Women treated for CIN3 face long-term Ca risks

Women who have been treated for cervical intraepithelial neoplasia grade 3 (CIN3) remain at increased risk for cervical and vaginal cancers as much as 25 years after treatment and should continue to be screened beyond current age recommendations for the general population, according to the findings of a recent population-based cohort study from Sweden.

The authors calculated that women treated for CIN3 are 2.34 times as likely to develop invasive cervical cancer as women in the general population (95% CI, 2.18–2.50). And while the increased risk decreases over time, it still exists 25 years after treatment and actually increases in women aged 50 years or more.

The authors also calculated that while the risk of vaginal cancer in these women is small in absolute terms (5/100,000 women years), it is still almost seven times that of women in the general population (incidence ratio 6.82). This risk decreases to 2.65 after 25 years.

The authors of an accompanying editorial believe that while a return to the widespread use of hysterectomy to treat CIN is clearly unacceptable, we must pay greater attention to the completeness of excision with techniques such as cold knife conization, particularly in older women who have a higher risk of cancer. They also believe that this study provides compelling evidence that women treated for CIN3 have a long-lasting excess risk of invasive cervical cancer and should be monitored beyond the age limit of regular screening.

Strander B, Andersson-Ellström A, Milsom I, et al. Long term risk of invasive cancer after treatment for cervical intraepithelial neoplasia grade 3: population based cohort study. BMJ. 2007;335:1077.

Ronco G, Sideri MG, Ciatto S. Cervical intraepithelial neoplasia and higher long term risk of cancer. BMJ. 2007;335:1053-1054.