HORMONE-RECEPTOR -POSITIVE BREAST CANCER: DIFFERENT PROGNOSIS OF BONE METASTASIS AMONG MOLECULAR SUBTYPES

Area of Science:

• Oncology
• Radiology
• Molecular Biology

Background:

• Hormone-receptor-positive breast cancer is a common subtype.
• Bone metastasis is a significant concern in breast cancer prognosis.
• Understanding metastasis patterns based on molecular subtypes and disease stage is crucial.

Purpose of the Study:

• To identify the probability of bone metastasis in hormone-receptor-positive breast cancer patients.
• To correlate bone metastasis with molecular subtypes (Luminal-A, Luminal-B) and disease stages (I, II, III).
• To evaluate the prognostic significance of molecular subtypes and stages in bone metastasis.

Main Methods:

• Retrospective study of 101 post-treated women with hormone-receptor-positive breast cancer (Stages I-III).
• Bone scintigraphy (BS) performed before and after treatment using Tc99m MDP radiotracer.
• Correlation of BS data with molecular subtype (Luminal-A, Luminal-B) and cancer stage.

Main Results:

• Luminal A subtype showed a higher incidence of bone metastasis across all stages compared to Luminal B.
• Stage II (p=0.022) and Stage III (p=0.001) showed statistically significant differences in bone metastasis rates between Luminal A and Luminal B subtypes.
• Luminal A patients had a higher probability of bone metastasis (e.g., 60.5% in Stage II), while Luminal B, though rarer, presented a more aggressive profile with metastasis in 25% of Stage II cases.

Conclusions:

• Luminal A breast cancer has a higher propensity for bone metastasis, but generally offers a better prognosis than the rarer, more aggressive Luminal B subtype.
• Molecular subtype and cancer stage are significant prognostic factors for bone metastasis in hormone-receptor-positive breast cancer.
• Considering both molecular subtypes and stages is vital for accurate prognosis and patient management.