We excluded all patients with eidence of cancer on biopsy specimens. ital status and death date information was queried using an institutionally approed Internet research and location serice.

• 我们排除所有在活检标本中有癌症迹象的患者。通过批准的常用因特网调查和地区服务得到患者的重要数据和死亡日期信息。