Cancer Is Not a Personality Test
Notwithstanding the claims of some alternative medical books and Web sites, there is no such thing as a "cancer personality," finds a new study of nearly 30,000 Swedes.
A number of psychologists and others have hypothesized that some people are more likely to get cancer because they are angry, neurotic or otherwise unstable. One Web site, for example, has claimed that "lack of self-esteem, the need to people-please, frustrated self-expression, sexual repression, a conflicted mother-daughter relationship, and other traits all are part of the breast cancer personality."
The earthquake that led to the tsunami also rattled Earth's axis and shifted the North Pole.
(Reuters)
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Such assessments have angered some doctors, patients and others because they seem to blame patients for their own disease.
The new study looked for links between cancer rates and two commonly measured personality traits: extraversion, which relates to a person's need for interaction with others; and neuroticism, a measure of emotional instability.
Led by Pernille Hansen of the Institute of Cancer Epidemiology in Copenhagen, the team reviewed decades-long health histories and personality data collected from 29,595 Swedes born between 1926 and 1958 as part of a twin registry that country maintains. They tallied 1,898 cases of cancer in the group but found no association between those diagnoses and any pattern of neuroticism or extraversion. The analysis, to be published in the March 1 issue of the journal Cancer and posted online last night, did not even find evidence that those personality traits were linked to risky behaviors, such as smoking, that might themselves increase one's odds of cancer.
The results affirm those of a Japanese study of more than 30,000 people, completed in 2003, that also found no link between cancer and personality traits. That study concluded that the emotional instability sometimes seen in cancer patients is the result, not the cause, of the diagnosis.
-- Rick Weiss
Giant Quake Has Ripple Effects
The earthquake that spawned the devastating Indonesian tsunami of Dec. 26 shifted the North Pole, shortened the length of a day, made the Earth rounder and imparted a "wobble" to its rotation, but the effects are tiny and in some cases not even discernible.
"If you consider the whole Earth, any earthquake will cause small changes," said geophysicist Benjamin Fong Chao, of NASA's Goddard Space Flight Center. "The effects are not just local."
NASA monitors the effects of earthquakes using laser-ranging and radar instruments on orbiting satellites, but ordinarily the changes in Earth's geophysics are so minuscule as to be imperceptible.
This was not the case with the 9.2-magnitude quake off the Sumatran coast, the biggest in a half-century and the first one large enough for changes to register on space-based instruments, Chao said.
The magnitude and location of the quake -- at the India and Burma tectonic plates -- caused Earth to become rounder by one part in 10 billion, Chao said. At the same time, Earth's rotation speeded up, shortening the length of a day by 2.68 microseconds.
The North Pole shifted about an inch in the direction of 145 East longitude, and the quake also imparted an extra wobble to Earth's axis, although that effect will dissipate over time, he said.
-- Guy Gugliotta
Viagra May Give Hearts a Boost
Viagra, the popular drug for erectile dysfunction, has unanticipated beneficial effects on the heart, new research suggests.
Hearts often become dangerously enlarged in people who have either untreated high blood pressure or a partial blockage of the large vessel leading from the heart -- a condition that causes a buildup of back pressure on the muscular pump.
David Kass of the Johns Hopkins Medical Institutions in Baltimore and his colleagues knew that the body tries to fight stress-induced heart enlargement by producing a blood chemical known as cGMP. And they knew that although cGMP helps reduce enlargement, it does not help enough -- in part, it seems, because almost as fast as the body makes the stuff it also makes an enzyme called PDE5A, which breaks cGMP down.
That's how they got onto sildenafil, otherwise known as Viagra. The drug works by blocking that same enzyme, PDE5A, which is, it turns out, a big culprit in erectile dysfunction. So the Hopkins team wondered: Might Viagra help boost levels of heart-healthy cGMP by suppressing the enzyme that normally breaks it down?
In a series of experiments with mice, the team showed that the drug did indeed slow the rate of cardiac enlargement in animals whose hearts were intentionally put under blood-pressure stress. Perhaps more medically relevant, they also showed that in mice whose hearts were already enlarged, the drug helped shrink those hearts. It also resulted in improved cardiac function.
Further studies should examine the potential value of Viagra and related drugs as treatments for heart disease, they wrote in yesterday's advance online edition of the journal Nature Medicine. No word from the researchers on the mice's sex lives.
-- Rick Weiss
