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.]