RESUMEN
AIMS: FOXL2 mutation has been consistently identified in adult granulosa cell tumours (A-GCTs). DICER1 mutations have been described predominantly in Sertoli-Leydig cell tumours (SLCTs). The prognostic implication of these mutations remains uncertain, as moderately sized studies have yielded variable outcomes. Our aim was to determine the implications of DICER1 and FOXL2 mutations in 156 ovarian sex cord-stromal tumours (SCSTs). METHODS AND RESULTS: FOXL2 mutations were found in 94% of pathologically confirmed A-GCTs (95/101), in one of eight juvenile granulosa cell tumours (J-GCTs), and in two of 19 SLCTs. DICER1 mutations in the RNase IIIb domain were found in six of 19 SLCTs, two of eight J-GCTs, and one of 12 undifferentiated SCSTs (Und-SCSTs). Comparison of DICER1-mutated SLCTs with DICER1-non-mutated SLCTs showed that patient age at diagnosis was lower and oestrogen receptor expression was more frequent in DICER1-mutated tumours. With a median follow-up of 22 months, two of five DICER1-mutated SLCTs relapsed, in contrast to none of eight DICER1-non-mutated tumours. CONCLUSIONS: Our results suggest that, in contrast to FOXL2 mutations in A-GCT, DICER1 mutations in SLCT might be more useful for prognosis than for diagnosis. However, study of a larger cohort of patients is necessary to establish this. Identification of genetic alterations in SCST offers promising therapeutic options.
Asunto(s)
ARN Helicasas DEAD-box/genética , Proteína Forkhead Box L2/genética , Tumor de Células de la Granulosa/genética , Neoplasias Ováricas/genética , Ribonucleasa III/genética , Tumor de Células de Sertoli-Leydig/genética , Tumores de los Cordones Sexuales y Estroma de las Gónadas/genética , Adolescente , Adulto , Anciano , Femenino , Tumor de Células de la Granulosa/diagnóstico , Tumor de Células de la Granulosa/patología , Humanos , Persona de Mediana Edad , Mutación , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/patología , Adhesión en Parafina , Pronóstico , Tumor de Células de Sertoli-Leydig/patología , Tumores de los Cordones Sexuales y Estroma de las Gónadas/diagnóstico , Tumores de los Cordones Sexuales y Estroma de las Gónadas/patología , Adulto JovenRESUMEN
OBJECTIVE: Ovarian sex cord-stromal tumors (SCSTs) are rare and their diagnosis is often difficult to establish. Recently, immunostaining and molecular analysis for Forkhead box L2 (FOXL2) have been developed in this pathology. This study aims to assess the benefit of an algorithm incorporating these new tools for a better diagnosis and classification of SCSTs METHODS: Seventy-two tumors with a potential diagnosis of SCSTs were addressed by 37 different pathologists to one French rare ovarian tumor expert center, member of the Rare Malignant Ovarian Tumor network (TMRO). Then a "second opinion" (SO) through an algorithm incorporating immunostaining (IHC) and molecular analysis of FOXL2 was performed for all these cases. This algorithm was then validated by all pathologists of the TMRO network. RESULTS: After a second opinion including molecular analysis and immunostaining for FOXL2 the initial diagnosis was changed in 15 of 72 samples (21%). FOXL2 mutation was present in 44 out of 47 adult granulosa cell tumors (94%), in 3 out of 8 Thecomas (37%), in 1 out of 10 Sertoli-Leydig cell tumors (SLSTs) (10%) and in 3 out of 5 undifferentiated-SCSTs (Und-SCSTs) (60%). Immunoexpression of FOXL2 was available in 45 cases of SCSTs: FOXL2 was expressed in 44 of them (98%). CONCLUSIONS: A second opinion in an expert center for all cases of SCSTs is fundamental to get an optimal classification of these rare tumors. This second opinion could be performed with an algorithm which integrates FOXL2 mutation and expression status of FOXL2 in order to standardize the practice.