About

Leslie Dennis, PhD, MS, is a Professor in the Department of Epidemiology & Biostatistics at the Mel and Enid Zuckerman College of Public Health, University of Arizona. She received her PhD in Epidemiology from the University of Washington in 1993 and her MS in Biometrics from the University of Colorado Health Sciences Center in 1988. Her research focuses on skin cancer, particularly melanoma etiology and prevention, as well as other cancers such as anogenital, hepatocellular, and prostate cancers, along with non-cancer topics. She employs various tools including mailed questionnaires, telephone interviews, molecular analyses of trace elements, and studies of sexually transmitted infections, with an interest in genetics. Dr. Dennis has expertise in conducting meta-analyses related to cancer risk factors and has served as a reviewer for several cancer and epidemiological journals. She has also contributed to grant review panels for the NCI and the American Cancer Society. Her teaching emphasizes developing students' problem-solving skills, independent research capabilities, and the application of epidemiological concepts.

Research topics

• Medicine
• Environmental health
• Demography
• Internal medicine
• Gynecology

Selected publications

• Environmental Nonessential Element Exposure and Urologic Cancer

  JAMA Network Open · 2026-05-22

  articleOpen access

  Importance: Urologic cancers have been linked to nonessential chemical elements with no known beneficial role in the body, though associations between low-level environmental exposure and urologic cancer risk are poorly understood. Objective: To systematically synthesize epidemiologic evidence on the association between environmental exposure to nonessential elements and risk of urologic cancers. Data Sources: English- and Chinese-language databases, including PubMed, Embase, Web of Science, Scopus, Cumulated Index in Nursing and Allied Health Literature, Cochrane Database of Systematic Reviews, China National Knowledge Infrastructure, and Wanfang, were searched from inception to January 27, 2026, without language restrictions. Study Selection: Cohort and case-control studies reporting associations between exposure to at least 1 nonessential element (eg, arsenic, cadmium, lead, vanadium, or nickel) and risk of urologic cancers (prostate, bladder, kidney, urinary tract, or testicular) were included. Data Extraction and Synthesis: Data were extracted independently by 4 author reviewers. Random-effects meta-analyses were conducted to estimate pooled relative risks (RRs) comparing the top vs bottom tertiles of exposure levels and to evaluate dose-response associations. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Main Outcomes and Measures: RRs for urologic cancers associated with exposure to nonessential elements. Results: Of 23 160 records screened, 68 studies met inclusion criteria and 62 were included in the meta-analysis. Comparing the top vs bottom tertile of exposure levels, pooled RRs for arsenic were 1.72 (95% CI, 1.33-2.22) for all urologic cancers, 1.60 (95% CI, 1.13-2.27) for bladder cancer, 1.19 (95% CI, 1.01-1.40) for prostate cancer, and 3.37 (95% CI, 1.71-6.66) for urothelial carcinoma (renal pelvis, ureter, urethra, and/or bladder). Arsenic exposure was not associated with kidney cancer (RR, 1.38; 95% CI, 0.76-2.52). A nonlinear dose-response association was observed between urologic cancer risk and drinking-water arsenic levels above 10 µg/L but not at or below this level; the RR steadily increased from concentrations of 10 to 429 µg/L. Estimated using the population attributable fraction, reducing arsenic concentrations in drinking water to 10 µg/L could potentially lower age-standardized annual rates of some urologic cancers by 0.1 to 31.8 cases per 100 000 population in high-exposure areas. Pooled RRs for overall urologic cancer risk were 1.38 (95% CI, 1.04-1.82) for top vs bottom tertile of cadmium exposure and 1.15 (95% CI, 1.05-1.26) for vanadium, whereas evidence for other elements was limited. Conclusions and Relevance: In this systematic review and meta-analysis of epidemiologic studies, environmental exposure to arsenic, cadmium, and vanadium was associated with increased risk of urologic cancers, although high heterogeneity across studies limited interpretability. These findings highlight the need for high-quality prospective studies to assess causality and quantify the public health burden from environmental exposure to nonessential elements.

