Pathologic complete response following neoadjuvant therapy for pancreatic ductal adenocarcinoma: defining the incidence, predictors, and outcomes

Pathologic complete response following neoadjuvant chemotherapy in pancreatic ductal adenocarcinoma: Impact on survival and recurrence

BACKGROUND

Pathologic complete response after neoadjuvant treatment in pancreatic ductal adenocarcinoma is a rare occurrence. Similar to other malignancies, achieving a pathologic complete response in pancreatic ductal adenocarcinoma seems to correlate with improved survival. However, because of the rarity of such events, the true significance of pathologic complete response in pancreatic cancer remains unclear. The aim of the present study was to investigate the impact of pathologic complete response on survival and recurrence.

METHODS

In a single-center retrospective study, pathologic complete response was defined as no evidence of viable tumor cells in resected specimen entirely sampled according to a rigorous protocol and in which a residual tumor bed was identified. Disease-specific survival and disease-free survival were measured from surgery. Independent predictors for disease-specific survival and disease-free survival were examined.

RESULTS

Overall, 403 patients were included. Pathologic complete response was found in 15 patients (3.8%), after chemotherapy alone. After a median follow-up of 42 months (95% CI 38-45), 3-year disease-specific survival was 87% in pathologic complete response patients vs 43% in those without pathologic complete response (P = .014). The recurrence rate was 40% (n = 6/15) in the pathologic complete response group compared with 69.8% (n = 271/388) in those without pathologic complete response. Disease-free survival was longer in the pathologic complete response group, with higher 1- and 3-year rates compared with the no-pathologic complete response group (80% vs 60% and 48% vs 24%, respectively). Pathologic complete response was found to be an independent protective factor for disease-specific survival (P = .035) but not for disease-free survival (P = .052).

CONCLUSION

Pathologic complete response in pancreatic ductal adenocarcinoma is not synonymous of cure but ensure a prolonged survival. Nevertheless, recurrence remains a significant concern, with high rates observed even among these exceptional responders.

Image-guided Ablative Procedures

Various image-guided ablative procedures include chemical and thermal ablation techniques and irreversible electroporation. These have been used for curative intent for small tumours and palliative intent for debulking, immunogenicity and pain control. Understanding these techniques is critical to avoiding complications and achieving superior clinical outcomes. Additionally, combination with immunotherapy and chemotherapies is rapidly evolving. There are numerous opportunities in interventional radiology to advance ablation techniques and seamlessly integrate into current treatment regimens for both benign and malignant tumours.

Pathological Complete Response in Patients With Resected Pancreatic Adenocarcinoma After Preoperative Chemotherapy

Importance

Preoperative chemo(radio)therapy is increasingly used in patients with localized pancreatic adenocarcinoma, leading to pathological complete response (pCR) in a small subset of patients. However, multicenter studies with in-depth data about pCR are lacking.

Objective

To investigate the incidence, outcome, and risk factors of pCR after preoperative chemo(radio)therapy.

Design, Setting, and Participants

This observational, international, multicenter cohort study assessed all consecutive patients with pathology-proven localized pancreatic adenocarcinoma who underwent resection after 2 or more cycles of chemotherapy (with or without radiotherapy) in 19 centers from 8 countries (January 1, 2010, to December 31, 2018). Data collection was performed from February 1, 2020, to April 30, 2022, and analyses from January 1, 2022, to December 31, 2023. Median follow-up was 19 months.

Exposures

Preoperative chemotherapy (with or without radiotherapy) followed by resection.

Main Outcomes and Measures

The incidence of pCR (defined as absence of vital tumor cells in the sampled pancreas specimen after resection), its association with OS from surgery, and factors associated with pCR. Factors associated with overall survival (OS) and pCR were investigated with Cox proportional hazards and logistic regression models, respectively.

Results

Overall, 1758 patients (mean [SD] age, 64 [9] years; 879 [50.0%] male) were studied. The rate of pCR was 4.8% (n = 85), and pCR was associated with OS (hazard ratio, 0.46; 95% CI, 0.26-0.83). The 1-, 3-, and 5-year OS rates were 95%, 82%, and 63% in patients with pCR vs 80%, 46%, and 30% in patients without pCR, respectively (P < .001). Factors associated with pCR included preoperative multiagent chemotherapy other than (m)FOLFIRINOX ([modified] leucovorin calcium [folinic acid], fluorouracil, irinotecan hydrochloride, and oxaliplatin) (odds ratio [OR], 0.48; 95% CI, 0.26-0.87), preoperative conventional radiotherapy (OR, 2.03; 95% CI, 1.00-4.10), preoperative stereotactic body radiotherapy (OR, 8.91; 95% CI, 4.17-19.05), radiologic response (OR, 13.00; 95% CI, 7.02-24.08), and normal(ized) serum carbohydrate antigen 19-9 after preoperative therapy (OR, 3.76; 95% CI, 1.79-7.89).

Conclusions and Relevance

This international, retrospective cohort study found that pCR occurred in 4.8% of patients with resected localized pancreatic adenocarcinoma after preoperative chemo(radio)therapy. Although pCR does not reflect cure, it is associated with improved OS, with a doubled 5-year OS of 63% compared with 30% in patients without pCR. Factors associated with pCR related to preoperative chemo(radio)therapy regimens and anatomical and biological disease response features may have implications for treatment strategies that require validation in prospective studies because they may not universally apply to all patients with pancreatic adenocarcinoma.

Neoadjuvant therapy for localized pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor with poor prognosis and rising incidence globally. Multimodal therapy that includes surgical resection and chemotherapy with or without radiation offers the best chance for optimal outcomes. The development of established criteria for anatomic staging of local primary tumors into potentially resectable (PR), borderline resectable (BR), and locally advanced (LA) has greatly clarified the optimal treatment strategies. While upfront surgical resection was traditionally the recommended approach for localized PDAC, increasingly neoadjuvant therapy (NT) is recommended prior to surgery. Whereas NT can lead to downstaging that facilitates surgical resection for BR/LA cancers, NT also enhances patient selection for surgery, improves margin-negative resection rates, and increases the odds of completing multimodality therapy for all patients with PDAC. Herein, we review the rationale for NT for localized PDAC and summarize existing and ongoing literature.

Type of neoadjuvant treatment strategy is associated with differential pathologic responses in pancreatic ductal adenocarcinoma

BACKGROUND

Tumor fibrosis after neoadjuvant treatment (NAT) for pancreatic ductal adenocarcinoma (PDAC) correlates with treatment response. Herein we assessed how different NAT strategies influence pathologic responses and survival.

METHODS

Patients with surgically resected PDAC who received NAT (1991-2020) were included. Descriptive statistics compared outcomes amongst fibrosis groups (none, minor <50 ​%, partial 51%-94 ​%, major ≥95 ​%) and NAT (chemotherapy alone, chemoradiation, or chemotherapy ​+ ​chemoradiation (total neoadjuvant therapy, TNT)).

RESULTS

Patients with major fibrosis most often received TNT (65.8 ​%, p ​< ​0.001). Major fibrosis was associated with the greatest rate of downstaging (77.8 ​%, p ​< ​0.001), highest R0 margin rate (100 ​%, p ​< ​0.01), and lowest mean positive lymph node ratio (0.80, p ​< ​0.01). Amongst complete responders, 11/14 (78.6 ​%) received TNT. Median overall (66.3 months, p ​= ​0.003) and disease-free (54.7months, p ​= ​0.05) survival were highest with major fibrosis.

CONCLUSIONS

Major fibrosis and complete pathologic responses after NAT are most frequent with a TNT strategy and are associated with improved outcomes.

