Objective: To determine whether fluid hysteroscopic directed biopsies , in pati ents with endometrial cancer upstages the tumor and worsens the prognosis. Study design: Between January 1996 and September 2001, a total of 62 consecutive pati ents with endometrial cancer, treated at our institution, were randomized 3 ∶2 to have or not to have a fluid hysteroscopic biopsy just prior to surgery. A tot al of 38 patients underwent a hysteroscopy after the induction of anesthesia. Al l patients had pelvic washings performed, followed by a hysterectomy, bilateral salpingooforectomy and pelvic +/-para-aortic lymph node dissections. Only sta ges I and II endometrioid type tumors or stage IIIa, secondary to positive pelvi c washings, were included in the study. Eight patients in the hysteroscopy group and four patients in the control group were excluded for various reasons. Patie nts received post-operative radiation therapy depending on the surgical-pathol ogical risk factors. The median follow up was 34 months. Fishers Exact Test wa s performed to compare differences between the hysteroscopic (n=30) and the cont rol (n=20) groups. Results: We found three patients (10%) with positive washing s in the hysteroscopic group compared to one (5%) among the controls (P=0.64), with a statistical power of < 20%. If the differences would persist, we would n eed 588 patients in each arm to obtain a power of 80%, and reach definitive con clusions. The Odds Ratio (OR) of performing a hysteroscopy and upstaging the tum or in this study was: 2.1 95%CI (0.20-21.09). Prognostic variables were compar ed between both groups and no differences were observed. All patients but one (d ead due to intercurrent disease), were alive and with no evidence of disease at the completion of the study. Conclusions: Fluid hysteroscopy and directed biopsi es may have a small risk of upstaging early endometrial cancers, but does not se em to influence prognosis. Objective: To determine whether fluid hysteroscopic directed biopsies, in pati ents with endometrial cancer upstages the tumor and worsens the prognosis. Study design: Between January 1996 and September 2001, a total of 62 consecutive pati ents with endometrial cancer, treated at our institution, were randomized 3: 2 to have or not to have a fluid hysteroscopic biopsy just prior to surgery. A tot of of 38 patients underwent a hysteroscopy after the induction of anesthesia. Al l patients had pelvic washings performed, followed by a hysterectomy, bilateral salpingooforectomy and pelvic +/- para-aortic lymph node dissections. Only sta ges I and II endometrioid type tumors or stage IIIa, secondary to positive pelvi c washings, were included in the study. Eight patients in the hysteroscopy group and four patients in the control group were excluded for various reasons. Patie nts post-operative radiation therapy depending on the surgical-pathol ogical risk factors. The median follo We found three patients (10%) with positive washing s (n = 30) and the cont rol (n = 20) groups. in the hysteroscopic group compared to one (5%) among the controls (P = 0.64), with a statistical power of <20%. If the differences would persist, we would not e 588 patients in each arm to obtain a power of 80 %, and reach definitive con clusions. The Odds Ratio (OR) of performing a hysteroscopy and upstaging the tum or in this study was: 2.1 95% CI (0.20-21.09). Prognostic variables were compar ed between both groups and no differences were observed. All patients but one (d ead due to intercurrent disease), were alive and with no evidence of disease at the completion of the study. Conclusions: Fluid hysteroscopy and directed biopsi es may have a small risk of upstaging early endometrial cancers, but does not se em to influence prognosis.