Understaging of clinical stage I pancreatic cancer and the impact of multimodality therapy

Preoperative Prediction of Long-Term Survival After Surgery in Patients with Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND

Although some clinical trials have demonstrated the benefits of neoadjuvant therapy for resectable pancreatic ductal adenocarcinoma (PDAC), its optimal candidate has not been clarified. This study aimed to detect predictive prognostic factors for resectable PDAC patients who underwent upfront surgery and identify patient cohorts with long-term survival without neoadjuvant therapy.

PATIENTS AND METHODS

A total of 232 patients with resectable PDAC who underwent upfront surgery between January 2008 and December 2019 were evaluated.

RESULTS

The median overall survival (OS) time and 5-year OS rate of resectable PDAC with upfront surgery was 31.5 months and 33.3%, respectively. Multivariate analyses identified tumor diameter in computed tomography (CT) ≤ 19 mm [hazard ratio (HR) 0.40, p < 0.001], span-1 within the normal range (HR 0.54, p = 0.023), prognostic nutritional index (PNI) ≥ 44.31 (HR 0.51, p < 0.001), and lymphocyte-to-monocyte ratio (LMR) ≥ 3.79 (HR 0.51, p < 0.001) as prognostic factors that influence favorable prognoses after upfront surgery. According to the prognostic prediction model based on these four factors, patients with four favorable prognostic factors had a better prognosis with a 5-year OS rate of 82.4% compared to others (p < 0.001). These patients had a high R0 resection rate and a low frequency of tumor recurrence after upfront surgery.

CONCLUSIONS

We identified patients with long-term survival after upfront surgery by prognostic prediction model consisting of tumor diameter in CT, span-1, PNI, and LMR. Evaluation of anatomical, biological, nutritional, and inflammatory factors may be valuable to introduce an optimal treatment strategy for resectable PDAC.

Meta-analysis of adjuvant chemotherapy versus no adjuvant chemotherapy for resected stage I pancreatic cancer

BACKGROUND

To evaluate comparative outcomes of pancreatic cancer resection with or without adjuvant chemotherapy in patients with stage I pancreatic cancer.

METHODS

A systematic search of MEDLINE, CENTRAL, and Web of Science and bibliographic reference lists were conducted. All comparative studies reporting outcomes of pancreatic cancer resection for stage I cancer with or without adjuvant chemotherapy were included, and their risk of bias was assessed using the Risk Of Bias In Non-randomized Studies-of Interventions tool. Survival outcomes were analyzed using the hazard ratio and odds ratio for the time-to-event and dichotomous outcomes, respectively.

RESULTS

We included 6 comparative studies reporting a total of 6,874 patients with resected stage 1 pancreatic cancer, of whom 3,951 patients had no adjuvant chemotherapy, and the remaining 2,923 patients received adjuvant chemotherapy. The use of adjuvant chemotherapy was associated with significantly higher overall survival (hazard ratio 0.71, 95% confidence interval 0.62-0.82, P < .00001) and 2-year survival (65.1% vs 57.4%, odds ratio 1.99; 95% confidence interval 1.01-1.41, P = .04) compared to no use of adjuvant chemotherapy. However, there was no statistically significant difference in 1-year (86.8% vs 78.4%, odds ratio 1.60; 95% confidence interval 0.72-3.57, P = .25), 3-year (46.0% vs 44.0%, odds ratio 1.07; 95% confidence interval 0.90-1.29, P = .43), or 5-year survival (24.8% vs 23.3%, odds ratio 1.03; 95% confidence interval 0.80-1.33, P = .81) between the 2 groups.

CONCLUSION

Meta-analysis of best available evidence (level 2a with low to moderate certainty) demonstrates that adjuvant chemotherapy may confer survival benefits for stage I pancreatic cancer when compared to the use of surgery alone. Randomized control trials are required to escalate the level of evidence and confirm these findings with consideration of contemporary chemotherapy agents and regimens.

