For patients with unresectable pancreatic cancer, current chemotherapies have negligible survival benefits. Thus, developing effective minimally invasive therapies is currently underway. This study was conducted to evaluate the efficacy of TACE plus RFA and/or 125
I radioactive seed implantation on unresectable pancreatic cancer. In the present study, there was no significant difference between the group without liver metastases and the group with oligonodular liver metastases in survival rate(P
= 0.239). However, the group without liver metastases had better survival than did patients with multinodular liver metastases (P
< 0.001). Also, patients with oligonodular liver metastases had better survival than did patients with multinodular liver metastases (P
< 0.001). Combined minimally invasive therapies resulted in a good tumor response for the control of liver metastases. In addition, the number of liver metastases was a significant factor in predicting prognosis and treatment response. These results are similar to our previous study of nasopharyngeal carcinoma
Data from the Surveillance, Epidemiology and End Results (SEER) 
registry between 2000 and 2007 indicate that the majority of pancreatic cancer is advanced (50.5% metastatic and 25.9% regional spread) at diagnosis. Liver metastasis is common in patients with pancreatic cancer and is difficult to treat. Therefore, the presence and extension of liver metastases are considered important prognostic factors
. Gemcitabine was the first clinical drug to clearly improve patient's quality of life and prolong survival. Single-agent gemcitabine has evolved as a standard treatment of locally advanced and metastatic pancreatic cancer, producing median OS ranging from 5 months to 8 months and 1-year OS rates ranging from 17% to 25%
. Many combination regimens have been compared with gemcitabine alone for metastatic pancreatic cancer, but only erlotinib in combination with gemcitabine has been found to significantly boost survival (median OS: 6 months) compared with gemcitabine alone,
. To attain locoregional disease control for patients with advanced pancreatic cancer, selecting effective treatments for liver metastases has become more crucial. Multimodal treatment protocols, including TACE, RFA, and 125
I radioactive seed implantation, have been established for the treatment of metastatic tumors. Because liver metastases are little supplied by the hepatic artery, to date, TACE was developed as a palliative treatment for liver metastasis
. The goal of this study was to evaluate the efficacy of combining TACE with RFA and/or radioactive seed implantation on disease control and survival. Although the results were not significant, we found that patients with oligonodular liver metastases, who were treated with RFA and/or radioactive seed implantation, had longer median survival than did patients without liver metastases and those who did not undergo these treatments. This suggests that RFA and radioactive seed implantation are effective options for obtaining locoregional disease control and survival benefits.
Most pancreatic cancer patients are diagnosed with advanced disease and have a median survival of approximately 6 months
. Late-stage clinical trials have generally failed to demonstrate improvement in outcome or to predict better survival in patients with metastatic pancreatic cancer
. In the current study, the median OS was 11 months. The 1-, 2-, and 3-year OS rates were 32.4%, 9.9%, and 6.6%, respectively. For all stages of pancreatic cancer, the 1-year relative survival rate is 20%
. In our cohort, the 1-year survival rate was 32.4% for all patients and 25.5% for patients with liver metastases. Since patients with oligonodular liver metastases had longer survival than did patients with multinodular liver metastases in this study, we observed that the number of liver metastases had a negative effect on local tumor response. In retrospective studies by Kelley et al
and Moureau-Zabotto et al
, the reported median survival was 8–14 months and the 1-year OS was 32%–62% for patients with locoregionally advanced disease. For metastatic pancreatic cancer patients who underwent chemotherapy, the median OS was 6–7.1 months
, whereas it was 9 months in our study. This result further confirms that RFA and radioactive seed implantation can be used to gain locoregional disease control and better survival benefits than that obtained with chemotherapy only for pancreatic cancer patients with liver metastases.
Our results confirm that oligonodular liver metastases predict longer survival in pancreatic cancer patients with hepatic metastases. However, this finding is inconsistent with results from other published studies
. There are several possible reasons for the disparate results. First, all patients in our study had stage III or stage IV disease and were subjected to different treatment strategies compared with patients enrolled in other studies. Second, we defined 3 as the critical number of liver lesions, whereas other studies set 5 as the critical level
. Third, most of our patients had good performance status at diagnosis [Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1], which predicts better survival
. Finally, in this study, the survival of all patients was calculated from the time of diagnosis other than from the first time of treatment. This criterion may be different from other studies, which may make the median survival of patients with metastases in our study longer than that reported by others.
The clinical predictors of survival in patients with metastatic pancreatic cancer that we identified here should be helpful in improving the design of clinical trials involving pancreatic cancer patients with liver metastases. These predictors can be easily assessed when liver metastasis is diagnosed, and they can be used to more accurately stratify patients into groups with fairly consistent outcomes and thus help to standardize reporting results of any therapeutic interventions with less samples and expense.
However, the retrospective nature and limited sample size of the study perhaps reduce the generalizability of our results. Furthermore, the results are based on a single institution specializing in cancer treatment and may not be generalized well to other institutions, given the different nature of health care delivery.