Neoadjuvant therapy for pancreatic ductal adenocarcinoma: Opportunities for personalized cancer care

Neoadjuvant therapy for localized pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor with poor prognosis and rising incidence globally. Multimodal therapy that includes surgical resection and chemotherapy with or without radiation offers the best chance for optimal outcomes. The development of established criteria for anatomic staging of local primary tumors into potentially resectable (PR), borderline resectable (BR), and locally advanced (LA) has greatly clarified the optimal treatment strategies. While upfront surgical resection was traditionally the recommended approach for localized PDAC, increasingly neoadjuvant therapy (NT) is recommended prior to surgery. Whereas NT can lead to downstaging that facilitates surgical resection for BR/LA cancers, NT also enhances patient selection for surgery, improves margin-negative resection rates, and increases the odds of completing multimodality therapy for all patients with PDAC. Herein, we review the rationale for NT for localized PDAC and summarize existing and ongoing literature.

Combining prognostic value of serum carbohydrate antigen 19-9 and tumor size reduction ratio in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a common cancer with increasing morbidity and mortality due to changes of social environment.

AIM

To evaluate the significance of serum carbohydrate antigen 19-9 (CA19-9) and tumor size changes pre- and post-neoadjuvant therapy (NAT).

METHODS

This retrospective study was conducted at the Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital. This study specifically assessed CA19-9 levels and tumor size before and after NAT.

RESULTS

A total of 156 patients who completed NAT and subsequently underwent tumor resection were included in this study. The average age was 65.4 ± 10.6 years and 72 (46.2%) patients were female. Before survival analysis, we defined the post-NAT serum CA19-9 level/pre-NAT serum CA19-9 level as the CA19-9 ratio (CR). The patients were divided into three groups: CR < 0.5, CR > 0.5 and < 1 and CR > 1. With regard to tumor size measured by both computed tomography and magnetic resonance imaging, we defined the post-NAT tumor size/pre-NAT tumor size as the tumor size ratio (TR). The patients were then divided into three groups: TR < 0.5, TR > 0.5 and < 1 and TR > 1. Based on these groups divided according to CR and TR, we performed both overall survival (OS) and disease-free survival (DFS) analyses. Log-rank tests showed that both OS and DFS were significantly different among the groups according to CR and TR (P < 0.05). CR and TR after NAT were associated with increased odds of achieving a complete or near-complete pathologic response. Moreover, CR (hazard ratio: 1.721, 95%CI: 1.373-3.762; P = 0.006), and TR (hazard ratio: 1.435, 95%CI: 1.275-4.363; P = 0.014) were identified as independent factors associated with OS.

CONCLUSION

This study demonstrated that post-NAT serum CA19-9 level/pre-NAT serum CA19-9 level and post-NAT tumor size/pre-NAT tumor size were independent factors associated with OS in patients with PDAC who received NAT and subsequent surgical resection.

The benefits of neoadjuvant therapy for patients with resectable pancreatic cancer: an updated systematic review and meta-analysis

Neoadjuvant therapy (NAT) was effective in improving overall survival (OS) of borderline resectable pancreatic cancer. However, its application in resectable pancreatic cancer remains controversial. This study aimed to determine whether NAT has a greater advantage over conventional upfront surgery (US) in terms of resection rate, R0 resection rate, positive lymph node rate, and OS. We identified articles before October 7, 2022, by searching four electronic databases. The studies included in the meta-analysis all met the inclusion and exclusion criteria. The Newcastle-Ottawa scale was used to evaluate the quality of the articles. OS, DFS, resection rate, R0 resection rate and positive lymph nodes rate were extracted. Odds ratio (OR), hazard ratio (HR) and 95% confidence intervals (CI) were calculated, and sensitivity analysis and publication bias were used to assess the sources of heterogeneity. In total, 24 studies, involving 1384 (35.66%) patients assigned to NAT and 2497 (64.43%) patients assigned to US, were included in the analysis. NAT could effectively prolong OS (HR 0.73, 95% CI 0.65-0.82, P < 0.001) and DFS (HR 0.72, 95% CI 0.62-0.84, P < 0.001). Subgroup analysis results of 6 randomized controlled trials (RCTs) also showed that RPC patients could benefit from NAT in the long term (HR 0.72, 95% CI 0.58-0.90, P = 0.003). NAT decreased resection rate (OR 0.43, 95% CI 0.33-0.55, P < 0.001), but was associated with increased R0 resection rate (OR 2.05, 95% CI 1.47-2.88, P < 0.001) and decreased positive lymph node rate (OR 0.38, 95% CI 0.27-0.52, P < 0.001). Although the application of NAT increases the risk of patients not being able to undergo surgical resection, it can prolong the OS and delay tumor progression in RPC. Therefore, we still expect larger and higher-quality RCTs to confirm the effectiveness of NAT.

