Pancreatic ductal adenocarcinoma: tumour regression grading following neoadjuvant FOLFIRINOX and radiation

The differential effect of neoadjuvant chemotherapy and chemoradiation on nodal downstaging in pancreatic adenocarcinoma

BACKGROUND/OBJECTIVES

Neoadjuvant chemotherapy (NCT) and chemoradiotherapy (NCRT) enhance resectability in patients with pancreatic adenocarcinoma (PDAC). This study compares the effect of NCT and NCRT on lymph nodal downstaging and survival.

METHODS

The 2004-2016 National Cancer Database Pancreas Participant User File was used to identify patients who underwent surgery for PDAC. Fisher's exact, Wilcoxon rank-sum, multivariate logistic regression, and log-rank were used. Downstaging was defined as clinically node-positive patients who demonstrated node-negativity on pathology.

RESULTS

Of 42,545 patients meeting criteria, 3311 received NCT and 1511 received NCRT. After surgery for clinically node-positive disease, 23.3% of NCT patients and 41.3% of NCRT patients demonstrated nodal downstaging. Younger age and lower tumor grade independently predicted downstaging. Downstaging after neoadjuvant therapy was associated with improved survival versus no nodal treatment response (29.8 vs. 22.8 months, p < 0.001). Downstaging by NCT was associated with improved overall survival versus downstaging by NCRT (37.5 vs. 26.6 months, p = 0.001). No survival difference existed between those with no nodal response after NCT or NCRT (p = 0.101).

CONCLUSIONS

Although nodal downstaging is more likely post-NCRT, survival is superior in those downstaged post-NCT. Overall survival is determined by the systemic burden of disease. Post-therapy histologic analysis may be less prognostic post-NCRT.

Pathologic tumor response to neoadjuvant therapy in resected pancreatic cancer: does it affect prognosis?

Neoadjuvant therapy (NAT) + surgical resection for pancreatic cancer (PC) has gained consensus in recent years. Pathological response (PR) is generally assessed according to the College of American Pathologists grading system, ranging from 0 (complete response) to 3 (no response). The aim of our study is to evaluate the PR in a series of resections for PC after NAT and its prognostic implication. 112 patients undergone NAT and resection for PC between 2011 and 2020 were retrospectively evaluated. PR was 0/1, 2 and 3 in 18 (15%), 79 (61%) and 29 (24%) cases, respectively. Chemotherapy regimens different from FOLFIRINOX and gemcitabine + nab-paclitaxel (OR 11.61 (2.53-53.36), p = 0.002) and lymphovascular invasion (OR 11.28 (1.89-67.23), p = 0.008) were associated to PR-3. Median follow-up was 25.8 (3.6-130.5) months. For PR-0/1, PR-2 and PR-3, median DFS was 45.8, 11.5, 4.6 months (p < 0.0001), respectively, while median OS was not reached, 27.1 and 17.5 months (p = 0.0006), respectively. At univariate analysis, PR-0/1 was significantly associated to better DFS and OS (HR 0.33 (0.17-0.67), p = 0.002; HR 0.20 (0.07-0.54), p = 0.002, respectively). At multivariate analysis, pancreaticoduodenectomy (HR 0.50 (0.30-0.84), p = 0.009), LNR (HR 27.14 (1.21-608.9), p = 0.038) and lymphovascular invasion (HR 1.99 (1.06-3.76), p = 0.033) were independently associated to DFS; pre-treatment CA 19.9 value (HR 1.00 (1.00-1.00), p = 0.025), post-treatment resectability status (HR 0.51 (0.28-0.95), p = 0.035), pancreaticoduodenectomy (HR 0.56 (0.32-0.99), p = 0.050), severe morbidity (2.99 (1.22-7.55), p = 0.017), LNR (HR 56.8 (2.08-1548.3), p = 0.017), lymphovascular invasion (HR 2.18 (1.08-4.37), p = 0.029) were independently associated to OS. PR did not reach statistical significance at multivariate analysis. A favorable PR is observed only in a limited number of cases. The prognostic role of PR, despite being promising, remains unclear and further multicentric studies are needed.

