A recently published paper has detailed a large clinical trial that found a HPV test was better than a Pap smear in detecting precancerous changes of the cervix. The test for HPV detected precancerous changes earlier and more accurately. The results of the decade-long study appeared in the Journal of the American Medical Association.
The Pap smear is a widely used test that has been a standard part of women’s preventive health care for decades. The conventional test involves letting a doctor or nurse scrape cells from the back of the cervix, which are visually inspected for signs of abnormality. In the United States, the conventional Pap smear has been largely replaced by a liquid-based Pap cytology test, but the specimen is taken in a similar process.
Another way to screen for cervical cancer risk is by directly testing for the human papillomavirus, or HPV. The HPV infection is the most common sexually transmitted infection, with about 80 million people in the United States are infected with the virus, according to the Centers for Disease Control and Prevention. Most infections go away by themselves within a year or two, but when infections last longer, they can cause cervical cancer as well as cancer of the anus, the penis, and the back of the throat.
Nearly all cases of cervical cancer are caused by HPV infections. Most medical groups, including the American College of Obstetricians and Gynecologists and the American Cancer Society, recommend that women of average risk get both HPV tests and Pap smears every five years between age 30 and 65. Cervical cells for both the Pap and HPV tests can be collected at the same time.
The recently published study found that the HPV test was more sensitive than the Pap smear at detecting precancerous changes in the cervix. The study involved about 19,000 women who were placed in two groups: one using the HPV test to screen for cervical cancer, and the other using Pap cytology. The researchers reported significantly more cases of precancerous lesions detected early in the trial among the women in the HPV-tested group, compared with the Pap cytology group.
Adding HPV testing to the Pap test group resulted in finding 25 lesions that would have not been found by the Pap test alone. Adding the Pap test to the HPV group, resulted in an additional three lesions found. The speed of detection is directly correlated with survival rates. According to the American Cancer Society, about 13,200 new cases of invasive cervical cancer will be diagnosed in the United States in 2018 and about 4,200 women will die of the disease.