While there is a lot of data to support the use of NAC, there are two major gaps in its widespread utilization:
- Only 40% of patients have major response to chemotherapy
- NAC is not widely used in most parts of the world
Three different molecular markers to discuss:
- Molecular subtypes
- COXEN model
- Genomic alterations
- Refer to Dr. Lerner’s talk for most recent update on the 5 molecular subtypes – but broadly separated into luminal and basal subtype
- Subtype is associated with response to chemotherapy
o P53 like tumors respond poorly
- Dr. Black worked with Genome Dx to generate a genomic test that could classify a patient sitting in front of you in clinic into 1 of 4 molecular classes
o Luminal tumors do well regardless of NAC
COXEN Model “Coexpression Extrapolation”
- Being developed based on 60 cell lines and their drug response
- Test a patient’s gene expression against the pool of cell line data to determine the best “match”
- Shown an accuracy ~80%
- Currently in a prospective study with SWOG – will finish accrual by the end of the year
- Individual Gene alterations, particularly DNA repair genes
- Will likely gain more recognition as predictors of response
- I.e. ERCC2 gene alterations were found only in patients with chemotherapy response – validated in a second cohort in FCCC
- Mutations in ATM, Rb1, FANC – 3 gene panel
- ERBB2 (Her2)
There is a lot of good work working to help strengthen the risk stratification of patients prior to NAC. By doing so, utilization in appropriate patients may increase and patients that wouldn’t have responded to NAC can go straight to RC or targeted therapy.
Presented by: Peter Black
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, Twitter: @tchandra_uromd at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal