Neoadjuvant Therapy for Localized Pancreatic Cancer: Support Is Growing?

Use of Vascular Shunt at the Time of Pancreatectomy with Venous Resection: A Systematic Review

BACKGROUND

The rising diffusion of vascular resections during complex pancreatectomy for malignancy, for both oncological and technical matters, brought with it the use of vascular shunts, either temporary or definitive, to prevent bowel congestion and liver ischemia. This study aimed to systematically review the literature on the technical feasibility of vascular shunts during advanced pancreatic surgery, analyzing intraoperative and postoperative outcomes.

METHODS

A systematic literature search was performed on PubMed, Scopus, Web of Science, and the Cochrane Library Central, according to PRISMA guidelines. Studies published before 2006 were excluded, considering the lack of a standardized definition of locally advanced pancreatic cancer. The main outcomes evaluated were the overall complication rate and shunt patency.

RESULTS

Among 789 papers retrieved from the database search, only five fulfilled the inclusion criteria and were included in the review, amounting to a total of 145 patients undergoing a shunt creation at the time of pancreatectomy. Pancreatic adenocarcinoma (PDAC) was found to be the most common diagnosis and pancreaticoduodenectomy was the main surgical procedure, accounting for 88% and 83% of the overall cohort, respectively. The distal splenorenal shunt was the most performed. Overall, 44 out of 145 patients (30%) experienced postoperative complications; the long-term patency of definitive shunts was 83% (110 out of 120 patients).

CONCLUSIONS

An increasing number of patients with borderline resectable or locally advanced PDAC are becoming amenable to resection and shunt creation may facilitate vascular resection with clear margins, becoming a valid tool of modern pancreatic surgery.

Neoadjuvant Treatment in Locally Advanced Pancreatic Cancer (LAPC) Patients with FOLFIRINOX or Gemcitabine NabPaclitaxel: A Single-Center Experience and a Literature Review

The optimal therapeutic strategy for locally advanced pancreatic cancer patients (LAPC) has not yet been established. Our aim is to evaluate how surgery after neoadjuvant treatment with either FOLFIRINOX (FFN) or Gemcitabine-NabPaclitaxel (GemNab) affects the clinical outcome in these patients. LAPC patients treated at our institution were retrospectively analysed to reach this goal. The group characteristics were similar: 35 patients were treated with the FOLFIRINOX regimen and 21 patients with Gemcitabine Nab-Paclitaxel. The number of patients undergoing surgery was 14 in the FFN group (40%) and six in the GemNab group (28.6%). The median Disease-Free Survival (DFS) was 77.10 weeks in the FFN group and 58.65 weeks in the Gem Nab group (p = 0.625), while the median PFS in the unresected group was 49.4 weeks in the FFN group and 30.9 in the GemNab group (p = 0.0029, 95% CI 0.138-0.862, HR 0.345). The overall survival (OS) in the resected population needs a longer follow up to be completely assessed, while the median overall survival (mOS) in the FFN group was 72.10 weeks and 53.30 weeks for the GemNab group (p = 0.06) in the unresected population. Surgery is a valuable option for LAPC patients and it is able to induce a relevant survival advantage. FOLFIRINOX and Gem-NabPaclitaxel should be offered as first options to pancreatic cancer patients in the locally advanced setting.

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.

A Therapeutic Strategy for Resectable Pancreatic Cancer Based on Risk Factors of Early Recurrence

OBJECTIVES

The aim of this study was to identify risk factors for early recurrence and assess the prognostic benefit of neoadjuvant therapy (NAT) for resectable pancreatic cancer.

METHODS

Patients with radiographically resectable pancreatic cancer according to the National Comprehensive Cancer Network guidelines were enrolled. We regarded recurrence within 6 months after surgery as early recurrence.

RESULTS

This study involved 115 patients (80 who underwent upfront surgery and 35 who received NAT). Serum carbohydrate antigen 19-9 greater than 85 U/mL and p53 expression in 0 or more than 80% of tumor cells were independent risk factors for early recurrence after upfront surgery. We classified patients into a high-risk group (1 or 2 risk factors) and a low-risk group (no risk factors). In the high-risk group, the median overall survival time of patients with NAT was significantly longer than that of patients without NAT (P = 0.028). By contrast, the median overall survival time was not different according to NAT in the low-risk group.

CONCLUSIONS

Serum carbohydrate antigen 19-9 and p53 expression of the primary tumor could be predictors of early recurrence in patients with resectable pancreatic cancer. The prognosis of patients with a high risk of early recurrence may be improved using NAT.

