[Metastatic lesions to the pancreas. When is resection reasonable?]

Rare Solid Pancreatic Lesions on Cross-Sectional Imaging

Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most common subtype is pancreatic ductal adenocarcinoma (PDAC), to a point that pancreatic cancer and PDAC are used interchangeably. But, in addition to PDAC, and to the other most common and well-known solid lesions, either related to benign conditions, such as pancreatitis, or not so benign, such as pancreatic neuroendocrine neoplasms (pNENs), there are solid pancreatic lesions considered rare due to their low incidence. These lesions may originate from a cell line with a differentiation other than exocrine/endocrine, such as from the nerve sheath as for pancreatic schwannoma or from mesenchymal cells as for solitary fibrous tumour. These rare solid pancreatic lesions may show a behaviour that ranges in a benign to highly aggressive malignant spectrum. This review includes cases of an intrapancreatic accessory spleen, pancreatic tuberculosis, solid serous cystadenoma, solid pseudopapillary tumour, pancreatic schwannoma, purely intraductal neuroendocrine tumour, pancreatic fibrous solitary tumour, acinar cell carcinoma, undifferentiated carcinoma with osteoclastic-like giant cells, adenosquamous carcinoma, colloid carcinoma of the pancreas, primary leiomyosarcoma of the pancreas, primary and secondary pancreatic lymphoma and metastases within the pancreas. Therefore, it is important to determine the correct diagnosis to ensure optimal patient management. Because of their rarity, their existence is less well known and, when depicted, in most cases incidentally, the correct diagnosis remains challenging. However, there are some typical imaging features present on cross-sectional imaging modalities that, taken into account with the clinical and biological context, contribute substantially to achieve the correct diagnosis.

Survival impact of pancreatic resection for metastases in the pancreas: A retrospective multi-center study

BACKGROUND

Pancreatic metastases from other primary malignancies are rare. There is no clear evidence for a treatment strategy for this condition. The purpose of this study was to assess the clinical outcomes, including prognostic factors for pancreatic resection of metastatic tumors in the pancreas, through a retrospective review.

METHODS

Data of 35 patients who underwent pancreatic resection for pancreatic metastasis between 2005 and 2020 in eight Japanese institutions were included in this study. Survival analyses were performed using the Kaplan-Meier method, and comparisons were made using the Cox proportional hazards model.

RESULTS

The median follow-up period was 35 months (range, 5-102 months). Median duration from resection for primary tumor to resection for metastatic pancreatic tumor was 10.6 years (range, 0.6-29.2 years). The 3- and 5-year survival rates after resection for metastatic tumors in the pancreas were 89% and 69%, respectively. In contrast, the 3- and 5-year disease-free survival rates after resection for metastatic tumors in the pancreas were 48% and 21%, respectively. Performance status ≥1 at the time of resection for metastatic tumors in the pancreas (HR: 7.56, p = 0.036) and pancreatic metastasis tumor diameter >42 mm (HR: 6.39, p = 0.02) were significant poor prognostic factors only in the overall survival.

CONCLUSIONS

The prognosis of pancreatic resection for metastatic tumors in the pancreas is relatively good for selected patients. However, because it is prone to recurrence after radical surgery, it should only be considered in patients with good PS.

Isolated Pancreatic Metastases of Renal Cell Carcinoma-Clinical Particularities and Seed and Soil Hypothesis

A meta-analysis of 1470 isolated pancreatic metastases of renal cell carcinoma revealed, that, in addition to the unusual exclusive occurrence of pancreatic metastases and the favourable treatment results, the isPMRCC is characterised by further peculiarities of the clinical course: The lack of prognostic significance of volume and growth rate dependent risk factors and the independence of treatment results from standard or local resections. As an explanation for all these peculiarities, according to today's knowledge, a strong acting seed and soil mechanism can serve, which allows embolized tumour cells to grow to metastases only in the pancreas, and prevents them definitively or for years in all other organs. The good prognosis affects not only isolated PM, but also multi-organ metastases of the RCC, in which the additional occurrence of PM is also associated with a better prognosis. Genetic studies revealed specific changes in cases of PM of RCC: Lack of loss of 9p21.3 and 14q31.2, which are otherwise specific gene mutations at the onset of generalization, a low weight genome instability index, i.e., high genetic stability, and a low rate of PAB1 and a high rate of BPRM1 alterations, which signal a more favourable course. The cause of pancreatic organotropism in isPMRCC is still unclear, so only those factors that have been identified as promoting organotropism in other, more frequent tumour entities can be presented: Formation of the pre-metastatic niche, chemokine receptor-ligand mechanism, ability to metabolic adaptation, and immune surveillance.

