# Polycyclic Aromatic Hydrocarbons, Vitamin D and Breast Cancer

> **NIH NIH F31** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2022 · $38,778

## Abstract

PROJECT SUMMARY
Applicant. This pre-doctoral fellowship (F31) application is designed to promote the training of Joyce Rhoden,
a pre-doctoral student in the Department of Epidemiology at the University of North Carolina. Her goal is to
become an independent researcher who conducts innovative, translational health research. During the F31
training the applicant will be mentored by her sponsors Drs. Marilie Gammon and Cathrine Hoyo.
Significance. Breast cancer is the most commonly diagnosed cancer among women in the United States.
Polycyclic aromatic hydrocarbons (PAHs) result from incomplete combustion and are ubiquitous. Many, but not
all, studies show positive associations between PAHs and breast cancer risk. Vitamin D significantly protects
against oxidative stress in breast epithelial cells and is associated with lower breast cancer risk. Vitamin D
prevents pre-neoplastic lesions in mammary gland explants after exposure to the PAH carcinogen 7,12-
dimethylbenz(a)-anthracene (DMBA). However, no epidemiologic study has examined if associations between
PAHs and breast cancer incidence vary with plasma vitamin D or vitamin D polymorphisms. The study
hypothesis is that elevated risks for breast cancer incidence associated with PAHs will be evident only in
women with low vitamin D levels, or with genotypes that may lower vitamin D levels. Aim 1. Determine if PAH
measures (PAH-DNA adducts and PAH sources (active and passive smoking, grilled/smoked foods, indoor
fireplace use, vehicular traffic)) interact with plasma 25-hydroxyvitaminD (25-OHD) concentrations to influence
breast cancer risk. Aim 2. Determine if PAH measures interact with any of 25 vitamin D-related genetic single-
nucleotide polymorphisms (SNPs) to influence breast cancer incidence. Aim 3. Determine if genetically
predicted vitamin D levels influences breast cancer risk and assess whether the genetically predicted vitamin D
levels modify the PAH-breast cancer associations. Approach. The dissertation will use existing information
from 1508 women with breast cancer and 1556 women without breast cancer. Measures of PAH and vitamin D
were assessed shortly after diagnosis. For Aims 1-3, logistic regression will be conducted to estimate odds
ratios and 95% confidence intervals to examine interaction on the multiplicative and additive scales. For Aim 3,
an adjusted two-stage least squares regression method will be used to estimate a weighted genetic predictive
score, which can then be used in logistic models. Innovation. This dissertation: (1) will be the first
epidemiologic study to examine interaction between PAHs and vitamin D in association with breast cancer risk;
(2) includes multi-level PAH and vitamin D measures; (3) explores biologically plausible SNPs; (4) will estimate
genetically predicted vitamin D levels; and (5) uses a well-characterized population-based sample. Impact.
The proposed dissertation may identify a potential low-cost risk reduction strategy for breast cancer.

## Key facts

- **NIH application ID:** 10322403
- **Project number:** 5F31CA247251-03
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Joyce Rhoden
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $38,778
- **Award type:** 5
- **Project period:** 2020-01-01 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10322403

## Citation

> US National Institutes of Health, RePORTER application 10322403, Polycyclic Aromatic Hydrocarbons, Vitamin D and Breast Cancer (5F31CA247251-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10322403. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*