Is Adjuvant Therapy Necessary for All Patients with Localized Pancreatic Cancer Who Have Received Neoadjuvant Therapy?

Survival benefit and impact of adjuvant chemotherapy following systemic neoadjuvant chemotherapy in patients with resected pancreas ductal adenocarcinoma: a retrospective cohort study

BACKGROUND

Patients with pancreatic ductal adenocarcinoma (PDAC) are increasingly receiving systemic neoadjuvant chemotherapy (NAC), particularly those with borderline resectable and locally advanced disease. However, the specific role of additional adjuvant chemotherapy (AC) in these patients is unknown. The objective of this study is to further assess the clinical benefit and impact of systemic AC in patients with resected PDAC after NAC.

METHODS

Data on PDAC patients with or without AC following systemic NAC and surgical resection were retrospectively retrieved from the Surveillance, Epidemiology, and End Results (SEER) database between 2006 and 2019. A matched cohort was created using propensity score matching (PSM), and baseline characteristics were balanced to reduce bias. Overall survival (OS) and cancer-specific survival (CSS) were calculated using matching cohorts.

RESULTS

The study enrolled a total of 1589 patients, with 623 (39.2%) in the AC group and 966 (51.8%) in the non-AC group [mean age, 64.0 (9.9) years; 766 (48.2%) were females and 823 (51.8%) were males]. All patients received NAC, and among the crude population, 582 (36.6%) received neoadjuvant radiotherapy, while 168 (10.6%) received adjuvant radiotherapy. Following the 1:1 PSM, 597 patients from each group were evaluated further. The AC and non-AC groups had significantly different median OS (30.0 vs. 25.0 months, P =0.002) and CSS (33.0 vs. 27.0 months, P =0.004). After multivariate Cox regression analysis, systemic AC was independently associated with improved survival ( P =0.003, HR=0.782; 95% CI, 0.667-0.917 for OS; P =0.004, HR=0.784; 95% CI, 0.663-0.926 for CSS), and age, tumor grade, and AJCC N staging were also independent predictors of survival. Only patients younger than 65 years old and those with a pathological N1 category showed a significant association between systemic AC and improved survival in the subgroup analysis adjusted for these covariates.

CONCLUSION

Systemic AC provides a significant survival benefit in patients with resected PDAC following NAC compared to non-AC patients. Our study discovered that younger patients, patients with aggressive tumors and potentially well response to NAC might benefit from AC to achieve prolonged survival after curative tumor resection.

Targeted therapy for pancreatic ductal adenocarcinoma: Mechanisms and clinical study

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and lethal malignancy with a high rate of recurrence and a dismal 5-year survival rate. Contributing to the poor prognosis of PDAC is the lack of early detection, a complex network of signaling pathways and molecular mechanisms, a dense and desmoplastic stroma, and an immunosuppressive tumor microenvironment. A recent shift toward a neoadjuvant approach to treating PDAC has been sparked by the numerous benefits neoadjuvant therapy (NAT) has to offer compared with upfront surgery. However, certain aspects of NAT against PDAC, including the optimal regimen, the use of radiotherapy, and the selection of patients that would benefit from NAT, have yet to be fully elucidated. This review describes the major signaling pathways and molecular mechanisms involved in PDAC initiation and progression in addition to the immunosuppressive tumor microenvironment of PDAC. We then review current guidelines, ongoing research, and future research directions on the use of NAT based on randomized clinical trials and other studies. Finally, the current use of and research regarding targeted therapy for PDAC are examined. This review bridges the molecular understanding of PDAC with its clinical significance, development of novel therapies, and shifting directions in treatment paradigm.

Optimal management of patients with operable pancreatic head cancer: A Markov decision analysis

INTRODUCTION

Neoadjuvant therapy (NAT) is an emerging strategy for operable pancreatic ductal adenocarcinoma (PDAC). While NAT increases multimodal therapy completion, it risks functional decline and treatment dropout. We used decision analysis to determine optimal management of localized PDAC and consider risks faced by elderly patients.

METHODS

A Markov cohort decision analysis model evaluated treatment options for a 60-year-old patient with resectable PDAC: (1) upfront pancreaticoduodenectomy or (2) NAT. One-way and probabilistic sensitivity analyses were performed. A subanalysis considered the scenario of a 75-year-old patient.

