We are grateful for the words that Gómez Sánchez et al. dedicated to our study.1 As the authors point out,2 screening for anal dysplasia is a complex topic for which there is still no single standardised protocol of action. The results of the latest studies3 have helped to set down clinical guidelines on the management of these patients4–6 but there is still controversy concerning which lesions detected at Pap smear screening are worthy of having their study completed with an HRA (high-resolution anuscopy); what effect HPV genotyping has on this; which lesions are treated; and what the most effective treatment would be.
At our centre we have modified the previous action protocol. Currently, we include HIV patients monitored by the Infectious Diseases Unit through an annual anal smear at our anal dysplasia screening. The ASCUS/atypia Pap smear findings of undetermined significance, LSIL with high-risk genotypes (HPV 16 or 18) and HSIL are subjected to HRA.
In our study, 64/66 patients with ASCUS results on anal Pap smear presented dysplasia in posterior anal biopsy, and half of these patients (32/64) had high-grade dysplasia. Pap smear is an effective initial diagnostic method because it is a non-invasive and easily reproduced test, although it may underdiagnose cases of dysplasia when compared to anal biopsy.4,7 For this reason, we consider that a patient with ASCUS in Pap smear deserves an HRA examination and biopsy of lesions suspected of dysplasia.8,9 Currently, the follow-up on patients with ASCUS in Pap smear screening is still not defined and the action taken depends on each centre: a) follow-up, b) HRA depending on the genotyping of the virus or c) HRA in all patients.4,5,7,10
Currently, we systematically perform HPV genotyping on all Pap smear and histology samples from screening patients and this is an additional tool that helps us detect which patients are at higher risk of developing high-grade dysplasia and who would benefit from HRA.4,8,11,12
Unlike the previous protocol, the results of LSIL in the biopsy will be monitored by a further Pap smear at 6–12 months. Patients with a histological result of HSIL will be treated with 80% TCA (trichloroacetic acid) in two sessions. In agreement with the authors, there is no current evidence regarding the treatment of low-grade dysplasia for the prevention of the development of anal squamous cell carcinoma.13,14 There are few centres that currently treat these lesions, and periodical follow-up by HRA is more common.4,5
The integration of HRA into routine clinical practice has improved the detection of lesions in the anal canal with better visualisation and resolution than previously used methods, such as the rigid manual anuscope. In our centre, we apply TCA treatment specifically by quadrants to those lesions suspected of dysplasia. During our follow-up, we did not report any serious side effects in patients undergoing this treatment, and it was generally well tolerated.
Finally, and despite the fact that Pap smear tests can lead to false negatives, it is still our method of choice to evaluate the efficacy of treatment, due to the characteristics mentioned above. In addition, these patients will continue the set screening and many of them will present re-infection with other HPV strains or persistence requiring, in most cases, another HRA over their follow-up.
Our goal is to carry out short to long term follow-up on the diagnosis and treatment of this pathology in future studies after the change in screening protocol. Prospective studies with longer follow-ups are needed to reach a consensus on the most appropriate management in the screening of patients with anal dysplasia.
