Ruscito I, et al. - Researchers analyzed data from studies assessing the impact of aldehyde dehydrogenase-1 (ALDH1) expression on ovarian cancer survival and clinico-pathological variables. These studies were identified via electronic searches of PubMed, MEDLINE and Scopus using the terms: “ovarian cancer” AND “immunohistochemistry” AND [“aldehyde dehydrogenase-1” OR “ALDH1” OR “cancer stem cell”]. Of 233 studies retrieved, 13 studies including 1885 patients met all selection criteria. Findings demonstrated the correlation of high levels of ALDH1 expression with worse OS and PFS in ovarian cancer patients. No correlation was found between ALDH1 expression and tumor histology, FIGO Stage, tumor grading lymph nodal status or patients' age at diagnosis.