Do evolutionary life-history trade-offs influence prostate cancer risk? a review of population variation in testosterone levels and prostate cancer disparities

Survival of veterans treated with enzalutamide and abiraterone for metastatic castrate resistant prostate cancer based on comorbid diseases

BACKGROUND

Comorbid diseases influence patient outcomes, yet little is known about how comorbidities interact with treatments for metastatic castrate-resistant prostate cancer (mCRPC). No head-to-head trials have compared the efficacy of abiraterone and enzalutamide - oral androgen-receptor targeted agents (ARTAs) for mCRPC. In patients with comorbid disease, outcomes with ARTAs may differ due to disparate mechanisms of action, adverse events, and drug interactions.

METHODS

Retrospective observational study of US veterans initiating treatment for mCRPC with abiraterone or enzalutamide between September 2014 and June 2017. Treatment duration and overall survival (OS) was compared based on age and comorbid diseases. The association between ARTA and OS was assessed using Cox proportional hazards and propensity-score matched modeling while adjusting for potential confounders. Sensitivity analyses were performed based on patient age, comorbidities, and subsequent treatments for mCRPC.

RESULTS

Of 5822 veterans treated for mCRPC, 43.0% initially received enzalutamide and 57.0% abiraterone. Veterans initially treated with enzalutamide versus abiraterone were older (mean 75.8 vs. 75.0 years) with higher mean Charlson comorbidity index (4.4 vs. 4.1), and higher rates of cardiovascular disease or diabetes (74.2% vs. 70.6%). In the entire population, veterans initially treated with enzalutamide had longer median OS compared to those initially treated with abiraterone (24.2 vs. 22.1 months, p = 0.001). In veterans with cardiovascular disease or diabetes, median treatment duration with enzalutamide was longer (11.4 vs. 8.6 months, p < 0.001) with longer median OS compared to abiraterone (23.2 vs. 20.5 months, p < 0.001). In a propensity score matched cohort, enzalutamide was associated with decreased mortality compared to abiraterone (HR 0.90, 95% CI 0.84-0.96).

CONCLUSIONS

Veterans with cardiovascular disease or diabetes had longer treatment duration and OS with enzalutamide compared to abiraterone. Further study of ARTA selection may benefit men with metastatic castrate resistant prostate cancer and likely hormone sensitive prostate cancer, especially among patients with comorbid diseases.

Evidence for an adolescent sensitive period to family experiences influencing adult male testosterone production

SignificanceTestosterone influences how animals devote energy and time toward reproduction, including opposing demands of mating and competition versus parenting. Reflecting this, testosterone often declines in new fathers and lower testosterone is linked to greater caregiving. Given these roles, there is strong interest in factors that affect testosterone, including early-life experiences. In this multidecade study, Filipino sons whose fathers were present and involved with raising them when they were adolescents had lower testosterone when they later became fathers, compared to sons whose fathers were present but uninvolved or were not coresident. Sons' own parenting behaviors did not explain these patterns. These results connect key social experiences during adolescence to adult testosterone, and point to possible intergenerational effects of parenting style.

Cancer Susceptibility as a Cost of Reproduction and Contributor to Life History Evolution

Reproduction is one of the most energetically demanding life-history stages. As a result, breeding individuals often experience trade-offs, where energy is diverted away from maintenance (cell repair, immune function) toward reproduction. While it is increasingly acknowledged that oncogenic processes are omnipresent, evolving and opportunistic entities in the bodies of metazoans, the associations among reproductive activities, energy expenditure, and the dynamics of malignant cells have rarely been studied. Here, we review the diverse ways in which age-specific reproductive performance (e.g., reproductive aging patterns) and cancer risks throughout the life course may be linked via trade-offs or other mechanisms, as well as discuss situations where trade-offs may not exist. We argue that the interactions between host–oncogenic processes should play a significant role in life-history theory, and suggest some avenues for future research.

Insights from evolutionarily relevant models for human ageing

As the world confronts the health challenges of an ageing population, there has been dramatically increased interest in the science of ageing. This research has overwhelmingly focused on age-related disease, particularly in industrialized human populations and short-lived laboratory animal models. However, it has become clear that humans and long-lived primates age differently than many typical model organisms, and that many of the diseases causing death and disability in the developed world are greatly exacerbated by modern lifestyles. As such, research on how the human ageing process evolved is vital to understanding the origins of prolonged human lifespan and factors increasing vulnerability to degenerative disease. In this issue, we highlight emerging comparative research on primates, highlighting the physical, physiological, behavioural and cognitive processes of ageing. This work comprises data and theory on non-human primates, as well as under-represented data on humans living in small-scale societies, which help elucidate how environment shapes senescence. Component papers address (i) the critical processes that comprise senescence in long-lived primates; (ii) the social, ecological or individual characteristics that predict variation in the pace of ageing; and (iii) the complicated relationship between ageing trajectories and disease outcomes. Collectively, this work provides essential comparative, evolutionary data on ageing and demonstrates its unique potential to inform our understanding of the human ageing process. This article is part of the theme issue 'Evolution of the primate ageing process'.

