Cancer Center (MDACC) criteria. Overall survival (OS) and progression free survival (PFS) were correlated to TRG score.

RESULTS

We evaluated 36 patients with a median follow-up of 13.8 months (range, 6.1-24.8 months). The most common induction chemotherapy regimen (82%) was GTX (gemcitabine, docetaxel, capecitabine). A median SBRT dose of 35 Gy (range, 30-40 Gy) in 5 fractions was delivered to the region of vascular involvement. The margin-negative resection rate was 97.2%. Improved response according to MDACC grade trended towards superior PFS (P=061), but not OS. Any neoadjuvant treatment effect according to MDACC scoring (IIa-IV vs. I) was associated with improved OS and PFS (both P=0.019). We found no relationship between CAP score and OS or PFS.

CONCLUSIONS

These data suggest that the increased pathologic response after induction chemotherapy and SBRT is correlated with improved survival for BRPC patients.

Advances of stereotactic body radiotherapy in pancreatic cancer

Pancreatic cancer (PCA) is one of the most aggressive tumors with few effective treatment modalities. It is the 4th and 7th leading cause of cancer death in the United States and China, respectively. At the time of diagnosis, only 20% of cases present with a resectable tumor, and about 40% with a locally advanced tumor that is considered unresectable. Even resected patients still have a poor prognosis, with an incidence of local recurrence ranging from 20% to 60%. It is also reported that up to 30% of PCA patients die from locally obstructive disease with few or no distant metastases. These findings have highlighted the importance of local radiation therapy in the treatment of PCA. As the role of conventional chemoradiotherapy remains controversial, the dawn of the pancreas stereotactic body radiation therapy (SBRT) era represents a potential paradigm shift in the management of PCA. SBRT delivers a higher biological effective dose to the tumor with sharp dose escalation in a shorter treatment time course. Pancreas SBRT is a novel therapeutic option to achieve local tumor control with minimal toxicity. Herein, we review the advancement of SBRT for PCA patients with different stages of pancreatic adenocarcinoma.

Dose escalation with a vessel boost in pancreatic adenocarcinoma treated with neoadjuvant chemoradiation

PURPOSE

Patients with pancreatic adenocarcinoma (PAC) are often treated with neoadjuvant chemoradiation (NACRT) in hopes of downstaging their disease for potential surgical resection. We hypothesized that increasing the radiation dose to the area of the tumor abutting the vessel(s) of concern would increase the rate of surgical resection in patients with borderline resectable PAC (BRPAC) and locally advanced PAC (LAPAC) treated with NACRT.

METHODS AND MATERIALS

We retrospectively reviewed consecutive cases of BRPAC and LAPAC treated with NACRT from January 2006 to December 2013, with or without a vessel boost (VB), at a single institution. The primary endpoints were rate of R0/R1 potentially curative surgical resection and acute toxicity. Univariate analysis with the Fisher exact test was performed to evaluate the effect of each variable. Multiple logistic regression was used to adjust for the following covariates: year of diagnosis, age, sex, carbohydrate antigen 19-9 (CA19-9) level at diagnosis, and BRPAC or LAPAC.

RESULTS

Of the 104 patients identified, 22% (n = 23) received a VB (median, 54 Gy; range, 54-64 Gy), and 78% (n = 81) received no boost (median, 50.4 Gy; range, 48.6-52.2 Gy). More patients in the VB group were treated from 2010 to 2013 (P < .001) and with intensity modulated radiation therapy (P = .002). Other baseline characteristics were balanced. After adjustment for covariates, there was a statistical trend toward increased surgical resection in patients who received a VB (odds ratio [OR], 2.77; 95% confidence interval [CI], 0.89-8.57; P = .077). Age (≥70 years; OR, 0.42; 95% CI, 0.16-1.05; P = .064) and LAPAC (OR, 0.32; 95% CI, 0.09-1.09; P = .068) also trended toward significance. CA19-9 ≥47.9 U/mL (OR, 0.24; 95% CI, 0.08-0.71; P = .010) was significant on multivariate analysis. There was no significant difference in acute or late toxicity between groups.