The role of resection for melanoma metastases to the pancreas

BACKGROUND

Among patients with distant metastatic melanoma, the site of metastases is the most significant predictor of survival and visceral-nonpulmonary metastases hold the highest risk of poor outcomes. However, studies demonstrate that a significant percentage of patients may be considered candidates for resection with improved survival over nonsurgical therapeutic modalities. We aimed at analyzing the results of resection in patients with melanoma metastasis to the pancreas by assessing the available evidence.

METHODS

The PubMed/MEDLINE, WoS, and Embase electronic databases were systematically searched for articles reporting on the surgical treatment of pancreatic metastases from melanoma. Relevant data from included studies were assessed and analyzed. Overall survival was the primary endpoint of interest. Surgical details and oncological outcomes were also appraised.

RESULTS

A total of 109 patients treated surgically for pancreatic metastases were included across 72 articles and considered for data extraction. Overall, patients had a mean age of 51.8 years at diagnosis of pancreatic disease. The cumulative survival was 71%, 38%, and 26% at 1, 3 and 5 years after pancreatectomy, with an estimated median survival of 24 months. Incomplete resection and concomitant extrapancreatic metastasis were the only factors which significantly affected survival. Patients in whom the pancreas was the only metastatic site who received curative resection exhibited significantly longer survival, with a 1-year, 3-year, and 5-year survival rates of 76%, 43%, and 41%, respectively.

CONCLUSION

Within the limitations of a review of non-randomized reports, curative surgical resection confers a survival benefit in carefully selected patients with pancreatic dissemination of melanoma.

Isolated Pancreatic Metastases of Renal Cell Cancer: Genetics and Epigenetics of an Unusual Tumour Entity

Isolated pancreatic metastases of renal cell carcinoma (isPMRCC) are a rare manifestation of metastatic renal cell carcinoma (mRCC) characterized by two peculiarities: (1). The definite or at least long-term exclusive occurrence of metastases in the pancreas and (2). an unusual low tumour aggressiveness with slow tumour progression and consecutive, good treatment results. According to current knowledge, the exclusive occurrence of pancreatic metastases is due to a highly specific and highly selective seed and soil mechanism, which does not allow metastases settlement outside the pancreas, and whose detailed genetic/epigenetic causes are not yet elucidated. Recent studies have shed light on some of the pathways involved for the protracted course of the disease and highlighted a special genetic profile (lack of loss of 9p, lower weight genome instability index, low frequency of BAP1 alterations, and a high frequency of PBRM1 loss), which deviates from the conventional mRCC profile. Finally, the question of the reasons for the long-term relative genetic stability of the involved cell clones, which is an essential prerequisite for a favourable prognosis, remains unanswered.

Tumour Evolution and Seed and Soil Mechanism in Pancreatic Metastases of Renal Cell Carcinoma

In metastatic renal cell carcinoma, pancreatic metastases can appear in two clinical manifestations: (a) very rarely as isolated pancreatic metastases and (b) in the context with multi-organ metastatic disease. Both courses are characterised by rare, unusual clinical features. For isolated pancreatic metastases, the literature shows no effect on survival in all 11 publications that examined the effect of singular versus multiple pancreatic metastases; a lack of effect on survival time was also present in all 8 studies on pancreatic metastases size, in 7 of 8 studies on the influence of disease-free interval (DFI), and in 6 of 7 studies on the influence of synchronous versus metachronous metastases. In multi-organ site metastases observations, on the other hand, all five available references showed significantly better results in patients with concurrent pancreatic metastases compared to those without pancreatic metastases, although the total number of affected organs in the pancreatic metastases cohort was larger. Tumour volume-dependent risk factors thus remain surprisingly ineffective in both groups, which contradicts the usual behaviour of solid tumours. The reasons for this unusual behaviour and possible relations to tumour evolution and the hypothesis of an influence of a seed and soil mechanism in the occurrence of pancreatic metastases in metastatic renal cell carcinoma are discussed.