"Infiltrative" Versus "Mass-Forming" Pancreatic Cancer: A New Radiological Classification System for Pancreatic Head Ductal Carcinoma and Its Pathological Correlation

Purpose

Resectability in localized pancreatic ductal adenocarcinoma (PDAC) is deemed through radiological criteria. Despite initial evaluation classifying tumors as "resectable," they often have ill-defined borders that can result in more extensive cancer than predicted on final pathology analysis. We attempt to categorize these tumors radiologically and define them as "infiltrative" and contrast them to more well-defined or "mass-forming" tumors and assess their correlation with surgical oncological outcomes. We hypothesize that mass-forming lesions will result in fewer positive resection margins.

Methods

Patients diagnosed with PDAC of the head of the pancreas and who underwent subsequent curative intent resection between 2016 and 2018 were included. A retrospective chart review of patients was conducted and computed tomography images at the time of diagnosis were reviewed by two radiologists and scored as "mass forming" or "infiltrative" using a newly developed classification system. These classifications were then correlated with margin status.

Results

Sixty-eight consecutive pancreatoduodenectomies performed for PDAC from 2016 to 2018 were identified. After screening, 54 patients were eligible for inclusion. Radiologically defined mass-forming lesions had a trend toward a lower rate of positive resection margins (35.7% vs. 50.0%; p = 0.18), specifically the bile duct margin and pancreas margin as well as an overall larger size (4.03 cm vs. 3.25 cm, p = 0.02) compared with infiltrative lesions.

Conclusion

We propose a new radiological definition of PDAC into "mass forming" and "infiltrative," a nomenclature that resonates with other tumor sites. Infiltrative lesions trended toward a higher rate of positive resection margins. This classification may help tailor therapy for infiltrative tumors toward a neoadjuvant approach even if they appear resectable.

Bayesian Approach to Understand the Association Between Treatment Down-staging and Survival for Patients With Pancreatic Adenocarcinoma

OBJECTIVE

To evaluate the association between staging concordance, treatment sequencing, and response to neoadjuvant therapy (NAT) on the survival of patients with pancreatic ductal adenocarcinoma (PDAC).

SUMMARY OF BACKGROUND DATA

NAT is increasingly utilized in the management of patients with PDAC, but it is unclear whether its benefit is contingent on tumor down-staging.

METHODS

This was a cohort study of stage I-III PDAC patients in the National Cancer Database (2006-2015) treated with upfront resection or NAT followed by surgery. We determined staging concordance using patients' clinical and pathological staging data. For NAT patients, we used Bayesian analysis to ascertain staging concordance accounting for down-staging.

RESULTS

Among 16,597 patients treated at 979 hospitals, 13,982 had an upfront resection and 2,615 NAT followed by surgery. Overall survival (OS) at 5-years ranged from 26.0% (95% CI 24.9%-27.1%) among cT1-2N0 patients to 18.6% (17.9%-19.2%) among cT1-3N+ ones. Patients with cT3-4 or cN+ tumors had improved OS after NAT compared to upfront surgery (all p< 0.001), while there was no difference among patients with cT1-2N0 (P = 0.16) disease. Relative to accurately staged cT1-2-3N+ or cT4 patients treated with upfront surgery, NAT was associated with a lower risk of death [HR 0.46 (0.37-0.57) for N+; HR 0.56 (0.40-0.77) for T4 disease], even among those without tumor down-staging [HR 0.81 (0.73-0.90) for N+; HR 0.48 (0.39-0.60) for T4].

CONCLUSIONS

NAT is associated with improved survival for PDAC, particularly for patients with more advanced disease and regardless of down-staging. Consideration should be given to recommending NAT for all PDAC patients.

Therapeutic targeting of STAT3 pathways in pancreatic adenocarcinoma: A systematic review of clinical and preclinical literature

BACKGROUND/OBJECTIVES

Pancreatic ductal adenocarcinoma is a highly lethal disease with increasing incidence. Due to high resistance, chemo/radiotherapy has limited success in pancreatic cancer and only marginally prolongs patient survival. Therefore, novel biomarkers and therapeutic targets are needed. In the present review, we performed a comprehensive summary of therapeutic approaches targeting the GP130/JAK/STAT3 pathway.

METHODS

We systematically reviewed the PubMed and Embase databases for preclinical and clinical studies, from inception to October 4, 2020, on drugs targeting the GP130/JAK/STAT3 pathway. Bias assessments and qualitative analyses were performed.

