Predictive factors for long-term survival after surgery for pancreatic ductal adenocarcinoma: Making a case for standardized reporting of the resection margin using certified cancer center data

Looking at or beyond the tumor - a systematic review and meta-analysis of quantitative imaging biomarkers predicting pancreatic cancer prognosis

OBJECTIVES

To evaluate the prognostic value of quantitative imaging biomarkers derived from computed tomography (CT) and magnetic resonance imaging (MRI) for pancreatic cancer (PC), with a particular focus on body composition parameters beyond the traditional intrinsic features of the tumor.

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched for articles on quantitative imaging biomarkers obtained from CT or MRI in predicting PC prognosis published between January 2014 and August 2024. The Newcastle-Ottawa scale was used to assess the quality of the included studies. Survival outcomes, such as overall survival (OS) and recurrence-free survival (RFS), were evaluated. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using a random-effects model. In case of high heterogeneity, subgroup analyses and sensitivity analyses were performed to identify potential sources of heterogeneity among the studies.

RESULTS

We performed a meta-analysis of ten imaging biomarkers investigated in 43 included studies. Larger tumor size, lower skeletal muscle radiodensity, lower skeletal muscle index (SMI), presence of sarcopenic obesity, lower psoas muscle index (PMI), higher visceral to subcutaneous adipose tissue area ratio, and lower visceral adipose tissue index were associated with significantly worse OS. In particular, lower SMI and lower PMI had relatively high HRs (1.65 for SMI, 95% CI 1.39-1.96, and 2.20 for PMI, 95% CI 1.74-2.78). Patients with lower SMI exhibited poorer RFS (HR 1.78, 95% CI 1.46-2.18). Subgroup analyses identified the origin region of the study and intervention type as potential factors of heterogeneity for SMI in predicting OS.

CONCLUSIONS

Imaging biomarkers indicating body composition at PC diagnosis may play an important role in predicting patient prognosis. Further prospective multi-center studies with large sample sizes are needed for validation and translation into clinical practice.

Peripheral Eosinophil Count May Be the Prognostic Factor for Overall Survival in Patients with Pancreatic Ductal Adenocarcinoma Undergoing Surgical Treatment

(1) Background: The importance of total eosinophil count in peripheral blood (EOS) as a type 2 inflammation marker is known to be fundamental in asthma, chronic sinusitis, and vasculitis. In cancer, despite their questionable antiproliferative effect, their role remains unclear. Our purpose was to describe the relationship between baseline blood EOS and overall survival (OS) in pancreatic ductal adenocarcinoma (PDAC) patients. (2) Methods: We retrospectively analyzed data from 137 adult patients who underwent surgical treatment for pancreatic ductal adenocarcinoma (PDAC) between the years 2012 and 2019. Patients with no recent history of systemic steroid use and without intraoperative metastases were included. Patients were categorized into two groups based on EOS (≥0.1 G/l and <0.1 G/l). Survival outcomes were analyzed using Cox proportional hazards regression models. (3) Results: According to EOS and PDAC stage, median OS values were as follows: in stage I-III, EOS ≥ 0.1 G/l group: 14.5 months, in stage I-III, EOS < 0.1 G/l group: 8.0 months, in stage IV, EOS ≥ 0.1 G/l group: 7.0 months, and in stage IV, EOS < 0.1 G/l group: 5.0 months. EOS < 0.1 G/l (vs. ≥0.1 G/l) was an independent prognostic factor for OS in both the uni- and multivariate Cox regression, respectively (HR = 1.48, p = 0.035 and HR = 1.57, p = 0.021). (4) Conclusions: Peripheral eosinophilia seems to be a potential independent prognostic factor. Further studies are necessary to confirm this hypothesis, since our findings suggest that type 2 inflammation may be the factor directly or indirectly lengthening the survival of patients with PDAC.

