Early sexual encounters linked to increased risk of cervical cancer among deprived women
One of the reasons why cervical cancer is more common among poorer women could be because they start having sex at a younger age than more affluent women, scientists have said.
Although deprived women are twice as likely to get cervical cancer as more affluent women, research has shown that their levels of infection with the human papillomavirus (HPV) - which is responsible for the majority of cases of cervical cancer - tend to be similar.
Researchers at the International Agency for Research on Cancer investigated the link between deprivation and higher cervical cancer risk. Until now, experts thought that the difference in cases of the disease could be just because poorer women were less likely to go for cervical screening.
Although screening uptake had an effect, this latest international study looked at many countries without screening programmes and found that poorer women were still more likely to develop the disease.
The researchers looked at how many years a woman had been in education, which gave them an indication of their socio-economic status.
As expected, researchers found that the least educated women were more likely to develop cervical cancer than the most educated women.
But the study also showed that the age at which a woman started having sex and the age at which she had her first baby were the most important factors explaining this increased risk.
Commenting on the study, which is published in the British Journal of Cancer, Dr Silvia Franceschi, lead author from the International Agency for Research on Cancer, said: "We weren't sure why cervical cancer is more common in poorer women.
"Levels of HPV infection were approximately the same across the board and, in some countries, even higher among the richest women.
"We now think that it's because in our study, poorer women had become sexually active on average four years earlier."
Dr Franceschi suggested that this exposure to HPV at an earlier age may give the virus "more time to produce the long sequence of events that are needed for cancer development".
The researcher also explained: "In a previous large international study, we also showed that this trend was not restricted to adolescence and that the risk of cervical cancer was also higher in women who had their first sexual intercourse at 20 rather than 25 years."
Dr Lesley Walker, director of cancer information at Cancer Research UK, said that the study raises some interesting questions.
"Although women can be infected by HPV at any age, infections at a very young age may be especially dangerous as they have more time to cause damage that eventually leads to cancer," she explained.
"Importantly, the results back up the need for the HPV vaccination to be given in schools at an age before they start having sex, especially among girls in deprived areas.
"We strongly advise all women to attend cervical screening when invited. Women should also visit their doctor without delay if they have symptoms - such as bleeding between periods or after the menopause and pain during sex."