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Posts Tagged ‘human papillomavirus’


Reporter: Aviva Lev-Ari, PhD, RN

Head and Neck Cancer Studies Suggest Alternative Markers More Prognostically Useful than HPV DNA Testing

September 18, 2012

NEW YORK (GenomeWeb News) – The presence or absence of human papillomavirus DNA on its own in an individual’s head or neck cancer does not provide enough information to help predict a patient’s survival, according to a pair of new papers in the journal Cancer Research.

Two research teams — headed by investigators at Brown University and Heidelberg University, respectively — looked at the reliability of using PCR-based HPV testing to determine which head and neck squamous cell carcinomas were HPV-related and, thus, more apt to respond to treatment.

Previous studies have shown that individuals with HPV-associated head and neck cancers tend to have more favorable outcomes than individuals whose head and neck cancers that are not related to HPV infection.

“Everybody who has studied it has shown that people with virally associated disease do better,” Brown University pathology researcher Karl Kelsey, a senior author on one of the new studies, explained in a statement.

“There are now clinical trials underway to determine if they should be treated differently,” he added. “The problem is that you need to appropriately diagnose virally related disease, and our data suggests that people need to take a close look at that.”

For their part, Kelsey and his co-authors from the US and Germany assessed the utility of testing for the presence of HPV by various means in individuals with head and neck cancer. This included PCR-based tests for HPV DNA in the tumor itself, tests aimed at detecting infection-associated antibodies in an individual’s blood, and tests for elevated levels of an HPV-related tumor suppressor protein.

For 488 individuals with HNSCC, researchers did blood-based testing for antibodies targeting HPV16 in general, as well as testing for antibodies that target the viral proteins E6 and E7.

For a subset of patients, the team assessed the tumors themselves for the presence of HPV DNA and/or for elevated levels of the host tumor suppressor protein p16.

Based on patterns in the samples, the group determined that the presence of viral E6 and E7 proteins in the blood was linked to increased survival for individuals with an oropharyngeal form of HNSCC, which affects part of the throat known as the oropharynx.

A positive test for HPV DNA alone was not significantly linked to head and neck cancer outcomes. On the other hand, when found in combination with E6 and E7 expression, a positive HPV16 test did coincide with improved oropharyngeal cancer outcomes.

Likewise, elevated levels of p16 in a tumor were not especially informative on their own, though they did correspond to better oropharyngeal cancer survival when found together with positive blood tests for E6 and E7.

Based on these findings, Kelsey and his team concluded that “[a] stronger association of HPV presence with prognosis (assessed by all-cause survival) is observed when ‘HPV-associated’ HNSCC is defined using tumor status (HPV DNA or P16) and HPV E6/E7 serology in combination rather [than] using tumor HPV status alone.”

In a second study, meanwhile, a German group that focused on the oropharyngeal form of the disease found its own evidence arguing against the use of HPV DNA as a solo marker for HPV-associated head and neck cancer.

For that analysis, researchers assessed 199 fresh-frozen oropharyngeal squamous cell carcinoma samples, testing the tumors for HPV DNA and p16. They also considered the viral load in the tumors and looked for gene expression profiles resembling those described in cervical carcinoma — another cancer associated with HPV infection.

Again, the presence of HPV DNA appeared to be a poor indicator of HPV-associated cancers or predictor of cancer outcomes. Whereas nearly half of the tumors tested positive for HPV16 DNA, just 16 percent and 20 percent had high viral loads and cervical cancer-like expression profiles, respectively.

The researchers found that a subset of HPV DNA-positive tumors with high viral load or HPV-associated expression patterns belonged to individuals with better outcomes. In particular, they found that cervical cancer-like expression profiles in oropharyngeal tumors coincided with the most favorable outcomes, while high viral load in the tumors came a close second.

“We showed that high viral load and a cancer-specific pattern of viral gene expression are most suited to identify patients with HPV-driven tumors among patients with oropharyngeal cancer,” Dana Holzinger, that study’s corresponding author, said in a statement.

“Once standardized assays for these markers, applicable in routine clinical laboratories, are established, they will allow precise identification of patients with oropharyngeal cancer with or without HPV-driven cancers and, thus, will influence prognosis and potentially treatment decisions,” added Holzinger, who is affiliated with the German Cancer Research Center and Heidelberg University.

In a commentary article online today in Cancer Research, Eduardo Méndez, a head and neck surgery specialist with the University of Washington and Fred Hutchinson Cancer Research Centerdiscussed the significance of the two studies and their potential impact on oropharyngeal squamous cell carcinoma prognoses and treatment.

