[Oligometastasis in pancreatic cancer : Current state of knowledge and spectrum of local therapy]

Combined Therapy of Chemotherapy and Radiofrequency Ablation for Pancreatic Cancer Patients With Metachronous Hepatic Metastatic Lesions After Radical Pancreatic Resection

PURPOSE

Hepatic metastasis frequently occurs in patients who have undergone radical pancreatic resection for pancreatic cancer. Besides chemotherapy, various local treatment approaches targeting hepatic lesions have been explored. However, research on radiofrequency ablation (RFA) as a localized therapy for hepatic metastasis is limited. Therefore, we conducted this retrospective study to provide clinical evidence.

METHODS

This is a single-center, retrospective, cohort study. After radical pancreaticoduodenectomy, 32 patients developed metachronous hepatic metastasis with fewer than 3 lesions, the largest of which was less than 3 cm in diameter. These patients underwent combined treatment with chemotherapy and RFA. After 8 weeks of chemotherapy, patients received RFA for hepatic lesions. Additional chemotherapy was administered, and the patients' tumor status and survival were monitored. The primary endpoint of this study was overall survival (OS). Factors affecting OS were analyzed using the Cox risk model.

RESULTS

Among the 32 patients, the mean OS was 28.4 months. Univariate and multivariate Cox regression analysis revealed that the time (in months) of liver metastasis (HR = 0.04, 95% CI: 0.01 to 0.19; P < 0.001), the number of liver metastases (HR = 7.08, 95% CI: 1.85 to 27.08, P = 0.004), and PD (progressive disease) response to the second round of chemotherapy (HR = 29.50, 95% CI: 1.46 to 597.27; P = 0.027) were independent predictors of poorer survival.

CONCLUSION

Combined therapy with RFA and chemotherapy is safe in patients with hepatic metastasis after radical pancreaticoduodenectomy. Early recurrence (≤12 months), three liver metastatic lesions, and a poor response to the second round of chemotherapy were associated with poor survival.

Surgical management of pancreatic cancer liver oligometastases

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer, which commonly metastasizes to the liver. The current standard of care for metastatic PDAC is systemic chemotherapy, however there are limited emerging data regarding surgical resection of pancreatic oligometastases in select patients. Here we review the literature addressing resection of PDAC liver oligometastases.

[Better Therapy for Pancreatic Cancer through More Radical Surgery?]

Despite advances in the treatment of pancreatic cancer, the survival of affected patients remains limited. A more radical surgical therapy could help to improve the prognosis, in particular by reducing the local recurrence rate, which is around 45% in patients with resected pancreatic cancer. In addition, patients with oligometastatic pancreatic cancer could also benefit from a more radical indication for surgery.Based on an analysis of the literature, important principles of pancreatic cancer surgery were examined.Even if even more radical surgical approaches such as an "extended" lymphadenectomy or a standard complete pancreatectomy do not bring any survival advantage, complete resection of the tumour (R0), a thorough locoregional lymphadenectomy and an adequate radical dissection in the area of the peripancreatic vessels including periarterial nerve plexuses should be the standard of pancreatic carcinoma resections. Whenever necessary to achieve an R0 resection, resections of the pancreas have to be extended, as well as additional venous vascular resections and multivisceral resections had to be performed. Simultaneous arterial vascular resections as part of pancreatic resections as well as surgical resections in oligometastatic patients should, however, be reserved for selected patients. These aspects of the surgical technique in pancreatic carcinoma mentioned above must not be neglected from the point of view of an "existing limited prognosis". On the contrary, they form the absolutely necessary basis in order to achieve good survival results in combination with system therapy. However, it may always be necessary to adapt these standards according to the age, comorbidities and wishes of the patient.