Prognosticators for Patients with Pancreatic Ductal Adenocarcinoma Who Received Neoadjuvant FOLFIRINOX or Gemcitabine/Nab-Paclitaxel Therapy and Pancreatectomy

Neoadjuvant FOLFIRINOX and gemcitabine/nab-paclitaxel (GemNP) therapies are increasingly used to treat patients with pancreatic ductal adenocarcinoma (PDAC). However, limited data are available on their clinicopathologic prognosticators. We examined the clinicopathologic factors and survival of 213 PDAC patients who received FOLFIRINOX with 71 patients who received GemNP. The FOLFIRINOX group was younger (p < 0.01) and had a higher rate of radiation (p = 0.049), higher rate of borderline resectable and locally advanced disease (p < 0.001), higher rate of Group 1 response (p = 0.045) and lower ypN stage (p = 0.03) than the GemNP group. Within FOLFIRINOX group, radiation was associated with decreased lymph node metastasis (p = 0.01) and lower ypN stage (p = 0.01). The tumor response group, ypT, ypN, LVI and PNI, correlated significantly with both DFS and OS (p < 0.05). Patients with the ypT0/T1a/T1b tumor had better DFS (p = 0.04) and OS (p = 0.03) than those with ypT1c tumor. In multivariate analysis, the tumor response group and ypN were independently prognostic factors for DFS and OS (p < 0.05). Our study demonstrated that the FOLFIRINOX group was younger and had a better pathologic response than the GemNP group and that the tumor response group, ypN, ypT, LVI and PNI, are significant prognostic factors for survival in these patients. Our results also suggest that the tumor size of 1.0 cm is a better cut off for ypT2. Our study highlights the importance of systemic pathologic examination and the reporting of post-treatment pancreatectomies.

The Histopathology of Neoadjuvant-Treated (NAT) Pancreatic Ductal Adenocarcinoma

Examination of pancreatic ductal adenocarcinoma after NAT with the intent of diagnosis and outcome prediction remains a challenging task. The lack of a uniform approach to macroscopically assess these cases along with variations in sampling adds to the complexity. Several TRG systems have been proposed to correlate with an overall survival. In clinical practice, most of these TRG schemes have shown low level of interobserver agreement arguing for a need of larger studies and more innovative ways to assess outcome in this population.

Artificial Intelligence-Based Segmentation of Residual Tumor in Histopathology of Pancreatic Cancer after Neoadjuvant Treatment

Simple Summary

The use of neoadjuvant therapy (NAT) in patients with pancreatic ductal adenocarcinoma (PDAC) is increasing. Objective quantification of the histopathological response to NAT may be used to guide adjuvant treatment and compare the efficacy of neoadjuvant regimens. However, current tumor response scoring (TRS) systems suffer from interobserver variability, originating from subjective definitions, the sometimes challenging histology, and response heterogeneity throughout the tumor bed. This study investigates if artificial intelligence-based segmentation of residual tumor burden in histopathology of PDAC after NAT may offer a more objective and reproducible TRS solution.

Abstract

Background: Histologic examination of resected pancreatic cancer after neoadjuvant therapy (NAT) is used to assess the effect of NAT and may guide the choice for adjuvant treatment. However, evaluating residual tumor burden in pancreatic cancer is challenging given tumor response heterogeneity and challenging histomorphology. Artificial intelligence techniques may offer a more reproducible approach. Methods: From 64 patients, one H&E-stained slide of resected pancreatic cancer after NAT was digitized. Three separate classes were manually outlined in each slide (i.e., tumor, normal ducts, and remaining epithelium). Corresponding segmentation masks and patches were generated and distributed over training, validation, and test sets. Modified U-nets with varying encoders were trained, and F1 scores were obtained to express segmentation accuracy. Results: The highest mean segmentation accuracy was obtained using modified U-nets with a DenseNet161 encoder. Tumor tissue was segmented with a high mean F1 score of 0.86, while the overall multiclass average F1 score was 0.82. Conclusions: This study shows that artificial intelligence-based assessment of residual tumor burden is feasible given the promising obtained F1 scores for tumor segmentation. This model could be developed into a tool for the objective evaluation of the response to NAT and may potentially guide the choice for adjuvant treatment.

Dataset for the reporting of carcinoma of the exocrine pancreas: recommendations from the International Collaboration on Cancer Reporting (ICCR)

BACKGROUND AND OBJECTIVES

Current guidelines for the pathology reporting on pancreatic cancer differ in certain aspects, resulting in divergent reporting practice and a lack of comparability of data. Here we report on a new international dataset for the pathology reporting of resection specimens with cancer of the exocrine pancreas (ductal adenocarcinoma and acinar cell carcinoma). The dataset was produced under the auspices of the International Collaboration on Cancer Reporting (ICCR), a global alliance of major (inter-)national pathology and cancer organisations.