CONCLUSIONS

In our retrospective series, dose escalation was associated with an improved surgical resection rate in BRPAC and LAPAC patients treated with NACRT, although this improvement was not statistically significant.

Downsizing Chemotherapy for Initially Unresectable Locally Advanced Biliary Tract Cancer Patients Treated with Gemcitabine Plus Cisplatin Combination Therapy Followed by Radical Surgery

BACKGOUND

We have treated patients with initially unresectable locally advanced biliary tract cancer (BTC) by administering gemcitabine and have found that surgical resection became feasible in some downsized patients. The aim of this study was to investigate the usefulness of downsizing combination chemotherapy using gemcitabine plus cisplatin to treat initially unresectable locally advanced BTC.

METHODS

The subjects of the study were 150 consecutive patients who were treated for BTC between October 2011 and April 2014. Downsizing chemotherapy was carried out for 39 patients (26.0 %) whose lesions were unresectable because of locally advanced BTC.

RESULTS

Reduction in tumor size with downsizing chemotherapy was seen in 18 patients, and surgical resection was performed in 10 of 39 patients (25.6 %). Median survival time in patients with surgical resection following downsizing chemotherapy and those with chemotherapy alone was 17.9 and 12.4 months, respectively (p = 0.0378). According to the historical comparison between gemcitabine and gemcitabine plus cisplatin chemotherapy, there is no significant difference in overall survival. However, there was a significant difference for the pathologic response rate (≥Grade III) to be higher in patients with gemcitabine plus cisplatin chemotherapy compared with gemcitabine monotherapy.

CONCLUSIONS

Preoperative downsizing chemotherapy with gemcitabine plus cisplatin provides longer survival by the conversion to the surgical resection in patients with initially unresectable locally advanced BTC. It may have the potential for disease eradication as a new multidisciplinary approach for initially unresectable locally advanced BTC.

Long-term outcomes of induction chemotherapy and neoadjuvant stereotactic body radiotherapy for borderline resectable and locally advanced pancreatic adenocarcinoma

PURPOSE

Limited data are available to guide neoadjuvant treatment of borderline resectable (BRPC) and locally advanced (LAPC) pancreatic cancer.

MATERIAL AND METHODS

We updated our institutional outcomes with a neoadjuvant chemotherapy and stereotactic body radiotherapy (SBRT) approach. An IRB-approved analysis was performed of all BRPC and LAPC patients treated with our departmental treatment protocol. After staging, medically fit patients underwent chemotherapy for 2-3 months, with regimen at the discretion of the treating medical oncologist. Patients then received SBRT delivered in five consecutive daily fractions with median total radiation doses of 30 Gy to tumor and 40 Gy dose painted to tumor-vessel interfaces. This was followed by restaging imaging for possible resection. Overall survival (OS), event free survival (EFS), and locoregional control (LRC) rates were estimated and compared by Kaplan-Meier and log-rank methods.

RESULTS

We identified 159 patients, 110 BRPC and 49 LAPC, with 14.0 months median overall follow-up. The resection and margin negative (R0) rate for BRPC patients who completed neoadjuvant therapy was 51% and 96%, respectively. Estimated median OS was 19.2 months for BRPC patients and 15.0 months for LAPC patients (p = 0.402). Median OS was 34.2 months for surgically resected patients versus 14.0 months for unresected patients (p < 0.001). Five of 21 (24%) LAPC patients receiving FOLFIRINOX chemotherapy underwent R0 resection. In LAPC, FOLFIRINOX recipients underwent R0 resection more often than other chemotherapy recipients (5 of 21 vs. 0 of 28, p = 0.011). There was a trend for improved survival in those resected LAPC patients (p = 0.09). For those not undergoing resection, one year LRC was 78%. Any grade ≥ 3 potentially radiation-related toxicity rate was 7%.

CONCLUSIONS

These data underscore the feasibility, safety, and effectiveness of neoadjuvant SBRT and chemotherapy for BRPC and LAPC.

Histopathological effects of preoperative chemoradiotherapy for pancreatic cancer: an analysis for the impact of radiation and gemcitabine doses

BACKGROUND AND PURPOSE

Histopathological findings of patients who underwent resection for pancreatic adenocarcinoma (PC) after preoperative chemoradiotherapy (CRT) reportedly showed beneficial effects. The purpose of our study was to evaluate the correlation between histopathological effects (HE) of preoperative CRT and treatment parameters [radiation and gemcitabine (GEM) doses].

