Problems of follow-up in patients with abnormal cytology by mass screening for uterine cervical cancer

Abstract

Objective : We analyzed the results, frequency, and term of follow-up in patients with abnormal cytology found in mass screening for uterine cervical cancer.
Study Design : From 1995 to 1999, 514407 participants underwent screening for uterine cervical cancer in Fukushima Prefecture. In 3821 patients with abnormal cytology, we compared positive predictive vales of over CIN3 between the first detailed examination and during follow-up. The frequency and term of follow-up in patients with the disappearance of abnormal cells were compared with those in patients with over CIN3.
Results : In 3372 patients with class IIIa, 103 cases of over CIN3 were detected at initial examination, and 65 cases were detected during follow-up. The positive predictive value of 5.1% at overall examination was significantly higher than that of 3.1% at initial examination. In 271 patients with class IIIb, 79 cases of over CIN3 were detected at initial examination, and 28 cases were detected during follow-up. The positive predictive value of 39.9% at overall examination was significantly higher than that of 29.2% at initial examination.
In patients with class IIIa and IIIb, 2388 (70.8%) and 74 (27.3%) patients had follow-up discontinued due to the disappearance of initial abnormal cells.
Conclusion : Follow-up of patients with class IIIa and IIIb cytology may significantly increase the positive predictive values of over CIN3 than at first examination. Follow-up should thus be may repeat for as long as necessary in patients who had not been detected with over CIN3 in earlier examinations. More detailed cytological reports based on the Bethesda system may distinguish patients with mildly abnormal cytology not requiring follow-up from patients referred for colposcopy.