Isolated Pancreatic Metastases of Renal Cell Carcinoma-A Paradigm of a Seed and Soil Mechanism: A Literature Analysis of 1,034 Observations

Previously documented arguments, in favor of the suspected impact of a seed and soil mechanism, in the development and progression of isolated pancreatic metastasis of renal cell carcinomas (isPM) are: (1) uniform and independent from the side of the primary tumor distribution of isPM within the pancreas and, (2) the similar survival rates for singular and multiple isPM. In addition, the present study adds new arguments that further confirm the importance of an seed and soil mechanism in isPM: (1) Within the singular isPM, the size of the metastasis does not affect the overall survival; (2) Within the group of multiple isPMs, the overall survival does not depend on the number of metastases; (3) For synchronous and metachronous isPM, survival rates are also not different, and (4) Within the group of metachronous isPM there is also no correlation between the overall survival and interval until metastases occurs. This unusual ineffectiveness of otherwise known risk factors of solid cancers can be explained plausibly by the hypothesis of a very selective seed and soil mechanism in isPM. It only allows embolized renal carcinoma cells in the pancreas to complete all steps required to grow into clinically manifest metastases. In all other organs, on the other hand, the body is able to eliminate the embolized tumor cells or at least put them into a dormant state for many years. This minimizes the risk of occult micrometastases in distant organs, which could later—after isPM treatment—grow into clinically manifest metastases, so that the prognosis of the isPM is only determined by an adequate therapy of the pancreatic foci, and prognostic factors, such as total tumor burden or interval until the occurrence of the isPM remain ineffective.

Observations on Solitary Versus Multiple Isolated Pancreatic Metastases of Renal Cell Carcinoma: Another Indication of a Seed and Soil Mechanism?

Isolated pancreas metastases are a rare type of metastasis of renal cell carcinoma, characterized by the presence of pancreatic metastases, while all other organs remain unaffected. In a previous study, we determined arguments from the literature which (a) indicate a systemic–haematogenic metastasis route (uniform distribution of the metastases across the pancreas and independence of the metastatic localization in the pancreas of the side of the renal carcinoma); and (b) postulate a high impact of a seed and soil mechanism (SSM) on isolated pancreatic metastasis of renal cell carcinoma (isPM) as an explanation for exclusive pancreatic metastases, despite a systemic haematogenous tumor cell embolization. The objective of the study presented was to search for further arguments in favor of an SSM with isPM. For that purpose, the factor’s histology, grading, and singular/multiple pancreas metastases were analyzed on the basis of 814 observations published up to 2018. While histology and grading allowed for no conclusions regarding the importance of an SSM, the comparison of singular/multiple pancreas metastases produced arguments in favor of an SSM: 1. The multiple pancreas metastases observed in 38.1% prove that multiple tumor cell embolisms occur with isPM, the exclusive “maturation” of which in the pancreas requires an SSM; 2. The survival rates (SVR), which are consistent with singular and multiple pancreas metastases (despite the higher total tumor load with the latter), prove that the metastasized tumor cells are not able to survive in all other organs because of an SSM, which results in identical SVR when the pancreatic foci are treated adequately.

Isolated pancreatic metastases from renal cell carcinoma: an outcome of a special metastatic pathway or of specific tumor cell selection?

Isolated pancreatic metastases (isPM) are a rare metastasizing pattern in the natural history of renal cell cancer. Their clinical hallmark is that they are confined to a single organ, the pancreas, while all other organs are unaffected for a long time. Almost all workers in the field suggested that mechanical tumor cell propagation to the pancreas may be the mechanism underlying this metastasizing pattern. In 2006 our group, by contrast, proposed an alternative mechanism, i.e. a special affinity of the tumor cells for the pancreas. In the present study an attempt was made to shed more light on the settlement of isPM by reviewing recent literature data. 666 observations of isPM reported in the literature were reviewed. The analyses showed that local lymphatic spread does not play a major role because the lymphatic system is, in general, rarely involved in isPM. This also applies to a local venous spread, because the site of pancreatic metastases is independent of the side affected by the primary renal cancer. But the results are compatible with a systemic metastatic pathway. That metastases in other organs, which would be expected given a systemic spread, are absent can plausibly be explained by a seed and soil mechanism: only the pancreas offers the tumor cell emboli an environment which is conducive to the growth of clinically manifest metastases, while settlement of metastatic tumor cells is prevented in all other organs.