WEIRD bodies: mismatch, medicine and missing diversity

Despite recent rapid advances in medical knowledge that have improved survival, conventional medical science's understanding of human health and disease relies heavily on people of European descent living in contemporary urban industrialized environments. Given that modern conditions in high-income countries differ widely in terms of lifestyle and exposures compared to those experienced by billions of people and all our ancestors over several hundred thousand years, this narrow approach to the human body and health is very limiting. We argue that preventing and treating chronic diseases of aging and other mismatch diseases will require both expanding study design to sample diverse populations and contexts, and fully incorporating evolutionary perspectives. In this paper, we first assess the extent of biased representation of industrialized populations in high profile, international biomedical journals, then compare patterns of morbidity and health across world regions. We also compare demographic rates and the force of selection between subsistence and industrialized populations to reflect on the changes in how selection operates on fertility and survivorship across the lifespan. We argue that, contrary to simplistic misguided solutions like the PaleoDiet, the hypothesis of evolutionary mismatch needs critical consideration of population history, evolutionary biology and evolved reaction norms to prevent and treat diseases. We highlight the critical value of broader sampling by considering the effects of three key exposures that have radically changed over the past century in many parts of the world-pathogen burden, reproductive effort and physical activity-on autoimmune, cardiometabolic and other mismatch diseases.

Mating induces switch from hormone-dependent to hormone-independent steroid receptor-mediated growth in Drosophila secondary cells

Male reproductive glands like the mammalian prostate and the paired Drosophila melanogaster accessory glands secrete seminal fluid components that enhance fecundity. In humans, the prostate, stimulated by environmentally regulated endocrine and local androgens, grows throughout adult life. We previously showed that in fly accessory glands, secondary cells (SCs) and their nuclei also grow in adults, a process enhanced by mating and controlled by bone morphogenetic protein (BMP) signalling. Here, we demonstrate that BMP-mediated SC growth is dependent on the receptor for the developmental steroid ecdysone, whose concentration is reported to reflect sociosexual experience in adults. BMP signalling appears to regulate ecdysone receptor (EcR) levels via one or more mechanisms involving the EcR's N terminus or the RNA sequence that encodes it. Nuclear growth in virgin males is dependent on ecdysone, some of which is synthesised in SCs. However, mating induces additional BMP-mediated nuclear growth via a cell type-specific form of hormone-independent EcR signalling, which drives genome endoreplication in a subset of adult SCs. Switching to hormone-independent endoreplication after mating allows growth and secretion to be hyperactivated independently of ecdysone levels in SCs, permitting more rapid replenishment of the accessory gland luminal contents. Our data suggest mechanistic parallels between this physiological, behaviour-induced signalling switch and altered pathological signalling associated with prostate cancer progression.

Cancer: A disease at the crossroads of trade-offs

Central to evolutionary theory is the idea that living organisms face phenotypic and/or genetic trade-offs when allocating resources to competing life-history demands, such as growth, survival, and reproduction. These trade-offs are increasingly considered to be crucial to further our understanding of cancer. First, evidences suggest that neoplastic cells, as any living entities subject to natural selection, are governed by trade-offs such as between survival and proliferation. Second, selection might also have shaped trade-offs at the organismal level, especially regarding protective mechanisms against cancer. Cancer can also emerge as a consequence of additional trade-offs in organisms (e.g., eco-immunological trade-offs). Here, we review the wide range of trade-offs that occur at different scales and their relevance for understanding cancer dynamics. We also discuss how acknowledging these phenomena, in light of human evolutionary history, may suggest new guidelines for preventive and therapeutic strategies.

