UPDATE: CERVICAL DISEASE
Here’s what you need to know about ACOG’s latest guidelines on screening for cervical cancer
IN THIS ARTICLE
Detection of CIN 3 does not peak until a woman reaches her late 20s, and the median detection of microinvasive cancer does not peak until she reaches her early 40s. These facts indicate that adolescents have the lowest risk of incipient cervical cancer but the highest risk of undergoing unnecessary procedures for HPV-related events—events that are highly likely to resolve without treatment.
From 1998 to 2006, an average of 14 cervical cancers occurred annually in women 15 to 19 years old, an incidence of only 1 or 2 cases of cervical cancer for every 1 million women in that age group ( TABLE 2 ).
TABLE 2
Incidence of invasive cervical carcinoma: United States, 1998-2003
| Age (y) | Average annual count | Incidence (95% CI) | Incidence as a percentage | Median age at diagnosis |
|---|---|---|---|---|
| All ages | 10,846 | 8.9 (8.8–9.0) | 100 | 47 |
| 0–14 | 0 | 0 | 0 | Not applicable (NA) |
| 15–19 | 14 | 0.2 (0.1–0.2) | 0.1 | NA |
| 20–24 | 123 | 1.6 (1.5–1.7) | 1.1 | NA |
| 25–29 | 543 | 6.9 (6.7–7.2) | 5.0 | NA |
| 30–34 | 1,045 | 12.3 (12.0–12.6) | 9.6 | NA |
| 35–39 | 1,350 | 14.6 (14.3–14.9) | 12.5 | NA |
| 40–44 | 1,534 | 16.3 (15.9–16.6) | 14.1 | NA |
| 45–49 | 1,323 | 15.4 (15.0–15.7) | 12.2 | NA |
| 50–59 | 1,958 | 14.5 (14.2–14.7) | 18.0 | NA |
| 60–69 | 1,352 | 14.8 (14.5–15.1) | 12.5 | NA |
| 70–79 | 1,008 | 12.9 (12.6–13.3) | 9.3 | NA |
| ≥80 | 595 | 11.2 (10.9–11.6) | 5.5 | NA |
| Source: Watson et al5 | ||||
In teens, screening does not reduce mortality
Even this low rate of cervical cancer might justify the screening of adolescents, provided such screening was shown to reduce the incidence of and mortality from cervical cancer in that age group. However, all data point to the opposite conclusion:
- The incidence of cervical cancer in this age group has not changed since the years between 1973 and 1977, a period that preceded the recommendation to begin screening at age 18 or first intercourse
- No data demonstrate a benefit of screening in women younger than 21 years in regard to future rates of CIN 2 and 3—or even that screening women 20 to 24 years old reduces the rate of cervical cancer in women 30 years or younger3
- CIN 2 and 3 do occur in adolescents, and the fear of delaying their diagnosis has driven much of the opposition to the guideline change—specifically, the omission of the option to begin screening within 3 years after first intercourse; however, even when high-grade CIN develops, spontaneous regression is common in this age group (e.g., 65% rate of regression of CIN 2 after 18 months; 75% after 36 months)
- When CIN 3 develops and persists, more than 10 years are typically required for the lesion to acquire the capacity to become invasive.1,2
In addition, extensive data suggest that screening adolescents may be harmful. Adverse psychological effects related to cervical cancer screening, evaluation of abnormal results, and treatment of CIN have been reported, including negative effects on sexual function and a higher risk of preterm and low-birth-weight infants.1
Virtually all studies of pregnancy outcomes following loop electrosurgical excision procedure (LEEP) have demonstrated a doubling or tripling of the rate of preterm birth.
Screening women 21 years or younger for cervical cancer may be harmful and lacks proven benefit. Screening should not begin until the patient is 21, regardless of the age of first intercourse.
Extend the screening interval to 2 years for women 21 to 29 years old
Both liquid-based and conventional methods of cervical cytology are acceptable for screening; hence, screening frequency should not vary based on the method used.1
The 2003 ACOG guidelines recommended annual cervical screening of women in their 20s using either conventional or liquid-based cytology. In contrast, in 2002, the American Cancer Society (ACS) recommended annual screening when the conventional Pap test was used, and a 2-year interval when screening involved liquid-based cytology. With ACOG’s latest recommendation—a 2-year interval for women 21 to 29 years old, regardless of test method—the College moves in line with the ACS in regard to liquid-based cytology. It also acknowledges more recent evidence that liquid-based cytology is no more sensitive than conventional cytology.1
Liquid-based cytology does have a number of other unquestionable advantages, however:
- It offers the convenience of being able to test for HPV, Neisseria gonorrhoeae, and Chlamydia trachomatis directly from the residual sample
- It produces fewer unsatisfactory cytology results than conventional cytology
- Cytotechnologists find liquid-based cytology easier to read.
More than 90% of Pap tests in the United States utilize liquid-based cytology, and that percentage is not likely to diminish.
Women 21 to 29 years old should have a Pap test every 2 years, regardless of the method used.
Some women 30 years and older can be screened every 3 years
Cervical cytology screening is recommended every 3 years for women age 30 years and older if:
- they have had three consecutive negative cervical cytology screening test results and have no history of CIN 2 or CIN 3, are not HIV-infected, are not immunocompromised, and were not exposed to diethylstilbestrol in utero or
- they have received negative test cotest results on both cervical cytology screening and HPV DNA testing and are considered low risk.1