METHODS AND RESULTS

According to the ICCR's rigorous process for dataset development, an international expert panel consisting of pancreatic pathologists, a pancreatic surgeon and an oncologist produced a set of core and non-core data items based on a critical review and discussion of current evidence. Commentary was provided for each data item to explain the rationale for selecting it as a core or non-core element, its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. Following international public consultation, the document was finalised and ratified, and the dataset, which includes a synoptic reporting guide, was published on the ICCR website.

CONCLUSIONS

This first international dataset for cancer of the exocrine pancreas is intended to promote high quality, standardised pathology reporting. Its widespread adoption will improve consistency of reporting, facilitate multidisciplinary communication and enhance comparability of data, all of which will help to improve the management of pancreatic cancer patients.

Biliary intervention rates during neoadjuvant therapy for adenocarcinoma of the pancreatic head

BACKGROUND

Neoadjuvant therapy prior to resection of adenocarcinoma of the pancreatic head increases time to surgery and thus the possibility of biliary complications. We hypothesized that biliary complications during neoadjuvant therapy negatively impact clinical outcomes.

METHODS

We completed a retrospective study of a cohort of borderline resectable patients consistently treated with neoadjuvant therapy from May 2014 through March 2019. Biliary complications were defined as new-onset biliary obstruction, existing stent failure, cholecystitis, and cholangitis.

RESULTS

Of 59 patients that met inclusion criteria, 34 (57.6%) went on to resection. Biliary complications affected 16 patients (27%); 8 (50%) of these patients went on to surgical resection. Of those 43 patients who did not have a biliary intervention, 26 went on to surgical resection (60.4%). There was no significant effect of a biliary complication on total number of chemotherapy cycles (p = 0.12), proceeding to surgical resection (p = 0.56) or on median survival (p = 0.23). Among patients who did proceed to surgery, there was a notable difference in median survival for patients who required a biliary intervention (17.9 vs 31.0 months) that did not reach significance (p = 0.35).

CONCLUSION

The need for further biliary interventions during neoadjuvant therapy for pancreatic adenocarcinoma is common, but does not appear to have a significant effect on number of cycles of neoadjuvant therapy or proceeding to surgical resection. Larger studies are necessary to determine if these events compromise overall survival.

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.

A Critical Assessment of Postneoadjuvant Therapy Pancreatic Cancer Regression Grading Schemes With a Proposal for a Novel Approach

Currently, there is no consensus on the optimal tumor response score (TRS) system to assess regression in pancreatic cancers resected after neoadjuvant therapy. We developed a novel TRS (Royal North Shore [RNS] system) based on estimating the percentage of tumor bed occupied by viable cancer and categorized into 3 tiers: grade 1 (≤10%), grade 2 (11% to 75%), and grade 3 (>75%). We assessed 147 resected carcinomas with this and other TRS systems (College of American Pathologists [CAP], MD Anderson Cancer Center [MDACC], and Evans). The 3-tiered RNS system predicted median survival after surgery for grades 1, 2, and 3 of 54, 23, and 9 months, respectively (P<0.05). The CAP, MDACC, and Evans systems also predicted survival (P<0.05) but less consistently. The median survival for MDACC and CAP grade 0 (complete regression) was less than MDACC grade 1 and CAP grades 1 and 2. There was no difference in survival between CAP grades 2 and 3 (P=0.960), Evans grades 1 and 2a (P=0.395), and Evans grades 2a and 2b (P=0.587). Interobserver concordance was weak for CAP (κ=0.431), moderate for MDACC (κ=0.691), minimal for Evans (κ=0.307), and moderate to strong for RNS (κ=0.632 to 0.84). Of age, sex, size, stage, grade, perineural and vascular invasion, extrapancreatic extension, margin status, and RNS score, only RNS score, vascular invasion, and extrapancreatic extension predicted survival in univariate analysis. Only extrapancreatic extension (P=0.034) and RNS score (P<0.0001) remained significant in multivariate analysis. We conclude that the RNS system is a reproducible and powerful predictor of survival after resection for pancreatic cancers treated with neoadjuvant therapy and should be investigated in larger cohorts.