Chemotherapy for malignant germ cell ovarian cancer in adult patients with early stage, advanced and recurrent disease

 

Abstract

Background

Malignant germ cell tumour of the ovary occurs in up to 0.07% of woman globally. Due to its rarity, evidence for treatment is lacking and often extrapolates clinical trial results of testicular germ cell cancers. The investigation on this rare tumour is further compounded by the fact that its occurrence in the adult population is even less compared to their paediatric counterpart. At present, the effectiveness of chemotherapy, regardless of stage in malignant germ cell tumour of the ovary is not entirely clear.

Objectives

To evaluate the effectiveness and safety of chemotherapy in adult women with early stage, advanced and recurrent malignant germ cell ovarian cancers.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Issue 1, 2010, Cochrane Gynaecological Cancer Group Trials Register, MEDLINE and EMBASE up to April 2010. We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies.

Selection criteria

We searched for randomised controlled trials (RCTs), quasi-RCTs and non-randomised studies that compared systemic therapy in adult women diagnosed with germ cell ovarian cancer who have confirmed pathological diagnoses.

Data collection and analysis

Two review authors independently assessed whether potentially relevant studies met the inclusion criteria, abstracted data and assessed risk of bias.

Main results

We found one RCT and one retrospective study that met our inclusion criteria. The data from these studies were too sparse to adequately assess the effectiveness and safety of adjuvant chemotherapy in the treatment of malignant germ cell ovarian cancer. All comparisons were restricted to single study analyses and this review was only based on 32 women, so it was not adequately powered to detect differences in survival. Adverse effects of treatment and recurrence-free survival were incompletely documented and QoL was not reported in any of the studies. We did not find any studies that reported specifically on adults so there were problems in separating data on adults and children in many of the potentially relevant studies.

Authors' conclusions

We found only low quality evidence on the use of chemotherapy in malignant germ cell tumours of the ovaries. Therefore we are unable to reach definite conclusions about the relative benefits and harms of chemotherapy use in this disease regardless of disease stage. Due to the benefit of chemotherapy in germ cell cancer of the testis, a trial of chemotherapy versus best supportive care is unlikely to be feasible. Despite this, good quality randomised studies are warranted in this disease to define the role of chemotherapy (type of chemotherapy, duration of treatment, benefit, short and long term toxicities). Given the rarity of this disease, we feel a trans-global approach would be essential in order to perform such trials.

 

Plain language summary

Chemotherapy for adult women diagnosed with a rare type of ovarian cancer of all stages (malignant germ cell cancer of the ovary)

Malignant germ cell cancer of the ovary (type of ovarian cancer) is a very rare type of cancer. Malignant ovarian germ cell cancer is a term used to describe a group of heterogeneous rare tumours affecting the ovaries. These tumours start in the egg (ovum) producing cells of the ovary, whereas the more common epithelial ovarian cancers start in the cells that cover the surface of the ovary. Unlike epithelial ovarian cancers, these tumours are often diagnosed early and a combination of surgery and chemotherapy usually results in favourable long term overall survival. Due to its rarity, this review is based on only one very small RCT and one small retrospective study. The data from these studies were too sparse to adequately assess the effectiveness and safety of chemotherapy after surgery (adjuvant chemotherapy) in the treatment of malignant germ cell ovarian cancer. All comparisons were restricted to single study analyses and this review was only based on 32 women, so it was not adequately powered to detect differences in survival. Adverse effects of treatment and recurrence-free survival were incompletely documented and QoL was not reported in any of the studies. We did not find any studies that reported specifically on adults as this disease usually afflicts younger people as opposed to the older population, so there were problems in separating data on adults and children in many of the studies. Many of the treatments used were taken from experiences of treating patients with testicular cancer, as they look similar under the microscope and behave similar clinically. Due to the small number of patients with malignant germ cell cancer in the two studies, our review shows that there were no good quality studies assessing the role of chemotherapy in this disease, be it in early or late stages. There was insufficient evidence to conclude that any form of chemotherapy or best supportive care is superior over the other. This review highlights the need for future good quality, well designed studies.

