Matsuo K, et al. - In this retrospective population-based study, researchers compared clinico-pathological features and consequences of mucinous borderline ovarian tumor (mucinous-BOT, n=2130) vs invasive well-differentiated mucinous ovarian cancer (mucinous-OC, n=581). Findings in the multivariable analysis highlighted more likeliness of being older, Eastern U.S. residents, and having undergone hysterectomy or lymphadenectomy in women with mucinous-OC vs those with mucinous-BOT, as well as a reduction over time was seen in the number of women diagnosed with mucinous-OC. Having stage T1c and a smaller tumor size was more likely in mucinous-OCs vs mucinous-BOT. Significantly poorer cause-specific survival was observed among women with mucinous-OC vs those with mucinous-BOT following propensity score matching in multivariable analysis. They found similar outcomes among subgroups for reproductive age, stage T1a disease, large tumor, and unstaged cases.