NCI investigators are collaborating with the Occupational Cancer Research Centre in Toronto, Canada, and the University of British Columbia in Vancouver, Canada on a pooled study of pesticide use data from three NCI case-control studies conducted in the 1980s and 90s with data from a Canada-wide study with similar pesticide data. Investigators will evaluate rare pesticides and cancer at multiple sites, including lymphoma, Multiple myeloma and immunoproliferative diseases and soft tissue sarcoma. They will also be able to evaluate sub-types of lymphoma and multiple pesticides, since this study will have more cases using pesticides than any other study in the world.