Hypothesis

Occurrence of cancer at multiple sites: Towards distinguishing multigenesis from metastasis

Wei-Kang Zhang^{* 1} , Chun Zhang^{* 2} , Jing J Zhang³ and Shi V Liu⁴

¹Department of General Surgery, Union Hospital, Huazhong Science and Technology University, Wuhan, China

²Institute of Hematology, Union Hospital, Huazhong Science and Technology University, Wuhan, China

³Waverly Primary Care, Cary, USA

⁴Eagle Institute of Molecular Medicine, Apex, USA

author email corresponding author email* Contributed equally

Biology Direct 2008, 3:14doi:10.1186/1745-6150-3-14

Published:	11 April 2008

Abstract

Background

Occurrence of tumors at multiple sites is a hallmark of malignant cancers and contributes to the high mortality of cancers. The formation of multi-site cancers (MSCs) has conventionally been regarded as a result of hematogenous metastasis. However, some MSCs may appear as unusual in the sense of vascular dissemination pattern and therefore be explained by alternative metastasis models or even by non-metastatic independent formation mechanisms.

Results

Through literature review and incorporation of recent advance in understanding aging and development, we identified two alternative mechanisms for the independent formation of MSCs: 1) formation of separate tumors from cancer-initiating cells (CICs) mutated at an early stage of development and then diverging as to their physical locations upon further development, 2) formation of separate tumors from different CICs that contain mutations in some convergent ways. Either of these processes does not require long-distance migration and/or vascular dissemination of cancer cells from a primary site to a secondary site. Thus, we classify the formation of these MSCs from indigenous CICs (iCICs) into a new mechanistic category of tumor formation – multigenesis.

Conclusion

A multigenesis view on multi-site cancer (MSCs) may offer explanations for some "unusual metastasis" and has important implications for designing expanded strategies for the diagnosis and treatment of cancers.

Reviewers

This article was reviewed by Carlo C. Maley nominated by Laura F. Landweber and Razvan T. Radulescu nominated by David R. Kaplan. For the full reviews, please go to the Reviewers' comments section.