RESULTS

For the base case, NAT offered an incremental survival gain of 4.6 months compared with SF (overall survival: 26.3 vs. 21.7 months). In one-way sensitivity analyses, findings were sensitive to recurrence-free survival for NAT patients undergoing adjuvant, probability of completing NAT, and probability of being resectable at exploration after NAT. On probabilistic analysis, NAT was favored in a majority of trials (97%) with a median survival benefit of 5.1 months. In altering the base case for the 75-year-old scenario, NAT had a survival benefit of 3.8 months.

CONCLUSIONS

This analysis demonstrates a significant benefit to NAT in patients with localized PDAC. This benefit persists even in the elderly cohort.

Borderline resectable pancreatic cancer: Certainties and controversies

Borderline resectable (BR) pancreatic ductal adenocarcinoma (PDAC) is currently a well-recognized entity, characterized by some specific anatomic, biological and conditional features: It includes patients with a stage of disease intermediate between the resectable and the locally advanced ones. The term BR identifies a tumour with an aggressive biological behaviour, on which a neoadjuvant approach instead of an upfront surgery one should be preferred, in order to obtain a radical resection (R0) and to avoid an early recurrence after surgery. Even if during the last decades several studies on this topic have been published, some aspects of BR-PDAC still represent a matter of debate. The aim of this review is to critically analyse the available literature on this topic, particularly focusing on: The problem of the heterogeneity of definition of BR-PDAC adopted, leading to a misinterpretation of published data; its current management (neoadjuvant vs upfront surgery); which neoadjuvant regimen should be preferably adopted; the problem of radiological restaging and the determination of resectability after neoadjuvant therapy; the post-operative outcomes after surgery; and the role and efficacy of adjuvant treatment for resected patients that already underwent neoadjuvant therapy.

Ten-year experience in optimizing neoadjuvant therapy for localized pancreatic cancer-Medical college of Wisconsin perspective

Treatment of localized pancreatic cancer has also evolved to prioritize preoperative (neoadjuvant) multimodality therapy over a surgery-first approach. Given the complexities of pancreatic cancer staging and the challenge of delivering multiple treatment modalities (chemotherapy, radiation therapy, and surgery), an experienced and highly integrated multidisciplinary team is necessary to achieve the best outcomes. In this review, we will discuss our institutional experience with neoadjuvant therapy, guiding principles for treatment, and outline the landscape for future investigations.

Adjuvant chemotherapy versus observation following neoadjuvant therapy and surgery for resectable stages I–II pancreatic cancer

Aim:

This National Cancer Database (NCDB) analysis was performed to evaluate the outcomes of adjuvant chemotherapy (AC) versus observation for resected pancreatic adenocarcinoma treated with neoadjuvant therapy (NT).

Materials and methods:

The NCDB was queried for primary stages I–II cT1-3N0-1M0 resected pancreatic adenocarcinoma treated with NT (2004–2015). Baseline patient, tumour and treatment characteristics were extracted. The primary end point was overall survival (OS). With a 6-month conditional landmark, Kaplan–Meier analysis, multivariable Cox proportional hazards method and 1:1 propensity score matching was used to analyse the data.

Results:

A total of 1,737 eligible patients were identified, of which 1,247 underwent post-operative observation compared to 490 with AC. The overall median follow-up was 34·7 months. The addition of AC showed improved survival on the multivariate analysis (HR 0·78, p < 0·001). AC remained statistically significant for improved OS, with a median OS of 26·3 months versus 22·3 months and 2-year OS of 63·9% versus 52·9% for the observation cohort (p < 0·001). Treatment interaction analysis showed OS benefit of AC for patients with smaller tumours.

Findings:

Our findings suggest a survival benefit for AC compared to observation following NT and surgery for resectable pancreatic adenocarcinoma, especially in patients with smaller tumours.

Adjuvant Chemotherapy Associated with Survival Benefit Following Neoadjuvant Chemotherapy and Pancreatectomy for Pancreatic Ductal Adenocarcinoma: A Population-Based Cohort Study

Background

Data supporting the routine use of adjuvant chemotherapy (AC) compared with no AC (noAC) following neoadjuvant chemotherapy (NAC) and resection for pancreatic ductal adenocarcinoma (PDAC) are lacking. This study aimed to determine whether AC improves long-term survival in patients receiving NAC and resection.

