Although surgical treatment is the only treatment for cholangiocarcinoma, most patients are diagnosed at a metastatic or locally advanced stage, and palliative chemotherapy is the main treatment method for this group of patients.~Recently, with the introduction of gemcitabine, cisplatin, and nab-paclitaxel combination chemotherapy for locally advanced cholangiocarcinoma, the treatment response rate is improving, and the number of cases of downgrade to an operable state is increasing.~However, there are no prospective studies confirming the rate of conversion surgery after gemcitabine, cisplatin, and Nab-paclitaxel combination therapy in locally advanced cholangiocarcinoma. As a result of long-term follow-up, more than 30% of patients relapsed, so it is urgent to develop predictive biomarkers before surgery.~There are reports that tumor DNA (ctDNA) accurately predicts recurrence after surgical treatment. Using blood samples that are relatively easy to collect compared to biopsies, it is possible to quantitatively measure tumor burden and to evaluate the effectiveness of systemic treatments such as chemotherapy. It is a very popular tool for measuring and predicting the success of surgical treatment in advanced solid cancer.~The purpose of this study was to determine the rate of conversion surgery after treatment with Gemcitabine, Cisplatin, and Nab-paclitaxel in patients with inoperable locally advanced cholangiocarcinoma through an observational study. In addition, the purpose of this study is to verify the performance of biomarkers in predicting recurrence and survival after ctDNA and RNA conversion surgery in a situation where there is no clinical strategy to select a group of patients who can try radical resection.
The objective of this observational study is to identify patients with locally advanced cholangiocarcinoma treated with nab-paclitaxel and gemcitabine-cisplatin chemotherapy.~In this clinical study, peripheral blood and tumor tissues will be analyzed at baseline and every 3 cycles after systemic drug treatment in patients with locally advanced cholangiocarcinoma, and correlation with treatment was analyzed. This is an exploratory study to discover biomarkers that are highly correlated with treatment response.