Conference Coverage

Survival Disparities and Tumor Aggressiveness in Patients With Breast Cancer, Coexisting Chronic Lymphocytic Leukemia

Anthony Calabro, MA

Key Highlights

  • Patients with breast cancer and chronic lymphocytic leukemia (CLL) had significantly worse overall and cause-specific survival compared with controls.
  • Higher rates of HER2-positive and triple-negative breast cancer were observed in the CLL group.
  • Patients with CLL presented with more advanced-stage disease at breast cancer diagnosis.
  • CLL-related immune dysregulation may contribute to more aggressive tumor biology.

Patients with breast cancer and coexisting chronic lymphocytic leukemia (CLL) demonstrate significantly worse survival outcomes and present with more aggressive tumor characteristics compared with those without CLL, according to the results of a matched-control study presented at the American Society of Clinical Oncology 2025 annual conference in Chicago, IL.

CLL is marked by genetic mutations such as TP53 and immune dysregulation, which heighten the risk of secondary malignancies. Breast cancer, being the most common cancer in women, is highly sensitive to tumor biology and stage at detection. This intersection of CLL and breast cancer creates a complex clinical challenge, as CLL may affect both the development and course of breast cancer due to impaired immune surveillance and oncogenic therapy effects.

Researchers utilized the SEER database to identify two cohorts: 677 patients with breast cancer and CLL and more than 1 million patients with breast cancer without CLL. Researchers selected a matched control cohort of 400,741 patients by age, race, and year of diagnosis. Statistical analyses included chi-square testing, logistic regression, and Kaplan-Meier survival analysis to compare tumor features and outcomes between the groups.

Compared with controls, patients with CLL were more often diagnosed between ages 70 and 74 (20.09% vs 19.12%) and were predominantly White (90.84%). These patients presented with more advanced breast cancer (T1 tumors: 50.52% vs 71.95%; metastasis: 4.87% vs 1.75%; P < .001) and had higher frequencies of HER2-positive (10.19% vs 7.14%) and TNBC subtypes (6.65% vs 4.77%). Although the odds ratio (OR) for TNBC was elevated (OR 1.16), it was not statistically significant (P = .33). Kaplan-Meier analysis revealed a hazard ratio of 2.07 for overall survival and 2.11 for cause-specific survival in the CLL group (both P < .001).

“Breast cancer patients with CLL have more advanced disease at presentation and significantly worse survival outcomes compared to their counterparts,” the authors concluded. “The increased

prevalence of TNBC and HER2-positive subtypes suggests more aggressive tumor biology, potentially driven by CLL-related immune dysfunction, treatment, and genetic factors. These findings underscore the importance of heightened surveillance and tailored management strategies for breast cancer patients with CLL.”

Reference:
Bhanushali V, Bhanushali C, Vojjala N, et al. Breast cancer in chronic lymphocytic leukemia patients: Characteristics and survival outcomes. Presented at: American Society of Clinical Oncology 2025 Annual Conference in Chicago, IL. Accessed June 4, 2025. https://www.asco.org/abstracts-presentations/ABSTRACT496392.