Methods

Patients receiving resection for PDAC following NAC from 2004 to 2016 were identified from the National Cancer Data Base (NCDB). Patients with a survival rate of < 6 months were excluded to account for immortal time bias. Propensity score matching (PSM) and Cox regression analysis were performed to account for selection bias and analyze the impact of AC on overall survival.

Results

Of 4449 (68%) noAC patients and 2111 (32%) AC patients, 2016 noAC patients and 2016 AC patients remained after PSM. After matching, AC was associated with improved survival (median 29.4 vs. 24.9 months; p < 0.001), which remained after multivariable adjustment (HR 0.81, 95% confidence interval [CI] 0.75–0.88; p < 0.001). On multivariable interaction analyses, this benefit persisted irrespective of nodal status: N0 (hazard ratio [HR] 0.80, 95% CI 0.72–0.90; p < 0.001), N1 (HR 0.76, 95% CI 0.67–0.86; p < 0.001), R0 margin status (HR 0.82, 95% CI 0.75–0.89; p < 0.001), R1 margin status (HR 0.77, 95% CI 0.64–0.93; p = 0.007), no neoadjuvant radiotherapy (NART; HR 0.84, 95% CI 0.74–0.96; p = 0.009), and use of NART (HR 0.80, 95% CI 0.73–0.88; p < 0.001). Stratified analysis by nodal, margin, and NART status demonstrated consistent results.

Conclusion

AC following NAC and resection is associated with improved survival, even in margin-negative and node-negative disease. These findings suggest completing planned systemic treatment should be considered in all resected PDACs previously treated with NAC.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-09823-0.

Clinical Benefits of Conversion Surgery for Unresectable Pancreatic Ductal Adenocarcinoma: A Single-Institution, Retrospective Analysis

BACKGROUND

Unresectable pancreatic ductal adenocarcinoma (UR-PDAC) has a poor prognosis. Conversion surgery is considered a promising strategy for improving the prognosis of UR-PDAC. This study aimed to investigate the clinical benefits of conversion surgery in patients with UR-PDAC.

METHODS

We retrospectively evaluated patients with PDAC who were referred to our department for possible surgical resection between January 2006 and December 2019. Conversion surgery was performed only in patients with UR-PDAC who could expect R0 resection. We analyzed the prognostic factors for overall survival among patients who underwent conversion surgery.

RESULTS

Overall, 638 patients with advanced pancreatic cancer were enrolled in this study. According to resectability, resectable cancer (R) was present in 180 patients, borderline resectable cancer (BR) was present in 60 patients, unresectable locally advanced cancer (UR-LA) was present in 252 patients, and unresectable cancer with distant metastasis (UR-M) was present in 146 patients. Conversion surgery was performed in 20 of the 398 UR cases (5.1%). The median period between the initial therapy and conversion surgery was 15.5 months. According to the Response Evaluation Criteria in Solid Tumors (RECIST) evaluation, the treatment response was CR in one patient, PR in 13, SD in five, and PD in one. Downstaging was pathologically determined in all cases. According to the Evans grading system, grade I was observed in four patients (20%), grade IIb was observed in seven (35%), III was observed in seven (35%), and IV was observed in two (10%). We compared the overall survival period from initial treatment among patients undergoing conversion surgery; the median overall survival durations in the conversion surgery, R, BR, UR-LA, and UR-M groups were 73.7, 32.7, 22.7, 15.7, and 8.8 months, respectively. Multivariate analysis revealed that the presence or absence of chemoradiotherapy (CRT) and the RECIST partial response (PR)/complete response (CR) for the main tumor were statistically significant prognostic factors for overall survival among patients undergoing conversion surgery (p = 0.004 and 0.03, respectively).

CONCLUSION

In UR-PDAC, it is important to perform multidisciplinary treatment, including CRT with conversion surgery.

Adjuvant Chemotherapy After Neoadjuvant Chemotherapy for Pancreatic Cancer is Associated with Improved Survival for Patients with Low-Risk Pathology

BACKGROUND

With limited evidence, the benefit of adjuvant chemotherapy (AT) after completion of neoadjuvant chemotherapy (NT) and surgical resection for patients with pancreatic adenocarcinoma is debated. Guidelines recommend 6 months of AT for patients receiving NT. However, the patient-derived benefit from additional AT remains unknown.

