Certainly it makes sense to consider genetic profile in treatment, but doesn't the statement "that drug should be used regardless of whether you have breast can

Certainly it makes sense to consider genetic profile in treatment, but doesn't the statement "that drug should be used regardless of whether you have breast cancer or lung cancer" ignore the local tumor microenvironment and possible differences in drug resistance expression between cell types, i.e., isn't reducing cancer down to genetic profile alone potentially as problematic as reducing cancer down to its tissue of origin?