Systemic Therapy for Metastatic Pancreatic Cancer

Pancreatic cancer is mainly diagnosed at an advanced, often metastatic stage and still has a poor prognosis. Over the last decades, chemotherapy of metastatic pancreatic cancer (mPDAC) has proven to be superior to a mere supportive treatment with respect to both survival and quality of life. Recently, even sequential treatment of mPDAC could be established. Options for first-line treatment are combination chemotherapy regimens such as FOLFIRINOX and gemcitabine plus nab-paclitaxel when the performance status of the patient is good. For patients with poorer performance status, gemcitabine single-agent treatment is a valid option. Recently, the PARP inhibitor olaparib has been demonstrated to improve progression-free survival when used as a maintenance treatment in the subgroup of patients with mPDAC and a BRCA1/-2 germ line mutation having received at least 16 weeks of platinum-based chemotherapy. This group of patients also benefits from platinum-based chemotherapy combinations. Therefore, the BRCA1/-2 stats should be examined early in patients with mPDAC even when the occurrence of these mutations is only about 5% in the general Caucasian population. After the failure of first-line treatment, patients should be offered a second-line treatment if their ECOG permits further treatment. Here, the combination of 5-FU/FA plus nanoliposomal irinotecan has shown to be superior to 5-FU/FA alone with respect to overall survival. Immune checkpoint inhibitors like PD1/PD-L1 mAbs are particularly efficacious in tumors with high microsatellite instability (MSI-h). Limited data in mPDACs shows that only a part of the already small subgroup of MSI-H mPDACs (frequency about 1%) appears to benefit substantially from a checkpoint inhibitor treatment. The identification of further subgroups, e.g., tumors with DNA damage repair deficiency, gene fusions, as well as novel approaches such as tumor-organoid-informed treatment decisions, may further improve therapeutic efficacy.

Simultaneous resection of the primary tumour and liver metastases after conversion chemotherapy versus standard therapy in pancreatic cancer with liver oligometastasis: protocol of a multicentre, prospective, randomised phase III control trial (CSPAC-1)

INTRODUCTION

Approximately 50% of pancreatic ductal adenocarcinoma (PDAC) patients are diagnosed with distant metastasis, especially liver metastasis. The current standard treatment for these stage IV patients is palliative chemotherapy. There is increasing agreement that synchronous PDAC and liver metastasis resection may benefit highly selected patients. Thus, the Chinese Study Group for Pancreatic Cancer (CSPAC)-1 trial is being launched to establish a strategy for selecting PDAC patients with liver oligometastases who may benefit from synchronous resection after conversion chemotherapy.

METHODS AND ANALYSIS

In this study, liver oligometastasis is defined as no more than three metastatic lesions irrespective of their distribution within the liver lobes. The trial contains two steps. In the first step, 1000 to 1200 needle biopsy-confirmed PDAC patients with liver oligometastases are eligible for inclusion. Candidates will receive first-line chemotherapy. The RECIST V.1.1 criteria combined with tumour markers will be applied to evaluate the tumour response to chemotherapy every two cycles. Pancreatic cancer and hepatic metastasis resectability will be identified by multidisciplinary teams. Approximately 300 patients who meet our criteria will enter the second step and be randomly assigned at a 1:1 ratio to simultaneous resection of the primary pancreatic cancer lesion and liver oligometastases if no extensive metastatic sites are found during surgery or standard chemotherapy. Postoperative chemotherapy is recommended, and regimen selection should be based on the preoperative chemotherapy regimen. The primary endpoint is real overall survival (from enrolment to death). This study was activated in July 2018 and is expected to complete accrual within 5 years.

ETHICS AND DISSEMINATION

This trial has been approved by the Clinical Research Ethics Committee of Fudan University Shanghai Cancer Centre. Written informed consent will be obtained from all participants. Serious adverse events will be reported. Trial results will be submitted for peer-reviewed publication.

TRIAL REGISTRATION NUMBER

NCT03398291; Pre-results.

Oligometastases in pancreatic cancer (Synchronous resections of hepatic oligometastatic pancreatic cancer: Disputing a principle in a time of safe pancreatic operations in a retrospective multicenter analysis)

The aim of the present review was to analyze the current data on surgery of synchronous liver metastases in pancreatic ductal adenocarcinoma (PDAC) in curative intent. A review of the literature was carried out to identify the current international concepts regarding surgery of liver metastases of PDAC and, furthermore, we addressed the current challenges of resection of liver metastases of PDAC. Resection of liver metastases in PDAC may provide survival benefit without compromising safety and quality of life in a highly selected group of patients.