METHODS

The National Cancer Database from 2006 to 2015 was used to identify patients undergoing NT. The chi-square test and multivariable logistic regression were used to identify differences between those receiving only NT and those receiving NT and AT. Survival analysis using the Kaplan-Meier method and the Cox proportional hazard ratio model was applied to the entire cohort and to subgroups with differing lymph node ratios (LNRs), tumor sizes, grades, and surgical margin statuses.

RESULTS

Of the 3897 patients who received NT, 36.7 % received additional AT. Analysis of the entire cohort showed that associated survival was significantly improved with NT and AT compared with NT alone (hazard ratio [HR], 0.83; p < 0.001). In the subgroup analysis, the survival benefit of additional AT remained significant for those with negative nodal disease, an LNR lower than 0.15, low-grade histology, and negative margin status. Overall survival did not differ between those receiving NT only and those receiving NT and AT in the group with an LNR of 0.15 or higher, high-grade histology, and positive margins.

CONCLUSION

This study identified an increasing trend in the use of AT after NT and showed an associated survival benefit for subgroups with low-risk pathologic features. These results suggest that the addition of AT after NT likely beneficial for these subgroups.

Adjuvant Pancreatic Cancer Management: Towards New Perspectives in 2021

Adjuvant chemotherapy is currently used in all patients with resected pancreatic cancer who are able to begin treatment within 3 months after surgery. Since the recent publication of the PRODIGE 24 trial results, modified FOLFIRINOX has become the standard-of-care in the non-Asian population with localized pancreatic adenocarcinoma following surgery. Nevertheless, there is still a risk of toxicity, and feasibility may be limited in heavily pre-treated patients. In more frail patients, gemcitabine-based chemotherapy remains a suitable option, for example gemcitabine or 5FU in monotherapy. In Asia, although S1-based chemotherapy is the standard of care it is not readily available outside Asia and data are lacking in non-Asiatic patients. In patients in whom resection is not initially possible, intensified schemes such as FOLFIRINOX or gemcitabine-nabpaclitaxel have been confirmed as options to enhance the response rate and resectability, promoting research in adjuvant therapy. In particular, should oncologists prescribe adjuvant treatment after a long sequence of chemotherapy +/- chemoradiotherapy and surgery? Should oncologists consider the response rate, the R0 resection rate alone, or the initial chemotherapy regimen? And finally, should they take into consideration the duration of the entire sequence, or the presence of limited toxicities of induction treatment? The aim of this review is to summarize adjuvant management of resected pancreatic cancer and to raise current and future concerns, especially the need for biomarkers and the best holistic care for patients.

The utilization and impact of adjuvant therapy following neoadjuvant therapy and resection of pancreatic adenocarcinoma: does more really matter?

BACKGROUND

Although neoadjuvant therapy is increasingly administered to patients with pancreatic ductal adenocarcinoma (PDAC), the impact of additional adjuvant therapy (AT) following resection is not well defined.

METHODS

The National Cancer Database (NCDB) was queried for patients who received neoadjuvant therapy followed by R0 or R1 resection for PDAC. Factors influencing survival, including the receipt of AT were evaluated.

RESULTS

Of patients receiving neoadjuvant therapy and resection 680 (33.8%) received AT and 1331 (66.2%) did not. For R0 resected patients (n = 1800), lymphovascular invasion (HR 1.24, p = 0.034) and increasing N classification (N1: HR 1.27, p = 0.019; N2: HR 1.51, p = 0.004) were associated with increased risk of death while AT was not associated with improved overall survival (OS) (HR 0.88, p = 0.179). Following R1 resection (n = 211), AT was associated with reduced risk of death (HR 0.57, p = 0.038). Within propensity matched cohorts, median OS for patients receiving and not receiving AT was 32.1 and 30.0 months after R0 resection (p = 0.184), and 23.6 and 20.5 months after R1 resection (p = 0.005).

CONCLUSION

This analysis demonstrated that AT did not yield OS benefit for patients who had neoadjuvant therapy and R0 resection and a statistically significant, although relatively short, improvement in OS for patients who underwent R1 resection.

Impact of Neoadjuvant Chemoradiation on Pathologic Response in Patients With Localized Pancreatic Cancer

Introduction/Background: Multimodal neoadjuvant therapy has resulted in increased rates of histologic response in pancreatic tumors and adjacent lymph nodes. The biologic significance of the collective response in the primary tumor and lymph nodes is not understood.