Preoperative chemotherapy, radiotherapy and surgical decision-making in patients with borderline resectable and locally advanced pancreatic cancer

Surgical resection combined with systemic chemotherapy is the cornerstone of treatment for patients with localized pancreatic cancer. Upfront surgery is considered suboptimal in cases with extensive vascular involvement, which can be classified as either borderline resectable pancreatic cancer or locally advanced pancreatic cancer. In these patients, FOLFIRINOX or gemcitabine plus nab-paclitaxel chemotherapy is currently used as preoperative chemotherapy and is eventually combined with radiotherapy. Thus, more patients might reach 5-year overall survival. Patient selection for chemotherapy, radiotherapy and subsequent surgery is based on anatomical, biological and conditional parameters. Current guidelines and clinical practices vary considerably regarding preoperative chemotherapy and radiotherapy, response evaluation, and indications for surgery. In this Review, we provide an overview of the clinical evidence regarding disease staging, preoperative therapy, response evaluation and surgery in patients with borderline resectable pancreatic cancer or locally advanced pancreatic cancer. In addition, a clinical work-up is proposed based on the available evidence and guidelines. We identify knowledge gaps and outline a proposed research agenda.

Complete Primary Pathological Response Following Neoadjuvant Treatment and Radical Resection for Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Neoadjuvant treatment (NAT) for borderline (BD) or locally advanced (LA) primary pancreatic cancer (PDAC) is now a widely adopted approach. We present a case series of patients who have achieved a complete pathological response of the primary tumour on final histology following neoadjuvant chemotherapy +/- chemoradiation and radical surgery.

METHODS

Patients who underwent radical pancreatic resection following neoadjuvant treatment between March 2006 and March 2023 at a single institution were identified by retrospective case note review of a prospectively maintained database.

RESULTS

Ten patients were identified to have a complete primary pathological response (ypT0) on postoperative histology. Before treatment, five patients were considered BD and five were LA according to National Comprehensive Cancer Network guidelines. All patients underwent staging Computed Tomography (CT) and nine underwent 18Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET/CT) imaging, with a mean maximum standardized uptake value (SUVmax) of the primary lesion at 6.14 ± 1.98 units. All patients received neoadjuvant chemotherapy, and eight received further chemoradiotherapy prior to resection. Mean pre- and post-neoadjuvant treatment serum Ca19-9 was 148.0 ± 146.3 IU/L and 18.0 ± 18.7 IU/L, respectively (p = 0.01). The mean duration of NAT was 5.6 ± 1.7 months. The mean time from completion of NAT to surgery was 13.1 ± 8.3 weeks. The mean lymph node yield was 21.1 ± 10.4 nodes, with one patient found to have 1 lymph node involved. All resections were reported to be R0. The mean length of stay was 11.8 ± 6.2 days. At the time of analysis, one death was reported at 35 months postoperatively. Two cases of recurrence were reported at 16 months (surgical bed) and 33 months (pulmonary). All other patients remain alive and under active surveillance. The current overall survival is 26.6 ± 20.7 months and counting.

CONCLUSIONS

Complete primary pathological response is uncommon but possible following neoadjuvant treatment in patients with PDAC. Further work to identify the common denominator within this unique cohort may lead to advances in the therapeutic approach and offer hope for patients diagnosed with borderline or locally advanced pancreatic ductal adenocarcinoma.

Neoadjuvant Immunotherapy for Localized Pancreatic Cancer: Challenges and Early Results

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease due to its late presentation and tendency to recur early even after optimal surgical resection. Currently, there are limited options for effective systemic therapy. In addition, PDAC typically generates an immune-suppressive tumor microenvironment; trials of immunotherapy in metastatic PDAC have yielded disappointing results. There is considerable interest in using immunotherapy approaches in the neoadjuvant setting in order to prime the immune system to detect and prevent micrometastatic disease and recurrence. A scoping review was conducted to identify published and ongoing trials utilizing preoperative immunotherapy. In total, 9 published trials and 27 ongoing trials were identified. The published trials included neoadjuvant immune checkpoint inhibitors, cancer vaccines, and other immune-modulating agents that target mechanisms distinct from that of immune checkpoint inhibition. Most of these are early phase trials which suggest improvements in disease-free and overall survival when combined with standard neoadjuvant therapy. Ongoing trials are exploring various combinations of these agents with each other and with chemotherapy and/or radiation. Rational combination immunotherapy in addition to standard neoadjuvant therapy has the potential to improve outcomes in PDAC, but further clinical trials are needed, particularly those which utilize an adaptive trial design.

