Cutaneous nevi, commonly known as moles, may be a novel predictor of breast cancer, according to two studies published in this week's PLOS Medicine. Jiali Han and colleagues from Indiana University and Harvard University, United States, and Marina Kvaskoff and colleagues from INSERM, France, report that women with a greater number of nevi are more likely to develop breast cancer.
The researchers reached these conclusions by using data from two large prospective cohorts– the Nurses' Health Study in the United States, including 74,523 female nurses followed for 24 years, and the E3N Teachers' Study Cohort in France, including 89,902 women followed for 18 years.
In the Nurses' Health Study, Han and colleagues asked study participants to report the number of nevi >3mm on their left arm at the initial assessment. They observed that women with 15 or more nevi were 35% more likely to be diagnosed with breast cancer than women who reported no nevi, corresponding to an absolute risk of developing breast cancer of 8.48% in women with no nevi and 11.4% for women with 15 or more nevi. In a subgroup of women, they observed that postmenopausal women with six or more nevi had higher blood levels of estrogen and testosterone than women with no nevi, and that the association between nevi and breast cancer risk disappeared after adjustment for hormone levels.
In the E3N Study, including mostly teachers, Kvaskoff and colleagues asked study participants to report whether they had no, a few, many, or very many moles. They observed that women with "very many" nevi had a 13% higher breast cancer risk than women reporting no nevi, although the association was no longer significant after adjusting for known breast cancer risk factors, especially benign breast disease or family history of breast cancer, which were themselves associated with nevi number.
These studies do not suggest that nevi cause breast cancer, but raise the possibility that nevi are affected by levels of sex hormones, which may be involved in the development of breast cancer. The findings do suggest that the number of nevi could be used as a marker of breast cancer risk, but it is unclear whether or how this information would improve risk estimation based on established risk factors. The accuracy of the findings is limited by the use of self-reported data on nevus numbers. Moreover, these findings may not apply to non-white women given that these studies involved mostly white participants.
In a linked Perspective, Barbara Fuhrman and Victor Cardenas discuss the potential implications of the findings from these studies. They say: "Additional studies should be carried out to investigate melanocytic nevi and other cutaneous features in association with the risks of breast cancer and other estrogen-related proliferative diseases. It is our hope that this research will provide etiologic insights and test practical uses of nevi and related phenotypes for their potential utility in breast cancer risk assessment."
Research Article
Funding: The Nurses' Health Study cohort is supported by NIH grants CA87969 and CA49449 (http://www.nih.gov/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Citation: Zhang M, Zhang X, Qureshi AA, Eliassen AH, Hankinson SE, et al. (2014) Association between Cutaneous Nevi and Breast Cancer in the Nurses' Health Study: A Prospective Cohort Study. PLoS Med 11(6): e1001659. doi:10.1371/journal.pmed.1001659
Author Affiliations:
Brigham and Women's Hospital, USA
Harvard Medical School, USA
Brown University Warren Alpert Medical School, USA
Harvard School of Public Health, USA
University of Massachusetts School of Public Health and Health Sciences, USA
Indiana University Richard M. Fairbanks School of Public Health, USA
Indiana University Melvin and Bren Simon Cancer Center, USA
Indiana University School of Medicine, USA
Tianjin Medical University Cancer Institute and Hospital, China
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http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1001659
Contact:
Jiali Han
Fairbanks School of Public Health, Indiana University
Indianapolis, IN
UNITED STATES
+1 (317) 278-0370
jialhan@iu.edu
Research Article
Funding: This work was supported by the Mutuelle Generale de l'Education Nationale (MGEN); the European Community; the French League against Cancer (LNCC); Gustave Roussy; and the French National Institutes for Health and Medical Research (Inserm). MK is financially supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme (#PIOF-GA-2011-302078) (URL: http://ec.europa.eu/research/mariecurieactions/about-mca/actions/iof/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist
Citation: Kvaskoff M, Bijon A, Mesrine S, Vilier A, Baglietto L, et al. (2014) Association between Melanocytic Nevi and Risk of Breast Diseases: The French E3N Prospective Cohort. PLoS Med 11(6): e1001660. doi:10.1371/journal.pmed.1001660
Author Affiliations:
Centre for Research in Epidemiology and Population Health, France
Universite Paris Sud, France
Gustave Roussy, France
Brigham and Women's Hospital, USA
Harvard Medical School, USA
QIMR Berghofer Medical Research Institute, Australia
Cancer Council of Victoria, Australia
University of Melbourne School of Population Health, Australia
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Contact:
Marina Kvaskoff
Brigham & Women's Hospital and Harvard Medical School
Boston, MA
UNITED STATES
+1 (617) 939-1617
n2mmk@channing.harvard.edu
And CESP Inserm U1018 Team 9,
EMT, Institut Gustave Roussy
94805 Villejuif cedex, France
+33 1 42-11-64-66
marina.kvaskoff@gustaveroussy.fr
Perspective Article
Funding: The authors did not receive any specific funding to write this manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Citation: Fuhrman B, Cardenas V (2014) Melanocytic Nevi as Biomarkers of Breast Cancer Risk. PLoS Med 11(6):e1001661. doi:10.1371/journal.pmed.1001661
Author Affiliations:
University of Arkansas for Medical Sciences Fay W. Boozman College of Public Health, USA
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Journal
PLOS Medicine