A case report of metastatic breast cancer successfully treated with lapatinib plus capecitabine therapy

Abstract

Background: Lapatinib is a dual tyrosine-kinase inhibitor which targets both human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR) tyrosine-kinases. Lapatinib showed promising results both in trastuzumab-naïve and in pretreated HER2 positive advanced breast cancer and has the advantage of being administered orally. It has been showed that lapatinib plus capecitabine is superior to capecitabine alone in HER2 positive advanced breast cancer patients previously treated with anthracycline, taxane and trastuzumab. Case-report: A 34-year-old woman was admitted to our hospital in January 2008 with a palpable nodule in the lower inner quadrant of the right breast (about 5 cm) and an enlarged homolateral axillary lymph node. The biopsies from the right breast nodule and axillary lymph node showed an invasive ductal carcinoma. Immunohistochemical (IHC) staining of estrogen and progesterone receptors was negative but HER2 status by FISH was positive. According to TNM classification, it was pT2N1M0. It was decided to start neoadjuvant chemotherapy with AC + TH schedule (doxorubicin 60 mg/m2 day 1 and cyclophosphamide 600 mg/m2 day 1 every 21 days for 4 cycles plus docetaxel 100 mg/m2 every 21 days for 4 cycles with concurrent trastuzumab 8mg/kg followed by 6 mg/kg) with good clinical response. Six months later she underwent radical modified mastectomy with axillary lymph nodes dissection and immediate breast reconstruction. Histological examination confirmed a 30 mm, grade 3, invasive ductal carcinoma with dermal and lymphatic invasion, and one metastatic lymph node (1/12 nodes). Computed tomography scans (CT) and bone scintigraphy didn't reveal any secondary lesion. She was submitted to radiotherapy and she completed one year treatment with trastuzumab in March 2009. She had no recurrence until April 2010, when she complained of sternal pain and dyspnea. CT showed carcinomatous lymphangitis and multiple liver metastasis. Bone scintigraphy revealed multifocal osteoblastic bone metastasis. Chemotherapy with lapatinib 1250 mg/day on days 1-21 plus capecitabine 2000 mg/m2/day on days 1-14 every 3 weeks and zoledronic acid was started. Capecitabine dose was reduced 25% due to hand - foot syndrome (grade 3). After one year of therapy, she has complete response of lung disease, partial response of liver disease and stabilization of bone metastasis. No other side effects of therapy were recorded and the patient shows an ECOG performance status of 0. Conclusion: Our case has no evidence of disease progression after fourteen months of lapatinib plus capecitabine therapy, which is significantly longer than the median of 6 months that it has been reported by the most important published trial. This supports the efficacy and good safety profile of this treatment in HER2 positive advanced and metastatic breast cancer.