Dramatic chemotherapy response in stage IIIB triple-negative breast cancer

What happened, in summary

A 49-year-old woman presented with a rapidly growing right-breast mass that had developed over three months. It began as a furuncle-like area, opened, and produced drainage. Examination showed an 18 by 17 cm fungating mass, while imaging found no lymph-node involvement or distant metastases.

Biopsy showed grade 3 invasive ductal carcinoma that was negative for estrogen receptor, progesterone receptor, and HER2, making it triple-negative. The cancer was classified as stage IIIB. Germline testing was negative for BRCA1 and BRCA2 but identified an FLCN c.1285delC mutation associated with Birt-Hogg-Dubé syndrome. Tumor testing also found a TP53 p.T150fs frameshift. The relationship between the inherited FLCN finding and her breast cancer remained uncertain.

She received dose-dense doxorubicin and cyclophosphamide, followed by 12 weekly paclitaxel treatments. Three cycles of carboplatin were added every three weeks. The mass began shrinking within two weeks and was reduced to a linear area of pink skin by the end of chemotherapy.

One month later, she underwent bilateral mastectomy with reconstruction and right sentinel-node biopsy. All three nodes were benign, although three small residual invasive foci remained in the skin, the largest measuring 0.7 cm. She then completed radiation to the right chest wall and six months of capecitabine. Mild to moderate neuropathy was managed with gabapentin. At 18 months after surgery, she had no recurrence and continued surveillance for breast cancer and other health risks associated with Birt-Hogg-Dubé syndrome.