  PublisherDOI

• Infertility burden among women firefighters: a cross-sectional exploratory analysis

  Occupational and Environmental Medicine · 2025-07-31

  articleOpen access

  OBJECTIVES: Despite biological and environmental plausibility, risk factors for infertility have not yet been studied among female firefighters. In this exploratory analysis, we investigated the burden of infertility among a subset of US firefighters enrolled in the Health and Wellness of Women Firefighters Study. METHODS: Women firefighters enrolled in the study responded to surveys administered in 2017 and 2019, reporting on their work environment, reproductive health, infertility history and fertility treatment history among those with infertility. Demographics and reproductive history of firefighters were compared by reported history of infertility. Log binomial regression models were used to estimate the association between occupational factors and risk of infertility. RESULTS: Of the 562 firefighters in our analysis, 168 of these women (30%) reported a history of infertility. A longer length of employment as a firefighter was associated with a modest, but non-statistically significant, increased relative risk of experiencing infertility (1.39, 95% CI 0.86 to 2.24). CONCLUSIONS: This exploratory analysis highlights an opportunity to further examine infertility and impaired fertility among firefighters. Future studies may focus on comparing the burden of infertility in firefighters to the general population and evaluating the influence of additional occupational factors.

  PublisherOA PDFDOI

• Agreement between the Spot Vision Screener and cycloplegic retinoscopy for toddlers with astigmatism

  Journal of American Association for Pediatric Ophthalmology and Strabismus · 2025-10-01

  article
  PublisherDOI

• Vision and developmental delay in toddlers

  Journal of American Association for Pediatric Ophthalmology and Strabismus · 2025-09-23

  articleOpen access
  PublisherOA PDFDOI

• Trace Element Concentrations of Arsenic and Selenium in Toenails and Risk of Prostate Cancer among Pesticide Applicators

  Current Oncology · 2024-09-14 · 1 citations

  articleOpen access1st authorCorresponding

  Prostate cancer is a common cancer among males in the US, but little is known about its risk factors, including trace elements. The primary aim of this study was to examine prostate cancer and its association with arsenic and selenium in toenails. We conducted a small, nested case-control study of men residing in Iowa within the Agricultural Health Study cohort, where we also collected toenail samples to test for arsenic and other trace elements. Toenail samples were sent for neutron activation analysis aimed at long-lived trace elements, including arsenic. Logistic regression was used to estimate odds ratios (ORs) for trace element exposures and prostate cancer. A total of 66 prostate cancer cases and 173 healthy controls returned questionnaires, over 99% of which included toenail samples. An increased risk was seen for the highest levels of arsenic (OR = 3.4 confidence interval (CI) of 1.3-8.6 and OR = 2.2, 95% CI of 0.9-5.6) and the highest level of selenium (2.0, 95% CI of 1.0-4.0). These data also show detectable levels of over 50% for 14 of 22 elements detected in the toenails. The association seen here with arsenic and prostate cancer further supports ecological studies finding an association with community levels of arsenic and prostate cancer incidence and mortality.

  PublisherOA PDFDOI

• Global Burden of Penile Cancer: A Review of Health Disparities for a Rare Disease

  Urology · 2024-09-19 · 7 citations

  review
  PublisherDOI

• Comparison of Prognostic Factors for Merkel Cell Carcinoma, Mucosal Melanoma and Cutaneous Malignant Melanoma: Insights into Their Etiologies

  Current Oncology · 2023-03-31 · 5 citations

  articleOpen access1st authorCorresponding

  Little is known about the epidemiology of Merkel cell carcinoma (MCC) and mucosal melanoma (MM). Using the United States (US) National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program data, we compared MCC and MM with cutaneous malignant melanoma (CMM) with respect to incidence rates and prognostic factors to better understand disease etiologies. We describe the proportional incidences of the three cancers along with their survival rates based on 20 years of national data. The incidence rates in 2000-2019 were 203.7 per 1,000,000 people for CMM, 5.9 per 1,000,000 people for MCC and 0.1 per 1,000,000 people for MM. The rates of these cancers increased over time, with the rate of MM tripling between 2000-2009 and 2010-2019. The incidences of these cancers increased with age and rates were highest among non-Hispanic Whites. Fewer MCCs and MMS were diagnosed at the local stage compared with CMM. The cases in the 22 SEER registries in California were not proportional to the 2020 population census but instead were higher than expected for CMM and MCC and lower than expected for MM. Conversely, MM rates were higher than expected in Texas and New York. These analyses highlight similarities in the incidence rates of CMM and MCC-and differences between them and MM rates-by state. Understanding more about MCC and MM is important because of their higher potential for late diagnosis and metastasis, which lead to poor survival.

