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Cancer is pervasive across multicellular species, but what explains the differences in cancer prevalence across species? Using 16,049 necropsy records for 292 species spanning three clades of tetrapods (amphibians, sauropsids, and mammals), we found that neoplasia and malignancy prevalence increases with adult mass (contrary to Peto's paradox) and somatic mutation rate but decreases with gestation time. The relationship between adult mass and malignancy prevalence was only apparent when we controlled for gestation time. Evolution of cancer susceptibility appears to have undergone sudden shifts followed by stabilizing selection. Outliers for neoplasia prevalence include the common porpoise (<1.3%), the Rodrigues fruit bat (<1.6%), the black-footed penguin (<0.4%), ferrets (63%), and opossums (35%). Discovering why some species have particularly high or low levels of cancer may lead to a better understanding of cancer syndromes and novel strategies for the management and prevention of cancer. Significance: Evolution has discovered mechanisms for suppressing cancer in a wide variety of species. By analyzing veterinary necropsy records, we can identify species with exceptionally high or low cancer prevalence. Discovering the mechanisms of cancer susceptibility and resistance may help improve cancer prevention and explain cancer syndromes., (©2024 The Authors; Published by the American Association for Cancer Research.)

Cancer, one of the leading causes of death worldwide, is a disease characterized by uncontrolled cell growth within the body. While there have been many improvements in the treatment of cancer clinically, there is now an urgent need to improve cancer-related communication. This study explores the impact of online health information, specifically cancer-related information and prevention, among members of the general public. Through a randomized survey, we examined what information leads people to take action to minimize their cancer risk and communicate with their providers. Through evaluation of the various modes of communication, we were able to provide insight into which are more effective and better received by members of the general public. Through this, ways of bettering these avenues of communication and strengthening the bond between them will be highlighted and more easily elaborated on by future studies. The results of our study indicated that 60% of participants asserted that they are motivated by online preventive information to take steps to limit their cancer risk, while only roughly 44% of participants overall agreed that their doctor has communicated with them about when proper cancer screenings should be scheduled for the future. Although patients may be turning to the Internet now more than ever due to various reasons, when comparing self-reported rates of comprehension among the study participants, 35% agreed that the cancer-related information they can access online is confusing, while fewer than 22% of participants agreed that the cancer-related information they receive directly from their doctor is confusing. This is indicative of the limitations the Internet may have when undertaking the role of being a medical resource, especially when acting as a replacement for in-person medical appointments where patients can communicate directly with their physicians. Ultimately, these results provide a unique perspective into how people receive, evaluate, and implement cancer-preventive steps and general health-related information in a post-COVID-19 world, where the Internet is now strongly embedded in healthcare.

Background and Objectives: Cancer develops across nearly every species. However, cancer occurs at unexpected and widely different rates throughout the animal kingdom. The reason for this variation in cancer susceptibility remains an area of intense investigation. Cancer evolves in part through the accumulation of mutations, and therefore, we hypothesized that germline mutation rates would be associated with cancer prevalence and mortality across species., Methodology: We collected previously published data on germline mutation rate and cancer mortality data for 37 vertebrate species., Results: Germline mutation rate was positively correlated with cancer mortality (P-value = 0.0008; R2 = 0.13). Controlling for species' average parental age, maximum longevity, adult body mass or domestication did not improve the model fit (the change (Δ) in Akaike Information Criterion (AIC) was less than 2). However, this model fit was better than a model controlling for species trophic level (ΔAIC > 2)., Conclusions and Implications: The increased death rate from cancer in animals with increased germline mutation rates may suggest underlying hereditary cancer predisposition syndromes similar to those diagnosed in human patients. Species with higher germline mutation rates may benefit from close monitoring for tumors due to increased genetic risk for cancer development. Early diagnoses of cancer in these species may increase their chances of overall survival, especially for threatened and endangered species., Competing Interests: J.D.S. is a co-founder and shareholder employed by Peel Therapeutics, Inc., and L.M.A. is a shareholder and consultant to Peel Therapeutics, Inc., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.)

Background and Objectives: Cancer is a disease that affects nearly all multicellular life, including the broad and diverse taxa of Aves. While little is known about the factors that contribute to cancer risk across Aves, life history trade-offs may explain some of this variability in cancer prevalence. We predict birds with high investment in reproduction may have a higher likelihood of developing cancer. In this study, we tested whether life history traits are associated with cancer prevalence in 108 species of birds., Methodology: We obtained life history data from published databases and cancer data from 5,729 necropsies from 108 species of birds across 24 taxonomic orders from 25 different zoological facilities. We performed phylogenetically controlled regression analyses between adult body mass, lifespan, incubation length, clutch size, sexually dimorphic traits, and both neoplasia and malignancy prevalence. We also compared the neoplasia and malignancy prevalence of female and male birds., Results: Providing support for a life history trade-off between somatic maintenance and reproduction, we found a positive relationship between clutch size and cancer prevalence across Aves. There was no significant association with body mass, lifespan, incubation length, sexual dimorphism, and cancer., Conclusions and Implications: Life history theory presents an important framework for understanding differences in cancer defenses across various species. These results suggest a trade-off between reproduction and somatic maintenance, where Aves with small clutch sizes get less cancer., Competing Interests: We declare we do not have any conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.)

Hershey and colleagues recently showed how clones in a triple-negative breast cancer cell line cooperate for their mutual fitness benefit. In this system, clones exchange soluble metabolites to increase their in vitro growth rate at low population densities, therefore mitigating the documented growth barrier that reduces individual fitness in small tumor cell populations (Allee effect). Such cooperation could aid important transitions in cancer progression in which cancer cell populations are small, like invasion or metastasis. Using orthotopic transplantation, the authors demonstrate that this cooperation is functional in one such transition in vivo, increasing the metastatic load and number of metastases, which are usually polyclonal. Together, these findings highlight the need to consider ecologic interactions to properly understand tumor growth dynamics, and how they complement the standing evolutionary model of cancer progression in our quest to understand and treat cancer., (©2023 American Association for Cancer Research.)