A New Strategy to Control and Eradicate "Undruggable" Oncogenic K-RAS-Driven Pancreatic Cancer: Molecular Insights and Core Principles Learned from Developmental and Evolutionary Biology

Oncogenic K-RAS mutations are found in virtually all pancreatic cancers, making K-RAS one of the most targeted oncoproteins for drug development in cancer therapies. Despite intense research efforts over the past three decades, oncogenic K-RAS has remained largely “undruggable”. Rather than targeting an upstream component of the RAS signaling pathway (i.e., EGFR/HER2) and/or the midstream effector kinases (i.e., RAF/MEK/ERK/PI3K/mTOR), we propose an alternative strategy to control oncogenic K-RAS signal by targeting its most downstream signaling module, Seven-In-Absentia Homolog (SIAH). SIAH E3 ligase controls the signal output of oncogenic K-RAS hyperactivation that drives unchecked cell proliferation, uncontrolled tumor growth, and rapid cancer cell dissemination in human pancreatic cancer. Therefore, SIAH is an ideal therapeutic target as it is an extraordinarily conserved downstream signaling gatekeeper indispensable for proper RAS signaling. Guided by molecular insights and core principles obtained from developmental and evolutionary biology, we propose an anti-SIAH-centered anti-K-RAS strategy as a logical and alternative anticancer strategy to dampen uncontrolled K-RAS hyperactivation and halt tumor growth and metastasis in pancreatic cancer. The clinical utility of developing SIAH as both a tumor-specific and therapy-responsive biomarker, as well as a viable anti-K-RAS drug target, is logically simple and conceptually innovative. SIAH clearly constitutes a major tumor vulnerability and K-RAS signaling bottleneck in pancreatic ductal adenocarcinoma (PDAC). Given the high degree of evolutionary conservation in the K-RAS/SIAH signaling pathway, an anti-SIAH-based anti-PDAC therapy will synergize with covalent K-RAS inhibitors and direct K-RAS targeted initiatives to control and eradicate pancreatic cancer in the future.

Decreased Skeletal Muscle Volume Is a Predictive Factor for Poorer Survival in Patients Undergoing Surgical Resection for Pancreatic Ductal Adenocarcinoma

BACKGROUND

The aim of this study was to investigate the impact of decreased skeletal muscle (SM) volume on survival outcomes in patients undergoing surgical resection for pancreatic ductal adenocarcinoma (PDAC).

METHODS

Between March 2000 and February 2015, 323 patients who underwent upfront surgical resection for PDAC were identified from the Mayo Clinic SPORE in Pancreatic Cancer. Body composition data, including SM area, subcutaneous adipose tissue area, and visceral adipose tissue area were calculated using an abdominal computed tomography (CT) image at the third lumbar spinal level. The body composition data were normalized by patients' height (e.g., SM index, cm²/m²) and analyzed as continuous variables. Clinicopathological findings and body composition data at initial diagnosis were evaluated for association with overall survival and recurrence-free survival.

RESULTS

Because the median SM index was significantly different between males vs. females (49.9 cm²/m² [range, 32.0-70.3] vs. 39.4 cm²/m² [range, 29.2-66.2], P < 0.001), it was standardized for each sex and used for further analyses. Parameters independently associated with a shorter overall survival were a larger tumor size (P = 0.007), a greater tumor extent (P = 0.037), a higher carbohydrate antigen 19-9 level (P < 0.001), and a smaller sex-standardized SM index (P = 0.011). Parameters independently associated with a shorter recurrence-free survival were female sex (P = 0.029), a larger tumor size (P < 0.001), a higher carbohydrate antigen 19-9 level (P = 0.001), and a smaller sex-standardized SM index (P = 0.007).

CONCLUSIONS

A smaller sex-standardized SM index is a predictive factor for shorter overall and recurrence-free survival in PDAC patients undergoing surgery.

Techniques of Vascular Resection and Reconstruction in Pancreatic Cancer

Multimodality therapy has become the standard approach for the treatment of pancreatic cancer. With improved response rates to newer chemotherapeutic agents, tumors that used to be considered unresectable are now being considered for operation. Neoadjuvant therapy for borderline resectable pancreatic cancer is considered standard of care and venous resection/reconstruction is no longer controversial. Arterial resection and reconstruction in select patients has also proven to be safe when done in highly specialized centers by high-volume surgeons. This article reviews indications for, and technical aspects of, vascular resection/reconstruction and shunting procedures during pancreatectomy, including critical elements of perioperative care.

Neoadjuvant therapy versus upfront surgical strategies in resectable pancreatic cancer: A Markov decision analysis

BACKGROUND

Neoadjuvant therapy is gaining acceptance as a valid treatment option for borderline resectable pancreatic cancer; however, its value for clearly resectable pancreatic cancer remains controversial. The aim of this study was to use a Markov decision analysis model, in the absence of adequately powered randomized trials, to compare the life expectancy (LE) and quality-adjusted life expectancy (QALE) of neoadjuvant therapy to conventional upfront surgical strategies in resectable pancreatic cancer patients.

