Department of Paediatrics, Division of Paediatric Oncology/Haematology, VU University Medical Center, PO Box 7057, Amsterdam, 1007MB, The Netherlands.
BMC Cancer. 2012 Aug 23;12:363. doi: 10.1186/1471-2407-12-363.
Advances in childhood cancer treatment over the past decades have significantly improved survival, resulting in a rapidly growing group of survivors. However, both chemo- and radiotherapy may adversely affect reproductive function. This paper describes the design and encountered methodological challenges of a nationwide study in the Netherlands investigating the effects of treatment on reproductive function, ovarian reserve, premature menopause and pregnancy outcomes in female childhood cancer survivors (CCS), the DCOG LATER-VEVO study.
The study is a retrospective cohort study consisting of two parts: a questionnaire assessing medical, menstrual, and obstetric history, and a clinical assessment evaluating ovarian and uterine function by hormonal analyses and transvaginal ultrasound measurements. The eligible study population consists of adult female 5-year survivors of childhood cancer treated in the Netherlands, whereas the control group consists of age-matched sisters of the participating CCS. To date, study invitations have been sent to 1611 CCS and 429 sister controls, of which 1215 (75%) and 333 (78%) have responded so far. Of these responders, the majority consented to participate in both parts of the study (53% vs. 65% for CCS and sister controls respectively). Several challenges were encountered involving the study population: dealing with bias due to the differences in characteristics of several types of (non-) participants and finding an adequately sized and well-matched control group. Moreover, the challenges related to the data collection process included: differences in response rates between web-based and paper-based questionnaires, validity of self-reported outcomes, interpretation of clinical measurements of women using hormonal contraceptives, and inter- and intra-observer variation of the ultrasound measurements.
The DCOG LATER-VEVO study will provide valuable information about the reproductive potential of paediatric cancer patients as well as long-term survivors of childhood cancer. Other investigators planning to conduct large cohort studies on late effects may encounter similar challenges as those encountered during this study. The solutions to these challenges described in this paper may be useful to these investigators.
NTR2922; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922
在过去几十年中，儿童癌症治疗方面的进展显著提高了生存率，由此产生了一个快速增长的幸存者群体。然而，化疗和放疗都可能对生殖功能产生不良影响。本文描述了一项在荷兰进行的全国性研究的设计和遇到的方法学挑战，该研究旨在调查治疗对女性儿童癌症幸存者（CCS）的生殖功能、卵巢储备、早绝经和妊娠结局的影响，该研究称为 DCOG LATER-VEVO 研究。
该研究是一项回顾性队列研究，由两部分组成：一份评估医疗、月经和产科史的问卷，以及一项通过激素分析和经阴道超声测量评估卵巢和子宫功能的临床评估。合格的研究人群由在荷兰接受治疗的儿童癌症 5 年幸存者的成年女性组成，而对照组由参与 CCS 的年龄匹配的姐妹组成。迄今为止，已向 1611 名 CCS 和 429 名姐妹对照组发出了研究邀请，其中 1215 名（75%）和 333 名（78%）做出了回应。在这些回应者中，大多数人同意参加研究的两部分（CCS 为 53%，姐妹对照组为 65%）。研究人群遇到了几个挑战：应对由于几种（非）参与者特征的差异而导致的偏差，并找到一个足够大和匹配良好的对照组。此外，数据收集过程中遇到的挑战包括：基于网络和基于纸质的问卷的回复率差异、自我报告结果的有效性、使用激素避孕药的女性的临床测量结果的解释以及超声测量的观察者内和观察者间变异。
DCOG LATER-VEVO 研究将提供有关儿科癌症患者以及儿童癌症长期幸存者的生殖潜力的宝贵信息。其他计划对晚期影响进行大型队列研究的研究人员可能会遇到与本研究中遇到的类似挑战。本文中描述的这些挑战的解决方案可能对这些研究人员有用。
NTR2922；http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922