Minocycline and photodynamic priming significantly improve chemotherapy efficacy in heterotypic spheroids of pancreatic ductal adenocarcinoma

The prognosis for patients with advanced-stage pancreatic ductal adenocarcinoma (PDAC) remains dismal. It is generally accepted that combination cancer therapies offer the most promise, such as Folforinox, despite their associated high toxicity. This study addresses the issue of chemoresistance by introducing a complementary dual priming approach to attenuate the DNA repair mechanism and to improve the efficacy of a type 1 topoisomerase (Top1) inhibitor. The result is a regimen that integrates drug-repurposing and nanotechnology using 3 clinically relevant FDA-approved agents (1) Top1 inhibitor (irinotecan) at subcytotoxic doses (2) benzoporphyrin derivative (BPD) as a photoactive molecule for photodynamic priming (PDP) to improve the delivery of irinotecan within the cancer cell and (3) minocycline priming (MNP) to modulate DNA repair enzyme Tdp1 (tyrosyl-DNA phosphodiesterase) activity. We demonstrate in heterotypic 3D cancer models that incorporate cancer cells and pancreatic cancer-associated fibroblasts that simultaneous targeting of Tdp1 and Top1 were significantly more effective by employing MNP and photoactivatable multi-inhibitor liposomes encapsulating BPD and irinotecan compared to monotherapies or a cocktail of dual or triple-agents. These data are encouraging and warrant further work in appropriate animal models to evolve improved therapeutic regimens.

Stereotactic body radiotherapy for pancreatic cancer - A systematic review of prospective data

Purpose

This systematic review aims to comprehensively summarize the current prospective evidence regarding Stereotactic Body Radiotherapy (SBRT) in various clinical contexts for pancreatic cancer including its use as neoadjuvant therapy for borderline resectable pancreatic cancer (BRPC), induction therapy for locally advanced pancreatic cancer (LAPC), salvage therapy for isolated local recurrence (ILR), adjuvant therapy after radical resection, and as a palliative treatment. Special attention is given to the application of magnetic resonance-guided radiotherapy (MRgRT).

Methods

Following PRISMA guidelines, a systematic review of the Medline database via PubMed was conducted focusing on prospective studies published within the past decade. Data were extracted concerning study characteristics, outcome measures, toxicity profiles, SBRT dosage and fractionation regimens, as well as additional systemic therapies.

Results and conclusion

31 studies with in total 1,571 patients were included in this review encompassing 14 studies for LAPC, 9 for neoadjuvant treatment, 2 for adjuvant treatment, 2 for ILR, with an additional 4 studies evaluating MRgRT. In LAPC, SBRT demonstrates encouraging results, characterized by favorable local control rates. Several studies even report conversion to resectable disease with substantial resection rates reaching 39%. The adoption of MRgRT may provide a solution to the challenge to deliver ablative doses while minimizing severe toxicities. In BRPC, select prospective studies combining preoperative ablative-dose SBRT with modern induction systemic therapies have achieved remarkable resection rates of up to 80%. MRgRT also holds potential in this context. Adjuvant SBRT does not appear to confer relevant advantages over chemotherapy. While prospective data for SBRT in ILR and for palliative pain relief are limited, they corroborate positive findings from retrospective studies.

Vein Wall Invasion Is a More Reliable Predictor of Oncological Outcomes than Vein-Related Margins after Pancreaticoduodenectomy for Early Stages of Pancreatic Ductal Adenocarcinoma

Pancreaticoduodenectomy (PD) with vein resection is the only potentially curative option for patients with pancreatic ductal adenocarcinoma (PDAC) with venous involvement. The aim of our study was to assess the oncological prognostic significance of the different variables of venous involvement in patients undergoing PD for resectable and borderline-resectable with venous-only involvement (BR-V) PDAC. We performed a retrospective analysis of prospectively acquired data over a 10-year period. Of the 372 patients included, 105 (28%) required vein resection and vein wall involvement was identified in 37% of those. A multivariable analysis failed to identify the vein-related resection margins as independent predictors for OS, DFS or LR. Vein wall tumour involvement was an independent predictor of OS (risk x1.7-2) and DFS (risk x1.9-2.2) in all models, while it replaced overall surgical margin positivity as the only parameter independently predicting LR during an analysis of separate resection margins (risk x2.4). Vein wall tumour invasion may be a more reliable predictor of oncological outcomes compared to traditionally reported parameters. Future studies should focus on possible pre-operative investigations that could identify these cases and management pathways that could yield a survival benefit, such as the use of neoadjuvant treatments.

