Human papillomavirus (HPV) is spread during sexual intercourse. The most common subtype of the virus is HPV16. Infection with HPV16 and other HPV subtypes can cause cervical cancer. However, only a small percentage of women who catch it develop cancer.
Writing in the journal Annals of Behavioural Medicine, the Scientists at Fox Chase Cancer Center in Philadelphia, said that the stressed women had a weaker immune response to the virus. Comparatively, most HPV infections in healthy women will disappear spontaneously over time.
The small study asked 78 women who had had abnormal smear tests to fill in a questionnaire about their day-to-day stresses over the previous month, and any major events such as fights or divorce over a longer period.
The scientists then measured their ability of the immune system to respond to HPV16 - the most common variety of the virus linked to cervical cancer. Similar tests were carried out on 28 women who had not received an abnormal smear test, and the results compared.
The researchers found that the immune response was weaker among women who reported higher levels of day-to-day stress. More than 55 percent of the women tested positive for one or more types of HPV.
"We were surprised to discover no significant association between the occurrence of major stressful life events and immune response to HPV16. This could be due to the amount of time that has passed since the event occurred and how individuals assess and cope with the event," explained Fox Chase Cancer Center's Carolyn Y. Fang.
That means women who report feeling more stressed could be at greater risk of developing cervical cancer because their immune system can't fight off one of the most common viruses that causes it.
However, the study did not prove that stress alone was the root cause of the problem.