Preoperative treatments in borderline resectable and locally advanced pancreatic cancer: current evidence and new perspectives

Surgery is the only curative treatment for non-metastatic pancreatic adenocarcinoma, but less than 20% of patients present a resectable disease at diagnosis. Treatment strategies and disease definition for borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) vary in the different cancer centres. Preoperative chemotherapy (CT) is the standard of care for both BRPC and LAPC patients, however literature data are still controversial concerning the type, dose and duration of the different CT regimens, as well as regarding the integration of radiotherapy (RT) or chemoradiation (CRT) in the therapeutic algorithm. In this unsettled debate, we aimed at focusing on the therapeutic regimens currently in use and relative literature data, to report international trials comparing the available therapeutic options or explore the introduction of new pharmacological agents, and to analyse possible new scenarios in microenvironment evaluation before and after neoadjuvant therapies or in patients' selection at a molecular level.

Prognostic value of major pathological response following neoadjuvant therapy for non resectable pancreatic ductal adenocarcinoma

BACKGROUND

The aim of this study is to evaluate the impact of major pathological response on overall survival (OS) in borderline resectable and locally advanced pancreatic ductal adenocarcinoma following neoadjuvant treatment, and to identify predictors of major pathological response.

METHODS

Patients surgically resected following neoadjuvant treatment between 2010 and 2020 at the Pederzoli Hospital were retrospectively analyzed. Pathologic response was assessed using the College of American Pathologists (CAP) score, and major pathological response was defined as CAP 0-1. OS was estimated and compared using the Kaplan-Meier method and log-rank test. A logistic and Cox regression model were performed to identify predictors of major pathologic response and OS.

RESULTS

Overall, 200 patients were included in the study. A major and complete pathological response were observed in 52(26.0%) and 15(7.3%) patients respectively. The 1-, 3-, 5-year OS was 92.7, 67.2, and 41.7%, and 71.0, 37.4, and 20.8% in patients with or without major pathologic response respectively (log-rank test p < 0.001). Major pathologic response was confirmed as independent predictor of OS (OR 0.50 95%CI 0.29-0.88, p = 0.01). Post-treatment CA19-9 normalization (OR 4.20 95%CI 1.14-10.35, p = 0.02) and radiological post-treatment tumor residual size<25 mm (OR 2.71 95%CI 1.27-5.79, p = 0.01) were found to be independent predictors of major pathologic response.

CONCLUSION

Patients experienced a major pathological response after neoadjuvant treatment have an increased survival, and major pathologic response is an independent predictor of OS. A normal CA19-9 value and radiological tumor size at restaging are confirmed to be independent predictors of major pathologic response.

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.

Pathological Response Predicts Survival after Pancreatectomy following Neoadjuvant FOLFIRINOX for Pancreatic Cancer

