About

Kathleen F. Arcaro, PhD, is a Professor at UMass Amherst and serves as the Project Director for the BRCA Breastmilk research project. The major goal of the research in the Arcaro lab is to develop tools for assessing individual breast cancer risk by studying breastmilk. Human milk contains multiple cell types, including epithelial cells from the lining of the ducts and lobules. Since cancer-related DNA methylation may occur decades before disease diagnosis, the lab focuses on determining the extent to which DNA methylation patterns in the sloughed epithelial cells can inform future breast cancer risk. This research aims to accurately assess individual risk, thereby providing women the opportunity to make informed decisions regarding preventative treatments.

Research topics

• Biology
• Medicine
• Chemistry
• Internal medicine
• Cancer research

Selected publications

• Accessing the DNA in Breast Tissue: Adhesive Cell Capture from Flow onto Fibers of Cellulose Papers

  ACS Applied Materials & Interfaces · 2026-02-19

  articleOpen access

  The epithelial cells in human breastmilk represent an underutilized tissue source for research on human breast health or, in future applications, molecular-level-based cancer screening or individualized assessment of cancer risk. It remains a challenge to collect the targeted species from the milk of lactating women and new mothers, individuals for whom laboratories may be inaccessible or for whom cancer screening is a low priority. A compact, mailable device, for instance based on paper, that removes liquid and collects DNA and other targeted components is preferred over mailing milliliters of refrigerated liquid. After establishing that human DNA in breastmilk resides mostly in its cells, we focus on cell capture, employing MCF-7 cells expressing the green fluorescent protein (GFP-MCF-7) as a means to track cell progression through layers of papers, determine cell capture mechanisms, and evaluate device designs during cell flow and water removal. We show that, for the current cellulose papers, cell capture is largely an adhesive process rather than one of size-based filtration, with cells passing through layers of paper intact until they are captured. The numbers of tracer cells captured on different surfaces, from the device entrance to a liquid reservoir, are shown to be proportional to the human DNA retained at those locations. In a simple model for milk, in which bovine serum albumin is added to cell suspensions, 1% protein minimally interferes but 5% protein blocks cell capture, further supporting a model of adhesion as opposed to filtration (size-based) retention. Further, the staggering of paper porosity to produce slower liquid travel through the device facilitates greater cell capture in regions with large pores, likely a result of the impact of wall shear rate on cell capture. Engineering calculations for estimated wall shear rates inside the papers revealed that the flow dependence of capture in paper layers behaves similarly to established epithelial cell capture in shear flow chambers.

  PublisherOA PDFDOI

• Understanding How Low Calorie Sweeteners Pass from Mother to Infants Through Breastmilk – Insights from Population Pharmacokinetic Modeling

