Evidence of Harm
Annually in the United States, an estimated 65 million women undergo cervical cancer screening; about 3.9 million (6%) will be referred for further evaluation. About 11,000 cases of invasive cervical cancer were diagnosed in 2008. Thus, Papanicolaou (Pap) test screening results in a large number of colposcopies for benign conditions.
The major potential harm of screening for cervical cancer lies in the screening detection of many cytologic abnormalities such as atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesions (LSIL), the majority of which would never progress to cervical cancer. Women with human papillomavirus (HPV)-positive ASCUS or LSIL on Pap testing are usually referred for colposcopy. Histological CIN 2+ is treated with cryotherapy or loop electrosurgical excision procedure. These procedures permanently alter the cervix and have consequences on fertility and pregnancy. Younger women are more likely to acquire HPV infections and be referred for diagnostic workup, and they are more likely to suffer harms from interventions for a condition that often resolves spontaneously.
Based on an analysis of screening records from nearly 350,000 women in Bristol, England, investigators projected that 1,000 women would need to be screened for cervical cancer for 35 years to prevent one death from the disease. For each death prevented, the authors estimated that more than 150 women have an abnormal result, more than 80 women are referred for investigation, and more than 50 women have treatment.References
- Solomon D, Breen N, McNeel T: Cervical cancer screening rates in the United States and the potential impact of implementation of screening guidelines. CA Cancer J Clin 57 (2): 105-11, 2007 Mar-Apr. [PUBMED Abstract]
- Davey DD, Woodhouse S, Styer P, et al.: Atypical epithelial cells and specimen adequacy: current laboratory practices of participants in the college of American pathologists interlaboratory comparison program in cervicovaginal cytology. Arch Pathol Lab Med 124 (2): 203-11, 2000. [PUBMED Abstract]
- Sadler L, Saftlas A, Wang W, et al.: Treatment for cervical intraepithelial neoplasia and risk of preterm delivery. JAMA 291 (17): 2100-6, 2004. [PUBMED Abstract]