Few women in the developing world are screened effectively for cervical cancer and those at highest risk of developing the disease are among the least likely to be screened, according to new research.
The study also finds striking inequalities in access to cervical cancer screening between and within countries, said study authors, Emmanuela Gakidou and colleagues from the University of Washington, Seattle.
Cervical cancer is the second-most common cancer in women and a leading cause of death worldwide. Since the 1970s, the developed world has seen a fall in the annual number of new cases of cervical cancer, and a fall in the death rate from the disease. This public health success is often credited to widespread screening programmes. But in the developing world, where most cervical cancer occurs, there is little information about rates of screening.
To address this lack of information and to estimate the magnitude of inequalities in access to screening services, Gakidou and colleagues analyzed World Health Organization surveys from 57 countries across all levels of economic development.
They calculated the results both in terms of effective coverage (the proportion of eligible women who had had a pelvic exam and a Pap smear test in the last three years) and crude coverage (the proportion of eligible women who reported they had just had a pelvic exam, regardless of when this occurred).
By both measures the researchers found a huge disparity in rates of cervical cancer screening; in terms of effective coverage only 19 percent of women in the developing world have been screened compared to 63 percent in developed countries.
The findings also show a wide gap between those countries with the most effective cervical cancer screening programmes and those where little screening for cervical cancer takes place at all. For example, over 80 percent of women receive effective screening in Austria compared to 1 percent or less in Ethiopia and Bangladesh. In 16 of the 57 countries studied, most women have never had a pelvic exam and in Ethiopia, Malawi and Bangladesh, this is true of 90 percent of women.
Screening low among high-risk women
The researchers found that poor women, who are likely to have higher exposure to cervical cancer risk factors such as smoking or unsafe sex, are less likely to get screened effectively. In developing countries as a whole, screening coverage rates also decline with advancing age, which is when cervical cancer incidence rates are known to be highest.
"Strategies for improving cervical cancer prevention must be adapted to meet the specific needs of individual countries," conclude the authors. "Expanded screening may be a viable option where sufficient infrastructure and health system access exists, but novel strategies need to be considered in other settings." – (EurekAlert!, June 2008)
Source: PLoS Medicine
Cervical Cancer Centre