RESULTS

Twenty-five preclinical and nine clinical trials were included in the review. All preclinical studies reported a favorable outcome in terms of pancreatic ductal adenocarcinoma progression. Futhermore, drugs targeting the GP130/JAK/STAT3 pathway were shown to be efficient chemosensitizers. However, high publication bias was assumed. In the clinical setting, bazedoxifene and itacitinib improved patient outcomes.

CONCLUSION

Preclinical studies strongly suggest significant efficacy of drugs targeting GP130/JAK/STAT3 in the treatment of pancreatic ductal adenocarcinoma and that these molecules are effective chemosensitizers. Though only a few trials have shown the efficacy in a clinical setting, the STAT3 pathway remains a promising drug target for future treatment of pancreatic ductal adenocarcinoma and may help overcome chemotherapy resistance.

Pathologic upstaging in resected pancreatic adenocarcinoma: Risk factors and impact on survival

BACKGROUND

Clinical and pathologic staging determine treatment of pancreatic cancer. Clinical stage has been shown to underestimate final pathologic stage in pancreatic cancer, resulting in upstaging.

METHODS

National Cancer Database was used to identify clinical stage I pancreatic adenocarcinoma. Univariate, multivariable logistic regression, and Cox proportional hazard ratio were used to determine differences between upstaged and stage concordant patients.

RESULTS

Upstaging was seen in 80.2% of patients. Factors found to be significantly associated with upstaging included pancreatic head tumors (OR 2.56), high-grade histology (OR 1.74), elevated Ca 19-9 (OR 2.09), and clinical stage T2 (OR 1.99). Upstaging was associated with a 45% increased risk of mortality compared to stage concordant disease (HR 1.44, p < .001).

CONCLUSION

A majority of clinical stage I pancreatic cancer is upstaged after resection. Factors including tumor location, grade, Ca 19-9, and tumor size can help identify those at high risk for upstaging.

Essential updates 2019/2020: Multimodal treatment of localized pancreatic adenocarcinoma: Current topics and updates in survival outcomes and prognostic factors

Overall survival of patients with localized pancreatic ductal adenocarcinoma (PDAC) is extremely poor. Therefore, the establishment of multimodal treatment strategies is indispensable for PDAC patients because surgical treatment alone could not contribute to the improvement of survival. In this review article, we focus on the current topics and advancement of the treatments for localized PDAC including resectable, borderline resectable, and locally advanced PDAC in accordance with the articles mainly published from 2019 to 2020. Reviewing the articles, the recent progress of multimodal treatments notably improves the prognosis of patients with localized PDAC. For resectable PDAC, neoadjuvant chemo or chemoradiation therapy, rather than upfront surgery, plays a key role, especially in patients with a large tumor, poor performance status, high tumor marker levels, peripancreatic lymph nodes metastasis, or neural invasion suspected on preoperative imaging. For borderline resectable PDAC, neoadjuvant treatments followed by surgery is a desirable approach, and maintenance of immunonutritional status during the treatments are also important. For locally advanced disease, conversion surgery has a central role in improving a survival outcome; however, its indication should be standardized.

Comparative Effectiveness of Neoadjuvant Therapy and Upfront Resection for Patients with Resectable Pancreatic Adenocarcinoma: An Instrumental Variable Analysis

BACKGROUND

Neoadjuvant therapy (NAT) is increasingly being used in the management of patients with resectable pancreatic ductal adenocarcinoma (PDAC); however, there is a lack of evidence regarding the benefit among these patients.

OBJECTIVE

The aim of this study was to evaluate overall survival (OS) in PDAC patients with resectable disease treated with NAT or upfront resection through instrumental variable (IV) analysis.

DESIGN

A national cohort study of resectable PDAC patients in the National Cancer Data Base (2007-2015) treated with either upfront surgery or resection after NAT. Using multivariable modeling and IV methods, OS was compared between those treated with NAT and upfront resection. The IV was hospital-level NAT utilization in the most recent year prior to treatment.

