% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Holch:300251, author = {J. W. Holch$^*$ and A. J. Ohnmacht and S. Stintzing$^*$ and K. Heinrich$^*$ and A.-L. Weiss$^*$ and V. Probst$^*$ and A. Stahler$^*$ and L. Fischer von Weikersthal and T. Decker and A. Kiani and F. Kaiser and T. Heintges and C. Kahl and F. Kullmann and H. Link and H.-G. Höffkes and M. Moehler and D. P. Modest and M. P. Menden and V. Heinemann}, title = {{FOLFIRI} with cetuximab or bevacizumab in {RAS} wild-type metastatic colorectal cancer: {R}efining first-line treatment selection by combining clinical parameters: {A} post hoc analysis of the randomized open-label phase {III} trial {FIRE}-3/{AIO} {KRK}0306.}, journal = {European journal of cancer}, volume = {220}, issn = {0959-8049}, address = {Amsterdam [u.a.]}, publisher = {Elsevier}, reportid = {DKFZ-2025-00712}, pages = {115388}, year = {2025}, abstract = {Primary tumor sidedness (PTS) with discrimination of left-sided (LC) and right-sided tumors (RC) guides patient selection for targeted first-line therapy in RAS wild-type (RAS-WT) metastatic colorectal cancer (mCRC). This study assessed the hypothesis whether considering PTS with additional clinical parameters better predicts the treatment benefit of targeted first-line treatment.In FIRE-3, first-line treatment with folinic acid, fluorouracil and irinotecan (FOLFIRI) plus cetuximab (FOLFIRI/Cet) was compared to FOLFIRI plus bevacizumab (FOLFIRI/Bev) in patients with RAS-WT mCRC and unresectable metastasis. We evaluated whether combining PTS with number of metastatic sites (NOM), liver-limited disease status (LLD), age, sex, or carcinoembryonic antigen level (CEA) better predicts treatment benefit regarding overall survival (OS). Here, Cox regression models with second-order interactions were applied. Further, the results were validated by policy learning and Lasso regression analysis.Among 400 RAS-WT mCRC patients, combining PTS with LLD status in a Cox regression model outperformed PTS alone for predicted treatment benefit (P = 0·005; c‑index=0·603). Significant OS benefit from FOLFIRI/Cet over FOLFIRI/Bev was observed in LC/non-LLD patients (HR=0·62; 95 $\%-confidence$ interval [CI]=0·46-0·82; P = 0·002), but mitigated in LC/LLD patients (HR=0·83; 95 $\%-CI=0·53-1·29;$ P = 0·400). In RC/non-LLD patients, FOLFIRI/Bev demonstrated a significant OS advantage over FOLFIRI/Cet (HR=2·09; 95 $\%‑CI=1·20-3·63;$ P = 0·010). However, RC/LLD patients showed potential benefit from FOLFIRI/Cet, though not statistically significant (HR=0·59; 95 $\%-CI=0·25-1·39;$ P = 0·218).Incorporating PTS and LLD status might improve selection of targeted first-line treatment in RAS-WT mCRC patients. FOLFIRI/Cet appears to be particularly beneficial for LC/non-LLD patients with mitigated benefit in patients with LC/LLD. In contrast, FOLFIRI/Bev is significantly favoured over FOLFIRI/Cet in patients with RC/non-LLD. Notably, RC/LLD patients may still benefit from anti-EGFR therapy despite right-sided primary tumor. These results are hypothesis-generating and warrant further validation.}, keywords = {Bevacizumab (Other) / Biomarker combination (Other) / Cetuximab (Other) / Comprehensive statistical modeling (Other) / FOLFIRI (Other) / Liver-limited disease (Other) / Metastatic colorectal cancer (Other) / Metastatic pattern (Other) / Predictive biomarker (Other) / Primary tumor sidedness (Other)}, cin = {MU01 / BE01}, ddc = {610}, cid = {I:(DE-He78)MU01-20160331 / I:(DE-He78)BE01-20160331}, pnm = {899 - ohne Topic (POF4-899)}, pid = {G:(DE-HGF)POF4-899}, typ = {PUB:(DE-HGF)16}, pubmed = {pmid:40179821}, doi = {10.1016/j.ejca.2025.115388}, url = {https://inrepo02.dkfz.de/record/300251}, }