MATERIAL AND METHODS

HE of CRT were assessed on 158 primary lesions of 157 patients with PC who underwent pancreatic resection after preoperative CRT with GEM between January 2006 and December 2011. The radiation dose delivered to the primary tumor site and surrounding regional nodal areas was 50 Gy until September 2009 followed by the dose escalation of a 10 Gy boost added for delivery with the field-in-field technique to the roots of the celiac and superior mesenteric arteries. Intravenous administration of GEM (1000 /m(2)) was initiated concurrently on days 1, 8, and 15, every 4 weeks and generally repeated for 3 cycles. HE of CRT on the primary tumor were categorized based on the number of tumor cells destroyed.

RESULTS

The median overall survival time was 74.5 months and 3-year and 5-year survival rates were 64.3% and 54.5%, respectively. Dose-volume parameters of radiation such as D33 with a cut-off value of 51.6 Gy were correlated significantly with HE (p=.0230). Lesions having received GEM>7625 mg/m(2) before surgical resection more frequently showed positive HE (p=.0002). Multivariate logistic regression analysis demonstrated that both D33 and cumulative GEM dose were significant predictors of definite HE (p=.0110 and <.0001, respectively).

CONCLUSIONS

Our retrospective analysis showed that dose intensity of radiation and GEM is significantly related to HE of preoperative CRT for PC.

The Role of Stereotactic Body Radiation Therapy for Pancreatic Cancer: A Single-Institution Experience

BACKGROUND

Stereotactic body radiation therapy (SBRT) is a promising option for patients with pancreatic cancer (PCA); however, limited data support its efficacy. This study reviews our institutional experience of SBRT in the treatment of locally advanced (LAPC) and borderline resectable (BRPC) PCA.

METHODS

Charts of all PCA patients receiving SBRT at our institution from 2010 to 2014 were reviewed. Most patients received pre-SBRT chemotherapy. Primary endpoints included overall survival (OS) and local progression-free survival (LPFS). Patients received a total dose of 25-33 Gy in five fractions.

RESULTS

A total of 88 patients were included in the analysis, 74 with LAPC and 14 with BRPC. The median age at diagnosis was 67.2 years, and median follow-up from date of diagnosis for LAPC and BRPC patients was 14.5 and 10.3 months, respectively. Median OS from date of diagnosis was 18.4 months (LAPC, 18.4 mo; BRPC, 14.4 mo) and median PFS was 9.8 months (95 % CI 8.0-12.3). Acute toxicity was minimal with only three patients (3.4 %) experiencing acute grade ≥3 toxicity. Late grade ≥2 gastrointestinal toxicity was seen in five patients (5.7 %). Of the 19 patients (21.6 %) who underwent surgery, 79 % were LAPC patients and 84 % had margin-negative resections.

CONCLUSIONS

Chemotherapy followed by SBRT in patients with LAPC and BRPC resulted in minimal acute and late toxicity. A large proportion of patients underwent surgical resection despite limited radiographic response to therapy. Further refinements in the integration of chemotherapy, SBRT, and surgery might offer additional advancements toward optimizing patient outcomes.

Stereotactic body radiation therapy in pancreatic cancer: the new frontier

Pancreatic cancer (PCA) remains a disease with a poor prognosis. The majority of PCA patients are unable to undergo surgical resection, which is the only potentially curative option at this time. A combination of chemotherapy and chemoradiation (CRT) are standard options for patients with locally advanced, unresectable disease, however, local control and patient outcomes remains poor. Stereotactic body radiation therapy (SBRT) is an emerging treatment option for PCA. SBRT delivers potentially ablative doses to the pancreatic tumor plus a small margin over a short period of time. Early studies with single-fraction SBRT demonstrated excellent tumor control with high rates of toxicity. The implementation of SBRT (3-5 doses) has demonstrated promising outcomes with favorable tumor control and toxicity rates. Herein we discuss the evolving role of SBRT in PCA treatment.