RESULTS

The cohort included 16,666 patients (14,012 upfront resection; 2654 NAT) treated at 779 hospitals. Among those treated with upfront resection, 59.9% received any adjuvant therapy. NAT patients had higher median (27.9 months, 95% confidence interval [CI] 26.2-29.1) and 5-year OS (24.1%, 95% CI 21.9-26.3%) compared with those treated with upfront surgery (median 21.2 months, 95% CI 20.7-21.6; 5-year survival 20.9%, 95% CI 20.1-21.7%). After multivariable modeling, NAT was associated with an approximately 20% decrease in the risk of death (hazard ratio [HR] 0.78, 95% CI 0.73-0.84), and this effect was magnified in the IV analysis (HR 0.61, 95% CI 0.47-0.79).

CONCLUSIONS

In patients with resectable PDAC, NAT is associated with improved survival relative to upfront resection. Given the benefits of multimodality therapy and the challenges in receiving adjuvant therapy, consideration should be given to treating all PDAC patients with NAT.

Decompositions of the Contribution of Treatment Disparities to Survival Disparities in Stage I-II Pancreatic Adenocarcinoma

BACKGROUND

Higher socioeconomic status (SES) and non-Hispanic White (NHW) race/ethnicity are associated with higher treatment rates and longer overall survival (OS) among US patients with stage I-II pancreatic ductal adenocarcinoma. The proportion of OS disparities mediated through treatment disparities (PM) and the proportion predicted to be eliminated (PE) if treatment disparities were eliminated are unknown.

METHODS

We analyzed 2007-2015 data from the Surveillance, Epidemiology, and End Results (SEER) census tract-level database and the National Cancer Database (NCDB) using causal mediation analysis methods to understand the extent to which treatment disparities mediate OS disparities. In the first set of decompositions, race/ethnicity was controlled for as a covariate proximal to SES, and lower SES strata were compared with the highest SES stratum. In the second set, an intersectional perspective was taken and each SES-race/ethnicity combination was compared with highest SES-NHW patients, who had the highest treatment rates and longest OS.

RESULTS

The SEER and NCDB cohorts contained 16,921 patients and 44,638 patients, respectively. When race/ethnicity was controlled for, PMs ranged from 43 to 48% and PEs ranged from 46 to 50% for various lower SES strata. When separately comparing each SES-race/ethnicity combination with the highest SES-NHW patients, results were similar for lower SES-NHW patients but differed markedly for non-Hispanic Black and Hispanic patients, for whom PMs ranged from 60 to 80% and PEs ranged from 55 to 75% for most lower SES strata.

CONCLUSIONS

These results suggest that efforts to reduce treatment disparities are worthwhile, particularly for NHB and Hispanic patients, and simultaneously point to the importance of non-treatment-related causal pathways.

Hospital clinical staging accuracy for upper gastrointestinal malignancy

BACKGROUND

Decisions about multimodality treatment for upper gastrointestinal malignancies are largely predicted on clinical staging information. However, hospital-level accuracy of clinical staging is currently unknown.

METHODS

A national cohort study of patients with adenocarcinoma of the esophagus, stomach, or pancreas in the NCDB (2006-2015) who were treated with upfront resection. Hospital-level staging accuracy (ascertained by comparing clinical stage to pathologic stage) was calculated. Within hospital correlation of staging accuracy across disease sites was evaluated using risk and reliability adjustment.

RESULTS

Overall, 1246 hospitals were evaluated. Median hospital T-staging accuracy was 77.5%, 73.7%, and 60.8% for esophageal, gastric, and pancreatic cancer, respectively. Median hospital N-staging accuracy was 80.2%, 72.9%, and 61.8%, respectively. For T-stage, over-staging was most frequently observed in esophageal patients (11.2%) while under-staging was most frequent in pancreatic patients (36.1%). For N-stage, over-staging was infrequent for all three, while under-staging was most common in pancreatic patients (37.4%). Correlation across disease sites was weak for both T- (best observed, r = .34) and N-stages (r = .30). When high volume hospitals were evaluated, correlation improved but accuracy rates were similar.

CONCLUSIONS

Despite the importance of clinical staging in multimodality treatment planning, hospitals inaccurately stage 20-40% of patients, with low correlation across disease sites.