Neo-Adjuvant Treatment in Primary Resectable Pancreatic Cancer: A Systematic Review and PRISMA-Compliant Updated Metanalysis of Oncological Outcomes

BACKGROUND

Despite advances in treatment, the prognosis of resectable pancreatic adenocarcinoma remains poor. Neoadjuvant therapy (NAT) has gained great interest in hopes of improving survival. However, the results of available studies based on different treatment approaches, such as chemotherapy and chemoradiotherapy, showed contrasting results. The aim of this systematic review and meta-analysis is to clarify the benefit of NAT compared to upfront surgery (US) in primarily resectable pancreatic adenocarcinoma.

METHODS

A PRISMA literature review identified 139 studies, of which 15 were finally included in the systematic review and meta-analysis. All data from eligible articles was summarized in a systematic summary and then used for the meta-analysis. Specifically, we used HR for OS and DFS and risk estimates (odds ratios) for the R0 resection rate and the N+ rate. The risk of bias was correctly assessed according to the nature of the studies included.

RESULTS

From the pooled HRs, OS for NAT patients was better, with an HR for death of 0.80 (95% CI: 0.72-0.90) at a significance level of less than 1%. In the sub-group analysis, no difference was found between patients treated with chemoradiotherapy or chemotherapy exclusively. The meta-analysis of seven studies that reported DFS for NAT resulted in a pooled HR for progression of 0.66 (95% CI: 0.56-0.79) with a significance level of less than 1%. A significantly lower risk of positive lymph nodes (OR: 0.45; 95% CI: 0.32-0.63) and an improved R0 resection rate (OR: 1.70; 95% CI: 1.23-2.36) were also found in patients treated with NAT, despite high heterogeneity.

CONCLUSIONS

NAT is associated with improved survival for patients with resectable pancreatic adenocarcinoma; however, the optimal treatment strategy has yet to be defined, and further studies are required.

Pathologic Tumor Regression is Associated With Improved Survival in Pancreatic Cancer

OBJECTIVES

The advent of effective chemotherapy regimens has increased the use of neoadjuvant multiagent chemotherapy in pancreatic cancer. However, the effect of tumor downstaging with neoadjuvant treatment on survival is unclear.

METHODS

Retrospective study included all resected patients with pancreatic adenocarcinoma who underwent neoadjuvant chemotherapy with FOLFIRINOX or gemcitabine/Abraxane. Downstaging was quantified using (1) difference between presenting AJCC clinical and final pathologic stage and (2) College of American Pathologists (CAP) Tumor Regression Grading Schema.

RESULTS

Eighty-seven patients met inclusion criteria. FOLFIRINOX was the most common regimen, 63.2% vs 21.8%. Change in regimen occurred in 15% of patients. Downstaging based on a difference in AJCC stage group occurred in only 4.6%. In contrast, 45.2% were classified as downstaged by the CAP Tumor Regression of 0-2. Downstaging was similar for FOLFIRINOX gemcitabine/Abraxane (64.7 vs 53.6, P = .12) using the CAP criteria. On univariate analysis, treatment regimen (gemcitabine/Abraxane vs FOLFIRINOX, median survival 27 vs 29 mo; HR 1.57, P = .2) had similar survival. Downstaging by the AJCC stage was not associated with improved survival (HR 1.51, P = .4). However, there was a survival benefit for those downstaged by the CAP Tumor Regression Grading Schema, the median survival of 41 mo vs 25 mo; HR 3.05, P = .009. Improved survival 3.32 (1.35-8.16), P = .009) was maintained on multivariate analysis.

CONCLUSION

Survival is significantly improved in those downstaged, as assessed by the CAP Tumor Regression Schema. Downstaging is an important prognostic variable that can help with joint decision making for clinicians and patients.

Impact of margin accentuation with intraoperative irreversible electroporation on local recurrence in resected pancreatic cancer

BACKGROUND

The purpose of this study was to evaluate the rates of local recurrence and margin positivity in patients with borderline resectable pancreatic cancer after pancreatectomy with or without irreversible electroporation with margin accentuation.

