Homogeneous pancreatic cancer spheroids mimic growth pattern of circulating tumor cell clusters and macrometastases: displaying heterogeneity and crater-like structure on inner layer.

It is possible to establish 3D CTC cluster models from homogenous PDA cell lines using hanging drop and ultra-low attachment plates. PDA cell line displays its own intrinsic properties or heterogeneity. The mechanism of formation of the crater-like structure as well as golf ball-like structure needs further exploration.