Experts Reveal Ethnic Differences in Early HR+ Breast Cancer and Genomic Insights in Women Post Partum

Hispanic ethnicity was found to be independently associated with a higher risk of nonalcoholic fatty liver disease (NAFLD) among patients with hormone receptor–positive early-stage breast cancer who received endocrine therapy (ET), according to findings from a retrospective study.¹ Additionally, patients with postpartum breast cancer (PPBC) experienced a higher recurrence score in the first year post partum, with a trend toward increase up to 3 years post partum, supporting the refinement of what constitutes PPBC to be 0 to 3 years post partum, according to data from another retrospective study.²

During the OncLive National Fellows Forum on breast cancer, which was held during the 2025 San Antonio Breast Cancer Symposium, oncology fellows with an interest in breast cancer from across the country gathered to share their research, network with their peers, and receive feedback from expert mentors. Vishnu Prasath, MD, and his group presented a study titled “Ethnic Differences in NAFLD Among Women With Early-Stage Breast Cancer Receiving Endocrine Therapy.” Lisa Zhang, MD, and her team presented a study titled “Clinical Implications of Genomic Signatures in Postpartum Breast Cancer (PPBC).”

Prasath is a fellow in the Divisions of Hematology and Medical Oncology at The Ohio State University College of Medicine in Columbus. Zhang is a hematology/oncology fellow at UCLA Health in Los Angeles, California.

“The forum was a wonderful educational experience for future breast oncologists, highlighted by the insightful and impactful feedback we received from leaders in the field,” Prasath said in a statement to Oncology Fellows. “The fellows all greatly appreciated the opportunity to practice delivering oral presentations and learned so much during the breakout sessions as well. I would highly recommend this incredible opportunity to every fellow interested in breast cancer.”

How did ethnic differences affect the incidence of NAFLD in ET-treated early-stage breast cancer?

Prasath and his teammates conducted a single-center retrospective cohort study that aimed to assess ethnic difference in NAFLD onset in women with early-stage hormone receptor–positive breast cancer who received ET from 2010 to 2013 at Loma Linda University in California.¹ The total cohort (n = 465) included 107 Hispanic and 358 non-Hispanic patients. The primary outcome was time to NAFLD onset; secondary end points included the cumulative incidence of NAFLD, recurrence-free survival (RFS), and overall survival (OS).

Findings from the study revealed that the cumulative incidence of NAFLD was greater among Hispanic patients compared with non-Hispanic patients, at respective rates of 20.6% and 11.7% (P = .02). Moreover, the NAFLD-free interval was shorter in Hispanic patients compared with non-Hispanic patients (HR, 2.23; 95% CI, 1.32-3.74; P = .0025).

“We identified a higher cumulative nonalcoholic fatty liver disease incidence in the Hispanic population in comparison with the non-Hispanic subgroup,” Prasath explained. “Notable predictors of nonalcoholic fatty liver disease included Hispanic ethnicity, overweight BMI [body mass index] status, and obese BMI status. We believe certain subpopulations of patients with breast cancer [who are] receiving ET may benefit from proactive hepatic surveillance in an effort to delay development of NAFLD and aid in earlier diagnosis of NAFLD.”

Additional findings from the study demonstrated that there was no significant difference in RFS (HR, 1.66; 95% CI, 0.84-3.26; P = .14) or OS (HR, 0.67; 95% CI, 0.20-2.26; P = .52) between Hispanic and non-Hispanic patients. Data from a univariable and multivariable analysis revealed that Hispanic ethnicity (HR, 1.75; 95% CI, 1.01-3.02; P = .04), a BMI from 25 to 29.9 (HR, 2.91; 95% CI, 1.32-6.46; P = .008), and a BMI of at least 30 (HR, 3.15, 95% CI, 1.42-6.97; P = .005) were independent predictors of NAFLD development. No significant associations were found with comorbidities, menopausal status, duration of ET, or type of ET.

“We would like to validate these findings at other centers to ensure outcomes are consistent and generalizable to a broader population than was originally studied,” Prasath said. “We are also interested in identifying and integrating objective liver assessments into standard survivorship care to see if proactive surveillance truly can improve outcomes for these patients who may be at a higher risk of developing NAFLD.”

What were the implications of genomic signatures in PPBC?

In their study, Zhang and her teammates conducted a retrospective, single-center study that included patients with estrogen receptor (ER)–positive, HER2-negative breast cancer who were 45 years or younger (n = 453).² The Oncotype Dx Recurrence Score assay was used to evaluate recurrence scores. Patients were stratified by whether they were nulliparous or were diagnosed with PPBC or postpartum-related breast cancer (PRBC).

The study authors sought to elucidate whether an elevated Oncotype Dx recurrence score could be used as a marker for aggressive ER-positive, HER2-negative breast cancers that occur in postpartum patients in order to better define PPBC. The final cohort included 387 young patients with breast cancer with a known reproductive history, consisting of women who were nulliparous (n = 153), as well as those with - PRBCs (n= 2), PPBC within 0 to 5 years (n = 85), PPBC within 5 to 10 years (n = 85), and those who were over 10 years post partum (n = 62).

Findings from the study showed that the recurrence scores among patients who were nulliparous, 0 to 5 years post partum, 5 to 10 years post partum, and 10 or more years post partum were 17.7 (range, 0-65), 21.9 (range, 3-65), 16.3 (range, 2-53), and 18.9 (range, 3-48), respectively. Compared with the nulliparous group, patients who were 0 to 5 years post partum had a significantly higher recurrence score (β, 4.38; 95% CI, 1.84-6.92; P < .001).

“We found that, especially within that first year post partum, patients had a significantly increased recurrence score of up to 13 points on average, higher than the nulliparous patients who were matched for age and lymph node status,” Zhang said. “In particular, we [saw that] up to [approximately] 3 years post partum, there [were] some increases in recurrence score. Our hope is that these data help us better refine how we define PPBC and help shed more light on the changes [such as] worse genomic signatures that are associated with PPBC.”

Additional findings from the study revealed that patients who were 1 (β, 13.22; 95% CI, 8.12-18.32; P < .001), 2 (β, 4.64; 95% CI, –0.16 to 9.44), and 3 years (β, 4.56; 95% CI, –0.76 to 9.87; P = .093) post partum had significantly increased recurrence scores compared with the nulliparous group.

“We often ask, ‘What is the date of first childbirth?’ But we don't ask, ‘What is the date of last childbirth?’ But that's actually what affects potentially higher risk of recurrence,” Zhang noted. “Ultimately, we found that in our patients [who are] up to 3 years post partum, their recurrence score was higher than we expected. For these patients who are recently post partum, oncologists might not normally be getting recurrence scores because they feel that potentially the other clinical pathologic features of the tumor are pretty low risk [in terms of] recurrence. Maybe in these patients, we should be reassessing and seeing whether we should be getting a recurrence score and then acting accordingly.”

References

1. Zektser Y, Guo M, Urueta Portillo D, Prasath V, El Warrak S. Ethnic differences in NAFLD among women with early-stage breast cancer receiving endocrine therapy. Presented at: OncLive National Fellows Forum: Breast Cancer; December 8, 2025; San Antonio, TX. Accessed February 18, 2026.
2. Haddad S, Zhang S, Shaik A, et al. Clinical implications of genomic signatures in postpartum breast cancer (PPBC). Presented at: OncLive National Fellows Forum: Breast Cancer; December 8, 2025; San Antonio, TX. Accessed February 18, 2026.