Hyperpigmentation following THC chemotherapy in a 51-year- old woman with metastatic HER2-enriched breast cancer

Abstract

Cutaneous hyperpigmentation is a frequent occurrence among breast cancer patients undergoing TCH (docetaxel, carboplatin, and trastuzumab) chemotherapy regimens but is underreported as an adverse event of chemotherapy. This case report describes a 51-year-old woman with metastatic Human Epidermal Growth Factor Receptor 2 (HER-2)-enriched invasive ductal carcinoma (T3N3aM1; bone/liver metastases) who developed diffuse hyperpigmentation after three cycles of docetaxel/carboplatin/trastuzumab (TCH) chemotherapy. Hyperpigmentation manifested as facial melasma-like patches and persisted until 1 year after chemotherapy. The incidence of hyperpigmentation in patients undergoing TCH/Taxane regimens for HER2-enriched subtype has been rarely documented in the literature. This HER2-enriched subtype, which is negative for hormonal receptors, shows a 2.1-fold higher rate of skin-related adverse events compared to luminal-HER2-positive tumours. This difference may be attributed to greater chemosensitivity and increased proliferative activity in this subtype. Management of hyperpigmentation during TCH chemotherapy involves the use of topical agents and continuation of chemotherapy for up to 6 cycles. In 83% of cases, pigmentation resolves within 2 to 6 months after treatment. Hyperpigmentation as a TCH-related toxicity in HER2-positive metastatic breast cancer can be a concerning and distressing symptom. Early recognition and dermatologic collaboration can improve quality of life