Methods: Patients with localized PC who received neoadjuvant therapy and surgery with histologic assessment of the primary tumor and local-regional lymph nodes were included. Histopathologic response was classified using the modified Ryan score as follows: no viable cancer cells (CR), rare groups of cancer cells (nCR), residual cancer with evident tumor regression (PR), and extensive residual cancer with no evident tumor regression (NR). Nodal status was defined by number of lymph nodes (LN) with tumor metastases: N0 (0 LN), N1 (1–3), N2 (≥4).

Results: Of 341 patients with localized PC who received neoadjuvant therapy and surgery, 107 (31%) received chemoradiation alone, 44 (13%) received chemotherapy alone, and 190 (56%) received chemotherapy and chemoradiation. Histopathologic response consisted of 15 (4%) CRs, 59 (17%) nCRs, 188 (55%) PRs, and 79 (23%) NRs. Patients who received chemotherapy alone had the worst responses (n = 21 for NR, 48%) as compared to patients who received chemoradiation alone (n = 25 for NR, 24%) or patients who received both therapies (n = 33 for NR, 17%) (Table 1; p = 0.001). Median overall survival for all 341 patients was 39 months; OS by histopathologic subtype was not reached (CR), 49 months (nCR), 38 months (PR), and 34 months (NR), respectively (p = 0.004). Of the 341 patients, 208 (61%) had N0 disease, 97 (28%) had N1 disease, and 36 (11%) had N2 disease. In an adjusted hazards model, modified Ryan score of PR or NR (HR: 1.71; 95% CI: 1.15–2.54; p = 0.008) and N1 (HR: 1.42; 95% CI: 1.1.02–2.01; p = 0.04), or N2 disease (HR: 2.54, 95% CI: 1.64–3.93; p < 0.001) were associated with increased risk of death.

Conclusions: Neoadjuvant chemotherapy alone is associated with lower rates of pathologic response. Patients with CR or nCR have a significantly improved OS as compared to patients with PR or NR. Nodal status is the most important pathologic prognostic factor. Neoadjuvant chemoradiation may be an important driver of pathologic response.

Neoadjuvant Therapy is Essential for Resectable Pancreatic Cancer

BACKGROUND

Awareness of the benefits of neoadjuvant therapy is increasing, but its use as an initial therapeutic option for patients with resectable pancreatic cancer remains controversial, especially for those patients without high-risk prognostic features. Even for patients with high-risk features who are candidates to receive neoadjuvant therapy, no standard regimen exists.

METHODS

In this review, we examined available data on the neoadjuvant therapy in patients with resectable pancreatic cancer, including prospective studies, retrospective studies, and ongoing clinical trials, by searching PubMed/MEDLINE, ClinicalTrials.gov, Web of Science, and Cochrane Library. The characteristics and results of screened studies were described.

RESULTS

Retrospective and prospective studies with reported results and ongoing randomized studies were included. For patients with resectable pancreatic cancer, neoadjuvant therapy provides benefits such as increased survival, decreased risk of comorbidities and mortality, and improved cost-effectiveness due to an increased completion rate of multimodal treatment. Highly active regimens such as FOLFIRINOX (folinic acid, fluorouracil, irinotecan, and oxaliplatin) or gemcitabine plus nab-paclitaxel are considered acceptable therapeutic regimens. Additionally, platinum-containing regimens other than FOLFIRINOX are acceptable for selected patients. Other therapies, such as chemoradiation treatment, immuno-oncology agents, and targeted therapies are being explored and the results are highly anticipated.

CONCLUSION

This review highlights the benefits of neoadjuvant therapy for resectable pancreatic cancer. Some regimens are currently acceptable, but need more evidence from well-designed clinical trials or should be used after being carefully examined by a multidisciplinary team.

Lymph Node Ratio in Pancreatic Adenocarcinoma After Preoperative Chemotherapy vs. Preoperative Chemoradiation and Its Utility in Decisions About Postoperative Chemotherapy

BACKGROUND

Single-center studies in pancreatic adenocarcinoma have suggested that preoperative chemotherapy (PCT) is associated with higher lymph node ratio (LNR) than preoperative chemoradiation (PCRT). The association of postoperative chemotherapy with overall survival (OS) in patients treated with PCT and PCRT remains unclear. Our objectives were to investigate whether (1) PCT is associated with higher LNR than PCRT and (2) postoperative chemotherapy is associated with longer OS after PCT and PCRT in LNR-stratified cohorts.

