medical Study : Lung cancer linked to risk of stroke

REUTERS - People recently diagnosed with lung cancer are at a higher risk of having a stroke than those without lung tumours, according to a Taiwanese study.

Xray image of lung cancer

Researchers at China Medical University looked at data covering more than 150,000 adults and found that among those with lung cancer, 26 in every 1,000 experienced a stroke every year, compared with 17 in 1,000 who did not have cancer.

Lifestyle issues that might influence stroke risk -- such as smoking, drinking or diet -- were not factored in, said Fung-Chang Sung, senior author of the study, which was published in the journal Stroke.

Couse of cancer

Type of Cancer	Risk factors
lung cancer	cigarette smoking; exposure to asbestos, uranium and nickel
skin cancer	excessive exposure to the sun, tanning salons
breast cancer	familial history - genetics
cervix cancer	human papilloma virus exposure
colon and rectum	high fat diet, low fiber
oral cancer	alcohol plus smoking, smokeless tobacco
urinary bladder	aniline dye exposure, cigarette smoking, exposure to parasite Schistosoma haematobium
leukemia	exposure to benzene, ionizing radiation

Still, the risk was highest during the first three months after a lung cancer diagnosis for men and during the first four-to-six months for women.

"Lung cancer is associated with increased risk of subsequent stroke within one year after diagnosis for men and two years after diagnosis for women," Sung and colleagues wrote, adding that the risk subsequently decreased after that period of time.

Chart below show us the % of mortality of cancer patient:

Cancer Type	Estimated New Cases	Estimated Deaths	Percent Mortality
Skin (non-melanoma)	>1,000,000	<1,000	0.1%
Lung (Including Bronchus)	215,020	161,840	75%
Prostate	186,320	28,660	15%
Breast (Female)	182,460	40,480	22%
Colon and Rectal (Combined)	148,810	49,960	34%
Bladder	68,810	14,100	20%
Non-Hodgkin Lymphoma	66,120	19,160	29%
Melanoma	62,480	8,420	13%
Kidney (Renal Cell) Cancer	46,232	11,059	24%
Leukemia (All)	44,270	21,710	49%
Endometrial	40,100	7,470	19%
Pancreatic	37,680	34,290	91%
Thyroid	37,340	1,590	4%

The researchers also found that a less common type of stroke -- hemorrhagic stroke, caused by sudden bleeding into the brain -- occurred more often among the lung cancer patients than ischemic stroke, which is usually caused by a clot blocking blood flow to brain tissue.

Some evidence suggests that excessive bleeding and blood clots, both of which can be caused by tumours, as well as chemotherapy side effects, could partly explain the apparent link between cancer and stroke, researchers note.

"The most common type of lung cancer, adenocarcinoma, increases the body's propensity to form blood clots, even more so than other types of cancer," said Andrew Russman, a stroke specialist at the Henry Ford Hospital in Detroit, who was not a part of the study.

More than 52,000 people with lung cancer and more than 104,000 people without lung cancer were selected from a nationwide health insurance database.

Most of the study population was blue-collar workers such as farmers, fishermen and vendors, who tended to have high blood pressure, diabetes and heart disease.

"There's a higher rate of high blood pressure and diabetes and pulmonary disease in patients with lung cancer," Russman said.

what's up doc

"I think this reflects the heavy burden of smoking and smoking-related risk factors in the population."
According to the American Lung Association, smoking is directly responsible for approximately 90 percent of lung cancer deaths, while the American Heart Association said in a report that strokes accounted for one of out eighteen deaths in the United States in 2007.

"In the U.S., smokers have twice the risk of having a stroke, regardless of lung cancer," Russman said.