METHODS

A Markov decision model was created to compare two strategies: attempted pancreatic resection followed by adjuvant chemoradiotherapy and neoadjuvant chemoradiotherapy followed by restaging with, if appropriate, attempted pancreatic resection. Data obtained through a comprehensive systematic search in PUBMED of the literature from 2000 to 2015 were used to estimate the probabilities used in the model. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Of the 786 potentially eligible studies identified, 22 studies met the inclusion criteria and were used to extract the probabilities used in the model. Base case analyses of the model showed a higher LE (32.2 vs. 26.7 months) and QALE (25.5 vs. 20.8 quality-adjusted life months) for patients in the neoadjuvant therapy arm compared to upfront surgery. Probabilistic sensitivity analyses for LE and QALE revealed that neoadjuvant therapy is favorable in 59% and 60% of the cases respectively.

CONCLUSION(S)

Although conceptual, these data suggest that neoadjuvant therapy offers substantial benefit in LE and QALE for resectable pancreatic cancer patients. These findings highlight the value of further prospective randomized trials comparing neoadjuvant therapy to conventional upfront surgical strategies.

Meta-analyses of treatment standards for pancreatic cancer

Pancreatic cancer is the most lethal common cancer with an estimated 5-year survival rate of 6-7% (across all stages). The only potential curative therapy is surgical resection in those with localized disease. Adjuvant (postoperative) therapy confers a survival advantage over postoperative observation alone. Neoadjuvant (preoperative) therapy offers the potential to downstage initially unresectable tumors for resection, sterilize resection margins and decrease locoregional recurrence, and identify a subset of patients with aggressive disease for whom surgery will not be beneficial. Induction chemotherapy followed by consolidation chemoradiation is another recommended approach in those with locally advanced disease. For those who cannot be downstaged, cannot tolerate surgery, or were diagnosed with metastatic disease, treatment remains palliative with chemotherapy being a critical component of this approach. Recently, intensive combination chemotherapy has been shown to improve survival rates in comparison to gemcitabine alone in advanced disease. The past few decades have afforded an accumulation of high-level evidence regarding neoadjuvant, adjuvant and palliative therapies in pancreatic cancer. There are numerous reviews discussing recent retrospective studies, prospective studies and randomized controlled trials in each of these areas. However, reviews of optimal and recommended treatment strategies across all stages of pancreatic cancer that focus on the highest levels of hierarchical evidence, such as meta-analyses, are limited. The discussion of novel therapeutics is beyond the scope of this review. However, an extensive and the most current collection of meta-analyses of first-line systemic and locoregional treatment options for all stages of pancreatic cancer to date has been accumulated.

Adjuvant and neoadjuvant therapies in resectable pancreatic cancer: a systematic review of randomized controlled trials

The timing of surgery and antineoplastic therapies in patients with resectable non-metastatic pancreatic cancer is still a controversial matter of debate, with special regard to neoadjuvant approaches. Following the criteria of the PRISMA statement, a literature search was conducted looking for RCTs focusing on adjuvant and neoadjuvant therapies in resectable pancreatic cancer. The quality of the available evidence was assessed using the Cochrane Collaboration's tool for assessing risk of bias. Data extraction was carried out by two independent investigators. The search led to the identification of 2830 papers of which 14 RCTs focusing on adjuvant and neoadjuvant treatment of resectable pancreatic cancer eligible for the systematic review. Risk of bias was estimated "unclear" in 3 studies and "high" in 5 studies. Median age ranged between 53 and 66. Overall survival in the surgery-only arms ranged between 11 and 20.2 months; in the adjuvant treatment arms 12.5-29.8 months; and in the neoadjuvant setting 9.9-19.4 months. Neoadjuvant protocols should be offered only in randomized clinical trials comparing the standard of care (surgery followed by adjuvant treatments) to a neoadjuvant approach followed by surgery and adjuvant treatment.

Neoadjuvant multimodal treatment of pancreatic ductal adenocarcinoma

Treatment of pancreatic ductal adenocarcinoma (PDAC) is increasingly multidisciplinary, with neoadjuvant strategies (chemotherapy, radiation, and surgery) administered in patients with resectable, borderline resectable, or locally advanced disease. The rational supporting this management is the achievement of both higher margin-negative resections and conversion rates into potentially resectable disease and in vivo assessment of novel therapeutics. International guidelines suggest an initial staging of the disease followed by a multidisciplinary approach, even considering the lack of a treatment approach to be considered as standard in this setting. This review will focus on both literature data supporting these guidelines and on new opportunities related to current more active chemotherapy regimens. An analysis of the pathological assessment of response to therapy and the potential role of target therapies and translational biomarkers and ongoing clinical trials of significance will be discussed.