Marion - If you mean there are no large (phase 3) randomized studies reflecting survival benefit derived from post resection adjuvant therapy, I agree with that.
However, there are small retrospective studies, based on small to large populations, that show there is a benefit. There are others that also say there is no benefit. Maybe others even show a negative impact.
Just glancing at some of the papers on my desk:
1. Murakami, "Gemcitabine-based adjuvant chemotherapy improves survival after aggressive surgery for hilar cholangiocarcinoma,", 2009, 42 patients, "Five-year actuarial survival rates of patients who did or did not receive adjuvant gemcitabine-based chemotherapy were 57% and 23%, respectively (P=0.026)."
2. Shinohara, "Radiotherpy is associated with improved survival in adjuvant and palliative treatment of extrahepatic cholangiocarcinomas", 2009, 4,758 patients, "The median overall survival time was 16 months for surgery and RT and 9 months for surgery alone.
3. Nakeeb, "Radiation therapy, chemotherapy and chemoradiation in hilar cholagiocarcinoma", 2005, "A carefully controlled trial from the John Hopkins Hospital did not demonstrate any benefit for adjuvant radiation therapy. A number of phase II trials of chemotherapy have demonstrated modest response rates (20-40%)...... Neither radiation therapy nor chemotherapy alone has been proven to prolong survival in completely or partially resected patients or in unresected patients."
4. Cereda, "Adjuvant treatment in biliary tract cancer: To treat or not to treat?", 2011, "A retrospective series of 73 patients with gallbladder cancer treated between 1985 and 2004 at Mayo Clinic suggested that adjuvant CRT may obtain a statistically significant improvement in OS only for patients with lymph node involvement ..... A more recent phase III trial exploring the role of single agent adjuvant chemotherapy with either gemcitabine or 5-fluorouracil, in 304 patients with ampullary adenocarcinoma submitted to curative resection did not demonstrate a survival benefit for any of the adjuvant therapy arms when compared to surgery alone."
And there are many more. I should look at all this in detail and try and figure out why the results vary so much.