A qualitative transcriptional prognostic signature for patients with stage I-II pancreatic ductal adenocarcinoma

Accurately prognostic evaluation of patients with stage I-II pancreatic ductal adenocarcinoma (PDAC) is of importance to treatment decision and patient management. Most previously reported prognostic signatures were based on risk scores summarized from quantitative expression measurements of signature genes, which are susceptible to experimental batch effects and impractical for clinical applications. Based on the within-sample relative expression orderings of genes, we developed a robust qualitative transcriptional prognostic signature, consisting of 64 gene pairs (64-GPS), to predict the overall survival (OS) of 161 stage I-II PDAC patients in the training dataset who were treated with surgery only. Samples were classified into the high-risk group when at least 25 of 64 gene pairs suggested it was at high risk. The signature was successfully validated in 324 samples from 6 independent datasets produced by different laboratories. All samples in the low-risk group had significantly better OS than samples in the high-risk group. Multivariate Cox regression analyses showed that the 64-GPS remained significantly associated with the OS of patients after adjusting available clinical factors. Transcriptomic analysis of the 2 prognostic subgroups showed that the differential expression signals were highly reproducible in all datasets, whereas the differences between samples grouped by the TNM staging system were weak and irreproducible. The epigenomic analysis showed that the epigenetic alternations may cause consistently transcriptional changes between the 2 different prognostic groups. The genomic analysis revealed that mutation‑induced disturbances in several key genes, such as LRMDA, MAPK10, and CREBBP, might lead to poor prognosis for PDAC patients. Conclusively, the 64-GPS can robustly predict the prognosis of patients with stage I-II PDAC, which provides theoretical basis for clinical individualized treatment.

County-level Variation in Use of Surgery and Cancer-specific Survival for Stage I-II Pancreatic Adenocarcinoma

OBJECTIVE

The aim of the study was to describe county-level variation in use of surgery for stage I-II pancreatic ductal adenocarcinoma (PDAC) and the association between county surgery rates and cancer-specific survival (CSS).

BACKGROUND

The degree of small geographic area variation in use of surgery for stage I-II PDAC and the association between area surgery rates and CSS remain incompletely defined.

METHODS

This is a retrospective cohort study of patients aged 18 to 80 years in the 2007 to 2015 Surveillance, Epidemiology, and End Results database with stage I-II PDAC without contraindications to surgery or refusal. Multilevel models were used to characterize county-level variation in use of surgery and CSS. County-specific risk- and reliability-adjusted surgery rates and CSS rates were calculated.

RESULTS

Of 18,100 patients living in 581 counties, 10,944 (60.5%) underwent surgery. Adjusted county-specific surgery rates varied 1.5-fold from 49.9% to 74.6%. Median CSS increased in a graded fashion from 13 months [interquartile range (IQR) 13-14] in counties with surgery rates of 49.9% to 56.9% to 18 months (IQR 17-19) in counties with surgery rates of 68.0% to 74.6%. Results were similar in multivariable analyses. Adjusted county 18-month CSS rates varied 1.6-fold from 32.7% to 53.7%. Adjusted county surgery and 18-month CSS rates were correlated (r = 0.54; P < 0.001) and county surgery rates explained approximately half of county-level variation in CSS. Only 18 (3.1%) counties had adjusted surgery rates of 68.0% to 74.6%, which was associated with the longest CSS.

CONCLUSIONS

County-specific rates of surgery varied substantially, and patients living in areas with higher surgery rates lived longer. These data suggest that increasing use of surgery in stage I-II PDAC could lead to improvements in survival.

Naturally occurring compounds as pancreatic cancer therapeutics

Naturally occurring small molecule compounds have long been in the spotlight of pancreatic cancer research as potential therapeutics to prevent cancer progression and sensitize chemoresistant tumors. The hope is that terminal pancreatic cancer patients receiving aggressive chemotherapy can benefit from an increase in treatment efficacy without adding further toxicity by way of utilizing natural compounds. While preclinical studies on a number of natural compounds, such as resveratrol, curcumin, rapalogs and cannabinoids, show promising preclinical results, little has translated into clinical practice, though a number of other compounds hold clinical potential. Nevertheless, recent advances in compound formulation may increase the clinical utility of these compounds.