Evidence for an additional metastatic route: in vivo imaging of cancer cells in the primo-vascular system around tumors and organs

Mol Imaging Biol. 2011 Jun;13(3):471-480. doi: 10.1007/s11307-010-0366-1.


Purpose: Researchers have been studying the mechanisms by which metastasis can be prevented via blocking the hematogenous and the lymphatic routes for a long time now. However, metastasis is still the single most challenging obstacle for successful cancer management. In a new twist that may require some retooling of this established approach, we investigated the hypothesis that tumor metastases can occur via an independent fluid-conducting system called the primo-vascular system.

Procedures: The dissemination and growth of near-infrared quantum dot (NIR QD)-electroporated cancer cells in metastatic sites were investigated using in vivo multispectral imaging techniques.

Results: Our results show that the NIR QD-labeled cancer cells were able to migrate through not only the blood vascular and lymphatic systems but also the primo-vascular system extending from around the tumor to inside the abdominal cavity. Furthermore, the NIR QD-labeled cancer cells, which had been seeded intraperitoneally, specifically infiltrated the primo-vascular system in the omentum and in the gonadal fat.

Conclusions: These findings strongly suggest that the primo-vascular system may be an additional metastasis route, complementing the lymphatic and hematogenous routes, which facilitate the dissemination and colonization of cancer cells at secondary sites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Movement
  • Diagnostic Imaging / methods*
  • Disease Models, Animal
  • Electroporation
  • Female
  • Gonads / pathology
  • Humans
  • Lymphatic Vessels / pathology
  • Mice
  • Mice, Nude
  • Neoplasm Metastasis*
  • Neoplasms / blood supply*
  • Neoplasms / pathology*
  • Omentum / pathology
  • Organ Specificity*
  • Ovarian Neoplasms / pathology
  • Quantum Dots
  • Subcutaneous Tissue / pathology
  • Tumor Stem Cell Assay
  • Xenograft Model Antitumor Assays