Neoadjuvant Chemotherapy for Pancreatic Adenocarcinoma Lessens the Deleterious Effect of Omission of Adjuvant Chemotherapy

Understanding surgical attrition for "resectable" pancreatic cancer

OBJECTIVES

We used a novel combined analysis to evaluate various factors associated with failure to undergo surgery in non-metastatic pancreatic cancer.

METHODS

We identified rates of surgery and reasons for surgical attrition from clinical trials, which studied neoadjuvant therapy in resectable pancreatic cancer. Next, we queried the National Cancer Database (NCDB) for Stage I-III, T1-3 pancreatic adenocarcinoma patients. We investigated the rates and factors associated with the receipt of surgery. Finally, we evaluated variable importance predicting the receipt of surgery.

RESULTS

In clinical trials, 25-30 % of patients did not undergo surgery, mostly due to disease progression. In the NCDB, the overall surgical rate was only 49 %, but increased to 67 % in a curated cohort meant to mirror clinical trial patients. Patients treated at low-volume institutions (OR = 0.64, 95 % CI: 0.61-0.67) and who were uninsured (OR = 0.56, 95 % CI: 0.52-0.62) and Medicaid-insured (OR = 0.67, 95 % CI: 0.64-0.71) were less likely to receive potentially curative surgery.

CONCLUSION

We have identified a realistic target surgery rate of 70%-75 % in potentially-resectable pancreatic cancer. While attrition to pancreatic cancer surgery is mostly due to tumor biology, our study identified the most important non-medical barriers, such as facility volume and insurance, affecting pancreatic cancer surgery.

Neoadjuvant Chemotherapy Versus Upfront Surgery for Resectable Pancreatic Adenocarcinoma: An Updated Nationwide Study

OBJECTIVE

The objective of this study was to assess the association of survival with neoadjuvant chemotherapy (NAC) in resectable pancreatic adenocarcinoma (PDAC).

BACKGROUND

The early control of potential micrometastases and patient selection using NAC has been advocated for patients with PDAC. However, the role of NAC for resectable PDAC remains unclear.

METHODS

Patients with clinical T1 and T2 PDAC were identified in the National Cancer Database from 2010 to 2017. Kaplan-Meier estimates, and Cox regression models were used to compare survival. To address immortal time bias, landmark analysis was performed. Interactions between preoperative factors and NAC were investigated in subgroup analyses. A propensity score analysis was performed to compare survival between multiagent NAC and upfront surgery.

RESULTS

In total, 4041 patients were treated with upfront surgery and 1,175 patients were treated with NAC (79.4% multiagent NAC, 20.6% single-agent NAC). Using a landmark time of 6 months after diagnosis, patients treated with multiagent NAC had longer median overall survival compared with upfront surgery and single-agent NAC. (35.8 vs 27.1 vs 27.4 mo). Multiagent NAC was associated with lower mortality rates compared with upfront surgery (adjusted hazard ratio, 0.77; 95% CI, 0.70-0.85), whereas single-agent NAC was not. The association of survival with multiagent NAC were consistent in analyses using the matched data sets. Interaction analysis revealed that the association between multiagent NAC and a lower mortality rate did not significantly differ across age, facility type, tumor location, CA 19-9 levels, and clinical T/N stages.

CONCLUSIONS

The findings suggest that multiagent NAC followed by resection is associated with improved survival compared with upfront surgery.

Advances in the management of pancreatic cancer

Pancreatic cancer remains among the malignancies with the worst outcomes. Survival has been improving, but at a slower rate than other cancers. Multimodal treatment, including chemotherapy, surgical resection, and radiotherapy, has been under investigation for many years. Because of the anatomical characteristics of the pancreas, more emphasis on treatment selection has been placed on local extension into major vessels. Recently, the development of more effective treatment regimens has opened up new treatment strategies, but urgent research questions have also become apparent. This review outlines the current management of pancreatic cancer, and the recent advances in its treatment. The review discusses future treatment pathways aimed at integrating novel findings of translational and clinical research.

The experience of neoadjuvant chemotherapy versus upfront surgery in resectable pancreatic cancer: a cross sectional study

BACKGROUND

Upfront resection (UR) followed by adjuvant chemotherapy remains the standard treatment for resectable pancreatic cancer. There is increasing evidence suggesting favourable outcomes toward neoadjuvant chemotherapy (NAC) followed by surgery.

METHODS

All clinical staging with resectable pancreatic cancer patients treated at a tertiary medical centre from 2013 to 2020 were identified. The baseline characteristics, treatment course, surgery outcome and survival results of UR or NAC were compared.