Background: The clinical course of complete pathologic response (cPR) in pancreatic cancer after neoadjuvant chemotherapy is not well known. The aim of this study was to investigate the clinical course of patients according to pathological response, including cPR, who received only FOLIFIRNOX in advanced pancreatic cancer. Methods: Patients who underwent pancreatectomy after FOLFIRINOX for pancreatic ductal adenocarcinoma (PDAC) from 2017 to 2019 were retrospectively reviewed. cPR was defined as an absence of residual tumor on pathologic report. A nearly complete pathologic response (ncPR) was defined as a tumor confined to pancreas parenchyma, less than 1 cm without lymph-node metastasis. cPR and ncPR were assigned into a favorable pathologic response group (fPR). Kaplan−Meier method and Cox proportional hazard models were used for analysis. Results: Of a total 64 patients, 8 (12.5%) had a cPR and 8 (12.5%) had a ncPR. In the fPR group, median OS and DFS were superior to those of non-pathologic response group (more than 60 months vs. 38 months, p < 0.001; more than 42 months vs. 10 months, p < 0.001). On multivariable analyses, fPR and adjuvant therapy were independent prognostic factors for OS (HR: 0.12; 95% CI: 0.02−0.96, p = 0.05; HR: 0.26; 95% CI: 0.09−0.74, p = 0.01) and DFS (HR: 0.31; 95% CI: 0.12−0.86, p = 0.02; HR:0.31; 95% CI: 0.13−0.72, p = 0.01). Conclusions: pathologic response predicts survival after pancreatectomy following neoadjuvant FOLFIRINOX for pancreatic cancer, and adjuvant chemotherapy following neoadjuvant treatment might be beneficial for OS and DFS.

Routine neoadjuvant chemotherapy for all patients with resectable pancreatic ductal adenocarcinoma? A review of the evidence

Pancreatic ductal adenocarcinoma is an aggressive malignancy that carries a poor prognosis because the majority of patients present with locally advanced or metastatic disease. However, even patients who are fortunate enough to present with resectable disease are often plagued by high recurrence rates. While adjuvant chemotherapy has been shown to decrease the risk of recurrence after surgery, post operative complications and poor performance status after surgery prevent up to 50% of patients from receiving it. Given the benefits of neoadjuvant therapy in patients with borderline resectable disease, it is understandable that neoadjuvant therapy has been steadily increasing in patients with resectable cancers as well. In this review paper, we highlight the rational and existing evidence of using neoadjuvant therapy in all patients with resectable pancreatic adenocarcinoma.

Total neoadjuvant therapy is associated with improved overall survival and pathologic response in pancreatic adenocarcinoma

BACKGROUND

Few studies have evaluated outcomes of total neoadjuvant therapy (TNT) compared with single modality neoadjuvant therapy (SMNT) or surgery first (SF) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

A single-institution retrospective review of PDAC patients who underwent pancreatectomy was conducted (1993-2019). Overall survival (OS) estimates from diagnosis and from surgery were determined using Kaplan-Meier methods; Cox proportional hazards models adjusted for covariates.

RESULTS

Surgery was performed upfront (SF) in 168 (46.9%), while 111 (31.0%) had chemotherapy or chemoradiation before resection (SMNT), and 79 (22.1%) underwent TNT (chemotherapy and chemoradiation). Resection margins were more frequently R0 in the TNT group (86.1%) compared with SMNT (64.0%) and SF (72%) (p < 0.001). Complete pathologic response was more common in the TNT group (10.1%) compared with SMNT (3.6%) or SF (0.6%) (p = 0.001), resulting in prolonged survival (median OS = 100.2 months). TNT patients demonstrated longer median OS from surgery (33.6 months) compared with SF (19.1 months) and SMNT (17.4 months) (p = 0.010), which persisted after controlling for covariates.

CONCLUSIONS

TNT is associated with more frequent complete pathologic response, a higher rate of margin negative resection, and prolonged OS as compared with SF or SMNT. Additional studies to identify subgroups that derive the greatest benefit are warranted.

Neoadjuvant Radiotherapy After (m)FOLFIRINOX for Borderline Resectable Pancreatic Adenocarcinoma: A TAPS Consortium Study

BACKGROUND

The value of neoadjuvant radiotherapy (RT) after 5-fluorouracil with leucovorin, oxaliplatin, and irinotecan, with or without dose modifications [(m)FOLFIRINOX], for patients with borderline resectable (BR) pancreatic ductal adenocarcinoma (PDAC) is uncertain.

