Primary tumor characteristics, prior treatments and CTC screening measurements of patients with advanced breast cancer.

Sixteen patients were recruited to the trial of a daily dose of lapatinib monotherapy. All patients had one or more EGFR positive CTCs. Twelve patients were assessed for HER2 positivity in their CTCs, and of the eleven assessable, ten (91%) had a proportion that were HER2 positive.aEastern Cooperative Oncology Group Status. 0 - Fully active, able to carry on all pre-disease performance without restriction, 1-Restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature, e.g., light house work, office work, 2 - Ambulatory and capable of all self-care but unable to carry out any work activities. Up and about more than 50% of waking hours.bIDC – Invasive ductal carcinoma, ILC – Invasive lobular carcinoma, PAP - Papillary.cCTCs present in 7.5 ml blood at screening or baseline as assessed by the CellSearch system.NK = not known, the assessment of EGFR on the primary tumor being made according to our published methods [25].