Why might variations in treatment response due to tumor heterogeneity complicate cancer care?

Variations in treatment response due to tumor heterogeneity can lead to inconsistencies in treatment effectiveness because tumors within the same patient can have different cellular compositions and characteristics. This variability means that a particular treatment that is effective on one part of the tumor may not be effective on another part. As a result, patients may experience varying outcomes from the same treatment regimen, which complicates the selection of the most appropriate therapy. Understanding and addressing this heterogeneity is critical in providing personalized medicine, as it allows healthcare providers to tailor treatments to the specific characteristics of each patient's tumor, potentially improving overall treatment success rates.