METHODS

We conducted an international retrospective cohort study including consecutive patients with BR PDAC who received (m)FOLFIRINOX as initial treatment (2012-2019) from the Trans-Atlantic Pancreatic Surgery Consortium. Because the decision to administer RT is made after chemotherapy, patients with metastases or deterioration after (m)FOLFIRINOX or a performance score ≥2 were excluded. Patients who received RT after (m)FOLFIRINOX were matched 1:1 by nearest neighbor propensity scores with patients who did not receive RT. Propensity scores were calculated using sex, age (≤70 vs >70 years), WHO performance score (0 vs 1), tumor size (0-20 vs 21-40 vs >40 mm), tumor location (head/uncinate vs body/tail), number of cycles (1-4 vs 5-8 vs >8), and baseline CA 19-9 level (≤500 vs >500 U/mL). Primary outcome was overall survival (OS) from diagnosis.

RESULTS

Of 531 patients who received neoadjuvant (m)FOLFIRINOX for BR PDAC, 424 met inclusion criteria and 300 (70.8%) were propensity score-matched. After matching, median OS was 26.2 months (95% CI, 24.0-38.4) with RT versus 32.8 months (95% CI, 25.3-42.0) without RT (P=.71). RT was associated with a lower resection rate (55.3% vs 72.7%; P=.002). In patients who underwent a resection, RT was associated with a comparable margin-negative resection rate (>1 mm) (70.6% vs 64.8%; P=.51), more node-negative disease (57.3% vs 37.6%; P=.01), and more major pathologic response with <5% tumor viability (24.7% vs 8.3%; P=.006). The OS associated with conventional and stereotactic body RT approaches was similar (median OS, 25.7 vs 26.0 months; P=.92).

CONCLUSIONS

In patients with BR PDAC, neoadjuvant RT following (m)FOLFIRINOX was associated with more node-negative disease and better pathologic response in patients who underwent resection, yet no difference in OS was found. Routine use of RT cannot be recommended based on these data.

Radiation therapy in borderline resectable pancreatic cancer: A review

BACKGROUND

Borderline resectable pancreatic cancer constitutes a complex clinical entity, presenting the clinician with a locally aggressive disease that has a proclivity for distant spread. The benefits of radiation therapy, such as improved local control and improved survival, have been questioned. In this review we seek to summarize the existing evidence on radiation therapy in borderline resectable pancreatic cancer and highlight future areas of research.

METHODS

A comprehensive review of PubMed for clinical studies reporting outcomes in borderline resectable pancreatic cancer was performed in June 2021, with an emphasis placed on prospective studies.

RESULTS

Radiologic "downstaging" in borderline resectable pancreatic cancer is a rare event, although some evidence shows increased clinical response to neoadjuvant chemotherapy over radiation therapy. Margin status seems to be equivalent between regimens that use neoadjuvant chemotherapy alone and regimens that include neoadjuvant radiation therapy. Local control in borderline resectable pancreatic cancer is likely improved with radiation therapy; however, the benefit of improved local control in a disease marked by systemic failure has been questioned. Although some studies have shown improved survival with radiation therapy, differences in the delivery and tolerance of chemotherapy between the neoadjuvant and adjuvant setting confound these results. When the evidence is evaluated as a whole, there is no clear survival benefit of radiation therapy in borderline resectable pancreatic cancer.

CONCLUSION

Once considered a staple of therapy, the role of radiation therapy in borderline resectable pancreatic cancer is evolving as systemic therapy regimens continues to improve. Increased clinical understanding of disease phenotype and response are needed to accurately tailor therapy for individual patients and to improve outcomes in this complex patient population.

Impact of pathological response after neoadjuvant chemotherapy on adjuvant therapy decisions and patient outcomes in gastrointestinal cancers

BACKGROUND

Neoadjuvant chemotherapy (NAC) is frequently used in gastrointestinal cancers (GIC), and pathological, radiological, and tumor marker responses are assessed during and after NAC.

AIM

To evaluate the relationship between pathologic, radiologic, tumor marker responses and recurrence-free survival (RFS), overall survival (OS), adjuvant chemotherapy (AC) decisions, and the impact of changing to a different AC regimen after poor response to NAC.