RESULTS

Finally, in 159 resectable patients, 46 patients (29%) underwent NAC and 113 patients (71%) received UR. In NAC, 11 patients (24%) did not receive resection, 4 (36.4%) for comorbidity, 2 (18.2%) for patient refusal and 2 (18.2%) for disease progression. In UR, 13 patients (12%) were unresectable intraoperatively; 6 (46.2%) for locally advanced and 5 (38.5%) for distant metastasis. Overall, 97% of patients in NAC and 58% of patients in UR completed adjuvant chemotherapy. As of data cut-off, 24 patients (69%) in NAC and 42 patients (29%) in UR were still tumour free. The median recurrence-free survival in NAC, UR with adjuvant chemotherapy and without adjuvant chemotherapy were 31.3 months (95% CI, 14.4-not estimable), 10.6 months (95% CI, 9.0-14.3) and 8.5 months (95% CI, 5.8-11.8), P =0.036; and the median overall survival in each group were not reached (95% CI, 29.7-not estimable), 25.9 months (95% CI, 21.1-40.5) and 21.7 months (12.0-32.8), P =0.0053. Based on initial clinical staging, the median overall survival of NAC was not significantly different from UR with a tumour less than or equal to 2 cm, P =0.29. NAC patients had a higher R0 resection rate (83% versus 53%), lower recurrence rate (31% versus 71%) and harvested median number lymph node (23 versus 15).

CONCLUSION

This study demonstrates that NAC is superior to UR in resectable pancreatic cancer with better survival.

Disparities in Receipt of Adjuvant Therapy After Upfront Surgical Resection for Pancreatic Ductal Adenocarcinoma

BACKGROUND

A multimodal approach of surgery and chemotherapy, with or without radiation, is the mainstay of therapy with curative-intent for resectable pancreatic ductal adenocarcinoma (PDAC). This study compared utilization trends and outcomes of upfront surgery with and without adjuvant therapy.

METHODS

The National Cancer Database was queried for patients with a diagnosis of stage 1 or 2 PDAC who underwent upfront resection. Multivariable regression was applied to identify factors associated with initiation of adjuvant therapy.

RESULTS

Of the 39,128 patients in the study, 67% initiated adjuvant therapy after resection, whereas 33% received upfront surgery alone. Receipt of adjuvant multimodal therapy increased from 59% in 2006 to 69% in 2017 (P < 0.0001). Non-white race was associated with lower odds of receiving adjuvant therapy after adjustment for income status, education attainment, and other variables (Hispanic/Spanish [odds ratio {OR}, 0.77; 95% confidence interval {CI}, 0.69-0.86] and non-Hispanic black [OR 0.84; 95% CI 0.78-0.91 vs non-Hispanic white; P < 0.001). The variables that contributed to receipt of adjuvant therapy were place of residence in high versus low education attainment area (OR 1.30; 95% CI 1.18-1.44; P < 0.0001) and lower odds for initiation of adjuvant therapy with increasing distance from the treating facility (> 50 miles [OR 0.51; 95% CI 0.47-0.54] vs <12.5 miles; P < 0.0001). The median unadjusted overall survival (OS) time was 18.2 months (95% CI 17.7-18.8 months) for upfront surgery alone and 25.3 months (95% CI 24.9-25.8 months) for surgery with adjuvant therapy.

CONCLUSIONS

The patients who underwent upfront surgical resection for PDAC showed wide socioeconomic disparities in the use of adjuvant therapy independent of insurance status, facility type, or travel distance.

Neoadjuvant Therapy Versus Upfront Resection for Nonpancreatic Periampullary Adenocarcinoma

BACKGROUND

In contrast to pancreatic ductal adenocarcinoma (PDAC), neoadjuvant therapy (NAT) for periampullary adenocarcinomas is not well studied, with data limited to single-institution retrospective reviews with small cohorts. We sought to compare outcomes of NAT versus upfront resection (UR) for non-PDAC periampullary adenocarcinomas.

PATIENTS AND METHODS

Using the National Cancer Database (NCDB), we identified patients who underwent surgery for extrahepatic cholangiocarcinoma, ampullary adenocarcinoma, or duodenal adenocarcinoma from 2006 to 2016. We compared outcomes between NAT versus UR groups for each tumor subtype with 1:3 propensity score matching. Cox regression was used to identify predictors of survival.

RESULTS

Among 7656 patients who underwent resection for non-PDAC periampullary adenocarcinoma, the proportion of patients who received NAT increased from 6 to 11% for cholangiocarcinoma (p < 0.01), 1 to 4% for ampullary adenocarcinoma (p = 0.01), and 5 to 8% for duodenal adenocarcinoma (p = 0.08). Length of stay, readmission, and 30-day mortality were comparable between NAT and UR. All tumor subtypes were downstaged following NAT (p < 0.01). The R0 resection rate was significantly higher in patients with extrahepatic cholangiocarcinoma who received NAT, and these patients had improved median overall survival (38 vs 26 months, p < 0.001). After adjustment for clinicopathologic factors and adjuvant chemotherapy, use of NAT was associated with improved survival in patients with cholangiocarcinoma [hazard ratio (HR) 0.69, 95% confidence interval (CI) 0.54-0.89, p = 0.004] but not duodenal or ampullary adenocarcinoma. The survival advantage for cholangiocarcinoma persisted after propensity matching.

CONCLUSION

This national cohort analysis suggests, for the first time, that neoadjuvant therapy is associated with improved survival in patients with extrahepatic cholangiocarcinoma.

