Posted on August 7th, 2009 by
American women undergo cervical cancer screening at a younger age than their European counterparts, but this early screening may be unnecessary and possibly even harmful, according to three studies recently published in the British Medical Journal.
Cervical cancer is generally preceded by precancerous changes to the cervix, which can be detected by a screening test called a Pap smear. During a Pap smear, a sample of cells from the cervix is taken with a small wooden spatula or brush and examined under the microscope. Routine screening with a Pap smear is used to detect precancerous or cancerous cells early before they have the chance to develop and spread.
In the United States, women are instructed to start regular Pap smears within three years of their first sexual intercourse or at age 21, whichever comes first. However, in England, women are recommended to begin regular Pap smears at age 25. In other parts of Europe, women may begin Pap screening as early as age 20.
Some research has indicated that there is no benefit to screening younger women for cervical cancer and that instead it may lead to earlier and unnecessary aggressive treatment. Researchers from Queen Mary College in London conducted a study comparing 4,012 women diagnosed with cervical cancer between 1990 and 2008 with a matched group of 7,889 women with no cervical cancer. The women ranged in age from 20 to 69. The results of the study were published in three separate papers that focused on the efficacy of screening and surveillance, follow-up with colposcopy and loop electrosurgical excision procedure (LEEP excision), as well as the cost benefits of screening.
In the first study, women whose Pap smears showed abnormal cells were either assigned to immediate colposcopy or to wait and come back for a follow-up Pap smear. The results showed no difference in outcomes among the two groups. Sometimes abnormal cells will spontaneously regress without further treatment; however colposcopy typically detects more abnormal cells and can lead to overtreatment. Regular Pap smears in women ages 22 to 24 did not reduce the incidence of cervical cancer over the next five years.
In the second study, women with abnormal Pap smears were referred for colposcopy and then were assigned to either immediate LEEP excision (surgical removal of abnormal cells) or up to four punch biopsy samples with a recall for LEEP excision if these biopsies showed neoplasia of grade II or higher. There were no significant differences in outcome among the two groups. The women who underwent the LEEP surgery reported more bleeding and discharge. The researchers concluded that immediate treatment with LEEP excision results in overtreatment.
Finally, the third study focused on a cost-benefit analysis, comparing women who were referred immediately for colposcopy to those who were treated with “watchful waiting.” The researchers found that there was no cost benefit to immediate colposcopy.
Taken together, these three studies indicate that early screening with Pap smear does not appear to reduce the incidence of cervical cancer or affect outcomes among younger women. Furthermore, it appears to result in more aggressive treatment that could cause unnecessary side effects. The data from these studies will add to the debate regarding the efficacy of screening younger women. In the meantime the U.S. guidelines still recommend that women begin screening three years after the first sexual intercourse or at the age of 21, whichever comes first.
 TOMBOLA Group. Cytological surveillance compared with immediate referral for colposcopy in management of women with low grade cervical abnormalities: Multicentre randomized controlled trial. BMJ. 2009; 339:b2546.
 TOMBOLA Group. Biopsy and selective recall compared with immediate large loop excision in management of women with low grade abnormal cervical cytology referred for colposcopy: Multicentre randomized controlled trial. BMJ. 2009; 339:b2548.
 TOMBOLA Group. Options for managing low grade cervical abnormalities detected at screening: Cost effectiveness study. BMJ. 2009; 339:b2549.
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