title: A circulating tumor cell cluster-based model for tumor metastasis (Hypothesis).
abstract: Metastasis is the major cause of mortality in patients with malignancies; however, the mechanisms of tumor cell dissemination and metastasis formation are obscure. Circulating tumor cells (CTCs) are believed to be a critical step for distant metastasis and are associated with a poor patient prognosis. The precise processes of metastasis formation from CTCs are vague. In the present study, we hypothesize that two CTC cluster-based mechanisms of tumor cell inoculation in ectopic organs may be viable: i) Formation of a micro-cancer embolus due to interception of CTC clusters by small vessels; and ii) formation of micrometastasis in an extravasation-dependent or -independent manner. Pathological evidence of micro-cancer emboli is critical for the verifications of this hypothesis. If proved true, this hypothesis will provide a novel perspective for cancer metastasis and has valuable clinical implications.
authors.affiliation: Department of Oncology, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang 310006, P.R. China.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Hong
authors.affiliation: Australian and New Zealand Army Corps Research Institute, University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Ziduo
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
keywords: CTC cluster; epithelial-mesenchymal transition; extravasation; metastasis; micro-cancer embolus