METHODS

Prospective data for preoperative stages IIB (borderline resectable) and III were evaluated, with 75 patients undergoing pancreatectomy with irreversible electroporation with margin accentuation compared to 71 patients who underwent pancreatectomy alone from March 2010 to November 2020.

RESULTS

Both irreversible electroporation with margin accentuation and pancreatectomy-alone groups were similar for body mass index, Charleston comorbidity index, and sex. The irreversible electroporation with margin accentuation group had significantly greater preoperative stage III (irreversible electroporation 83% vs pancreatectomy alone 51%; P = .0001), with similar tumor location (head 64% vs 72%) and tumor size (median 2.9 vs 2.8). Neoadjuvant/induction chemotherapy and prior radiation therapy was similar in both groups (irreversible electroporation with margin accentuation 89% vs 72%). Surgical therapy included a greater percentage of pancreaticoduodenectomy in the pancreatectomy-alone group. Despite greater stage and greater percentage of margin positivity (irreversible electroporation with margin accentuation 27% vs 20%; P = not significant), rates of local recurrence were similar. The mean disease-free interval for local recurrence from time of diagnosis was similar (irreversible electroporation with margin accentuation 15.8 vs 16.5 pancreatectomy alone; P = not significant) and time of treatment (irreversible electroporation with margin accentuation 9.4 vs 10.5 months; P = not significant). Overall survival was improved with the irreversible electroporation with margin accentuation group, with a mean of 34.2 months versus 27.9 months in the pancreatectomy-alone group.

CONCLUSION

Irreversible electroporation with margin accentuation is safe and effective in stages IIB and III pancreatic adenocarcinomas that are technically resectable. Despite higher margin positivity rates, the time to local recurrence and the effects of recurrence were the same in the pancreatectomy-alone group.

Preoperative downstaging of pancreatic cancer is associated with improved survival after multi-agent chemotherapy, but not after radiation

BACKGROUND

Downstaging has been associated with improved survival for many cancers. However, the implications of downstaging are unclear for pancreatic cancer in an era of effective neoadjuvant systemic chemotherapy.

METHODS

NCDB retrospective cohort study of resected pancreatic carcinoma treated with neoadjuvant therapy.

RESULTS

The study included 73,985 patients: 66,589 with no neoadjuvant therapy, 2,102 neoadjuvant radiation therapy (N-RT), 3,195 neoadjuvant multiagent chemotherapy (N-MAC) and 2.099 with both neoadjuvant radiation and multiagent chemotherapy. There was increased use of N-MAC over the period of this study. Patients selected for treatment with N-MAC had longer survival from surgery on univariate (23.1 vs. 18.7 months, p = < 0.01) and multivariate analyses HR 0.81 (0.76-0.87, p < 0.001) compared to those selected with N-RT. Downstaging was similar in N-RT and N-MAC groups (25.1 vs. 24.1%, p = 0.43). Downstaging following N-MAC was associated with a survival benefit, HR 0.85 (0.74-0.98). However, downstaging following N-RT was not associated with a survival advantage, HR 1.12 (0.99-0.99).

CONCLUSION

Clinicians have rapidly adopted N-MAC for treatment of pancreatic cancer. Although the rates of downstaging are similar between treatment groups, response translates into increased survival only with N-MAC and not with N-RT.

The impact of resection margin distance on survival and recurrence in pancreatic ductal adenocarcinoma in a retrospective cohort analysis

BACKGROUND

The prognostic effect of resection margin status following pancreatoduodenectomy for pancreatic ductal adenocarcinoma (PDAC) remains controversial, even with the implementation of standardized pathological assessment. We therefore investigated the impact of resection margin (RM) status and RM distance in curative resected PDAC on overall survival (OS), disease-free survival (DFS) and recurrence.

METHOD

108 patients were retrieved from a prospectively maintained database of a certified pancreatic cancer center. Distribution and relationships between circumferential resection margin (CRM) involvement (CRM≤1mm; CRM>1mm; CRM≥2mm) and their prognostic impact on OS and DFS were assessed using Kaplan-Meier statistics and the Log-Rank test. Multivariate logistic regression was used explain the development of a recurrence 12 months after surgery.

