Variation of CTC count and aneuploidy prior and post chemotherapy. (A) CTCs of 12 metastatic patients were dynamically monitored prior and after chemotherapy. PC-1~PC-12 are the codes of 12 metastatic pancreatic ductal adenocarcinoma patients, respectively. CTC numbers for PC-1, PC-2, PC-3, PC-4, PC-6, PC-7, PC-9, PC-10, PC-12 were obviously increased after chemotherapy, especially for PC-4, and PC-9. CTC numbers for PC-5, PC-11 were slightly decreased after chemotherapy. CTC numbers for PC-8 exhibited a stable tendency prior to and after chemotherapy; (B) The proportion of triploid CTC prior- and post-chemotherapy was statistically significant (χ2 = 30.381, p < 0.001). PC-9 presented numerous multiploid CTCs (146 CTCs/7.5 mL) after 3 weeks of chemotherapy, which spread the distribution of the CTCs, therefore we rejected PC-9 in this study. CTC: circulating tumor cells.