A46Lapatinib and continuous metronomic capecitabine in HER2 positive advanced breast cancer (ABC): a single center experience

Background: The efficacy of lapatinib (Lap) plus capecitabine (Cap) in HER2 amplified advanced breast cancer (ABC) has been widely reported in literature. However, cutaneous and gastro-intestinal toxicity may interfere with the optimal treatment delivery. Methods: In this observational cohort study, 24 patients (pts) with HER2 amplified ABC from a single Institution who received Lap/continuous metronomic Cap modified schedule (Lap, 1250 mg/daily, plus Cap, 1500 mg/daily) were enrolled from November 2009 to December 2014. We report data on efficacy and tolerability . Results: In our analysis, 23 pts were evaluable for toxicity and 20 pts for response. Median age was 51 years (range 34-70). Median follow-up was 25 months (range 1-53). The majority of pts (84%) had visceral metastases and about half of pts (52.5%) received ≥ 3 previous lines for advanced disease. The overall response rate (ORR) was 40%, with 2 complete responses (CR) and 6 partial response (PR). Four pts had prolonged stable disease (SD) (21%). The clinical benefit rate (CBR= partial response PR + complete response CR + prolonged stable disease SD ≥ 24 weeks) was achieved in 60% of pts. Four progressive disease (PD) were observed (20%). Median progression free survival (PFS) was 4.8 months, median overall survival (OS) 27 months. Treatment was well tolerated, mainly in terms of photosensitivity reaction during sun exposure. Main toxicities were grade 2 (G2): hand-foot syndrome (HFS) in 7 pts (30%), diarrhea in 5 pts (21%), ungueal alterations in 3 pts (13%), rash in 2 pts (8%). No grade 3 or 4 specific Lap/continuous metronomic Cap induced toxicities were reported. Three pts had dose reduction for gastrointestinal toxicity and 2 treatment discontinuations for persistent diarrhea G2. Conclusions: Our analysis showed that Lap/continuous metronomic Cap modifies schedule is active as treatment in HER2 positive ABC and minimally toxic. This combination might be considered when low toxicity burden is advisable and could allow sun exposure contrary to literature data.