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.

Surgical resection rates after neoadjuvant therapy for localized pancreatic ductal adenocarcinoma: meta-analysis

BACKGROUND

Neoadjuvant therapy is increasingly being used before surgery for localized pancreatic cancer. Given the importance of completing multimodal therapy, the aim of this study was to characterize surgical resection rates after neoadjuvant therapy as well as the reasons for, and long-term prognostic impact of, not undergoing resection.

METHODS

A systematic review and meta-analysis of prospective trials and high-quality retrospective studies since 2010 was performed to calculate pooled resection rates using a generalized random-effects model for potentially resectable, borderline resectable, and locally advanced pancreatic cancer. Median survival times were calculated using random-effects models for patients who did and did not undergo resection.

RESULTS

In 125 studies that met the inclusion criteria, neoadjuvant therapy consisted of chemotherapy (36.8 per cent), chemoradiation (15.2 per cent), or chemotherapy and radiation (48.0 per cent). Among 11 713 patients, the pooled resection rates were 77.4 (95 per cent c.i. 71.3 to 82.5), 60.6 (54.8 to 66.1), and 22.2 (16.7 to 29.0) per cent for potentially resectable, borderline resectable, and locally advanced pancreatic cancer respectively. The most common reasons for not undergoing resection were distant progression for resectable and borderline resectable cancers, and local unresectability for locally advanced disease. Among 42 studies with survival data available, achieving surgical resection after neoadjuvant therapy was associated with improved survival for patients with potentially resectable (median 38.5 versus 13.3 months), borderline resectable (32.3 versus 13.9 months), and locally advanced (30.0 versus 14.6 months) pancreatic cancer (P < 0.001 for all).

CONCLUSION

Although rates of surgical resection after neoadjuvant therapy vary based on anatomical stage, surgery is associated with improved survival for all patients with localized pancreatic cancer. These pooled resection and survival rates may inform patient-provider decision-making and serve as important benchmarks for future prospective trials.

Routine neoadjuvant chemotherapy for all patients with resectable pancreatic ductal adenocarcinoma? A review of the evidence

Pancreatic ductal adenocarcinoma is an aggressive malignancy that carries a poor prognosis because the majority of patients present with locally advanced or metastatic disease. However, even patients who are fortunate enough to present with resectable disease are often plagued by high recurrence rates. While adjuvant chemotherapy has been shown to decrease the risk of recurrence after surgery, post operative complications and poor performance status after surgery prevent up to 50% of patients from receiving it. Given the benefits of neoadjuvant therapy in patients with borderline resectable disease, it is understandable that neoadjuvant therapy has been steadily increasing in patients with resectable cancers as well. In this review paper, we highlight the rational and existing evidence of using neoadjuvant therapy in all patients with resectable pancreatic adenocarcinoma.

RRP9 promotes gemcitabine resistance in pancreatic cancer via activating AKT signaling pathway

BACKGROUND

Pancreatic cancer (PC) is a highly lethal malignancy regarding digestive system, which is the fourth leading factor of cancer-related mortalities in the globe. Prognosis is poor due to diagnosis at advanced disease stage, low rates of surgical resection, and resistance to traditional radiotherapy and chemotherapy. In order to develop novel therapeutic strategies, further elucidation of the molecular mechanisms underlying PC chemoresistance is required. Ribosomal RNA biogenesis has been implicated in tumorigenesis. Small nucleolar RNAs (snoRNAs) is responsible for post-transcriptional modifications of ribosomal RNAs during biogenesis, which have been identified as potential markers of various cancers. Here, we investigate the U3 snoRNA-associated protein RRP9/U3-55 K along with its role in the development of PC and gemcitabine resistance.

METHODS

qRT-PCR, western blot and immunohistochemical staining assays were employed to detect RRP9 expression in human PC tissue samples and cell lines. RRP9-overexpression and siRNA-RRP9 plasmids were constructed to test the effects of RRP9 overexpression and knockdown on cell viability investigated by MTT assay, colony formation, and apoptosis measured by FACS and western blot assays. Immunoprecipitation and immunofluorescence staining were utilized to demonstrate a relationship between RRP9 and IGF2BP1. A subcutaneous xenograft tumor model was elucidated in BALB/c nude mice to examine the RRP9 role in PC in vivo.