 

Resumen

Antecedentes

Quimioterapia para el cáncer de ovario de células germinales en pacientes adultas con enfermedad en estadio inicial, avanzado y recidivante

El tumor maligno de células germinales del ovario se presenta en hasta el 0,07% de las mujeres a nivel mundial. Debido a su baja incidencia, las pruebas de su tratamiento son insuficientes y por lo general se extrapolan los resultados de los ensayos sobre el cáncer testicular de células germinales. La investigación de este tumor poco frecuente se ve además obstaculizada por el hecho de que su incidencia en adultos es aún menor en comparación con la población pediátrica. Todavía no se tiene un conocimiento claro sobre la efectividad de la quimioterapia, independientemente del estadio del tumor maligno de células germinales del ovario.

Objetivos

Evaluar la efectividad y la seguridad de la quimioterapia en pacientes adultas con cáncer de ovario de células germinales en estadios temprano, avanzado y recidivante.

Estrategia de búsqueda

Se realizaron búsquedas en el Registro Cochrane Central de Ensayos Controlados (Cochrane Central Register of Controlled Trials) (CENTRAL) número 1, 2010, Registro de Ensayos del Grupo Cochrane de Cáncer Ginecológico (Cochrane Gynaecological Cancer Group), MEDLINE y en EMBASE hasta abril 2010. También se buscó en los registros de ensayos clínicos, los resúmenes de reuniones científicas y en las listas de referencias de los estudios incluidos.

Criterios de selección

Se buscaron ensayos controlados aleatorios (ECA), cuasialeatorios y estudios no aleatorios que compararan tratamientos sistémicos en pacientes adultas con diagnóstico de cáncer de ovario de células germinales y diagnósticos patológicos confirmados.

Obtención y análisis de los datos

Dos revisores evaluaron de manera independiente si los estudios potencialmente relevantes cumplían los criterios de inclusión, resumieron los datos y evaluaron el riesgo de sesgo.

Resultados principales

Se encontraron un ECA y un estudio retrospectivo que cumplían los criterios de inclusión. Los datos de estos estudios eran muy escasos para evaluar adecuadamente la efectividad y la seguridad de la quimioterapia posquirúrgica en el tratamiento del cáncer de ovario de células germinales. Todas las comparaciones se limitaron a los análisis de un solo estudio, y esta revisión se basó exclusivamente en 32 pacientes, por tanto no tuvo un adecuado poder estadístico para detectar diferencias en la supervivencia. Los efectos adversos del tratamiento y la supervivencia sin recidiva no se documentaron debidamente; además, ninguno de los estudios informó la CdV. No se hallaron estudios que informaran específicamente acerca de los adultos, en consecuencia hubo inconvenientes para distinguir los datos de adultos y niños en muchos de los estudios potencialmente relevantes.

Conclusiones de los autores

Sólo se hallaron pruebas de baja calidad acerca del uso de la quimioterapia para los tumores malignos de células germinales de los ovarios. Por tanto no se pudo establecer conclusiones definitivas acerca de los efectos beneficiosos y perjudiciales relativos de la quimioterapia en esta patología, independientemente del estadio de la enfermedad. Es poco probable que se realice un ensayo sobre la quimioterapia versus el mejor tratamiento médico de apoyo, debido a los beneficios de la quimioterapia en el cáncer testicular de células germinales. A pesar de ello, se justifica la realización de estudios aleatorios de buena calidad sobre esta enfermedad para establecer el rol de la quimioterapia (tipo de quimioterapia, duración del tratamiento, beneficios y efectos adversos a corto y largo plazo). Dada la baja frecuencia de esta patología, creemos que es imprescindible adoptar un enfoque intercontinental para poder realizar estos ensayos.

Traducción

Traducción realizada por el Centro Cochrane Iberoamericano