“…In line with this, across the extracted observational studies, 22 described the line of treatment as only 'palliative', and therefore these reports are discussed separately from studies designating a line of therapy. Of these reports, half included therapies other than systemic chemotherapy (n = 11), eight palliative systemic chemotherapy (without specifying line of therapy, including gem-based chemotherapies [n = 1], GEMCIS [n = 1], mixed systemic chemotherapies [n = 3], mixed systemic chemotherapies as well as nonactive treatment [n = 3]) and six mixed treatments [57,65,[84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102]. In line with BTC treatment guidelines, non-active treatments (including stenting and biliary drainage) were reported in eight studies [57,85,86,88,93,100,102,103].…”