Abstract 759P
Background
International consensus guidelines recommend adjuvant chemotherapy (Ch) for high-risk muscle-invasive bladder cancer (HR-MIBC) patients (pT3/4 and/or pN +). In this setting, identification of clinical and molecular/genomic predictors of relapse is a medical unmet need towards personalized medicine.
Methods
We conducted a retrospective study to establish how Immunohistochemistry based molecular subtypes (GATA3, FOXA1, KRT5/6, KRT14) (BASQ-like, Luminal-like, mixed) relate to outcome (metastasis-free survival-MFS and disease specific survival-DSS) based to adjuvant platinum-based Ch in patients with HR-MIBC between 2000-2014 at 15 Spanish hospitals. Institutional Review Board approved was mandatory. According to estimated 5-y survival of stage III MIBC, 439 pts were required.
Results
485 pts were registered, 373 pts had an adequate tumor sample and 344 met all selection criteria. Median age (64 y), 85% g3 histology, 86% pathological pure UC, stage IIIa/IIIb 57%/41%, > 1LN + 43%, cis-based Ch 76% and carbo-based Ch 24%. After a median follow-up of 94 months, the mMFS was 22.9 months and mDSS was 47.4 months. Tumor subtype distribution was as follows: BASQ-L (26%), Luminal-L (54%), mixed (20%). Patients with BASQ-L tumors had the lowest relapse rate (p=0.093). TNM, LV invasion and micropapillary histology were strong predictors of outcome. The 5-y MFS rate by subtype were BASQ-like 47.10 %, Luminal-like 36.6 %, mixed 25.8 % and the 5-y DSS rate were: BASQ-L, 59.8%; Luminal-L, 44%; mixed, 40.2%.
Conclusions
In this retrospective study of adjuvant Ch in HR-MIBC, we did not find that Immunohistochemistry-based molecular subtyping provides additional information on patient outcomes (MFS and DSS). However, our findings suggest a benefit of adjuvant Ch in patients with BASQ-L tumors.
Clinical trial identification
Legal entity responsible for the study
The authors.
Funding
Fundacion Cientifica Asociacion Española Contra el Cancer (FAECC).
Disclosure
D. Castellano Gauna: Advisory/Consultancy: Bayer; Advisory/Consultancy: Roche; Advisory/Consultancy: Pfizer; Advisory/Consultancy: Ipsen; Advisory/Consultancy: Astellas; Advisory/Consultancy: Janssen; Advisory/Consultancy: MSD. E. Grande: Advisory/Consultancy: Roche; Advisory/Consultancy: Pfizer; Advisory/Consultancy: Astellas; Advisory/Consultancy: Janssen; Advisory/Consultancy: MSD; Advisory/Consultancy: Eisai; Advisory/Consultancy: Novartis; Advisory/Consultancy: Ipsen. M.A. Climent Duran: Advisory/Consultancy: Roche; Advisory/Consultancy: Astellas; Advisory/Consultancy: Janssen; Advisory/Consultancy: MSD; Advisory/Consultancy: Pfizer. N. Lainez: Advisory/Consultancy: Pfizer; Advisory/Consultancy: Astellas; Advisory/Consultancy: Sanofi; Advisory/Consultancy: Ipsen; Advisory/Consultancy: Roche. I. Duran: Advisory/Consultancy: Astellas; Advisory/Consultancy: Janssen; Advisory/Consultancy: MSD; Advisory/Consultancy: Pfizer; Advisory/Consultancy: Roche; Advisory/Consultancy: Ipsen; Advisory/Consultancy: AstraZeneca. S. Vazquez Estevez: Advisory/Consultancy: Janssen; Advisory/Consultancy: Roche; Advisory/Consultancy: Astellas; Advisory/Consultancy: Ipsen. B. Mellado Gonzalez: Advisory/Consultancy: Roche; Advisory/Consultancy: Astellas; Advisory/Consultancy: Bayer; Advisory/Consultancy: Janssen; Advisory/Consultancy: MSD. M. Lázaro Quintela: Advisory/Consultancy: Pfizer; Advisory/Consultancy: Ipsen; Advisory/Consultancy: Janssen; Advisory/Consultancy: Astellas. E. Gonzalez Billalabeitia: Advisory/Consultancy: Astellas; Advisory/Consultancy: Janssen; Advisory/Consultancy: Bayer; Advisory/Consultancy: AstraZeneca; Advisory/Consultancy: Roche. A. Font: Advisory/Consultancy: Roche; Advisory/Consultancy: Astellas; Advisory/Consultancy: Janssen; Advisory/Consultancy: MSD; Advisory/Consultancy: Bayer. All other authors have declared no conflicts of interest.