from 3 to 132 months. They assessed the recurrence rates of HGCIN in relation to the woman’s age, the depth of the excised tissue specimen, and the histological status of the ectocervical and endocervical margins. They found that posi- tive endocervical margins, in all age groups, and a depth <10 mm in women aged 35 years or older resulted in higher rates of recurrence. A depth of excision of <10 mm was not associated with treatment failure in women younger than 35 years. These results seem reassuring because they support the recommendation for treatment of young women with HGCIN with a less extensive LLETZ procedure, thereby reducing the risk of subsequent obstetric morbidity without compromising any oncological safety. The authors have pro- posed treating older women with deeper LLETZ. However, the dose–effect relation with cone depth was nonlinear, probably because the lesion size was not controlled for. As the authors acknowledge, an additional factor apart from the depth of excision, is the use of diathermy ball ablation to the loop crater in some cases, which could add some additional therapeutic effect by the further destruction of any residual disease on the surface of the crater. The data described by Ang et al. are relevant for clinical practice, but our knowl- edge is still insufficient. A group of gynaecologists and epi- demiologists met at the 5th Congress of the European Federation for Colposcopy (Berlin, 27–29 May 2010) and at the 26th International Conference of the Papillomavirus Society (Montreal, 3–8 July 2010) to address this problem. 4 Three priorities for further action and research were pro- posed: (i) to design a standardised data collection form con- taining a list of relevant and uniformly defined variables (patient, lesion and treatment characteristics); (ii) to per- form an individual patient data meta-analysis from available databases to allow for a better assessment of the relation between the dimensions of the excised cone and obstetric outcomes; and (iii) to define the best set of variables that predict obstetric and oncological outcomes of CIN treat- ment. Gynaecology societies and research funding agencies should consider these initiatives as a high priority on their research agenda. Funding Financial support was received from: (1) FNRS (le Fonds national de la Recherche scientifique), through TELEVIE, Brussels, Belgium (ref 7.4.628.07.F) and (2) the 7th Frame- work Programme of DG Research through the PREHDICT project (grant No. 242061, coordinated by the Vrije Uni- versiteit Amsterdam, the Netherlands). j References 1 Ghaem-Maghami S, Sagi S, Majeed G, Soutter WP. Incomplete exci- sion of cervical intraepithelial neoplasia and risk of treatment failure: a meta-analysis. Lancet Oncol 2007;8:985–93. 2 Arbyn M, Kyrgiou M, Simoens C, Raifu AO, Koliopoulos G, Martin- Hirsch P, et al. Peri-natal mortality and other severe adverse preg- nancy outcomes associated with treatment of cervical intraepithelial neoplasia: a meta-analysis. BMJ 2008;337:a1284. 3 Noehr B, Jensen A, Frederiksen K, Tabor A, Kjaer SK. Depth of cervical cone removed by loop electrosurgical excision procedure and subse- quent risk of spontaneous preterm delivery. Obstet Gynecol 2009;114: 1232–8. 4 Arbyn M, Steben M. Highlights of the 26th International Papillomavi- rus Conference and Workshops (Montreal, 3–8 July 2010). Future Oncol 2010;6:1711–24. M Arbyn, a C Simoens, a F Goffin, b B Noehr c & F Bruinsma d a Unit of Cancer Epidemiology, Scientific Institute of Public Health, Brussels, Belgium b Department of Gynaecology and Obstetrics, University of Liege, Liege, Belgium c Department of Gynaecology and Obstetrics, Hilleroed University Hospital/Institute of Cancer Epide- miology, Danish Cancer Society, Copenhagen, Denmark d Mother and Child Health Research, La Trobe University, Melbourne, Vic., Australia Accepted 11 April 2011. DOI: 10.1111/j.1471-0528.2011.03068.x Treatment of cervical cancer precursors: influence of age, completeness of excision and cone depth on therapeutic failure, and on adverse obstetric outcomes Authors’ reply Sir, We thank Marc Arbyn et al., 1 for their observations regarding our paper. The intention of our paper was to identify the optimum depth of large loop excision of the transformation zone (LLETZ) treatment in women under and over the age of 35 years that ensured low recurrence rates of disease, but at the same time minimised the excessive depth of excision so as to reduce potential adverse obstetric outcomes. This was a pragmatic clinical study so that colposcopists had an evidence base to guide them when judging depth of treatment. In the Midlands region in the UK, a large audit undertaken by the Quality Assurance reference centre in 2005 demonstrated that in 26 colposcopy clinics evaluating practice of over 100 col- poscopists, more than a third of colposcopists routinely excise LLETZs to a depth of more than 10 mm, and a minority routinely excise to a depth significantly greater than this (West Midlands regional Colposcopy Audit. Pre- sented at BSCCP Birmingham 2008). This variation in practice is likely to be present throughout the UK and in other countries. Our results clearly demonstrate that most ª 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology ª 2011 RCOG 1275 Correspondence