Cervical Cancer Screening By Pap Smear

Bradley Linzie, MD, FCAP, right, describes the difference between normal and cancerous cells to Gulirana Minhas, of Richfield, Minn., after she received her Pap test result during a free breast and cervical cancer screening program at the NorthPoint Health and Wellness Center in Minneapolis, Minn., Tuesday, October 5, 2010. (Craig Lassig/AP Images for College of American Pathologists/See, Test and Treat)

When it comes to screening for cervical cancer, American women can choose the Pap test or the human papillomavirus (HPV) test. The Pap has been the mainstay of screenings since Georgios Papanicolaou developed it in the late 1920s—still most successful cancer screening program in history. The HPV test looks for highest risk strains of the virus responsible for causing nearly all cervical cancer.

The debate over which of these is most effective and reliable at detecting and preventing cervical cancer has driven frequent, often confusing changes in cervical cancer screening guidelines from a multiple medical organizations over the past decade The most recent screening recommendations came from the US Preventive Services Task Force a few weeks ago.

While USPSTF recommendations for women ages 21-29 remained the same as before (a Pap every 3 years), the USPSTF gives women ages 30-65 a choice: a Pap every 3 years, an HPV test every 5 years or a Pap plus HPV test every 5 years.

So what’s a woman to do?

Choose both.

At least, that’s what nearly every other relevant medical organization recommends and what published evidence seems to support at this point in time. In fact, the day before the USPSTF published their recommendations, a study in the >American Journal of Clinical Pathology found that Pap tests detected more cancers than the HPV test in more than 300,000 screenings between 2003-2009.

“Co-testing is the safest way for patients to screen for cervical cancer,” said the study’s lead author, R. Marshall Austin, MD, PhD, a professor of pathology and director of cytopathology at University of Pittsburgh Medical Center Magee-Womens Hospital in Pennsylvania.

Austin said many women don’t realize it’s still possible to get cancer even with regular screenings. No screening test is perfect; there will always be missed cases (false negatives) and false alarms (false positives).

But co-testing offers the best of both worlds. HPV can take decades to develop into cancer, so identifying current infections with a high-risk HPV strain gives healthcare providers an opportunity to set up follow-up surveillance for women before the cancer has a chance to develop.

And Pap tests have come a long way from the “Pap smear” used from the 30s through the end of the 20th century. Today’s liquid-based cytology—an examination of cervical cells under a microscope—is even more accurate at revealing abnormal cell patterns than the smear  on a slide used for so long.

“We’ve done a poor job of educating people that even the best screening is not going to result in no cancers,” Austin said. “But if you want as close as possible to no cancers, there’s no question about it — the data all point to co-testing.”

By preferentially suggesting women get either a Pap or an HPV test, the USPSTF recommendations differ from those of 23 other organizations who developed consensus guidelines in 2012 and recommend co-testing (both a Pap and HPV test every 5 years) as the preferred screening method.

Those nearly two dozen organizations that continue to recommend co-testing include the American College of Obstetricians and Gynecologists ACOG, the American Cancer Society, the American Society for Colposcopy and Cervical Pathology (ASCCP) and American Society for Clinical Pathology (ASCP).

Yet co-testing wasn’t even in the USPSTF’s initial draft recommendations when they published the draft for public comment in September 2017. It was only after researchers and patient advocates strongly argued for including co-testing to avoid missing cancers, particularly in women of color, that the USPSTF backtracked and added co-testing back as one of their recommended options.

Professional disagreements about the different screening methods can become intense. When Austin submitted his study for review, one of its reviewers was Mark Schiffman, MD, MPH, a senior investigator at the National Cancer Institute who has long championed the value of the HPV test for screening. Schiffman wrote at length about findings from a study he conducted that contradicted what Austin found, instead suggesting that Pap tests weren’t as highly effective as the HPV test.

But Austin said it depends on the quality of the Pap and its analysis—and what you’re willing to learn.

“We try to learn from examples where the system fails,” Austin said. “For over 20 years, I’ve been studying cases of women who are screened and still get cervical cancer.”

His institution uses computer-assisted imaging to interpret pathology findings from Pap tests.

“I realized pretty early on that there are certain types of cell patterns that you see on these Pap tests that are very significant but may not be recognized, and that’s how I train our cytologists and pathologists,” Austin said. “Because of this, I feel completely confident that our laboratory catches things that are commonly missed.”

At institutions or clinics that aren’t as thorough or conscientious with Pap tests as Austin’s lab, the benefit of co-testing may not be as dramatically evident. In his study, 13% of cervical cancer cases developed after a negative HPV test but a positive Pap. But even if other institutions caught just half that much, it would mean that 1 in 15 women with cervical cancer would identified early on instead of being missed as the cancer continues growing.

Co-testing also helps healthcare providers plan more precise follow-up when the two tests’ results are contradictory, potentially saving women an extra trip to the clinic or more invasive procedures such as biopsies (depending on the specific results of the tests together).

In any case, the USPSTF recommendations certainly do not end the debate over the best screening regiment for cervical cancer.

“The USPSTF hasn’t changed either the ACOG or the ASCCP or ASCP guidelines,” Austin said. “They’re gong to be revisited, and this will be another debate that will go on, but right now, those guidelines are that co-testing is the preferred method.”