Pancreatic metastasis of renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is a common cancer, but pancreatic metastasis of RCC is unusual. Because of the rarity and peculiarity, pancreatic lesions from RCC metastasis were described mostly in case reports which highlight the importance of a systematic analysis of this clinical condition.

DATA SOURCES

Data of 7 patients with pancreatic metastasis of RCC treated in the Peking Union Medical College Hospital were extracted and 193 similar patients reported in the past 10 years from the literature were analyzed. Epidemiological, pathological and follow-up information were investigated. Potential prognostic factors were compared with corresponding data reported 10 years ago.

RESULTS

Multivariate Cox regression showed that asymptomatic metastasis and surgical procedure were independent factors associated with better survival. Compared with the data reported 10 years ago, follow-up of RCC patients has been emphasized in recent years, and atypical surgery is frequently used since it has similar effect as typical surgery on tumor resection while it is able to preserve more pancreatic function.

CONCLUSION

Surgical treatment should be an option as long as the pancreatic metastasis of RCC is resectable.

Extended resection in pancreatic metastases: feasibility, frequency, and long-term outcome: a retrospective analysis

Background

Metastases to the pancreas are rare, accounting for less then 2 % of all pancreatic malignancies. However, both the benefit of extended tumor resection and the ideal oncological approach have not been established for such cases; therefore, we evaluated patients with metastasis to the pancreas who underwent pancreatic resection.

Methods

Between 1994 and 2012, 676 patients underwent pancreatic surgery in our institution. We retrospectively reviewed patients’ medical records according to survival, and surgical and non-surgical complications. Student’s t-test and the log-rank test were used for statistical analysis.

Results

Eighteen patients (2.7 %) received resection for pancreatic metastases (12 multivisceral resections and 6 standard resections). The pancreatic metastases originated from renal cell carcinoma (n = 10), malignant melanoma (n = 2), neuroendocrine tumor of the ileum (n = 1), sarcoma (n = 1), colon cancer (n = 1), gallbladder cancer (n = 1), gastrointestinal stromal tumor (n = 1), and non-small cell lung cancer (n = 1). The median time between primary malignancy resection to metastasectomy was 83 months (range, 0–228 months). Minor surgical complications (Grade I-IIIa) occurred in six patients (33.3 %) whereas major surgical complications (Grade IIIb-V) occurred in three patients (16.6 %). No patients died during hospitalization. The median follow-up was 76 months (range, 10–165 months). One-year, 3-year and 5-year survival for standard resection versus multivisceral resection was 83, 50, and 56 % versus 83, 66, and 50, respectively. Twelve patients died after a median of 26 months (range, 5–55 months).

Conclusions

A surgical approach with curative intent is justified in select patients suffering from metastases to the pancreas and offers good long-term survival. The resection of pancreatic metastases of different tumor types was associated with favorable morbidity and mortality when compared with resection of the primary pancreatic malignancies. Our findings also demonstrated that multivisceral resection was feasible, with acceptable long term outcomes, even though morbidity rates tended to be higher after multivisceral resection than after standard resection.

A case report of a solitary pancreatic metastasis of an adrenocortical carcinoma

Background

Solitary metastases to the pancreas are rare. Therefore the value of resection in curative intention remains unclear. In the literature there are several promising reports about resection of solitary metastasis to the pancreas mainly of renal origin.

Case presentation

Here we report for the first time on the surgical therapy of a 1.5 cm solitary pancreatic metastasis of an adrenocortical carcinoma. The metastasis occurred almost 6 years after resection of the primary tumor. A partial pancreatoduodenectomy was performed and postoperatively adjuvant mitotane treatment was initiated. During the follow-up of 3 years after surgery no evidence of tumor recurrence occurred.

Conclusion

Resection of pancreatic tumors should be considered, even if the mass is suspicious for metastatic disease including recurrence of adrenocortical cancer.

Diagnosis and treatment of pancreatic metastases in 22 patients: a retrospective study

Background

Pancreatic metastases (PMs) are rare and lack of guidelines for diagnosis and treatments .The aim of this study is to explore the diagnosis, treatment, and prognosis of pancreatic metastases.

Methods

Twenty-two patients with pancreatic metastases who had been hospitalized at the First Affiliated Hospital of China Medical University from October 1980 to October 2012 were included in the present retrospective study. Seven patients had gastric cancer, five had colon cancer, two each had lung and liver cancer, and one each had bladder cancer, gallbladder cancer, breast cancer, nasopharyngeal cancer, renal cell carcinoma, and carcinoid.

