Advancing environmental epidemiologic methods to confront the cancer burden

Area of Science:

• Environmental Epidemiology
• Cancer Research
• Toxicology

Background:

• Identifying environmental carcinogens and their impact on specific cancers is challenging, especially in non-occupational settings with chronic, low-level exposures.
• Existing cancer studies often exclude individuals with prior cancers and begin recruitment midlife, missing susceptible populations with early-life exposures and germline susceptibility.
• Advances in exposure measurement and multi-omic platforms offer opportunities but face challenges in study design.

Purpose of the Study:

• To highlight the challenges in studying environmental carcinogens in non-occupational settings.
• To demonstrate the importance of integrating susceptibility factors and exposure windows, using breast cancer as an example.
• To advocate for new study designs that better capture the impact of environmental exposures on cancer risk and mortality.

Main Methods:

• Review of existing challenges in environmental epidemiology study designs.
• Conceptual demonstration using breast cancer to illustrate the integration of susceptibility and exposure windows.
• Proposal for alternative study designs, specifically early-onset case-control studies.

Main Results:

• Current study designs may fail to capture individuals most susceptible to environmental exposures due to germline factors and early-life exposures.
• Integrating susceptibility (germline and exposure windows) provides a more comprehensive understanding of environmental harm.
• Relying solely on existing cohorts is insufficient for understanding environmental exposure effects.

Conclusions:

• New, diverse, early-onset case-control studies are beneficial for understanding environmental exposures' impact on cancer risk and mortality.
• Study design is critical for accurately assessing the effects of environmental exposures.
• A more complete picture of environmental harm requires considering susceptibility and specific exposure windows.