p16 Immunoreactivity Correlates With Morphologic Diagnosis of HPV-associated Anal Intraepithelial Neoplasia: A Study of 1000 Biopsies

Anal and Perianal Preneoplastic Lesions

Anal cancer, mainly squamous cell carcinoma, is rare but increasing in prevalence, as is its precursor lesion, anal squamous dysplasia. They are both strongly associated with human papillomavirus infection. The 2-tiered Lower Anogenital Squamous Terminology classification, low-grade SIL and high-grade SIL, is preferred to the 3-tiered anal intraepithelial neoplasia classification because of better interobserver agreement and clearer management implications. Immunohistochemistry with p16 is helpful to corroborate the diagnosis of squamous dysplasia. Similarly, immunohistochemistry is helpful to differentiate primary Paget disease from secondary Paget disease, which is usually due to anal squamous mucosal/epidermal involvement by primary rectal adenocarcinoma.

HPV virus and biomarkers of resistance to chemoradiation in circulating tumor cells from patients with squamous cell carcinoma of the anus

Localized anal cancer is mostly represented by squamous cell carcinoma of the anus (SCCA) and is cured in ≥80 % of cases by chemoradiation (CRT). Development of techniques for detection/evaluating circulating tumor cells (CTCs) for diagnosis/ prognosis/response to therapy can change the manner we treat/follow SCCA patients.

OBJECTIVE

to detect CTCs from patients with SCCA and evaluate the presence of HPV virus, p16 expression and markers related to resistance to CRT (RAD23B/ ERCC1/ TYMS) in CTCs at baseline and after CRT.

METHODS

CTCs were isolated/quantified by ISET®, protein expressions were analyzed by immunocytochemistry and HPV DNA was detected by chromogenic in situ hybridization.

RESULTS

We enrolled 15 patients: median age was 61 (43-73) years, the majority was women (10/15). CTCs were detected in all patients at baseline (median= 0.4 (0.4-3.33) CTCs/mL) and in 8/9 patients, after CRT (median= 2.33 (0-7.0) CTCs/mL). DNA from HPV was found in CTCs in 14/15 patients (93.33 %) at baseline and in 7/9 (77.7 %) after treatment. At a median follow-up of 22.20 (1.45-38.55) months, three patients expressed ERCC1 in CTCs after treatment, with one of them having disease recurrence.

CONCLUSION

We showed that detection of HPV in CTCs from patients with non-metastatic SCCA is feasible and appears to be a sensitive diagnostic method. These results may be clinically useful for better monitoring these patients. However, future larger cohorts may demonstrate whether there is any correlation between the presence of HPV and the expression of screening markers for CRT in SCCA.

Anal intraepithelial neoplasia: a review of terminology, differential diagnoses, and patient management

Despite the knowledge of etiological association with high-risk human papilloma viruses and high-risk patient cohorts, the incidence of anal squamous cell carcinoma has continued to rise. The known precursor lesion (in particular, high-grade squamous intraepithelial lesion) makes it amenable to screening and surveillance strategies. However, the diagnosis of anal intraepithelial neoplasia suffers from interpretation challenges leading to high interobserver variability, along with numerous differential diagnoses and lingering terminology issues. Proper treatment of anal lesions requires accurate diagnosis, and while a variety of modalities are available for treatment, the rate of recurrence remains high and each modality has its own set of side effects and complications. The aim of this review article is to outline the diagnostic considerations and provide practical tips for diagnosing anal squamous intraepithelial lesions.