@article {FRITZ1585, author = {PETER FRITZ and J{\"U}RGEN DIPPON and SIMON M{\"U}LLER and SVEN GOLETZ and CHRISTIAN TRAUTMANN and XENOPHON PAPPAS and GERMAN OTT and HILTRUD BRAUCH and MATTHIAS SCHWAB and STEFAN WINTER and THOMAS M{\"U}RDTER and FRIEDHELM BRINKMANN and SIMONE FAISST and SUSANNE R{\"O}SSLE and ANDREAS GERTEIS and GODEHARD FRIEDEL}, title = {Is Mistletoe Treatment Beneficial in Invasive Breast Cancer? A New Approach to an Unresolved Problem}, volume = {38}, number = {3}, pages = {1585--1593}, year = {2018}, publisher = {International Institute of Anticancer Research}, abstract = {Background/Aim: In this retrospective study, we compared breast cancer patients treated with and without mistletoe lectin I (ML-I) in addition to standard breast cancer treatment in order to determine a possible effect of this complementary treatment. Patients and Methods: This study included 18,528 patients with invasive breast cancer. Data on additional ML-I treatments were reported for 164 patients. We developed a {\textquotedblleft}similar case{\textquotedblright} method with a distance measure retrieved from the beta variable in Cox regression to compare these patients, after stage adjustment, with their non-ML-1 treated counterparts in order to answer three hypotheses concerning overall survival, recurrence free survival and life quality. Results: Raw data analysis of an additional ML-I treatment yielded a worse outcome (p=0.02) for patients with ML treatment, possibly due to a bias inherent in the ML-I-treated patients. Using the {\textquotedblleft}similar case{\textquotedblright} method (a case-based reasoning approach) we could not confirm this harm for patients using ML-I. Analysis of life quality data did not demonstrate reliable differences between patients treated with ML-I treatment and those without proven ML-I treatment. Conclusion: Based on a {\textquotedblleft}similar case{\textquotedblright} model we did not observe any differences in the overall survival (OS), recurrence-free survival (RFS), and quality of life data between breast cancer patients with standard treatment and those who in addition to standard treatment received ML-I treatment.}, issn = {0250-7005}, URL = {https://ar.iiarjournals.org/content/38/3/1585}, eprint = {https://ar.iiarjournals.org/content/38/3/1585.full.pdf}, journal = {Anticancer Research} }