Adiposity, CVD risk factors and testosterone: Variation by partnering status and residence with children in US men

Background and objectives: In many settings, partnered, invested fathers have lower testosterone than single men or fathers who are not involved in caregiving. Reduced testosterone has been identified as a risk factor for multiple chronic diseases, and men's health also commonly varies by life history status. There have been few tests of whether variation in testosterone based on partnering and parenting has implications for men's health. Methodology: We analysed data from a US population-representative sample (NHANES) of young-to-middle aged US men (n = 875; mean age: 29.8 years ± 6.0 [SD]). We tested for life history status differences in testosterone, adiposity levels and biomarkers of cardiovascular disease (CVD)-risk (HDL cholesterol; triglycerides; white blood cell count [WBC]). Results: Partnered men residing with children (RC) had lower testosterone and elevated abdominal adiposity compared to never married men not residing with children. While they did not significantly differ for WBC or triglycerides, partnered RC men also had comparatively lower HDL. Partnered RC males' lower testosterone accounted for their relatively elevated adiposity, but testosterone, adiposity, and health-related covariates did not explain their relatively reduced HDL. Conclusions and implications: Our results linking life history status-based differences in testosterone and adiposity, alongside our complementary HDL findings, indicate that testosterone-related psychobiology might have implications for partnered RC men's CVD risk in the US and other similar societal settings. These types of socially contextualized observations of men's health and physiological function particularly merit incorporation in clinical discussions of fatherhood as a component of men's health.

Cancer susceptibility and reproductive trade-offs: a model of the evolution of cancer defences

The factors influencing cancer susceptibility and why it varies across species are major open questions in the field of cancer biology. One underexplored source of variation in cancer susceptibility may arise from trade-offs between reproductive competitiveness (e.g. sexually selected traits, earlier reproduction and higher fertility) and cancer defence. We build a model that contrasts the probabilistic onset of cancer with other, extrinsic causes of mortality and use it to predict that intense reproductive competition will lower cancer defences and increase cancer incidence. We explore the trade-off between cancer defences and intraspecific competition across different extrinsic mortality conditions and different levels of trade-off intensity, and find the largest effect of competition on cancer in species where low extrinsic mortality combines with strong trade-offs. In such species, selection to delay cancer and selection to outcompete conspecifics are both strong, and the latter conflicts with the former. We discuss evidence for the assumed trade-off between reproductive competitiveness and cancer susceptibility. Sexually selected traits such as ornaments or large body size require high levels of cell proliferation and appear to be associated with greater cancer susceptibility. Similar associations exist for female traits such as continuous egg-laying in domestic hens and earlier reproductive maturity. Trade-offs between reproduction and cancer defences may be instantiated by a variety of mechanisms, including higher levels of growth factors and hormones, less efficient cell-cycle control and less DNA repair, or simply a larger number of cell divisions (relevant when reproductive success requires large body size or rapid reproductive cycles). These mechanisms can affect intra- and interspecific variation in cancer susceptibility arising from rapid cell proliferation during reproductive maturation, intrasexual competition and reproduction.

Adversity, Adaptive Calibration, and Health: The Case of Disadvantaged Families

Epidemiologists and medical researchers often employ an allostatic load model that focuses on environmental and lifestyle factors, together with biological vulnerabilities, to explain the deterioration of human physiological systems and chronic degenerative disease. Although this perspective has informed medicine and public health, it is agnostic toward the functional significance of pathophysiology and health deterioration. Drawing on Life History (LH) theory, the current paper reviews the literature on disadvantaged families to serve as a conceptual model of stress-health relationships in which the allocation of reproductive effort is instantiated in the LH strategies of individuals and reflects the bioenergetic and material resource tradeoffs. We propose that researchers interested in health disparities reframe chronic degenerative diseases as outcomes resulting from strategic calibration of physiological systems to best adapt, survive, and reproduce in response to demands of specific developmental contexts. These effects of adversity on later-age degenerative disease are mediated, in part, by socioemotional and cognitive mechanisms expressed in different life history strategies.

The Paternal Provisioning Hypothesis: effects of workload and testosterone production on men's musculature

OBJECTIVES

Testosterone supports male reproduction through a broad range of behavioral and physiological effects, including the maintenance of sexually dimorphic muscle used in male-male competition. Although it is often assumed that a persistent relationship exists between men's testosterone production and musculature, most studies either fail to find evidence for such a relationship, or document very weak associations. In nonhuman primates, by contrast, correlations between testosterone and muscle mass are higher. Here, we propose the "Paternal Provisioning Hypothesis," which predicts that men's skeletal muscle is less dependent on the effects of androgens than that of other primates, and more sensitive to the physical demands of men's work. This permits human fathers to downregulate testosterone, which has negative impacts on pair-bonding and parenting effort, but without sacrificing the strength and musculature necessary to provision mates and offspring.

