The future of cytology laboratories
Authors: Smith J. 
Published: September 2007

This presentation will consider the impact of established and potential changes to cervical screening practice on the structure and organisation of cervical cytology laboratories in the UK. Although full roll out of liquid based cytology in England will not be achieved until 2008, implementation of liquid‐based cytology (LBC) combined with the change in the screening age range and frequency has already resulted in a decrease in the total number of tests examined despite an increased number of women aged 25–64 being screened, reflecting a more efficient screening programme with fewer unnecessary tests outside the recommended screening age range [1]. Laboratories in England and Scotland have reported a decreased workload and increased productivity and efficiency, with no adverse effect on quality [2–4]. There is a growing mismatch between screening workload and capacity, with the potential to achieve laboratory reconfiguration within a managed network, as recommended in the Carter report [5]. However the potential for conflict between the Carter report recommendations and the autonomy of NHS foundation trusts will need to be addressed if laboratory reconfiguration is to be achieved.

LBC provides the platform for automation of the screening process and human papillomavirus (HPV) and other evolving molecular testing. The MAVARIC trial due to report in 2010 will inform the decision about the adoption or otherwise of automation in the NHS Cervical Screening Programme (NHSCSP). In previous studies the systems currently under evaluation (Focal Point™ GS and ThinPrep® Imager) have been shown to increase productivity with no loss of sensitivity or specificity [6,7]. The adoption of automation in cervical screening will be a further driver for laboratory reconfiguration by amalgamation of workloads and an extended working day to achieve cost‐effective utilization of the equipment. It may also call into question the role of the cytology screener as currently utilized in the UK cervical screening programmes.

Whilst the results of the ARTISTIC and TOMBOLA trials are awaited, sentinel sites have been established to evaluate the practical implications of introducing HPV testing for triage of low‐grade cytological abnormalities and follow up after treatment of CIN. A recent study from the USA suggests that the adoption of primary HPV testing in conjunction with cytology screening in women aged 30 years and older would result in a 30% reduction in the number of cervical screening tests performed [8]. It is likely that if HPV testing is adopted there will be a further reduction in laboratory workload, and as such HPV testing will be another driver for laboratory reconfiguration.

Similarly, a modelling study from the UK predicted that HPV 16/18 vaccination of a cohort of 12‐year‐old girls would result over the lifetime of the cohort in a 23% reduction in the number of abnormal cytology tests [9], assuming that vaccine protection lasted for life and the introduction of vaccination did not also allow a reduction in screening frequency [10]. Furthermore, falling lesion prevalence is likely to decrease both the sensitivity and specificity of screening cytology tests and may be a driver for automation or the adoption of primary screening by HPV testing with secondary cytology triage [10].

In summary, LBC implementation and change in the screening age range and frequency has been an initial driver to laboratory reconfiguration, in accordance with political objectives. In the longer term, this may be accelerated by automation, HPV testing and HPV vaccination and will also demand a revision of laboratory staffing levels and skill mix. Potential models of laboratory configuration and staffing will be outlined. However, whether all the developments described above are affordable, measured against manual test evaluation estimated to prevent up to 4500 deaths per annum in England at an annual cost of about £160 million remains to be determined [11].

References:

1. NHSCSP Annual Review 2006. Patnick J (ed.). Sheffield, UK, NHSCSP; 2007.

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5. Lord Carter of Coles. Report of the Review of NHS Pathology Services in England 2006. Department of Health.

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9. Kohli M, Ferko N, Martin A. et al. Estimating the long‐term impact of a prophylactic human papillomavirus 16/18 vaccine on the burden of cervical cancer in the UK. Br J Cancer 2007; 96(1):143–50.

10. Franco EL, Cuzick J, Hildesheim A, de Sanjose S. Chapter 20: issues in planning cervical cancer screening in the era of HPV vaccination. Vaccine 2006; 24 (Suppl. 3):S171–S177.

11. Peto J, Gilham C, Fletcher O, Matthews FE. The cervical cancer epidemic that screening has prevented in the UK. Lancet 2004; 364(9430):249–56.