A pioneering Air Force study identifies more than three times the expected incidence of often deadly invasive cancers.  
But the discovery has not prompted warnings to troops, new health policies—or even plans for further study.
Statistical details

Standardized Incidence Ratios (SIRs)
(Ratios calculated for US Air Force active duty personnel
vs age-, sex- and ethnicity-matched US general
population SEER data)

Females, all invasive cancers: SIR
0.96, CI: 0.89-1.03
Females, invasive vulvar cancer: SIR 3.54, CI: 1.77-6.28
Females, invasive cervical cancer: SIR
3.19, CI: 2.74-3.70
Females, oral squamous cell carcinoma: SIR
2.08, CI:
0.95–3.91
Males, all invasive cancers:SIR
0.50, CI:0.48-.053
Males, invasive prostate adenocarcinoma: SIR 1.44, CI:
1.21-1.69
Cancer Vaccine, Education Key
Marts also thinks servicewomen are prime
candidates for receiving new vaccines that protect
against HPV infection. “The armed forces vaccinate
against a zillion other things,” she says. “They might
as well use this one too. Why not go for it? We have
a preventable cancer, here.”

Clifford agrees, but notes that vaccines will not
remedy the current epidemic. "A vaccine will only
offer protection to future generations of women, as
they need to be administered before initiation of
sexual activity," he says.

Marts thinks the Air Force should consider a two-
pronged response to Yamane’s findings. “Make
condoms available and give them safer sex
counseling," she says. "Part of the problem with
safer sex is that condom use is still controlled by the
male sex partner. There’s a message that needs to
be conveyed to women about negotiating condom
use, and that can require some assertiveness
training.”  Condom use decreases but does not
eliminate the risk of HPV transmission.

But there is no new push to warn the troops about
their special risk. Nor are there any immediate plans
to follow up on Yamane’s findings with additional
research that could determine exactly what risk
factors are responsible for the Air Force cancers.

"I haven’t received any heads up that someone is
planning a follow up," Yamane says. "I hope follow
ups will occur. The Air Force is just one component
of the DoD. The picture is incomplete."

A 2002 Pentagon
report indicates that lifetime risks of
sexually transmitted disease infections are higher in
the Army and Navy than the Air Force, indicating that
soldiers and sailors may face even worse risks for
HPV related cancers than Air Force personnel.
According to Col Wilma Larsen at the Carl R Darnall
Army Medical Center in Fort Hood, Texas, the Army
has no plans to study HPV infection rates, but
studies are under way to assess abnormal Pap tests
and gynecological cancers in active duty soldiers.  

“At the very least, other branches of the military
should see if women are taking advantage of the
opportunity to access gynecological exams,” says
Marts.

The Navy does not track or study HPV infection
rates, according to Navy Bureau of Medicine public
affairs officer Christine Mahoney, who notes that the
Navy does offer comprehensive sexual health
lectures to female sailors and Marines in boot camp.

The Army and Navy both require annual Pap
screens for active duty servicewomen.

According to the National Cancer Institute (
NCI), 78
percent of civilian cervical cancers are detected
before they become invasive. Only invasive cervical
cancers are reported in the Air Force study. Mortality
rates are not reported in the study.

Prostate cancer rates a mirage?
Yamane found that the rate of prostate cancer is 44
percent higher in Air Force men than civilians. But
he believes that universal military medical care and
resulting “over-ascertainment bias” might be
responsible for the apparent elevation.  

"Military personnel have a high level of access to
health care," he notes. "Increased opportunities for  
prostate-specific antigen (PSA) testing could have
spuriously increased our incidence of prostate
adenocarcinoma." PSA tests are used to screen men
for prostate cancer.

Judd Moul of Duke University agrees. “I’m pretty sure
that’s it—ascertainment bias,” he says. “Over time,
they should see fewer invasive cases. Every time we
start PSA screening in a population, we see massive
‘stage migration.’ In other words, more localized, early
stage cancers and fewer advanced cases are
identified through time.”

"Other studies have shown that the harder you look
for prostate cancer, the more you find," says John
Concato of Yale University.
by Bryant Furlow
November 12, 2006—Women in the US Air Force
face more than three times the risk seen among
civilians of developing invasive, deadly—and
preventable—reproductive organ cancers, according
to the first comprehensive cancer assessment of Air
Force personnel.

But nobody has told them.

The study, completed last year, identifies marked
elevations in the rates of cervical and vulvar cancer,
as well as prostate adenocarcinoma in men. The
study was subsequently published in the August
2006 issue of  
Aviation Space & Environmental
Medicine.

Author Grover Yamane of the Air Force Institute for
Operational Health found that when Air Force and
US civilian populations are compared, Air Force
women's rates of cervical and vulvar cancers are
more than three times those of civilians, when
matched for age and ethnicity.

Based on civilian rates, Yamane expected to identify
56 cases of invasive cervical cancer among Air
Force women. He confirmed 180.  

Yamane also found that Air Force men are 44
percent more likely than civilians to be diagnosed
with invasive prostate adenocarcinoma.  

STD epidemic to blame?
Both prostate adenocarcinoma and cervical cancer
have been linked to exposure to trichloroethylene
(
TCE) — an industrial solvent and ubiquitous
pollutant at military air bases.

But such dramatic elevations in women’s
reproductive cancer rates are more likely due to an
epidemic of aggressively carcinogenic strains of
human papillomavirus (HPV), researchers say.

"Cervical cancer and vulvar cancer are caused by
sexually transmitted, high-risk types of HPV,"
explains professor Geoff Garnett, an authority on
HPV at Imperial College in London. "A group of
women with a significantly higher than expected
incidence of such cancers could have a higher
prevalence of high risk HPV infections, and also may
be less well screened for precancerous lesions."  

Yamane agrees that HPV infection could be driving
the Air Force's gynecological cancer rates. "The
frequency of unsafe sexual practices among active
duty Air Force women may be high," he notes, citing
military health surveys.

"My first question would be how well these military
women attend screening programs, and to try and
improve coverage rates," says Gary Clifford, an
expert on viral infection and cancer at the
International Agency for Research on Cancer (
IARC)
in Lyon, France.

Air Force records indicate that many Air Force
service-women may not be undergoing the regular
gynecological screening exams. A 2001 Air Force
records review found that 27% of active duty women
had no indication in their medical records of
undergoing such screens during the previous three
years.

“Cervical cancers, with regular Pap tests, are going
to be caught when they’re just a patch of abnormal
cells on the cervix,” says Sherry Marts of the Society
for Women's Health Research in Washington, DC.
“This is an easily treated, curable disease. It’s truly a
tragedy that anybody dies of this cancer.”

The Air Force study did not analyze mortality rates.

For the time being, safe sex education and early
detection through frequent screening exams may be
the only tools available to stem the tide of invasive
HPV related cancers.
US Air Force Study Finds High Rates of Reproductive Cancers