Cancer tumors exhibit an accumulation of mutations in DNA (something distinct from inheriting a mutation that increases one’s likelihood of getting a given type of cancer [previous post]). This results in tumors having particular genetic profiles in different people even if the people are diagnosed as having the “same” cancer. Sometimes the effectiveness of a treatment can be predicted according to the genetic profile of the tumor. Clinical researchers are gathering data in the hope of classifying the genetic profiles into groups in relationship to their response to available treatment options.
1. The genetic profile of a tumor changes as the disease progresses.
2. The heterogeneity of the genetic profiles of tumors might not allow clear grouping or not into groups related to response to available treatment options. (Consider, as relevant analogies: a. genetic heterogeneity in single-locus diseases, such as PKU; and b. the difficulty that “genomic studies have had… identifying causally relevant genetic variants behind variation in human traits… Even when many genetic variants are examined together, only a small fraction of the variation in the trait is associated with—or in statistical terms, “accounted for” by—the genetic variants [Taylor 2014, 124].)
3. Customized treatment, although described as personalized cancer therapy, “involve[s…] people [being] treated according to their group membership. Moreover, this phase may not be a passing one (Taylor 2014, 135ff; see previous post).
Taylor, Peter J. (2014) Nature-Nurture? No: Moving the Sciences of Variation and Heredity Beyond the Gaps.
(Introduction to this series of posts)