But he also cautioned that more research is needed to understand whether the patterns described in the new studies hold in other populations and to tease apart the prognostic importance of HPV infection in relation to additional prognostic markers.

 

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Reported by: Dr. Venkat S Karra, Ph.D.

Two-thirds of Americans aged 15 to 24 have engaged in oral sex, according to a broad new survey of young people’s sexual habits.

The data, published Aug. 16 in the U.S. Centers for Disease Control and Prevention’s National Health Statistics Reports, also reveals that about one-quarter of young people try oral sex before they engage in intercourse.

“I don’t think these numbers are surprising, but I do think that it’s important that this data has been captured at all, because it’s really important to have, and has for a long time been a fuzzy area in our understanding of sexual behavior,” said one expert, Dr. Christopher Hurt, A clinical assistant professor in the division of infectious disease at the University of North Carolina.

He said the findings are also valuable because too many people of all ages mistakenly believe that oral sex is “risk-free.”

“That’s not the case,” Hurt said. “Studies looking, for example, at patients visiting STD [sexually transmitted disease] clinics have shown that 5 to 10 percent have gonorrhea in the throat. And it’s often asymptomatic and can be transmitted through oral sex.”

Gonorrhea is becoming increasingly resistant to antibiotics, and a report released last week by the CDC noted that certain strains are resistant to all but one such drug. Oral sex can also raise risks for infection with chlamydia, herpes and syphilis, the CDC noted.

Oral sex is also increasingly linked to transmission of the human papillomavirus (HPV), which may be linked to cancers of the throat and oral cavity, in addition to cervical cancer, experts say.

While the odds of contracting any sexually transmitted disease from oral sex remain lower than that for unprotected intercourse, the CDC has stated that “numerous studies have demonstrated that oral sex can result in the transmission of HIV and other sexually transmitted diseases.”

The new report is based on data from the agency’s seventh National Survey of Family Growth, involving interviews conducted between 2007 and 2010 with nearly 22,700 people between the ages of 15 and 44.

Even though the survey found that about one-quarter of Americans aged 15 to 24 engaged in oral sex before they moved on to intercourse, for about another quarter of respondents the opposite was true — they tried penile-vaginal intercourse prior to engaging in oral sex. Among males, 12 percent said their first experience with both practices occurred at the same time, while a little more than 7 percent of women said that that was the case for them.

Examining behaviors solely among the youngest participants — those 15 to 19 years old — the CDC team found that more than half of American girls and boys in this age group had already engaged in some form of sexual contact with someone of the opposite sex (55 percent of girls and 58 percent of boys).

Among the survey’s other findings:

  • About 5 percent of women and nearly 7 percent of men aged 15 to 24 said that at the time of the survey they had only engaged in oral sex, not intercourse. Another 28 percent of women and nearly 29 percent of men said they had had no sexual experiences with an opposite-sex partner whatsoever.
  • Among girls aged 15 to 19 years, oral sex and vaginal intercourse experience were equally common (48 percent and 47 percent, respectively), while among similarly aged boys oral sex was slightly more common (49 percent) compared to intercourse (44 percent).
  • Rates of sexual behaviors did not appear to vary widely by race. For example, among females aged 15 to 24, nearly three-quarters (74 percent) of black women, 68 percent of Hispanic women and 66 percent of white women said they had had vaginal intercourse.
  • Among males aged 15 to 24, about seven in 10 black and Hispanic men said they had had intercourse, compared with 63 percent of white men. There were no appreciable racial differences observed in terms of the percentages of those who said they had engaged in oral sex, the CDC survey found.

According to Hurt, young people need to be properly armed with knowledge before they engage in their first sexual activity, and that includes information on the risks that accompany oral sex.

“I would say that the risk of STD transmission through oral sex is underappreciated and underestimated,” he said. “As part of sex education programs, kids need to be made aware of that fact: that oral sex is not a completely risk-free activity.”

SOURCES: Christopher Hurt, M.D., clinical assistant professor, division of infectious diseases, University of North Carolina, Chapel Hill; Aug. 16, 2012, U.S. Centers for Disease Control and Prevention’s National Center for Health Statistics report, Prevalence and Timing of Oral Sex with Opposite-Sex Partners Among Females and Males Aged 15-24 Years: United States: 2007-2010

Source

http://www.nlm.nih.gov/medlineplus/news/fullstory_128320.html

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