  2026-01-01

  articleOpen access

  <p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" dir="auto" id="d627246e142"> <b>Objectives:</b> Forty-four percent of lactating women report consuming beverages containing low-calorie sweeteners (LCS) in a given week [ <a class="xref-link" href="#r1">1</a>, <a class="xref-link" href="#r2">2</a>]; yet, in vitro and rodent studies, as well as observational studies in humans, suggest that early life LCS exposure may have potential negative effects on infant health [ <a class="xref-link" href="#r6">6</a>– <a class="xref-link" href="#r10">10</a>]. Despite these concerns, evidence-based guidelines for maternal LCS intake during lactation are lacking. This research aims to characterize the pharmacokinetics of ace-K and sucralose in mothers and infants using data from infant plasma, maternal breast milk, and maternal plasma collected after maternal LCS beverage consumption. <p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" dir="auto" id="d627246e159"> <b>Methods:</b> This prospective pharmacokinetic (PK) study included 40 exclusively breastfeeding mothers, 4–24 weeks postpartum, and their infants. Each mother consumed 20 oz of Ocean Spray Diet Cranberry™, containing 17.4 mg ace-K and 94.8 mg sucralose. Rich plasma and breast milk samples were collected serially from mothers, and a heel-stick blood sample was also collected from each infant at designated times post-ingestion of breast milk. <p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" dir="auto" id="d627246e164">Ace-K and sucralose concentrations were quantified using LC-MS [ <a class="xref-link" href="#r11">11</a>]. Nonlinear mixed-effects modeling was performed jointly on plasma and breast milk data [ <a class="xref-link" href="#r12">12</a>], using Pumas v2.0 [ <a class="xref-link" href="#r13">13</a>]. Maternal covariates (age, weight, postpartum age) were tested. Infant models were derived by physiologically scaling maternal models and fit to infant concentrations via post hoc prediction. Simulations of real-world maternal consumption patterns estimated infant exposure. <p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" dir="auto" id="d627246e175"> <b>Results:</b> Pharmacokinetic analysis included 488 maternal plasma, 360 breast milk, and 40 infant plasma observations for both ace-K and sucralose. Ace-K PK was described by a one-compartment model with simultaneous zero- and first-order absorption and first-order elimination. The breast milk volume was fixed physiologically, and a fixed transfer rate of 0.01 h ^-1 from milk to plasma enabled estimation of the milk entry rate (1 h ^-1). Mean apparent clearance and volume estimates were 10 L/h and 30 L, respectively. <p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" dir="auto" id="d627246e186">Sucralose PK was described by a two-compartment model with zero-order absorption and first-order elimination. An additional breast milk compartment, with volume fixed to physiological capacity [ <a class="xref-link" href="#r14">14</a>], and transit compartments were added to capture the lag between plasma and milk concentrations. Mass transfer to milk was assumed negligible. Postpartum age decreased milk transfer over time. The mean apparent clearance central volume was 130L/h and 770 L, respectively. <p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" dir="auto" id="d627246e191">Infant models were scaled using allometry and maturation functions for clearance and volume (total body water). Simulations across ages and weights, based on CDC growth charts and age-appropriate milk intake, showed that daily maternal consumption of 1–3 LCS beverages resulted in infant exposures &gt;5-fold lower than levels associated with harm in animal studies. <p xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" dir="auto" id="d627246e193"> <b>Conclusions:</b> In conclusion, the pharmacokinetics of ace-K and sucralose were adequately characterized in the breast milk and plasma of lactating mothers and infants. Findings contribute to a better understanding of LCS exposure during lactation and will help inform evidence-based recommendations on maternal LCS consumption while breastfeeding.

  PublisherDOI

• Comparison of Ion Selective Electrodes for the Measurement of Sodium and Potassium in Human Milk

  Journal of Human Lactation · 2026-03-17

  article

  BACKGROUND: Accessible and cost-effective measures of human milk biomarkers are needed for lactation screening and management. Sodium (Na), potassium (K), and the sodium-potassium (Na/K) ratio in human milk show promise as indicators of secretory activation and mammary gland health. RESEARCH AIM: This validation study compares the accuracy and precision of handheld and benchtop ion selective electrodes (ISE) as compared to inductively coupled plasma mass spectrometry (ICP-MS) for the measurement of Na and K in defatted and whole milk. METHODS: = 27) were assessed for Na and K in defatted and whole milk using ICP-MS, handheld, and benchtop ISE instruments. Bland-Altman analysis was performed to compare Na, K and Na/K measurements in whole versus defatted milk and between instruments. RESULTS: All three assay methods provided high precision for Na and K concentrations in both whole and defatted milk. Na/K ratios were similar between whole and defatted milk for both ICP-MS and the handheld ISE. Measurements of Na and Na/K were systematically higher with both ISE instruments as compared to ICP-MS. However, the systematic difference was approximately three times greater in the benchtop ISE as compared to the handheld ISE. This resulted in identification of a larger number of cases of elevated mammary epithelium permeability (MEP) with the benchtop ISE as compared to handheld ISE or ICP-MS. CONCLUSIONS: Meaningful assessment of Na and Na/K in whole milk is possible using the handheld ISE. Its portability and ease of use suggest potential for assessing Na and K in human milk at the point-of-care for use in both research and clinical applications.

