Cervical cancer screening: How our approach may change
Accumulating evidence has begun to alter priorities in testing modalities and in testing intervals, and further changes may be on the way.
What about the alternative screening guideline?
In early 2015, the American Society for Colposcopy and Cervical Pathology (ASCCP) and the Society of Gynecologic Oncology (SGO) co-sponsored an expert panel representing several specialty societies. The panel released interim guidelines for cervical cancer screening reflecting a growing body of evidence that favors HPV testing as the primary modality.12 Additionally, in January 2016, these guidelines received an evidence-level B rating from the American Congress of Obstetricians and Gynecologists.13 Primary HPV screening is also the topic of research and discussion for USPSTF’s pending 2018 update of cervical cancer screening strategies.14
The alternative algorithm from the ASCCP and SGO recommends cervical cancer screening with HPV testing alone starting at the age of 25 and, if results are negative, repeating at 3-year intervals.12 If a patient tests positive for any of the 14 identified high-risk HPV types, reflex cytology is indicated with a referral for colposcopy if an abnormality is identified.12 If the cytology result is normal, follow-up with another HPV test in 12 months is recommended.12
Over the last 12 years, multiple international studies have demonstrated the efficacy of high-risk HPV testing in primary screening for cervical cancer.15 The most recent study conducted in the United States from 2008 to 2011—Addressing THE Need for Advanced HPV Diagnostics (ATHENA)—enrolled 42,000 women older than 25 years to compare the screening modalities of cytology alone, cytology and HPV testing combined, and HPV testing alone.16 The purpose of the study was to determine the safety of the cobas HPV test as a co-test and as a primary screening modality in women older than 25 years. (Many HPV tests are commercially available, but only the cobas HPV test is FDA-approved for primary screening.12)
ATHENA researchers concluded that HPV testing was more sensitive than cytology, but less specific.16 The researchers also concluded that adding cytology to the HPV test increased the sensitivity by less than 5% and that HPV was better at detecting CIN 2+ lesions than cytology alone.12,16 Another recently published study conducted at a tertiary care hospital with a smaller sample (1000 patients) corroborated the ATHENA results.17
For patients in their late 20s, this alternative strategy may increase the number of subsequent colposcopies. However, during the clinical trials just described, the absolute number of colposcopies needed to detect high-grade disease was the same as seen with the current guidelines. This finding indicates that, with the current algorithm, clinically significant pathology due to high-risk HPV may be missed in the 25-to-29 age group.8
Looking ahead. The alternative screening strategy is already being adopted in Australia, the Netherlands, and the United Kingdom.15 For providers in the United States considering this alternative strategy, the recommendation is to initiate cervical cancer screening with cytology alone at age 21, manage results appropriately, and then transition the patient to primary HPV testing with the FDA-approved test at age 25.12 This recommendation may be modified in the future. However the guidelines might change, patients will benefit only if the guidelines are implemented consistently in practice.
CORRESPONDENCE
Sabrina Hofmeister, DO, 1121 E. North Ave, Milwaukee, WI 53212; shofmeister@mcw.edu.