METHODS

We tested predictions of the Paternal Provisioning Hypothesis by assessing parental status, salivary testosterone levels, anthropometry, and strength among 122 men (ages 18-78) at the Mogielica Human Ecology Study Site in rural Poland. We chose this population because men practice subsistence agriculture, regularly engaging in physically demanding labor. Grip and chest strength were assessed using a dynamometer, and upper-body musculature was estimated from arm muscle circumference.

RESULTS

In this population, testosterone showed no association with measures of strength or musculature, and was lower in older men and pair-bonded fathers. Marital and parental status and workload, by contrast, were positive predictors of muscle mass and strength measures.

DISCUSSION

These findings offer support for the Paternal Provisioning Hypothesis.

Adolescent testosterone, muscle mass and glucose metabolism: evidence from the 'Children of 1997' birth cohort in Hong Kong

AIMS

Diabetes rates are high in Asia despite relatively low rates of obesity, which might be related to lower muscle mass. Muscle mass plays an important role in glucose metabolism. Peak muscle mass is obtained in late adolescence. We tested the hypothesis that pubertal testosterone is negatively associated with glucose metabolism mediated by muscle mass.

METHODS

Participants aged 15 years (278 boys and 223 girls) were recruited from the Hong Kong's 'Children of 1997' birth cohort in 2012. Multivariable linear regression with multiple imputation and inverse probability weighting was used to examine the adjusted associations of pubertal testosterone with skeletal muscle index, body fat percentage, fasting glucose, insulin and homeostasis model of assessment - insulin resistance.

RESULTS

Total testosterone was negatively associated with fasting glucose (-0.008, 95% confidence interval -0.015 to -0.002), insulin (-0.43, 95% confidence interval -0.56 to -0.30) and insulin and homeostasis model of assessment - insulin resistance (-0.09, 95% confidence interval -0.12 to -0.06) adjusted for sex, birth weight, highest parental education, mother's place of birth and physical activity. These associations were attenuated by additional adjustment for skeletal mass index or body fat percentage.

CONCLUSIONS

Adolescent glucose metabolism may be influenced by testosterone, perhaps partially via skeletal muscle mass.

Modern reproductive patterns associated with estrogen receptor positive but not negative breast cancer susceptibility

It has long been accepted that modern reproductive patterns are likely contributors to breast cancer susceptibility because of their influence on hormones such as estrogen and the importance of these hormones in breast cancer. We conducted a meta-analysis to assess whether this ‘evolutionary mismatch hypothesis’ can explain susceptibility to both estrogen receptor positive (ER-positive) and estrogen receptor negative (ER-negative) cancer. Our meta-analysis includes a total of 33 studies and examines parity, age of first birth and age of menarche broken down by estrogen receptor status. We found that modern reproductive patterns are more closely linked to ER-positive than ER-negative breast cancer. Thus, the evolutionary mismatch hypothesis for breast cancer can account for ER-positive breast cancer susceptibility but not ER-negative breast cancer.

Testosterone concentrations in young healthy US versus Chinese men

BACKGROUND

Previous small studies examining differences in testosterone concentrations by ethnicity found mixed results for Caucasians and Chinese men, which might be confounded by age differences and living standards. The aim of the present study is to examine the differences in total, free, and bioavailable testosterone concentrations between healthy young men from the United States (US) and from the most economically developed part of China, i.e., Hong Kong (HK).

METHODS

Cross-sectional analysis based on 365 young men from the Third National Health and Nutrition examination Survey (NHANES III) in the US and 299 Chinese men recruited from university students. All participants were aged from 18 to 29 years. Main outcome measures were total testosterone (TT) and calculated bioavailable testosterone (Bio T) and free testosterone (FT).

RESULTS

In both US and Chinese men, TT, FT, and Bio T concentration peaked at 20-24 years of age, at 23.19, 0.49, and 12.23 nmol/l in US men, and 20.72, 0.48 and 12.59 nmol/l in Chinese men, respectively. Among those aged 18-24 years, after adjusting for age, US men had higher TT (mean, 95% confidence interval: 21.64, 21.31-21.99 versus 20.20, 20.12-20.28 nmol/l), but not FT (0.47, 0.47-0.48 versus 0.47, 0.47-0.47 nmol/l) or Bio T (11.90, 11.83-11.97 versus 12.39, 12.35-12.42 nmol/l) than Chinese men.

CONCLUSIONS

TT, but not FT or Bio T concentrations are lower in young healthy Chinese men than US men. These differences apparent in young men may be important in understanding different patterns of diseases between Western and Asian populations.