RESULTS

Significantly elevated RRP9 expression was observed in PC tissues than normal tissues, which was negatively correlated with patient prognosis. We found that RRP9 promoted gemcitabine resistance in PC in vivo and in vitro. Mechanistically, RRP9 activated AKT signaling pathway through interacting with DNA binding region of IGF2BP1 in PC cells, thereby promoting PC progression, and inducing gemcitabine resistance through a reduction in DNA damage and inhibition of apoptosis. Treatment with a combination of the AKT inhibitor MK-2206 and gemcitabine significantly inhibited tumor proliferation induced by overexpression of RRP9 in vitro and in vivo.

CONCLUSIONS

Our data reveal that RRP9 has a critical function to induce gemcitabine chemoresistance in PC through the IGF2BP1/AKT signaling pathway activation, which might be a candidate to sensitize PC cells to gemcitabine. Video abstract.

Short- and Long-Term Outcomes of Pancreatic Cancer Resection in Elderly Patients: A Nationwide Analysis

BACKGROUND

The number of elderly patients with pancreatic cancer is growing, however clinical data on the short-term outcomes, rate of adjuvant chemotherapy, and survival in these patients are limited and we therefore performed a nationwide analysis.

METHODS

Data from the prospective Dutch Pancreatic Cancer Audit were analyzed, including all patients undergoing pancreatic cancer resection between January 2014 and December 2016. Patients were classified into two age groups: <75 and ≥75 years. Major complications (Clavien-Dindo grade 3 or higher), 90-day mortality, rates of adjuvant chemotherapy, and survival were compared between age groups. Factors associated with start of adjuvant chemotherapy and survival were evaluated with logistic regression and multivariable Cox regression analysis.

RESULTS

Of 836 patients, 198 were aged ≥75 years (24%) and 638 were aged <75 years (76%). Median follow-up was 38 months (interquartile range [IQR] 31-47). Major complications (31% vs. 28%; p = 0.43) and 90-day mortality (8% vs. 5%; p = 0.18) did not differ. Adjuvant chemotherapy was started in 37% of patients aged ≥75 years versus 69% of patients aged <75 years (p < 0.001). Median overall survival (OS) was 15 months (95% confidence interval [CI] 14-18) versus 21 months (95% CI 19-24; p < 0.001). Age ≥75 years was not independently associated with OS (hazard ratio 0.96, 95% CI 0.79-1.17; p = 0.71), but was associated with a lower rate of adjuvant chemotherapy (odds ratio 0.27, 95% CI 0.18-0.40; p < 0.001).

CONCLUSIONS

The rate of major complications and 90-day mortality after pancreatic resection did not differ between elderly and younger patients; however, elderly patients were less often treated with adjuvant chemotherapy and their OS was shorter.

Predictive Biomarkers for a Personalized Approach in Resectable Pancreatic Cancer

The mainstay treatment for patients with immediate resectable pancreatic cancer remains upfront surgery, which represents the only potentially curative strategy. Nevertheless, the majority of patients surgically resected for pancreatic cancer experiences disease relapse, even when a combination adjuvant therapy is offered. Therefore, aiming at improving disease free survival and overall survival of these patients, there is an increasing interest in evaluating the activity and efficacy of neoadjuvant and perioperative treatments. In this view, it is of utmost importance to find biomarkers able to select patients who may benefit from a preoperative therapy rather than upfront surgical resection. Defined genomic alterations and a dynamic inflammatory microenvironment are the major culprits for disease recurrence and resistance to chemotherapeutic treatments in pancreatic cancer patients. Signal transduction pathways or tumor immune microenvironment could predict early recurrence and response to chemotherapy. In the last decade, distinct molecular subtypes of pancreatic cancer have been described, laying the bases to a tailored therapeutic approach, started firstly in the treatment of advanced disease. Patients with homologous repair deficiency, in particular with mutant germline BRCA genes, represent the first subgroup demonstrating to benefit from specific therapies. A fraction of patients with pancreatic cancer could take advantage of genome sequencing with the aim of identifying possible targetable mutations. These genomic driven strategies could be even more relevant in a potentially curative setting. In this review, we outline putative predictive markers that could help in the next future in tailoring the best therapeutic strategy for pancreatic cancer patients with a potentially curable disease.