Microsatellite instability is an independent indicator of recurrence in sporadic stage I-II endometrial adenocarcinoma

Purpose: The aim of this study was to define the prognostic role of microsa tellite status in 65 stage I-II primary sporadic endometrioid endometrial a denocarcinoma (EEA) patients. Patients and Methods: Familiarity for neoplasia was ascertained in all pati ents on the basis of a questionnaire. Microsatellite status was assessed by matching normal and tumoral DNA probed for five dinucleotide repeats and o ne mononucleotide repeat marker. Microsatellite status was analyzed in rela tion to clinicopathologic characteristics of the patients and length of dis ease-free survival (DFS), Results: Eleven tumors (17%) of 65 had instability at two or more loci and were considered as unstable or microsatellite instability (MI), Tumors with no instability or instability at one locus were classified as microsatelli te stable (MS). The percentage of MI was significantly higher in poorly tha n in well to moderately differentiated tumors (50% v 9%; P = .003), The 5-y ear DFS rate of MI patients wets 63% (95% confidence interval [Cl], 35% to 91%) versus 96% (95% CI, 91% to 101%) of MS patients (P = .0004). In multiv ariate analysis, only the presence of MI, stage II of disease, and depth of myometrial invasion greater than 50% retained independent prognostic roles . Conclusion: The assessment of microsatellite status may provide useful info rmation for preoperative prognostic characterization of stage I-II primary sporadic EEA patients in which more individualized treatment options can be attempted.