METHODS

A retrospective cohort study was performed of patients with pancreatic adenocarcinoma treated with PCT or PCRT followed by resection between 2006 and 2014 in the National Cancer Database. Temporal trends were evaluated with Cuzick's test. OS was evaluated with multivariable Cox regression and inverse probability weighted (IPW) Cox regression.

RESULTS

Of 4187 patients, 1993 (47.6%) received PCT. PCT rates were stable at approximately 30% in 2006-2010 (p = 0.33) but increased to 64.9% by 2014 (p < 0.001). Node positivity rates were higher after PCT than PCRT (62.7 vs. 41.8%, P < 0.001) and mean LNR was higher (0.10 [95% CI 0.096, 0.11] vs. 0.058 [95% CI 0.052, 0.063], P < 0.001). Postoperative chemotherapy was associated with longer OS in patients with LNR 0.01-0.149 after PCT by univariate analysis (median OS 34.5 vs. 26.5 months, P = 0.002), multivariable Cox regression (HR 0.64, 95% CI 0.48, 0.84), and IPW Cox regression (HR 0.72, 95% CI 0.55, 0.94). Postoperative chemotherapy was not associated with longer OS for patients who were node-negative or who had LNR ≥ 0.15 after PCT or for any patient subgroups after PCRT.

CONCLUSIONS

PCT is associated with a higher LNR and higher rates of node positivity than PCRT. Postoperative chemotherapy is associated with longer OS than observation in patients with a LNR of 0.01-0.149 after PCT.

What Makes a Pancreatic Cancer Resectable?

The majority of patients with localized pancreatic cancer who undergo surgery with or without adjuvant therapy will develop metastatic disease, suggesting that surgery alone is not sufficient for cure and micrometastases are present at the time of diagnosis even when not clinically apparent. As such, the field is rapidly moving to consensus on treatment sequencing, which emphasizes the early delivery of systemic therapy and the application of surgery to the population of patients most likely to receive clinical benefit from such large operations-namely, those with stable or responding disease following systemic therapy and often chemoradiation. There remains incomplete consensus about the definition of what is operable (both tumor anatomy and patient age/comorbidities) and whether the operation should be performed in a high-volume center by more experienced surgeons. In this article, we try to provide a comprehensive description of when surgery should be performed and what constitutes an operable tumor. Such information is critically important for the optimal delivery of stage-specific therapy and to allow physicians to provide accurate expectations to all patients for treatment outcome. The complex issues of where and by whom such large operations should be performed is beyond the scope of this review.

Comparative outcomes of adenosquamous carcinoma of the pancreas: An analysis of the National Cancer Database

BACKGROUND

A paucity of data exists regarding the natural history and outcome measures of adenosquamous carcinoma of the pancreas (ASCP), a histology distinct from pancreatic adenocarcinoma (PDAC). The aim of this study is to characterize the clinicopathological features of ASCP in a large cohort of patients comparing outcome measures of surgically resected patients to PDAC.

METHODS

We identified patients diagnosed with ASCP or PDAC from the National Cancer Database from 2004 to 2012. Patient demographics, tumor characteristics, treatment regimens, and overall survival were analyzed between the groups.

RESULTS

We identified 207 073 patients: 205 328 (99%) in the PDAC group and 1745 (1%) in the ASCP group. ASCP tumors were larger, located more frequently in a body/tail location (36% vs 24%, P < 0.001), undifferentiated/anaplastic histology (41% vs 17%, P < 0.001), and early stage presentation, (39% vs 32%, P < 0.001). There was no significant difference in OS when comparing all patients with PDAC and ASCP (6.2 months and 5.7 months, P = 0.601). In surgical patients ASCP histology was associated with worse OS (14.8 months vs 20.5 months, P < 0.001) but had lower nodal involvement (55% vs 61%, P < 0.001). ASCP histology was independently associated with worse OS, after adjusting for tumor characteristics, treatment, and patient demographics. In patients with only resected ASCP histology, negative lymph node status, R0 surgical resection, and receipt of chemotherapy was independently associated with improved overall survival following surgical resection.

CONCLUSION

Although patients with ASCP and PDAC tumors have similar survival when non-surgical and surgical patients are combined, ASCP is associated with worse survival in stage I/II resected patients.