Adjuvant and neoadjuvant treatment patterns among resectable pancreatic cancer patients in the USA

Aim: Chemotherapy is standard before and/or after pancreatic cancer resection, yet benefits of pre-resection chemotherapy are unclear. Real-world pre- and post-resection treatment patterns were evaluated retrospectively. Methods: Neoadjuvant (3-months pre-surgery) and adjuvant (6-months post-surgery) treatment claims from 1 January 2016 to 31 December 2019 in US adults with resectable pancreatic cancer were analyzed. Results: Of the 737 patients, 29% received no chemotherapy in either setting; 22% received chemotherapy in both settings. In the neoadjuvant and adjuvant settings, 69 and 33% of patients, respectively, received no treatment at all. FOLFIRINOX and gemcitabine monotherapy were the most common chemotherapies in the neoadjuvant and adjuvant settings, respectively. Adjuvant FOLFIRINOX increased post-2018, whereas gemcitabine-based regimens decreased. Conclusion: Several chemotherapy regimens were used in both settings. Treatment patterns differed between the two settings.

Advances in the Surgical Treatment of Pancreatic Cancer

Three recent advances in the surgical approach to pancreatic cancer over the past decade have improved both short- and long-term outcomes for patients with nonmetastatic, operable pancreatic cancer. These include (1) minimally invasive pancreatectomy to reduce operative morbidity while adhering to principles of open oncologic resections, (2) neoadjuvant chemotherapy to treat radiographically occult metastatic disease and improve locoregional control, and (3) applying irreversible electroporation as an adjunct to surgery, allowing a fraction of locally advanced pancreatic cancer to be resected.

Factors associated with inability to return to intended oncologic treatment in pancreatic cancer

BACKGROUND

Return to Intended Oncologic Treatment (RIOT) has been proposed as a quality metric in the care of cancer patients. We sought to define factors associated with inability to RIOT in Pancreatic Ductal Adenocarcinoma (PDAC) patients.

METHODS

The NCDB was queried for patients who underwent pancreaticoduodenectomy for pathologic stage IB, IIA, or IIB PDAC from 2010 to 2016. Multivariable binary logistic regression models identified factors associated with failure to RIOT, and Kaplan-Meier survival analysis and Cox multivariable regression models demonstrated the impact of failure to RIOT on survival.

RESULTS

Increasing age (p < .001), Hispanic race (p = .002), pathological stage IB (p = .004) and IIA (p = .001) as compared to IIB, increasing hospital stay (p < .001), and open surgical approach (p = .024) were associated with increased risk of inability to RIOT. Male sex (p < .001), Charlson-Deyo scores of 0 (p < .001) and 1 (p = .001) as compared to >2, negative surgical margins (p = .048), receiving care at academic institutions (p = .001), and increasing institutional case volume (p = .001) were associated with improved odds of RIOT.

CONCLUSIONS

Patient features can impact RIOT and should be considered when designing multi-modality treatment strategies.

Prognosis of Upfront Surgery for Pancreatic Cancer: A Systematic Review and Meta-Analysis of Prospective Studies

BACKGROUND

The rate of patients with pancreatic ductal adenocarcinoma (PDAC) receiving neoadjuvant chemotherapy is increasing, but upfront resection is still offered to most patients with resectable or borderline resectable disease. Encouraging data reported in adjuvant chemotherapy trials prompts surgeons towards upfront surgery, but such trials are subject to a significant selection bias. This systematic review aims to summarize available high-quality evidence regarding survival of patients treated with upfront surgery for PDAC.

METHODS

Pubmed, Cochrane, and Web of Science Databases were interrogated for prospective studies published between 2000 and 2021 that included at least a cohort of patients treated with upfront surgery for resectable or borderline resectable PDAC. The Cochrane Collaboration's risk-of-bias tool for randomized trials (RoB-2) was used to assess risk of bias in all randomized studies. Patient weighted median overall survival (OS) and disease-free survival (DFS) were calculated.

RESULTS

Overall, 8,341 abstracts were screened, 17 reports were reviewed in full text, and finally 5 articles and 1 conference abstract underwent data extraction. Included studies were published between 2014 and 2021. All studies were RCTs comparing different neoadjuvant treatment strategies to upfront surgery. Three studies included only resectable PDAC patients, two studies recruited patients with resectable and borderline resectable disease, and one study selected only borderline resectable patients. A total of 439 patients were included in the upfront resection cohorts of the 6 studies, ranging between 20 to 180 patients per study. The weighted median OS after upfront surgery was 18.8 (95% CI 12.4 - 20.6) months. Median DFS was 9 (95% CI 1.6 - 12.5) months. Resection rate was 74.5% (range 65-90%). Adjuvant treatment was initiated in 68% (range 43-77%) of resected patients.

CONCLUSIONS

High-quality data for PDAC patients undergoing upfront surgery is scarce. Meta-analysis from the included studies showed a significantly shorter OS and DFS compared to recently published studies focusing on adjuvant combination chemotherapy, suggesting that the latter may overestimate survival due to the exclusion of most patients scheduled for upfront surgery.