In a case-control study of 1031 epithelial ovarian cancers and 2311 control
s conducted in Italy, 56 cases and 116 controls reported history of benign
ovarian cysts, corresponding to a relative risk of 1.3 (95% confidence inte
rval = 0.9-1.8). In a subset of 255 histologically reviewed cases, mucinous
and endometrioid ovarian neoplasms and neoplasms of stage I or II arose mo
re frequently from cysts, while use of oral contraceptives or parity were n
ot significantly related to history of ovarian cysts. (C) 2001 Lippincott W
illiams & Wilkins.