Do Patients Diagnosed with Metastatic Pancreatic Cancer Benefit from Primary Tumor Surgery? A Propensity-Adjusted, Population-Based Surveillance, Epidemiology and End Results (SEER) Analysis

Abstract

BackgroundWith the progress in surgical techniques and management of complications, pancreatic resection can be safely performed in experienced hospitals. Pancreatic resection enables surgeons to assess the effect of surgery for metastatic cases, even when there is limited information. In the present study we evaluated the role of primary tumor resection for metastatic pancreatic cancer (mPC) by using the Surveillance, Epidemiology and End Results (SEER) database.Material/MethodsMetastatic pancreatic cancer patients treated at our hospital from 2004 to 2015 were identified. The effect of surgery on cancer-specific survival was assessed by restricted mean survival time (RMST) and stabilized inverse probability of treatment weight-adjusted analysis after propensity score matching (PSM).ResultsA total of 2694 mPC patients were included. Of this population, 365 adults underwent primary tumor resection. After propensity matching, postsurgical patients had longer RMST than non-surgery patients (1: 1 PSM 11.60 months vs. 8.98 months; 1: 2 PSM 11.61 months vs. 9.10 months; p<0.01). Stabilized inverse probability of treatment weight-adjusted analysis yielded similar results (p<0.01).ConclusionsOur study supports the hypothesis that patients with mPC can benefit from primary tumor surgery. However, the surgical inclusion criteria and the appropriate role of surgery, such as its effect on symptom control, quality of life, and the extent to which it prolongs survival for metastatic pancreatic cancer, remain to be completely assessed by well-designed, prospective, randomized clinical trials.

Locoregional Treatment of Metastatic Pancreatic Cancer Utilizing Resection, Ablation and Embolization: A Systematic Review

“…Five large database studies focused on the effects of surgical removal of the primary pancreatic tumor in case of metastatic disease ( Table 1 ) [ 19 , 20 , 21 , 22 , 23 ]. They included a total of 61,035 patients from the SEER database.…”

“…In PDAC, the most significant predictor of long-term survival is an R0 resection of the primary tumor since this remains the only possible curative option. Primary resection (margin) status was a frequently mentioned significant prognostic factor [ 20 , 21 , 22 , 23 , 24 , 28 , 31 , 37 , 46 , 54 ], confirming its substantial influence on survival and highlights its advantage as patient selection criterium [ 26 , 52 , 86 ]. However, this is specifically the case for metachronous disease, as for synchronous disease intra-operative efforts must be made to attain this information.…”

“…Younger age [20,21] Caucasian ethnicity [20,21] Married [20,21] Female [20,21] Later era of diagnosis [22] Tumor in pancreatic head [20] Well/moderate differentiation of tumor (histological grade) [20,22,23] Longer DFI [23] Single-organ metastatic disease [23] Chemotherapy (pre-and/or post local treatment) [20,22] Primary tumor resection [20][21][22][23] Local metastatic treatment [21] Hepatic resection Lower tumor stage [24,25] Tumor in pancreatic body/tail [26] Smaller primary tumor size [27] Well/moderate differentiation of tumor (histological grade) [25] Lower tumor marker CA19-9 levels pre-or post-treatment(s) [25,28,29] Fewer and/or smaller liver lesions [28] Metachronous (instead of synchronous) [30] Absence of lymph node status [25,31] Chemotherapy (pre-and/or post local treatment) [25,28,29] Primary tumor resection [28,29] Better primary resection status [24,31] Better liver resection status [25] Pulmonary resection…”

Metastatic pancreatic adenocarcinomas could be classified into M1a and M1b category by the number of metastatic organs

“…With the remarkable progress of surgical techniques and procedures, extended surgical approaches can also be performed with low morbidity and mortality rates in well-selected mPC patients [20]. A SEER-based respective study showed that primary tumor resection could prolong the long-term survival of mPC patients [21]. However, they did not divided mPC patients into subgroups further according to metastatic sites.…”

Worth it or not? Primary tumor resection for stage IV pancreatic cancer patients: A SEER‐based analysis of 15,836 cases

“…[10][11][12][13] Thus far, primary tumor resection (PTR) for stage IV PC remains controversial. [14][15][16][17][18][19][20][21][22] A previous study by our group discovered that surgery helped to prolong the overall survival (OS) of patients with stage IV PC. 14 Some also advocated PTR and emphasized the importance of patient selection, 15,20 while others reported no survival benefits from PTR.…”