Embracing a Fuller History of the Application of Evolution to Medicine

In a recent blog post (http://evmed.asu.edu/blog/evolutionary-medicine-top-ten-questions), Randy Nesse suggests that the presentations and discussions at the second annual conference of the International Society for Evolution, Medicine, and Public Health (ISEMPH) were

“… instigated 25 years ago as George Williams and I discussed and grappled with how evolution could be useful for medicine, and what to call the enterprise.”

In her chapter (Bentley, 2016) introducing the just published book, “Evolutionary Thinking in Medicine: from Research to Policy and Practice,” the author acknowledges activity that can be considered evolutionary medicine in the years prior to 1991 but confines it to before roughly 1940.  Following the end of World War II, Professor Bentley finds little to no evidence of significant work in the field until the 1990s.  Unfortunately, these claims disregard substantial numbers of evolution-related studies that either influenced fundamental understanding of human health and disease or affected medical practice. (more…)

Evolutionary Determinants of Cancer

Mel Greaves, The Institute of Cancer Research

July 20, 2015, doi: 10.1158/2159-8290.CD-15-0439 Full Text PDF

Abstract

Our understanding of cancer is being transformed by exploring clonal diversity, drug resistance, and causation within an evolutionary framework. The therapeutic resilience of advanced cancer is a consequence of its character as a complex, dynamic, and adaptive ecosystem engendering robustness, underpinned by genetic diversity and epigenetic plasticity. The risk of mutation-driven escape by self-renewing cells is intrinsic to multicellularity but is countered by multiple restraints, facilitating increasing complexity and longevity of species. But our own species has disrupted this historical narrative by rapidly escalating intrinsic risk. Evolutionary principles illuminate these challenges and provide new avenues to explore for more effective control.

Significance: Lifetime risk of cancer now approximates to 50% in Western societies. And, despite many advances, the outcome for patients with disseminated disease remains poor, with drug resistance the norm. An evolutionary perspective may provide a clearer understanding of how cancer clones develop robustness and why, for us as a species, risk is now off the scale. And, perhaps, of what we might best do to achieve more effective control. Cancer Discov; 5(8); 1–15. ©2015 AACR.

Toward an evolutionary model of cancer: Considering the mechanisms that govern the fate of somatic mutations

Andrii I. Rozhok and James DeGregori


PNAS July 21, 2015 vol. 112 no. 298914-8921

Abstract

Our understanding of cancer has greatly advanced since Nordling [Nordling CO (1953) Br J Cancer7(1):68–72] and Armitage and Doll [Armitage P, Doll R (1954) Br J Cancer 8(1):1–12] put forth the multistage model of carcinogenesis. (more…)

Extent of Tumor Evolution as Assessed by Numbers of Nonsynonymous Somatic Mutations Correlates with the Effectiveness of Anti-Checkpoint Therapy

It would be hard to identify an approach to cancer treatment that has received more attention recently than anti-checkpoint therapy (Pollack, 2015).  This strategy for eliminating tumor cells is based on interfering with one or another pathway that inhibits the initial activation or functions of T cells, such as CD8+ cytotoxic T cells (CTL).  Activated tumor-specific CTL can directly kill their targets.  However, if copies of the T-cell surface molecule, PD-1, are bound by their physiological ligands on tumor cells, either PD-L1 or PD-L2, or other cells the ability of the T cell to perform its functions is substantially reduced.  A report published in Science (2015) by Rizvi et al. last month addresses the question of whether tumor mutation burden correlates with response to anti-checkpoint therapy for non-small cell lung cancer (NSCLC).

(more…)

Altered Androgen Receptor Ligand Specificity in Prostate Cancer Cells Treated with an Androgen Biosynthesis Inhibitor

Carcinomas of the prostate are the most common cancers affecting men and a leading cause of male cancer deaths in the United States (CDC web site, Cancer Prevention and Control).  Given the unique association of the prostate with males, it makes sense that prosate carcinoma cells are often dependent for continued growth and proliferation on signaling by the androgen receptor, as andogens are primarily associated with physiological effects critical for male sexual development.  Therefore, therapies aimed at inhibiting either androgen synthesis or androgen receptor function make great sense. In a recent paper by Chen et al. (2014), Steven Balk and colleagues demonstrate that treatment of castration-resistant prostate cancer with a drug (abiraterone) that inhibits the production of androgens can select for mutant androgen receptors (AR) that more effectively recognize and get activated by a non-androgen. (more…)