RESULTS

63 out of 108 patients had medial RM and 32 posterior RM involvement. There was no significant difference in OS and DFS between CRM≤1mm and CRM>1mm resections. Clearance at the medial margin of ≥2mm had an impact on OS and DFS, (RM≥2mm vs. RM<2mm: median OS 29.8 vs 16.8 months, median DFS 19.6 vs. 10.3 months). Multivariate analysis demonstrated that age, medial RM ≥2mm, lymph node status and chemotherapy were prognostic factors for OS and DFS. Posterior RM had no influence on OS or DFS.

CONCLUSION

Not all RM seem to have the same impact on OS and DFS, and a clearance of 1mm for definition of a negative RM (i.e. CRM>1mm) seems not sufficient. Future studies should include more patients to stratify for potential confounders we could not account for.

TRIAL REGISTRATION

This study was registered with the German Clinical Trials Registry (reference number DRKS0017425).

Plasma Extracellular Vesicle Characteristics as Biomarkers of Resectability and Radicality of Surgical Resection in Pancreatic Cancer-A Prospective Cohort Study

Due to possible diagnostic misjudgment of tumor resectability, patients with pancreatic ductal adenocarcinoma (PDAC) might be exposed to non-radical resection or unnecessary laparotomy. With small extracellular vesicles (sEV) obtained by liquid biopsy, we aimed to evaluate their potential as biomarkers of tumor resectability, radicality of resection and overall survival (OS). Our prospective study included 83 PDAC patients undergoing surgery with curative intent followed-up longitudinally. sEV were isolated from plasma, and their concentration and size were determined. Fifty patients underwent PDAC resection, and thirty-three had no resection. Preoperatively, patients undergoing resection had higher sEV concentrations than those without resection (p = 0.023). Resection was predicted at the cutoff value of 1.88 × 109/mL for preoperative sEV concentration (p = 0.023) and the cutoff value of 194.8 nm for preoperative mean diameter (p = 0.057). Furthermore, patients with R0 resection demonstrated higher preoperative plasma sEV concentrations than patients with R1/R2 resection (p = 0.014). If sEV concentration was above 1.88 × 109/mL or if the mean diameter was below 194.8 nm, patients had significantly longer OS (p = 0.018 and p = 0.030, respectively). Our proof-of-principle study identified preoperative sEV characteristics as putative biomarkers of feasibility and radicality of PDAC resection that also enable discrimination of patients with worse OS. Liquid biopsy with sEV could aid in PDAC patient stratification and treatment optimization in the future.

Flexible semiparametric mode regression for time-to-event data

The distribution of time-to-event outcomes is usually right-skewed. While for symmetric and moderately skewed data the mean and median are appropriate location measures, the mode is preferable for heavily skewed data as it better represents the center of the distribution. Mode regression has been introduced for uncensored data to model the relationship between covariates and the mode of the outcome. Starting from nonparametric kernel density based mode regression, we examine the use of inverse probability of censoring weights to extend mode regression to handle right-censored data. We add a semiparametric predictor to add further flexibility to the model and we construct a pseudo Akaike's information criterion to select the bandwidth and smoothing parameters. We use simulations to evaluate the performance of our proposed approach. We demonstrate the benefit of adding mode regression to one's toolbox for analyzing survival data on a pancreatic cancer data set from a prospectively maintained cancer registry.

Risk factors of positive resection margin differ in pancreaticoduodenectomy and distal pancreatosplenectomy for pancreatic ductal adenocarcinoma undergoing upfront surgery

OBJECTIVE

Positive resection margin indicates worse prognosis. The present study identified the independent risk factors of R1 resection in pancreaticoduodenectomy (PD) and distal pancreatosplenectomy (DP) for patients with pancreatic ductal adenocarcinoma (PDAC).

METHOD

Consecutive patients who were operated from 1st December 2017 to 30th December 2018 were analyzed retrospectively. A standardized pathological examination with digital whole-mount slide images (DWMSIs) was utilized for evaluation of resection margin status. R1 was defined as microscopic tumor infiltration within 1 mm to the resection margin. The potential risk factors of R1 resection for PD and DP were analyzed separately by univariate and multivariate logistic regression analyses.