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Bradley Linzie, MD, FCAP, right, describes the difference between normal and cancerous cells to Gulirana Minhas, of Richfield, Minn., after she received her Pap test result during a free breast and cervical cancer screening program at the NorthPoint Health and Wellness Center in Minneapolis, Minn., Tuesday, October 5, 2010. (Craig Lassig/AP Images for College of American Pathologists/See, Test and Treat)

When it comes to screening for cervical cancer, American women can choose the Pap test or the human papillomavirus (HPV) test. The Pap has been the mainstay of screenings since Georgios Papanicolaou developed it in the late 1920s—still most successful cancer screening program in history. The HPV test looks for highest risk strains of the virus responsible for causing nearly all cervical cancer.

The debate over which of these is most effective and reliable at detecting and preventing cervical cancer has driven frequent, often confusing changes in cervical cancer screening guidelines from a multiple medical organizations over the past decade The most recent screening recommendations came from the US Preventive Services Task Force a few weeks ago.

While USPSTF recommendations for women ages 21-29 remained the same as before (a Pap every 3 years), the USPSTF gives women ages 30-65 a choice: a Pap every 3 years, an HPV test every 5 years or a Pap plus HPV test every 5 years.

So what’s a woman to do?

Choose both.

At least, that’s what nearly every other relevant medical organization recommends and what published evidence seems to support at this point in time. In fact, the day before the USPSTF published their recommendations, a study in the >American Journal of Clinical Pathology found that Pap tests detected more cancers than the HPV test in more than 300,000 screenings between 2003-2009.

“Co-testing is the safest way for patients to screen for cervical cancer,” said the study’s lead author, R. Marshall Austin, MD, PhD, a professor of pathology and director of cytopathology at University of Pittsburgh Medical Center Magee-Womens Hospital in Pennsylvania.

Austin said many women don’t realize it’s still possible to get cancer even with regular screenings. No screening test is perfect; there will always be missed cases (false negatives) and false alarms (false positives).

But co-testing offers the best of both worlds. HPV can take decades to develop into cancer, so identifying current infections with a high-risk HPV strain gives healthcare providers an opportunity to set up follow-up surveillance for women before the cancer has a chance to develop.

And Pap tests have come a long way from the “Pap smear” used from the 30s through the end of the 20th century. Today’s liquid-based cytology—an examination of cervical cells under a microscope—is even more accurate at revealing abnormal cell patterns than the smear  on a slide used for so long.

“We’ve done a poor job of educating people that even the best screening is not going to result in no cancers,” Austin said. “But if you want as close as possible to no cancers, there’s no question about it — the data all point to co-testing.”

By preferentially suggesting women get either a Pap or an HPV test, the USPSTF recommendations differ from those of 23 other organizations who developed consensus guidelines in 2012 and recommend co-testing (both a Pap and HPV test every 5 years) as the preferred screening method.

Those nearly two dozen organizations that continue to recommend co-testing include the American College of Obstetricians and Gynecologists ACOG, the American Cancer Society, the American Society for Colposcopy and Cervical Pathology (ASCCP) and American Society for Clinical Pathology (ASCP).

Yet co-testing wasn’t even in the USPSTF’s initial draft recommendations when they published the draft for public comment in September 2017. It was only after researchers and patient advocates strongly argued for including co-testing to avoid missing cancers, particularly in women of color, that the USPSTF backtracked and added co-testing back as one of their recommended options.

Professional disagreements about the different screening methods can become intense. When Austin submitted his study for review, one of its reviewers was Mark Schiffman, MD, MPH, a senior investigator at the National Cancer Institute who has long championed the value of the HPV test for screening. Schiffman wrote at length about findings from a study he conducted that contradicted what Austin found, instead suggesting that Pap tests weren’t as highly effective as the HPV test.

But Austin said it depends on the quality of the Pap and its analysis—and what you’re willing to learn.

“We try to learn from examples where the system fails,” Austin said. “For over 20 years, I’ve been studying cases of women who are screened and still get cervical cancer.”

His institution uses computer-assisted imaging to interpret pathology findings from Pap tests.

“I realized pretty early on that there are certain types of cell patterns that you see on these Pap tests that are very significant but may not be recognized, and that’s how I train our cytologists and pathologists,” Austin said. “Because of this, I feel completely confident that our laboratory catches things that are commonly missed.”

At institutions or clinics that aren’t as thorough or conscientious with Pap tests as Austin’s lab, the benefit of co-testing may not be as dramatically evident. In his study, 13% of cervical cancer cases developed after a negative HPV test but a positive Pap. But even if other institutions caught just half that much, it would mean that 1 in 15 women with cervical cancer would identified early on instead of being missed as the cancer continues growing.

Co-testing also helps healthcare providers plan more precise follow-up when the two tests’ results are contradictory, potentially saving women an extra trip to the clinic or more invasive procedures such as biopsies (depending on the specific results of the tests together).

In any case, the USPSTF recommendations certainly do not end the debate over the best screening regiment for cervical cancer.

“The USPSTF hasn’t changed either the ACOG or the ASCCP or ASCP guidelines,” Austin said. “They’re gong to be revisited, and this will be another debate that will go on, but right now, those guidelines are that co-testing is the preferred method.”

Source : https://www.forbes.com/sites/tarahaelle/2018/09/14/which-screening-test-to-prevent-cervical-cancer-go-with-co-testing/

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Cervical Cancer Screening By Pap Smear

Source:BBC

Cervical Cancer Screening By Pap Smear