This book is comprised of four distinct sections: Epidemiology, Pathology, Molecular Genetics, and Inherited Susceptibility, with each section divided into chapters categorized by disease. Section A reviews the epidemiology of prostate and testicular cancer, with an emphasis on clinical and environmental factors associated with these diseases. Section B begins by describing various pathological features of prostate cancer, followed by descriptions of the wide variety of testicular cancers as well as a brief section on the use of tumor markers for monitoring disease. Section C focuses on somatic genetic changes in prostate and testicular cancers using new technologies such as comparative genomic hybridization and gene expression profiling. Section D concentrates on the progress made toward understanding inherited susceptibility to prostate cancer and to testicular cancer.