RESULTS

For the 192 patients who underwent PD, and the 87 patients who underwent DP, the R1 resection rates were 31.8% and 35.6%, respectively. Univariate analysis on risk factors of R1 resection for PD were tumor location, lymphovascular invasion, N staging, and TNM staging; while those for DP were T staging and TNM staging. Multivariate logistic regression analysis showed the location of tumor in the neck and uncinate process, and N1/2 staging were independent risk factors of R1 resection for PD; while those for DP were T3 staging.

CONCLUSIONS

The clarification of the risk factors of R1 resection might clearly make surgeons take reasonable decisions on surgical strategies for different surgical procedures in patients with PDAC, so as to obtain the first attempt of R0 resection.

Prognostic Impact of Resection Margin Status on Distal Pancreatectomy for Ductal Adenocarcinoma

Pancreatic cancer is associated with a poor prognosis. While surgical resection is the only treatment option with curative intent, most patients die of locoregional and/or distant recurrence. The prognostic impact of the resection margin status has received much attention. However, the evidence is almost exclusively related to pancreatoduodenectomies, while corresponding data for distal pancreatectomy specimens are limited. The key data, such as the rate of microscopic margin involvement (“R1”), the site of margin involvement, and the impact of R1 on patient outcome, are divergent between studies and do not currently allow any general conclusions. The main reasons for the variability in the published data are the small size of the study cohorts and their heterogeneity, as well as the marked divergence in pathology examination practices. The latter is a consequence of the lack of concrete guidance, both for grossing and microscopic examination. The increasing administration of neoadjuvant chemo(radio)therapy introduces a further factor of uncertainty as the conventional definition of a tumour-free margin (“R0”) based on 1 mm clearance is inadequate for these specimens. This review discusses the published data regarding the prognostic impact of margin status in distal pancreatectomy specimens along with the challenges and uncertainties that are related to the assessment of the margins.

Diagnostic Accuracy of CT for Evaluating Circumferential Resection Margin Status in Resectable or Borderline Resectable Pancreatic Head Cancer: A Prospective Study Using Axially Sliced Surgical Pathologic Correlation

OBJECTIVE

CT plays a central role in determining the resectability of pancreatic cancer, which directs the use of neoadjuvant therapy. This study aimed to assess the diagnostic accuracy of CT in predicting circumferential resection margin (CRM) involvement in patients with resectable or borderline resectable pancreatic head cancer.

MATERIALS AND METHODS

Seventy-seven patients who were scheduled for upfront surgery for resectable or borderline resectable pancreatic head cancer were prospectively enrolled, and 75 patients (38 male and 37 female; mean age ± standard deviation, 68 ± 11 years) were finally analyzed. The CRM status was evaluated separately for the superior mesenteric artery (SMA) and posterior and superior mesenteric vein/portal vein (SMV/PV) margins. Three independent radiologists reviewed the preoperative CT images and evaluated the resection margin status. The reference standard for CRM status was pathologic examination of pancreaticoduodenectomy specimens in an axial plane perpendicular to the axis of the second portion of the duodenum. The diagnostic accuracy of CT was assessed for overall CRM involvement, defined as involvement of the SMA or posterior margins (per-patient analysis), and involvement of each of the three resection margins (per-margin analysis). The data were pooled using a crossed random effects model.

RESULTS

Forty patients had pathologically confirmed overall CRM involvement in pancreatic cancer, while CRM involvement was not seen in 35 patients. For overall CRM involvement, the pooled sensitivity and specificity were 15% (95% confidence interval: 7%-49%) and 99% (96%-100%), respectively. For each of the resection margins, the pooled sensitivity and specificity were 14% (9%-54%) and 99% (38%-100%) for the SMA margin, 12% (8%-46%) and 99% (97%-100%) for the posterior margin; and 37% (29%-53%) and 96% (31%-100%) for the SMV/PV margin, respectively.

CONCLUSION

CT showed very high specificity but low sensitivity in predicting pathological CRM involvement in pancreatic cancer.