HPV test beats Pap for cervical cancer screening

May 18, 2011 By MARILYNN MARCHIONE , AP Medical Writer

Two big studies suggest possible new ways to screen healthy people for cervical or prostate cancers, but a third disappointed those hoping for a way to detect early signs of deadly ovarian tumors.

Researchers found:

-For women 30 and over, a test for the virus, HPV, is better than a Pap smear for predicting risk, and those who test negative on both can safely wait three years to be screened again.

-A single PSA at ages 44 to 50 might help predict a man's risk of developing advanced prostate cancer or dying of it up to 30 years later. The is notoriously unreliable, but using it this way separates men who need a close watch from those who are so low-risk that they can skip testing for five years or more.

-Screening women with no symptoms for with a blood test and an ultrasound exam is harmful. It didn't prevent deaths and led to thousands of false alarms, unneeded surgeries and serious complications.

The last study is a warning to people who get screening tests that aren't recommended, or who question whether screening can ever hurt.

"The answer is, it could hurt a lot," said Dr. Allen Lichter, chief executive of the American Society of Clinical Oncology. The group published these and 4,000 other studies Wednesday, ahead of its annual meeting next month.

Cervical cancer is easy to prevent. It's very slow-growing and screening finds precancerous cells and allows early treatment. The new study was the first big one to examine a newer screening tool, HPV tests, with or without in routine practice.

For a Pap test, cells scraped from the cervix, the gateway to the uterus, are checked under a microscope. But this can miss problems or raise false alarms.

HPV tests detect the , which causes most cases of cervical cancer. But HPV is "the common cold" of the nether regions - most sexually active young people have been exposed to it, said Debbie Saslow, the American Cancer Society's director of breast and gynecologic cancer. Most infections go away on their own; they're only a cancer risk when they last a year or more.

Younger women tend to have short-term infections, so Pap tests are a better way to screen them. HPV tests are approved as an option along with Paps for women 30 and older, and the cancer society says that if a woman tests negative on both, she can wait three years to be screened again. Few take this advice, though.

"Women still want their annual Pap and doctors still want to give them," and think it's rationing care to test less often, Saslow said.

The new study gives "very, very solid support" for screening less often, Lichter said.

Hormuzd Katki of the National Cancer Institute studied more than 330,000 women getting HPV and Pap tests through Kaiser Permanente Northern California for five years.

Only about three out of 100,000 women each year developed cervical cancer after negative HPV and Pap tests. HPV tests were twice as good as Paps for predicting risk. Adding a Pap after a negative HPV test did little to improve risk prediction.

However, if an HPV test was positive, a helped confirm or rule out the need for follow-up.

The study didn't look at the downside of HPV testing - how many false alarms and needless procedures it triggered. HPV tests cost $80 to $100 compared to $20 to $40 for Paps.

The prostate study sought a better way to use PSA tests, which are troublesome because PSA can be high for many reasons besides cancer, and doctors don't know which cancers need treatment or whether screening saves lives. Most groups don't recommend PSA tests, but most men over 50 get them anyway.

The new study "is not going to end the controversy, but it suggests a very interesting middle ground," Lichter said.

Researchers at Memorial Sloan-Kettering Cancer Center in New York used stored blood samples that 12,000 Swedish men gave for a heart study decades ago, when most were 44 to 50 years old. They also had second samples from some of them six years later, and samples from other 60-year-old men.

Looking 27 years later, researchers saw that 44 percent of cancer deaths occurred in men whose initial PSAs had been in the top 10 percent when they were 44 to 50 years old.

Conversely, scoring below the median meant very little cancer risk years later.

"They're identifying a group of guys who don't need to be screened, or need to be screened less often," said Dr. Otis Brawley, the cancer society's chief medical officer.

The results are "provocative," but this type of study can't prove that screening prevents deaths, said Dr. Matthew R. Smith of the Massachusetts General Hospital Cancer Center. Few of the Swedish men were treated for prostate cancer as most men are today, which can affect survival.

The National Cancer Institute, the Swedish Cancer Society and several foundations paid for the work, and one researcher holds patents for two PSA-related tests.

Baseline PSA tests for men in their 40s can't be recommended yet, Brawley said. The cancer society says men should be informed of the risks and benefits of PSA tests starting at age 50, and sooner for blacks and those with family history of prostate cancer.

The government-funded ovarian cancer study involved nearly 80,000 women. Half were screened annually with an ultrasound for four years and a blood test for six years. The blood test looked for CA-125, a substance often elevated in ovarian cancer.

After 13 years, there were no major differences in ovarian cancers found or deaths from the disease. Screening found only 212 cancers while giving 3,285 false alarms that led to 1,080 unneeded biopsy surgeries and 163 serious complications.

"So many people say `how can cancer screening be harmful?' This thing documents it," Brawley said.

The results don't apply to using these tests on women with symptoms of ovarian cancer or abnormal physical exams. That's still the best way to check for ovarian in those cases.

More information:
CDC on HPV tests: www.cdc.gov/hpv/Screening.html

Cancer Society on HPV: tinyurl.com/44gnadx

Cervical cancer science review: tinyurl.com/6lc2rzg

Oncology society: www.cancer.net


Related Stories

Recommended for you

Lung cancer triggers pulmonary hypertension

November 17, 2017
Shortness of breath and respiratory distress often increase the suffering of advanced-stage lung cancer patients. These symptoms can be triggered by pulmonary hypertension, as scientists at the Max Planck Institute for Heart ...

Researchers discover an Achilles heel in a lethal leukemia

November 16, 2017
Researchers have discovered how a linkage between two proteins in acute myeloid leukemia enables cancer cells to resist chemotherapy and showed that disrupting the linkage could render the cells vulnerable to treatment. St. ...

Computer program finds new uses for old drugs

November 16, 2017
Researchers at the Case Comprehensive Cancer Center at Case Western Reserve University School of Medicine have developed a computer program to find new indications for old drugs. The computer program, called DrugPredict, ...

Pharmacoscopy improves therapy for relapsed blood cancer in a first clinical trial

November 16, 2017
Researchers at CeMM and the Medical University of Vienna presented a preliminary report in The Lancet Hematology on the clinical impact of an integrated ex vivo approach called pharmacoscopy. The procedures measure single-cell ...

Wider sampling of tumor tissues may guide drug choice, improve outcomes

November 15, 2017
A new study focused on describing genetic variations within a primary tumor, differences between the primary and a metastatic branch of that tumor, and additional diversity found in tumor DNA in the blood stream could help ...

A new strategy for prevention of liver cancer development

November 14, 2017
Primary liver cancer is now the second leading cause of cancer-related death worldwide, and its incidences and mortality are increasing rapidly in the United Stated. In late stages of the malignancy, there are no effective ...


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) May 19, 2011
A new report has found that 50% of men may have HPV. many are not aware of it because it usually has no symptoms.

If you're infected by HPV or other STDs, you're invited to join STDdatings. com. It was created to help people learn STD prevention, share medical treatments, find trusted people to talk. All personal info is private and anonymous.
not rated yet Jun 11, 2011
A newer report showed that posts by CarringSpammer were all spam pushing a dating site.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.