Metastatic invasive lobular carcinoma (ILC) presents significant intra-patient variability in crucial prognostic and predictive markers, raising important questions about the effectiveness of single-site biopsies for treatment decisions. Researchers have tapped into two postmortem tissue donation programs-UPTIDER in Belgium and Hope for Others in the United States-to analyze the heterogeneity in stromal tumour-infiltrating lymphocytes (sTIL), estrogen receptors (ER), progesterone receptors (PR), human epidermal growth factor receptor 2 (HER2), and KI67 across metastatic tissues.
The study involved a comprehensive analysis of 306 metastases collected during 12 patients’ autopsies, yielding an average of 27 samples per patient. Notably, both primary tumors and metastases exhibited low sTIL levels, with median values at 2% (ranging from 0.67% to 6.67%) in primary tumors and 0.67% (from 0% to 13.33%) in metastases. Regression modeling revealed a significant decline in ER and PR expression in metastases compared to primary tumors, with p-values less than 0.01. Moreover, the proliferation index as indicated by KI67 expression was significantly elevated in the metastases, presenting a p-value of 0.02. Almost all patients had low HER2 expression in their metastases, though the proportion varied dramatically, from 7.5% to 100%. This data underscores the remarkable biological diversity inherent in metastatic ILC at the patient level.
Additionally, the study investigated the concordance between radiological and pathological findings in identifying metastatic ILC. Central evaluations showed moderate concordance, with a median agreement of 78% at the organ level (ranging from 33.33% to 100%) and 71% at the patient level (ranging from 55.88% to 85.29%). These results suggest discrepancies between imaging and pathological assessments, holding important implications for disease monitoring and management.
The insights derived from this research underscore that relying on a single metastatic biopsy may not provide a comprehensive view of the biological landscape of metastatic ILC. Given the observed variability in hormone receptor expression, proliferation indices, and HER2 statuses, it becomes crucial for clinicians to adopt more inclusive strategies for detecting and monitoring metastases effectively. These findings highlight the necessity for personalized therapeutic planning, considering the tumor’s multifaceted nature.
This research, titled “Clinical and histopathological characterization of metastatic lobular breast cancer: lessons learned from post-mortem tissue donation programs,” emphasizes the need for improved diagnostic methodologies in light of the complexities found in metastatic breast cancer. As ongoing studies pave the way for enhanced understanding and treatment options, the focus will continue to be on evolving the standard of care for patients facing this challenging diagnosis.
In summary, the study presents vital information about the heterogeneity of metastatic ILC, advocating for a broader approach in treatment planning and monitoring.
Tags: metastatic invasive lobular carcinoma, breast cancer, biopsies, hormone receptor, HER2, tumor heterogeneity, patient management.
Original Source: https://www.emjreviews.com/oncology/news/metastatic-breast-cancer-shows-biomarker-differences/
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Publish Date: 2026-02-23 15:51:00
