Several national organizations have recommended stopping cervical cancer screening or no longer screening low-risk women at the age of 65 or 70 years following a history of normal screens. In 1996, Kaiser Permanente Northern California (KPNC) stopped screening women at age 65 years who had 3 consecutive negative Papanicolaou (Pap) smears. The decision of KPNC to stop screening in this population was based on observational data for about 1.4 million female members for the years 1988 to 1994.
One long-term prospective study showed that a single human papillomavirus (HPV) test forecasts CIN2+ and the subsequent diagnosis of cancer for 18 years of follow-up. This and other observations suggested that HPV testing was useful for determining which women could safely exit screening. In 2003, a single negative HPV cotest was added as an alternative criterion for exiting screening in women 65 years or older. A number of studies have suggested the risk of cancer after 3 consecutive negative Pap tests is higher than the risk of cancer after a negative cotest. There is little direct evidence for or against the safety of exiting screening in this population.
This observational study investigated the safety of stopping antecedent screening of women 65 years or older diagnosed with cervical cancer. Databases at KPNC and the regional Cancer Registry were used to examine screening histories of women 65 years or older who were diagnosed with cervical cancer between 2003 and 2008.
During the 6-year study period, 56 KPNC members 65 years or older were diagnosed with invasive cervical cancer. Over this same period, there were 1,323,100 member-years of women 65 years or older. The annual risk of invasive cervical cancer in women 65 years or older in this population was 4.2/100,000 per year; 59% (33/56) of the cancers were diagnosed in women who had 1 or more prior negative PAP smears. Fourteen (25%) of the 33 women with invasive cervical cancer had 3 consecutive negative Pap smears before diagnosis. Among the 46,401 women with 1 or more negative cotests at 65 years or older, 3 had a subsequent diagnosis of invasive cancer during 132,639 women-years of follow-up (2.3/100,000 per year).
These findings show that most women diagnosed with cervical cancer at 65 years or older fail to meet the criteria to stop screening. As with other age groups, a few cervical cancers will occur in women 65 years or older despite multiple negative tests. There is no evidence that continued screening in this older population can prevent these cancers.