The patient with quadruple cancer was a 32 year-old female who had osteosarcoma, bilateral breast cancer and adenocarcinoma of the lung. When chromosomal analysis of peripheral blood lymphocyte was performed, two abnormal cells were detected among 42 cells examined. The first cell showed a translocation involving chromosome 1 and 20 and trisomic for chromosome 19. The second cell was trisomic for chromosome x. Southern blot analysis of DNA from peripheral blood lymphocyte revealed that there was no difference in the expression of Rb gene between the patient and healthy adult.