Results

No specific syndrome or imageological change was found for the pancreatic metastases. The most common symptoms were abdominal pain and jaundice. Hypo-echoic lesions with well-defined margins were found on ultrasonic examinations, and low-density lesions with heterogeneous enhancement were identified in CT images. Nineteen of the 22 received treatment. Three of the 8 patients (34.1%) that had undergone operation experienced complications, but all patients recovered after conventional treatment. Follow-up studies were performed for 17 patients (77.3%), and the median survival time from the diagnosis of pancreatic metastases was 13.2 months (range, 2 to 68 months). Of the five patients who underwent radical resection, one was lost to follow-up, one died at fifteen months postoperation, and the other three are still alive and free from disease (disease-free survival ranging from five to thirty-three months from the diagnosis of the pancreatic metastases).

Conclusion

Pancreatic metastases are rare lesions with no specific symptoms. Radical resection should be performed if possible; however, aggressive treatment should be performed for unresectable pancreatic metastases.

Breast cancer metastases to the pancreas

INTRODUCTION

The pancreas can serve as the destination for metastatic spread of malignancies from multiple organ sites. Breast cancer metastases to the pancreas are part of this spectrum and surgeons evaluate such patients as part of their practice. Uniform clinical guidelines for these cases do not exist and care is primarily driven by the personal experience of the treating surgeon.

DISCUSSION

We present two patients with breast cancer metastases to their pancreas and review their workup and clinical management in light of our experience and the existing published literature. We propose that metastatic disease to the pancreas has to remain in the differential diagnosis for any patient with a new pancreatic mass and prior cancer history. Surgical resection is a viable treatment option for patients with isolated metastatic disease to the pancreas if the underlying biology of the metastatic tumor is favorable.

Pancreatic metastases from renal cell carcinoma: the state of the art

Pancreatic metastases are rare, with a reported incidence varying from 1.6% to 11% in autopsy studies of patients with advanced malignancy. In clinical series, the frequency of pancreatic metastases ranges from 2% to 5% of all pancreatic malignant tumors. However, the pancreas is an elective site for metastases from carcinoma of the kidney and this peculiarity has been reported by several studies. The epidemiology, clinical presentation, and treatment of pancreatic metastases from renal cell carcinoma are known from single-institution case reports and literature reviews. There is currently very limited experience with the surgical resection of isolated pancreatic metastasis, and the role of surgery in the management of these patients has not been clearly defined. In fact, for many years pancreatic resections were associated with high rates of morbidity and mortality, and metastatic disease to the pancreas was considered to be a terminal-stage condition. More recently, a significant reduction in the operative risk following major pancreatic surgery has been demonstrated, thus extending the indication for these operations to patients with metastatic disease.

Metastatic tumors in the pancreas in the modern era

BACKGROUND

Tumors metastasizing to the pancreas are rare, and published series are limited by few patients treated for extended periods of time. Renal cell cancer (RCC) is the most common primary tumor metastasizing to the pancreas. Our aim was to describe the clinicopathologic characteristics and patient outcomes in a modern series of patients who underwent metastasectomy, with an emphasis on RCC.

STUDY DESIGN

Retrospective review of all pancreatic resections between January 1993 and October 2009.

RESULTS

We identified 40 patients with a median age of 62 years; 55% were female. Patients most commonly presented with abdominal pain (47.5%). Operations performed included 10 pancreaticoduodenectomies, 1 middle, 23 distal, 3 total pancreatectomies, and 3 enucleations. Primary cancers were RCC (n = 20), ovarian (n = 6), sarcoma (n = 3), colon (n = 3), melanoma (n = 2), and others (n = 6). Median survival for all patients after metastasectomy was 4.4 years. Median survival after metastasectomy for RCC was 8.7 years, and the 5-year actuarial survival was 61%. For RCCs, pancreas was the first site of an extrarenal recurrence in 85% and was synchronous with the primary in 5% of patients. There was no survival difference if the time interval to metastasis was shorter than the median (8.7 years), if tumor nodules were multiple or bigger than the median (3 cm), or if the pancreas was not the first site of metastases.

CONCLUSIONS

An aggressive approach to lesions metastatic to the pancreas is often warranted if the patient can be rendered free of disease. Although patients with RCC can experience long-term survival after metastasectomy, survival is less favorable for other primary tumors.

