Effect of defibrination with batroxobin on growth and metastasis of JW sarcoma in mice

In order to gather information on the possible role of fibrin in tumour and metastasis growth, the development of JW sarcoma (JWS) was studied in BALB/c mice defibrinated with batroxobin. The spontaneous lung metastasis number was significantly reduced (as compared with controls) in mice defibrinated during the initial phase of tumour growth and dissemination, whereas it was unaffected in mice given batroxobin at later stages. Lung colony formation, upon i.v. injection of JWS cells, was also reduced in defibrinated mice. In this experimental model, removal of the host's circulating fibrinogen appeared therefore of benefit only during lodgement of cancer cells.