  PublisherDOI

• Immune response in breastmilk of Black women to SARS-CoV-2 infection and vaccination against COVID-19

  Frontiers in Nutrition · 2026-01-12

  articleOpen accessSenior authorCorresponding

  Introduction: In the United States, Black lactating women are underrepresented in health-related studies. This underrepresentation is a concern when interpreting results from studies of the immune response to SARS-CoV-2 in breastmilk because we know that individuals vary greatly in their response to both infection and vaccination. Additionally, few studies of the immune response in human milk include analysis of mammary epithelium permeability, despite the knowledge that elevated permeability can alter constituents in milk. To address these gaps, we enrolled local Black breastfeeding mothers during a 3-day breastfeeding conference in New Orleans to assess the immune response in milk to infection or vaccination with SARS-CoV-2. Materials and methods: = 16) received kits with instructions to collect bilateral milk samples, dried blood spots (DBS), and saliva. Concentrations of anti-SARS-CoV-2 antibodies against both the Wuhan and Omicron variants were determined in milk, DBS, and saliva using the ELISA test. The concentration of a panel of cytokines was determined in milk, and the permeability of the mammary gland was assessed. Results: Among the 16 lactating women who provided samples, 8 had a positive COVID-19 test within the previous 19 months, and 12 had received an mRNA-based COVID-19 vaccine within the previous 16 months. Milk and maternal blood spots from all participants were positive for all anti-SARS-CoV-2 antibody classes tested, while only a subset of saliva samples were positive for all anti-SARS-CoV-2 antibody classes. A significant correlation was found between mammary epithelium permeability and concentrations of IL-1β, IL-6, and IL-8 cytokines. Conclusion: Results from this small pilot study supported the need to include a diverse population in breastmilk studies, as the immune response in milk varied greatly among individuals. Future studies assessing the response to infections and vaccinations in lactating women should include analysis of milk from both breasts, as well as assessment of mammary epithelium permeability.

  PublisherOA PDFDOI

• Accessing the DNA in Breast Tissue: Adhesive Cell Capture from Flow onto Fibers of Cellulose Papers

  ChemRxiv · 2026-02-03

  articleOpen access

  The epithelial cells in human breastmilk represent an underutilized tissue source for research on human breast health or, in future applications, molecular-level based cancer screening or individualized assessment of cancer risk. It remains a challenge to collect the targeted species from the milk of lactating women and new mothers, individuals for whom labs may be inaccessible or for whom cancer screening is a low priority. A compact, mailable device, for instance based on paper, that removes liquid and collects DNA and other targeted components is preferred over mailing milliliters of refrigerated liquid. After establishing that human DNA in breastmilk resides mostly in its cells, we focus on cell capture, employing MCF-7 cells expressing the green fluorescent protein (GFP-MCF-7) as a means to track cell progression through layers of papers, determine cell capture mechanisms, and evaluate device designs during cell flow and water removal. We show that, for the current cellulose papers, cell capture is largely an adhesive process rather than one of size-based filtration, with cells passing through layers of paper intact until they are captured. The numbers of tracer cells captured on different surfaces, from the device entrance to a liquid reservoir, are shown to be proportional to the human DNA retained at those locations. In a simple model for milk, in which bovine serum albumin is added to cell suspensions, 1% protein minimally interferes but 5% protein blocks cell capture, further supporting a model of adhesion as opposed filtration (size-based) retention. Further, the staggering of paper porosity to produce slower liquid travel through the device facilitates greater cell capture in regions with large pores, likely a result of the impact of wall shear rate on cell capture. Engineering calculations for estimated wall shear rates inside the papers revealed that the flow dependence of capture in paper layers behaves similarly to established epithelial cell capture in shear flow chambers.