METHODS AND RESULTS

Medical records of GIC patients treated with NAC at Mount Sinai between 1/2012 and 12/2018 were reviewed. One hundred fifty-six patients (58.3% male, mean age 63 years) were identified. Primary tumor sites were: 43 (27.7%) pancreas, 62 (39.7%) gastroesophageal, and 51 (32.7%) colorectal. After NAC, 31 (19.9%) patients had favorable pathologic response (FPR; defined as College of American Pathologists [CAP] score 0-1). Of 107 patients with radiological data, 59 (55.1%) had an objective response, and of 113 patients with tumor marker data, 61 (54.0%) had a ≥50% reduction post NAC. FPR, but not radiographic or serological responses, was associated with improved RFS (HR 0.28; 95% CI 0.11-0.72) and OS (HR 0.13; 95% CI 0.2-0.94). Changing to a different AC regimen from initial NAC, among all patients and specifically among those with unfavorable pathological response (UPR; defined as CAP score 2-3) after NAC, was not associated with improved RFS or OS.

CONCLUSIONS

GIC patients with FPR after NAC experienced significant improvements in RFS and OS. Patients with UPR did not benefit from changing AC. Prospective studies to better understand the role of pathological response in AC decisions and outcomes in GIC patients are needed.

How to select the most appropriate adjuvant treatment after neoadjuvant treatment and resection for locally advanced pancreatic cancer?

Adjuvant chemotherapy (ACT) significantly improves survival of patients undergoing upfront surgery for resectable pancreatic cancer. After introducing the concept of neoadjuvant therapy (NAT) with potent chemotherapy regimens, long term survival has been achieved even in patients with borderline and locally advanced pancreatic cancer (BR/LAPC) following radical resection. The observed pathologic tumor response is strongly predictive of survival and provides a unique opportunity to visualize to what extent the cancer has been sensitive to the administered chemotherapy regimen and may potentially give hint how to personalize further oncologic treatment. Current literature provides only limited and heterogeneous data as to whether and what type of ACT is beneficial after NAT and resection for BR/LAPC. Larger studies suggest that ACT may bring survival advantage and should be attempted particularly in node-positive disease and preferably with more potent regimen such as FOLFIRINOX, if tolerable. In case of complete pathologic response, particularly after FOLFIRINOX, it does not seem beneficial to deescalate the treatment during ACT, but whether continuation on the same regimen is worthwhile needs to be further examined. In case of gemcitabine-based treatment as NAT, continuation with more cycles seems to be of value unless tumor biology proves to be too aggressive, with high lymph node ratio. Whether switch to a different regimen should be sought, if tolerability allows it, needs to be further studied. Whether it is the exact treatment sequence (NAT, ACT or both) of the potent chemotherapy regimens like FOLFIRINOX and gemcitabine-nab-paclitaxel or the total dose of chemotherapy that has impact on survival in BR/LAPC, is unknown.

Neoadjuvant therapy for pancreatic ductal adenocarcinoma: Opportunities for personalized cancer care

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy that is best treated in a multidisciplinary fashion using surgery, chemotherapy, and radiation. Adjuvant chemotherapy has shown to have a significant survival benefit in patients with resected PDAC. However, up to 50% of patients fail to receive adjuvant chemotherapy due to postoperative complications, poor patient performance status or early disease progression. In order to ensure the delivery of chemotherapy, an alternative strategy is to administer systemic treatment prior to surgery. Precision oncology refers to the application of diverse strategies to target therapies specific to characteristics of a patient’s cancer. While traditionally emphasized in selecting targeted therapies based on molecular, genetic, and radiographic biomarkers for patients with metastatic disease, the neoadjuvant setting is a prime opportunity to utilize personalized approaches. In this article, we describe the current evidence for the use of neoadjuvant therapy (NT) and highlight unique opportunities for personalized care in patients with PDAC undergoing NT.

