In the 1960s, adenocarcinoma accounted for 5% of all cervical malignancies diagnosed in the United States; it now accounts for more than 25%. Cytology screening alone is not effective in diagnosing adenocarcinoma in situ (AIS); Pap testing finds less than 5% of the atypical glandular lesions characteristic of AIS; less than 50% of AIS cases are detected before a definitive tissue diagnosis.
Concurrent squamous abnormalities are present in cone biopsy specimens from many patients with AIS. It has been hypothesized that Pap tests in such patients detect squamous rather than glandular abnormalities. New guidelines published by several national organizations recommend omitting Pap tests in patients younger than 21 years, screening patients aged 21 to 29 years every 3 years with cytology alone, and using human papillomavirus (HPV) and cytology cotesting in patients aged 30 to 65 years.
This retrospective cohort study was designed to determine how the updated guidelines affected the timing of diagnosis and treatment of AIS at a single institution. Cases of AIS were identified through a search of the computerized hospital databases for the International Classification of Diseases, Ninth Revision, Clinical Modification code 233.1. Pathology review confirmed the diagnosis. Abstracts of medical records were examined for clinical history, patient demographics, procedures used for diagnosis and treatment, and the frequency or type of follow-up. The study population was composed of patients with AIS who underwent fertility-preserving interventions for squamous abnormalities but who also were found to have AIS in the final pathology report.
Of the 242 patients identified who met criteria for inclusion, 208 (86%) had confirmed Pap test abnormalities at the time of presentation. The mean time from abnormal Pap test to AIS diagnosis was longer among patients 30 years or older compared with patients 30 years or younger (29 months vs 21 months; P < 0.011). Sixteen of the 17 patients younger than 21 years with AIS had an abnormal Pap screen showing squamous dysplasia and no glandular abnormalities. Subsequent triage and excisional procedures (loop excisional electrocautery procedure or cold-knife cone) eventually led to the diagnosis of AIS.
Recent revisions in national guidelines for cervical cancer screening do not appear to negatively affect the diagnosis of AIS among patients 30 years or older but are clearly detrimental for detection among patients younger than 21 years and in those aged 21 to 29 years.