Peto's paradox revisited: black box vs mechanistic approaches to understanding the roles of mutations and promoting factors in cancer

Exposomal determinants of non-genetic plasticity in tumor initiation

The classical view of cancer as a genetically driven disease has been challenged by recent findings of oncogenic mutations in phenotypically healthy tissues, refocusing attention on non-genetic mechanisms of tumor initiation. In this context, gene-environment interactions take the stage, with recent studies showing how they unleash and redirect cellular and tissue plasticity towards protumorigenic states in response to the exposome, the ensemble of environmental factors impinging on tissue homeostasis. We conceptualize tumor-initiating plasticity as a phenotype-transforming force acting at three levels: cell-intrinsic, focusing on mutant epithelial cells' responses to environmental variation; reprogramming of non-neoplastic cells of the host, leading to protumor micro- and macroenvironments; and microbiome ecosystem dynamics. This perspective highlights cell, tissue, and organismal plasticity mechanisms underlying tumor initiation that are shaped by the exposome, and how their functional investigation may provide new opportunities to prevent, detect, and intercept cancer-promoting plasticity.

The Association between Breast Cup Size and Breast Cancer Incidence: Insights from a Global Dataset

The relationship between breast size and breast cancer risk is complex and not fully understood. This study investigates how breast size, categorized by cup size, correlates with age-standardized rates (ASR) of breast cancer incidence. Data were collected from two sources: breast cancer incidence rates from the Global Cancer Observatory (GCO) and breast size data from "Data Pandas," an open-access database. This allowed for a cross-country analysis of breast cancer incidence and breast size characteristics. Descriptive statistics indicated that ASR increased with larger cup sizes, ranging from 34.72 (AA) to 90.17 (C). An ANOVA test revealed significant differences in mean ASR among cup size groups (F=14.416, P<0.001), with Bonferroni comparisons showing distinct clusters: smaller sizes (AA, AA-A, A) differed significantly from larger sizes (A-B, B, B-C, C).The largest mean ASR difference was between groups A and C (-42.93, P=0.001), highlighting higher ASR in larger cup sizes. This suggests a significant association between breast cup size and breast cancer ASR, potentially linked to physiological or hormonal factors.Despite limitations, these findings prompt further investigation. The next phase will focus on breast cancer patients, addressing relevant risk factors for a more comprehensive understanding of the associations observed.

Hybrid Nanofibrous Membrane with Durable Electret for Anti-Wetting Air Filtration

Electrospun fibrous materials with fine fibers and small pores are fundamental for particulate matter (PM) filtration, addressing its harmful environmental and health impacts. However, the existing electrospun fibers are still limited to their sub-micron diameters and unstable surface electrostatic effect, leading to deteriorated filtration performance after prolonged storage or wetting. Herein, the study creates nanofibrous membranes with long-time stable electrostatics by electret-enhanced electrospinning. The phase separation and polarization of the charged jet are manipulated to achieve rapid stretch and strong electret. The obtained membrane exhibits nanosized structures with fiber diameters of ≈220 nm, pore size <1 µm, as well as robust surface potential of 0.4 kV. By virtue of the synergistic effects of sieving and adsorption, the nanofibrous membrane showed a remarkable PM0.3 filtration efficiency of 96.6% and pressure drop of 140 Pa, even reaching the N90 standard after five wetting cycles. The design of such durable membranes will offer a new sight in the functional filtration materials.

Multimodal Spatial Profiling Reveals Immune Suppression and Microenvironment Remodeling in Fallopian Tube Precursors to High-Grade Serous Ovarian Carcinoma

High-Grade Serous Ovarian Cancer (HGSOC) originates from fallopian tube (FT) precursors. However, the molecular changes that occur as precancerous lesions progress to HGSOC are not well understood. To address this, we integrated high-plex imaging and spatial transcriptomics to analyze human tissue samples at different stages of HGSOC development, including p53 signatures, serous tubal intraepithelial carcinomas (STIC), and invasive HGSOC. Our findings reveal immune modulating mechanisms within precursor epithelium, characterized by chromosomal instability, persistent interferon (IFN) signaling, and dysregulated innate and adaptive immunity. FT precursors display elevated expression of MHC-class I, including HLA-E, and IFN-stimulated genes, typically linked to later-stage tumorigenesis. These molecular alterations coincide with progressive shifts in the tumor microenvironment, transitioning from immune surveillance in early STICs to immune suppression in advanced STICs and cancer. These insights identify potential biomarkers and therapeutic targets for HGSOC interception and clarify the molecular transitions from precancer to cancer.

Mutations, Bottlenecks, and Clonal Sweeps: How Environmental Carcinogens and Genomic Changes Shape Clonal Evolution during Tumor Progression

The transition from a single, initiated cell to a full-blown malignant tumor involves significant genomic evolution. Exposure to carcinogens-whether directly mutagenic or not-can drive progression toward malignancy, as can stochastic acquisition of cancer-promoting genetic events. Mouse models using both carcinogens and germline genetic manipulations have enabled precise inquiry into the evolutionary dynamics that take place as a tumor progresses from benign to malignant to metastatic stages. Tumor progression is characterized by changes in somatic point mutations and copy-number alterations, even though any single tumor can itself have a high or low burden of genomic alterations. Further, lineage-tracing, single-cell analyses and CRISPR barcoding have revealed the distinct clonal dynamics within benign and malignant tumors. Application of these tools in a range of mouse models can shed unique light on the patterns of clonal evolution that take place in both mouse and human tumors.

Chance, ignorance, and the paradoxes of cancer: Richard Peto on developing preventative strategies under uncertainty

During the early 1980s both cancer biology and epidemiological methods were being transformed. In 1984 the leading cancer epidemiologist Richard Peto - who, in 1981, had published the landmark Causes of Cancer with Richard Doll - wrote a short chapter on "The need for ignorance in cancer research", in which the worlds of epidemiology and speculative Darwinian biology met. His reflections on how evolutionary theory related to cancer have become known as "Peto's paradox", whilst his articulation of "black box epidemiology" provided the logic of subsequent practice in the field. We reprint this sparkling and prescient example of biologically-informed epidemiological theorising at its best in this issue of the European Journal of Epidemiology, together with four commentaries that focus on different aspects of its rich content. Here were provide some contextual background to the 1984 chapter, and our own speculations regarding various paradoxes in cancer epidemiology. We suggest that one reason for the relative lack of progress in indentifying novel modifiable causes of cancer over the last 40 years may reflect such exposures being ubiquitous within environments, and discuss the lessons for epidemiology that would follow from this.