作者复习了50例遗传性视网膜母细胞瘤患者的病历,以研究死亡原因和眼外笫二恶性瘤的发病率。这些患者第二肿瘤的发病率在10年时为6％,20年时为14％,30年时为14％。最初的研究认为,这些肿瘤由放射治疗引起,因为它们好发于接受较大放射量的区域。新的调查表明放疗不是唯一因素,因有14％的这类患者用外科手术治疗而未用放射治疗亦发生第二肿瘤。据新近对不用放射治疗或用放射治疗但肿瘤 The author reviewed the medical records of 50 patients with hereditary retinoblastoma to study the cause of death and the incidence of extraocular tumors. The incidence of secondary tumors in these patients was 6% at 10 years, 14% at 20 years, and 14% at 30 years. Initial studies suggested that these tumors were caused by radiation therapy because they occurred in areas that received larger amounts of radiation. New investigations indicate that radiotherapy is not the only factor, as 14% of these patients have undergone surgery and have not had radiation therapy. According to recent radiation therapy but without radiation but tumor