title: Efficacy of lapatinib monotherapy on occult breast cancer presenting with cutaneous metastases: A case report.
abstract: The case of a 72-year-old female who identified a lymph node enlargement in the left axilla is reported in the present study. A lymph node biopsy revealed a metastatic adenocarcinoma of the axillary lymph node. Following various assessments, the patient was diagnosed with occult breast cancer and lymph node metastases, for which treatment was initiated. Trastuzumab monotherapy was administered as the patient was elderly, positive for the hepatitis B virus and exhibited the following immunostaining/immunohistochemical analysis results: Estrogen receptor (ER) negative (-), progesterone receptor (PgR) negative (-) and human epidermal growth factor receptor 2 (HER2) positive (3+). Breast ultrasonography was performed 10 months after the initial trastuzumab administration and the left axillary lymph node enlargement had reduced in size and severity. However, a skin rash (erythema) was observed encompassing the left breast and extending into the axilla. As determined by the result of a skin biopsy of this area, the patient was diagnosed with occult breast cancer with cutaneous metastases. The immunohistochemical analysis results obtained from the skin biopsy were similar to those obtained from the lymph nodes: ER (-), PgR (-) and HER2 (3+). Therefore, the patient was switched from trastuzumab to lapatinib monotherapy. The erythema completely disappeared after two months of treatment. At present (34 months following lapatinib monotherapy initiation) no new lesions or severe side-effects have been observed.
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Noguchi
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Kamio
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Kamio
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Miura
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Tamaki
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Nishizawa
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Aoyama
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Oochi
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Kameoka
keywords: cutaneous metastases; lapatinib monotherapy; occult breast cancer; serum human epidermal growth factor receptor 2