All patients undergo blood collection before their first dose of first-line chemotherapy* to determine baseline CTC count. Patients with < 5 CTCs at baseline are assigned to group I. Patients with ≥ 5 CTCs at baseline undergo a second blood draw on day 22 (after completion of 1 course of chemotherapy). Patients with < 5 CTCs after completing 1 course of chemotherapy are assigned to group 2. Patients with ≥ 5 CTCs after completion of 1 course of chemotherapy are assigned to group 3.