Rapid Hemostasis and Significant Tumor Regression in Ulcerative Breast Cancer Via Combined Modified Lattice Radiotherapy and Systemic Therapy: A Case Report

Ulcerative giant breast cancer (UGBC) presents management challenges including uncontrolled bleeding, infection, and rapid tumor progression, which often culminate in life-threatening complications. Traditional spatially fractionated radiotherapy (SFRT) like lattice radiotherapy (LRT) offers potential for palliating bulky tumors, although its application in UGBC remains limited. We report a 51-year-old woman with a hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative stage IIIC UGBC (20.5 cm × 6.98 × 18.17 cm ulcerative lesion). Treatment consisted of modified lattice radiotherapy (mLRT: 15 Gy×3 fractions), followed by volumetric-modulated arc therapy (VMAT: 36 Gy/20 fractions) and systemic therapy (exemestane, capecitabine, CDK4/6 inhibitor). Rapid hemostasis was achieved within 5 days, with 39.7% tumor reduction at week 4 and progressive wound healing. At 3-month follow-up after the completion of mLRT and prior to definitive radiotherapy, the tumor had achieved a 61.8% volume reduction, with only minimal residual disease remaining. The radiation-induced skin reaction gradually alleviated with symptomatic treatment. This case demonstrates mLRT's efficacy in achieving rapid hemostasis and significant tumor regression for chemotherapy-refusing UGBC patients. The combined approach of mLRT, VMAT, and systemic therapy provides a promising multidisciplinary strategy for symptom control and quality-of-life improvement. Further prospective studies are needed to validate these findings.