  PublisherOA PDFDOI

• Subclinical mastitis during lactation: A modifiable risk factor for breast cancer?

  Medical Hypotheses · 2025-11-03

  articleOpen accessSenior authorCorresponding
  PublisherOA PDFDOI

• Figure S5 from Urinary Levels of Endocrine-Disrupting Chemicals and Breast Density in Young Women

  2025-08-01

  preprintOpen access

  &lt;p&gt;Scatter Plots of % Breast Density and Concentrations of Phthalates.&lt;/p&gt;

  PublisherDOI

• Urinary Levels of Endocrine-Disrupting Chemicals and Breast Density in Young Women

  Cancer Epidemiology Biomarkers & Prevention · 2025-05-16 · 3 citations

  articleOpen access

  BACKGROUND: Endocrine-disrupting chemicals (EDC) found in many household and personal care products have hormonal properties and effects on the mammary gland. It is unclear whether urinary concentrations of EDCs are associated with higher percent breast density, a major risk factor of breast cancer. METHODS: We conducted a cross-sectional study of 97 college-aged women. We quantified individual levels of bisphenol A, bisphenol S, bisphenol F, triclosan, triclocarban, 3-benzophenone, seven phthalate metabolites, four parabens, and two other phenols in three 24-hour urine samples combined into a single pooled sample. Each woman had non-enhanced MRI to assess percent breast density. Associations between estimated concentrations of individual EDCs and percent breast density were analyzed using adjusted linear regression. RESULTS: There was no evidence of a statistically significant increase in mean percent breast density in the middle or highest tertile for any EDC measured. There was a suggestion that the mean percent breast density was elevated in individuals in the middle and highest tertile levels of ethyl paraben compared with those in the lowest tertile, with a relative increase in mean percent breast density of 16% (β = 1.16; 95% CI, 0.92-1.46) in tertile 2 and 24% (β = 1.24; 95% CI, 0.99-1.57) in tertile 3, relative to tertile 1 (Ptrend = 0.07). Similar trends in percent breast density were observed for methylparaben, propylparaben, and butylparaben. CONCLUSIONS: Urinary levels of EDCs were not associated with percent breast density in college-aged women. IMPACT: The estimated effect of EDCs on the breast tissue of young women is unclear and warrants larger studies.

  PublisherOA PDFDOI

• Figure S1 from Urinary Levels of Endocrine-Disrupting Chemicals and Breast Density in Young Women

  2025-08-01

  preprintOpen access

  &lt;p&gt;Heatmap of scaled urinary concentrations of environmental chemicals.&lt;/p&gt;

  PublisherDOI

• Figure S2 from Urinary Levels of Endocrine-Disrupting Chemicals and Breast Density in Young Women

  2025-08-01

  preprintOpen access

  &lt;p&gt;Scatter Plots of Percent Breast Density and Concentrations of Phenols.&lt;/p&gt;

  PublisherDOI

Recent grants

• Fruit and vegetable intervention in lactating women to reduce breast cancer risk: effects on breast cell DNA methylation, breast inflammation, and weight

  NIH · $633k · 2019–2024

• NIH Grant R01ES009795

  NIH · $490k · 2004

• Fruit and vegetable intervention in lactating women to reduce breast cancer risk: effects on breast cell DNA methylation, breast inflammation, and weight

  NIH · $2.6M · 2019–2025

Frequent coauthors

• Brian T. Pentecost

  University of Massachusetts Boston

  52 shared

• John F. Gierthy

  49 shared

• Sallie S. Schneider

  Baystate Medical Center

  44 shared

• Eva P. Browne

  University of Massachusetts Amherst

  44 shared

• Douglas L. Anderton

  42 shared

• Chung M. Wong

  36 shared

• Christopher N. Otis

  Mexican Social Security Institute

  36 shared

• Kurunthachalam Kannan

  34 shared

Labs

• UMass Breastmilk LabPI

Awards & honors

• CNRE Achievement Award for Outstanding Teaching