Fortner RT, et al. - Given the differences in ovarian cancer risk factors according to histotype and the considerable variability in outcomes seen within subtypes, researchers examined the influence of risk factor profiles on tumor aggressiveness, defined by time between diagnosis and death and independent of histology. From 21 prospective cohorts, they classified 4,584 invasive epithelial ovarian cancers as highly aggressive (death in <1 year, n=864), very aggressive (death in 1 to < 3 years, n=1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n=1,691). Relative to nulliparity, a first/single pregnancy was inversely correlated with highly aggressive disease; no association for subsequent pregnancies was identified. Conversely, there was a comparable correlation of first and subsequent pregnancies with less aggressive disease. Association of family history of ovarian cancer only with risk of less aggressive disease was noted. Increased risk of highly aggressive disease was observed with high BMI and current smoking status. Outcomes suggest a direct correlation of ovarian cancer risk factors with subtypes defined by tumor aggressiveness, rather than through differential effects on histology.