Metastatic patterns of cancers: results from a large autopsy study.

CONTEXT: Many studies have addressed metastatic patterns seen among various cancers. No recent studies, however, provide quantitative analyses of such patterns arising from a broad range of cancers based primarily on postmortem tissue analyses.
OBJECTIVE: To provide a quantitative description of metastatic patterns among different primary cancers based on data obtained from a large, focused autopsy study.
DESIGN: Review of data from 3827 autopsies, performed between 1914 and 1943 on patients from 5 affiliated medical centers, comprising 41 different primary cancers and 30 different metastatic sites.
RESULTS: Testicular cancers were most likely to metastasize (5.8 metastases per primary cancer), whereas duodenal cancers were least likely to do so (0.6 metastases per primary cancer). Preferred metastatic sites varied among the primary cancers analyzed. Overall, regional lymph nodes were the most common metastatic target (20.6% of total), whereas testes were the least common (0.1% of total).
CONCLUSIONS: Not surprisingly, different primary cancers tended to metastasize, with differing frequencies, to different sites. These varying metastatic patterns might be helpful in deducing the origins of cancers whose primary sites are unclear at presentation.