Added Value of Radiotherapy Following Neoadjuvant FOLFIRINOX for Resectable and Borderline Resectable Pancreatic Cancer: A Systematic Review and Meta-Analysis

Background

The added value of radiotherapy following neoadjuvant FOLFIRINOX chemotherapy in patients with resectable or borderline resectable pancreatic cancer ((B)RPC) is unclear. The objective of this meta-analysis was to compare outcomes of patients who received neoadjuvant FOLFIRINOX alone or combined with radiotherapy.

Methods

A systematic literature search was performed in Embase, Medline (ovidSP), Web of Science, Scopus, Cochrane, and Google Scholar. The primary endpoint was pooled median overall survival (OS). Secondary endpoints included resection rate, R0 resection rate, and other pathologic outcomes.

Results

We included 512 patients with (B)RPC from 15 studies, of which 7 were prospective nonrandomized studies. In total, 351 patients (68.6%) were treated with FOLFIRINOX alone (8 studies) and 161 patients (31.4%) were treated with FOLFIRINOX and radiotherapy (7 studies). The pooled estimated median OS was 21.6 months (range 18.4–34.0 months) for FOLFIRINOX alone and 22.4 months (range 11.0–37.7 months) for FOLFIRINOX with radiotherapy. The pooled resection rate was similar (71.9% vs. 63.1%, p = 0.43) and the pooled R0 resection rate was higher for FOLFIRINOX with radiotherapy (88.0% vs. 97.6%, p = 0.045). Other pathological outcomes (ypN0, pathologic complete response, perineural invasion) were comparable.

Conclusions

In this meta-analysis, radiotherapy following neoadjuvant FOLFIRINOX was associated with an improved R0 resection rate as compared with neoadjuvant FOLFIRINOX alone, but a difference in survival could not be demonstrated. Randomized trials are needed to determine the added value of radiotherapy following neoadjuvant FOLFIRINOX in patients with (B)PRC.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10276-8.

Trends in the utilization of neoadjuvant therapy for pancreatic ductal adenocarcinoma

For patients with localized pancreatic cancer, neoadjuvant therapy (NT) is increasingly delivered before surgery to maximize the receipt of multimodality therapy and the odds of a margin-negative resection. Three decades of refining the use of NT have led to its acceptance as a valid treatment approach for pancreatic adenocarcinoma. In this review, we discuss the rationale for and recent global trends in the utilization of NT for patients with pancreatic cancer.

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.

Is Complete Pathologic Response in Pancreatic Cancer Overestimated? A Systematic Review of Prospective Studies

BACKGROUND

In literature, percentages of pathologic complete response (pCR) in patients presenting with resectable (RES), borderline resectable (BLR) or locally advanced (LA) pancreatic cancer (PaC) after neoadjuvant treatment (NADT) are variable, ranging 0-33%. Those data come mostly from retrospective reviews of single centres. The objective of this systematic review is to assess the incidence of pCR.

METHODS

Following the criteria of the PRISMA statement, a literature search was conducted looking for prospective papers focusing on neoadjuvant treatment in PaC. Retrospective papers, other than ductal carcinoma histologies and trials including metastatic patients, were excluded from the present review. Data extraction was carried out by 3 independent investigators. Meta-analysis was performed with ProMeta3 Software (Internovi, 2015). PROSPERO registry: CRD42018095641.

RESULTS

The literature search of Embase, Cochrane and Medline with the terms "neoadjuvant OR preoperative", "pancreatic OR pancreas" and "cancer OR adenocarcinoma OR tumor" led to the identification of 3128 papers. We restricted the search to humans, last 10 years and English language articles resulting in 1158 eligible articles to review. Extended paper revision led to the inclusion of 27 papers. Complete pathologic response ranged 0-11.11%, at the meta-analysis 4% (95% CI 3-5%), in prospective studies 0-9.09% and in prospective databases 1.63-11.11%.

CONCLUSIONS

Pathologic complete response in pancreatic cancer is actually infrequent: high-quality studies provide a more reliable picture of neoadjuvant effects, high rates of pCR are reported in selected retrospective studies but it is overestimated.