Assessment of cytologic follow‐up as the recommended management for patients with atypical squamous cells of undetermined significance or low grade squamous intraepithelial lesions

BACKGROUND: The optimal management of low grade Papanicolaou (Pap) smear abnormalities remains controversial. This center's experience with recommending cytologic follow-up for women with atypical cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesions (LSIL) was reviewed to determine outcome and patient/physician compliance. METHODS: The records were reviewed on women with Pap smears reported as either ASCUS (320) or LSIL (112) who did not have a history of dysplasia. The cytologic and colposcopic follow-up for a 2-year period was obtained from the laboratory data base that includes the colposcopy and cancer referrals for this region. Repeat Pap smear in 6 months was recommended. If patients subsequently demonstrated high grade SIL (HSIL) or persistent ASCUS or LSIL over three time intervals, colposcopic evaluation was recommended. RESULTS: The outcome was determined by the most significant diagnosis among the follow-up Pap smears or colposcopic biopsies. 29% of patients were lost to follow-up. Of the remaining patients, 70.5% reverted to normal or benign cellular changes, 25.3% persisted as ASCUS or LSIL, and 5.2% progressed to HSIL. The majority of patients (68%) were referred for colposcopy for persistent mildly abnormal Pap smears. The timing of referral ranged from 3-30 months. CONCLUSIONS: These results suggest that cytologic follow-up of women with low grade Pap smear abnormalities will identify a large number whose smears will regress to normal. A small but significant proportion of women showed subsequent HSIL. Most HSIL was detected within 1 year of the initial abnormal Pap smear and the majority of intervening Pap smears also were abnormal. Approximately one third of patients did not have follow-up within the study system and their outcome was uncertain. Although the recommendations are standard, patterns of follow-up and referral to colposcopy varied widely, suggesting that the guidelines need to be reinforced to both patients and physicians. [See editorial on pages 1-4, this issue.]