David Brill
Cervical cancer screening should not stop at age 50, even in women who have had several all-clears in the past, new evidence suggests.
An analysis of national data from the Netherlands found that older women were just as likely to develop cancer after three negative smear tests as younger women.
Previous studies had found that pre-invasive disease is rare in well-screened over-50s, prompting calls for screening to be stopped at this age.
The Dutch study, however, focused instead on the incidence of full-blown cancers. It included data from 445,382 women aged 30 to 44 at the time of their third negative smear, and 218,847 women aged 45 to 54. [BMJ 2009 Apr 24;338:b1354]
After 10 years of follow-up the cumulative incidence of cancer was similarly low: 41 per 100,000 in the younger age group, and 36 per 100,000 in the older age group (P=0.48).
The findings suggest that age should not be the decisive factor for early cessation of screening in well-screened women, said lead author Dr. Matejka Rebolj. They do not, however, provide a definitive answer as to whether it will ultimately prove worthwhile to continue universal screening after three negative tests.
“We cannot really say with these data whether you should continue screening or not. However we can say that if you’re screening younger women, then in order to make your policy consistent you should continue screening women above the age of 50,” said Rebolj, a postdoctoral researcher at the University of Copenhagen, Denmark.
“The next logical step would be to do a proper cost-effectiveness analysis to determine whether this low absolute level of risk does warrant further screening. Until then we should encourage women to continue screening at the regular interval recommended in each particular country.”
Singapore oncologist Dr. Francis Chin praised the quality of the data, and said that the findings support Singapore’s policy of continuing screening up to age 69.
“This study confirms the importance of screening in the age group over 50 years old, because the risk of cervical cancer after several negative smears is similar in older versus younger patients,” said Chin, consultant radiation oncologist at the National Cancer Centre Singapore.
“The predilection of doctors has always been that screening and early detection is better than treating cancer in the later stages. These data confirm and validate this policy,” he said.
Singapore’s Health Promotion Board (HPB) agreed that the study supports the current guidelines of its CervicalScreen Singapore initiative, implemented in 2004. The program, which promotes screening every 3 years, will continue to focus on increasing its coverage of eligible women, said Dr. Shyamala Thilagaratnam, director, Healthy Ageing Division, HPB.
Several previous studies have proposed that cervical screening should stop at 50, notably a 1997 paper which found that only 1 percent of 23,440 previously screened over-50s had significant cytological abnormalities. The authors concluded that ending screening in this group could reduce anxiety and enable better allocation of resources to targeting higher-risk women. [Br J Obstet Gynaecol 1997 May;104(5):586-9]
The case against this argument, however, could be furthered strengthened by another recent paper, supporting the findings of the Dutch study. UK researchers, reviewing National Health Service screening records for 2 million women, found that two thirds of all the lesions detected in over-50s were found in women who had had previously had negative smears results. Discontinuation of screening would therefore lead to the majority of important abnormalities being missed, the researchers say. [Br J Cancer 2009 May 5; Epub ahead of print]
Singapore physician Dr. Siew Wei Fong concurred with the conclusion that screening should continue beyond the age of 50, in light of the recent evidence. She added that she does not expect any change in screening practices at the Singapore Polyclinics, where she is senior family physician.
Previous studies had found that pre-invasive disease is rare in well-screened over-50s, prompting calls for screening to be stopped at this age.
The Dutch study, however, focused instead on the incidence of full-blown cancers. It included data from 445,382 women aged 30 to 44 at the time of their third negative smear, and 218,847 women aged 45 to 54. [BMJ 2009 Apr 24;338:b1354]
After 10 years of follow-up the cumulative incidence of cancer was similarly low: 41 per 100,000 in the younger age group, and 36 per 100,000 in the older age group (P=0.48).
The findings suggest that age should not be the decisive factor for early cessation of screening in well-screened women, said lead author Dr. Matejka Rebolj. They do not, however, provide a definitive answer as to whether it will ultimately prove worthwhile to continue universal screening after three negative tests.
“We cannot really say with these data whether you should continue screening or not. However we can say that if you’re screening younger women, then in order to make your policy consistent you should continue screening women above the age of 50,” said Rebolj, a postdoctoral researcher at the University of Copenhagen, Denmark.
“The next logical step would be to do a proper cost-effectiveness analysis to determine whether this low absolute level of risk does warrant further screening. Until then we should encourage women to continue screening at the regular interval recommended in each particular country.”
Singapore oncologist Dr. Francis Chin praised the quality of the data, and said that the findings support Singapore’s policy of continuing screening up to age 69.
“This study confirms the importance of screening in the age group over 50 years old, because the risk of cervical cancer after several negative smears is similar in older versus younger patients,” said Chin, consultant radiation oncologist at the National Cancer Centre Singapore.
“The predilection of doctors has always been that screening and early detection is better than treating cancer in the later stages. These data confirm and validate this policy,” he said.
Singapore’s Health Promotion Board (HPB) agreed that the study supports the current guidelines of its CervicalScreen Singapore initiative, implemented in 2004. The program, which promotes screening every 3 years, will continue to focus on increasing its coverage of eligible women, said Dr. Shyamala Thilagaratnam, director, Healthy Ageing Division, HPB.
Several previous studies have proposed that cervical screening should stop at 50, notably a 1997 paper which found that only 1 percent of 23,440 previously screened over-50s had significant cytological abnormalities. The authors concluded that ending screening in this group could reduce anxiety and enable better allocation of resources to targeting higher-risk women. [Br J Obstet Gynaecol 1997 May;104(5):586-9]
The case against this argument, however, could be furthered strengthened by another recent paper, supporting the findings of the Dutch study. UK researchers, reviewing National Health Service screening records for 2 million women, found that two thirds of all the lesions detected in over-50s were found in women who had had previously had negative smears results. Discontinuation of screening would therefore lead to the majority of important abnormalities being missed, the researchers say. [Br J Cancer 2009 May 5; Epub ahead of print]
Singapore physician Dr. Siew Wei Fong concurred with the conclusion that screening should continue beyond the age of 50, in light of the recent evidence. She added that she does not expect any change in screening practices at the Singapore Polyclinics, where she is senior family physician.
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