ORTHOTOPIC ENGRAFTMENT OF HUMAN LUNG-TUMORS IN SCID MICE FOR THE STUDY OF METASTASIS

This study presents a new technique for the orthotopic engraftment of human lung tumours in SCID mice and demonstrates the importance of a m ore clinically relevant route of tumour propagation for the study of m etastatic potential. The orthotopic engraftment of human lung tumour b iopsy specimens was performed via an anterior thoracotomy into SCID mi ce. Engraftment of non-small cell lung cancer specimens from nine pati ents into 52 SCID mice yielded a 31% engraftment rate and a 50% metast asis rate. Unlike subcutaneous inoculation, the engraftment rates foll owing the orthotopic inoculation did not vary between squamous cell ca rcinomas and adenocarcinomas. Direct visceral pleural invasion was see n in most cases. Orthotopically placed tumours grew 5-fold by 4 to 6 m onths. Unique to this model was the observation of metastasis to clini cally relevant sites, such as the adrenal gland and supraclavicular ly mph nodes. Contralateral lung metastases were also noted in 37.5%, and one ovarian metastasis occurred. The procedure was well tolerated, wi th survival rates of 98%.