Systematic review of pancreatic surgery for metastatic renal cell carcinoma

BACKGROUND

This study examined the clinical outcome of patients with pancreatic metastases from renal cell carcinoma (RCC).

METHODS

A systematic literature search produced individual data for 311 surgically and 73 non-surgically treated patients with pancreatic RCC metastases. A further ten patients underwent resection at the authors' institution.

RESULTS

In the resected group, pancreatic metastases were solitary in 65.3 per cent, symptomatic in 57.4 per cent, and were preceded and/or accompanied by extrapancreatic disease in 22.3 per cent. Respective values in the unresected group were 59, 60 and 58 per cent. Disease-free survival rates were 76.0 and 57.0 per cent respectively at 2 and 5 years after resection, and overall survival rates were 80.6 and 72.6 per cent. The only significant risk factor for disease-free survival after pancreatic resection was extrapancreatic disease (P = 0.001), and that for overall survival was symptomatic RCC metastasis (P = 0.031). Two- and 5-year overall survival rates were 41 and 14 per cent respectively in unresected patients.

CONCLUSION

The actuarial 5-year overall survival rate following pancreatic surgery for RCC metastases was 72.6 per cent, as determined by pooled analysis from published series. Extrapancreatic disease was an independent risk factor for recurrence, but had no significant impact on overall survival.

The role of surgery in the management of isolated metastases to the pancreas

Metastasectomy with curative intent has become standard practice for the management of some malignancies. Resection of isolated metastatic colorectal cancer, gastrointestinal stromal tumours, neuroendocrine cancers, renal-cell cancer and sarcoma is associated with longer survival or even cure. The strongest evidence in favour of metastasectomy exists for colorectal cancer, in which resection of limited metastatic disease in some patients is associated with 5-year survival rates of more than 50%.(1-3) High incidence of the disease, predictable tumour biology, and development of successful chemotherapies have encouraged metastasectomy. Furthermore, improved safety of complex surgeries over the past several decades has lowered the threshold for more aggressive surgical intervention. Most literature on metastasectomy pertains to the resection of disease involving the liver, lung, and brain. However, metastasectomy has been described for almost every organ system, including the pancreas. In this Review, we discuss resection of isolated cancer metastases to the pancreas. Pancreatic metastasectomy is most often done through a formal pancreatic resection such as pancreaticoduodenectomy or distal pancreatectomy. Less often, pancreatic metastasectomy is done by enucleation or a pancreas sparing operation such as a central pancreatectomy.

Pancreatic resection of isolated metastases from nonpancreatic primary cancers

BACKGROUND

The goal of this study is to report the safety and efficacy of pancreatic resection for isolated metastatic cancers from nonpancreatic primary disease.

METHODS

We retrospectively identified patients from a single institution's prospectively gathered pancreaticobiliary database from 1970 to 2007 who underwent a pancreatic resection for metastatic disease.

RESULTS

Forty-nine patients were identified with metastatic lesions to the pancreas. Pancreaticoduodenectomy, distal pancreatectomy, and total pancreatectomy were performed in 31, 14, and 4 patients, respectively. Pathology distribution was as follows: 21 renal cell carcinoma (RCC), 6 gallbladder cancer, 4 lung cancer, 4 ovarian cancer, 4 sarcoma, 3 melanoma, 2 colon cancer, 1 breast cancer, 1 hepatocellular carcinoma, 1 seminoma, 1 Langerhans cell histiocytosis, and 1 nonpancreatic endocrine cancer. Postoperative morbidity was 48%. There were no perioperative deaths. A statistically significant difference in survival was found between cancer types (P = .007) with median survivals ranging from 4.8 years for RCC to .9 years for melanoma. Univariate analysis demonstrated a survival disadvantage for patients with perineural (hazard ratio [HR] = 5.4, P = .004) and vascular invasion (HR = 4.4, P = .002). The most commonly resected metastatic lesion of the pancreas was RCC. Eighteen of the 23 patients with RCC had a metachronous lesion with a median length between initial operation and pancreatic resection of 9.3 years. Metachronous lesions had a survival similar to that of synchronous lesions (HR = 1.0, P = .98). Vascular invasion (HR = 2.4, P = .007) and lymph node metastases (HR = 24.1, P = .01) were associated with greater mortality.

CONCLUSION

Long-term survival can be achieved in patients undergoing resection of isolated metastases to the pancreas.