  PublisherOA PDFDOI

• A meta-analysis of sunburn and basal cell carcinoma risk

  Cancer Epidemiology · 2023-05-17 · 21 citations

  reviewSenior author
  PublisherDOI

• Validity of a Self-Assessment Skin Tone Palette Compared to a Colorimeter for Characterizing Skin Color for Skin Cancer Research

  Current Oncology · 2023-03-08 · 7 citations

  articleOpen accessSenior authorCorresponding

  Our goal is to determine whether our objective 9-point Self-Assessment Skin Tone Palette (SASTP) is correlated with a colorimeter’s assessment of a melanin index, so that Hispanic and Black people can be included in skin cancer research where scales were developed for White populations. Subjects were asked to self-identify their skin tones using the SASTP. This study assessed the criterion validity of the SASTP by measuring a range of skin colors compared to a melanin index reported from a colorimeter for the upper-inner arm (non-sun-exposed skin color), and the outer forearm (sun-exposed). Among 188 non-artificial tanners, 50% were White, 30% were Hispanic or White-Hispanic, and 20% were other racial categories. Meanwhile, 70% were female (30% male) and 81% were age 18–29 (19% age 30+). The mean melanin of the upper-inner arm decreased with lighter skin color and stronger tendency to burn. The SASTP in comparison to melanin index values was correlated for both the upper-inner arm (r = 0.81, p < 0.001) and the outer forearm (r = 0.77, p < 0.001). The SASTP provides a 9-point scale that can be considered as an alternative, less expensive method that is comparable to the objective colorimeter melanin index, which may be useful in studies on skin cancer among White, non-White, and Hispanic peoples.

  PublisherOA PDFDOI

• Ambient UVR and Environmental Arsenic Exposure in Relation to Cutaneous Melanoma in Iowa

  International Journal of Environmental Research and Public Health · 2022-02-03 · 13 citations

  articleOpen accessSenior author

  Intermittent sun exposure is the major environmental risk factor for cutaneous melanoma (CM). Cumulative sun exposure and other environmental agents, such as environmental arsenic exposure, have not shown consistent associations. Ambient ultraviolet radiation (UVR) was used to measure individual total sun exposure as this is thought to be less prone to misclassification and recall bias. Data were analyzed from 1096 CM cases and 1033 controls in the Iowa Study of Skin Cancer and Its Causes, a population-based, case-control study. Self-reported residential histories were linked to satellite-derived ambient UVR, spatially derived environmental soil arsenic concentration, and drinking water arsenic concentrations. In men and women, ambient UVR during childhood and adolescence was not associated with CM but was positively associated during adulthood. Lifetime ambient UVR was positively associated with CM in men (OR for highest vs. lowest quartile: 6.09, 95% confidence interval (CI) 2.21-16.8), but this association was not as strong among women (OR for highest vs. lowest quartile: 2.15, 95% CI 0.84-5.54). No association was detected for environmental soil or drinking water arsenic concentrations and CM. Our findings suggest that lifetime and adulthood sun exposures may be important risk factors for CM.

  PublisherOA PDFDOI

Recent grants

• NIH Grant K07CA104556

  NIH · $790k · 2011

• NIH Grant R03CA088834

  NIH · $74k · 2002

• NIH Grant R03CA099520

  NIH · $70k · 2005

• NIH Grant R01CA118493

  NIH · $1.6M · 2015

• NIH Grant R03CA078201

  NIH · $71k · 2000

Frequent coauthors

• Dan York

  John F. Kennedy Medical Center

  36 shared

• Virginia Brandt

  RELX Group (United States)

  36 shared

• Ian Cordes

  36 shared

• Robin Arnicar

  RELX Group (United States)

  36 shared

• Dakota South

  RELX Group (Netherlands)

  36 shared

• Karl Steinberg

  California State University, San Marcos

  36 shared

• Jennifer Heffernan

  RELX Group (United States)

  36 shared

• Florida Evans

  RELX Group (United States)

  36 shared

Awards & honors

• Diversity and Inclusiveness Committee at the Mel and Enid Zu…
• University of Arizona’s Undergraduate Council and its Curric…