Update From the Medical Journals: November 2010 - What Your Doctor Is Reading - Harvard Commentaries

What's the latest news in the medical journals this month? Find out what your doctor is reading.

CT Scans For Smokers May Reduce Lung Cancer Deaths
For Heart Failure, Triple Drug Treatment Is Best
More News in Brief: Six Dialysis Sessions Per Week Are Better than Three, Experts Call New Cholesterol Drug "Spectacular," and HPV Vaccine Can Prevent Genital Warts

Most lung cancer is already in an advanced stage when it is diagnosed, so it can't be cured with surgery. Annual chest X-rays can miss many cancers that are small enough to treat and are not a useful screening test. But there may be a way to find early lung cancers, according to the National Lung Screening Trial. It found that yearly CT scans can reduce your chance of dying from lung cancer if you are a heavy smoker.

The National Cancer Institute (NCI) funded the large study. Because of the significant results, the NCI ended the study earlier than planned and announced the results in a press release November 4. The study included 53,000 current or former heavy smokers — people with a history of smoking enough cigarettes to add up to a pack per day for 30 years. They were 55 to 74 years old and had no signs or history of lung cancer.

Researchers randomly divided them into two groups. One group received a "spiral" computed tomography (CT) scan once a year for three years. The spiral CT shows the lungs in detail, so it can find small cancers. The other group received X-rays once a year for three years. Researchers kept track of both groups for another five years. During that time, people who got the CT scans were 20% less likely to die of lung cancer than those who got X-rays: In the spiral CT group, 354 people died compared with 442 people in the X-ray group.

A 20% difference sounds like a lot. However, it's important to consider how many people need to be tested to potentially save one life. This is a more telling number. According to this study, to save 1 smoker or former smoker from dying of lung cancer within 5 years, 303 people need to get a CT scan every year for 3 years.

The scans are not a perfect test. One out of four of the smokers who had the scans had a false positive test. That is, the scans showed possible lung cancer, but additional testing showed there was no cancer after all. Like any X-ray test, the scans exposed patients to radiation.

Stopping smoking is the best way to prevent lung cancer. But the question of the day is whether smokers or former smokers should get a CT scan based on these results. It's too early to have the answer. We have seen only a press release from those who conducted the study. The full study has yet to be published. Experts will need to weigh the benefits of this intensive screening plan with the costs, the false positive results, and the risks that come from repeated exposures to radiation.

People who have heart failure take medicines known as ACE inhibitors and beta blockers. They decrease symptoms and help people stay alive longer. Previous studies have shown that adding medicine from a third drug category can also be beneficial to people with advanced heart failure. The two available drugs in the third category include spironolactone (Aldactone) and eplerenone (Inspra). They are known as mineralocorticoid receptor antagonists or potassium-sparing diuretics. The drugs are not the same as the diuretic furosemide (Lasix), which is commonly used to relieve symptoms in heart failure.

Now a new study published online by the New England Journal of Medicine on November 15 shows that even people with mild heart failure can benefit from the addition of spironolactone or eplerenone. (Experts believe they have essentially the same effect.) The study included 2,700 people who had a weak heart muscle. (This is known as "systolic" heart failure.) The people who took eplerenone were about 37% less likely to die or be hospitalized during the year after the drug was added compared with patients in the study who received placebo.

Many doctors have not insisted on giving either of these additional drugs to people with mild heart-failure symptoms. They require fairly frequent blood tests to check for side effects, such as an increase in a person's potassium level. But the results of this study are compelling and show that all patients who have heart failure have a good reason to be on a complete "package" of medicines for their heart.

Six Dialysis Sessions Per Week Are Better than Three. People who require dialysis treatments to stay alive after kidney failure normally receive three treatments a week. Each one lasts from two to four hours. That is a lot of time, but would longer sessions be better? A small study published November 20 in the New England Journal of Medicine looked to answer this question. Researchers randomly assigned 245 patients to receive either three or six weekly sessions. According to the findings, people who had six sessions had better heart health, blood pressure control, overall physical health and survival than people who had three sessions. Patients who were assigned to six sessions did have more problems or complications relating to vascular access (a surgical connection between an artery and vein that is a suitable place to attach the dialysis machine). Even if more time on the dialysis machine can lead to better physical health, it is doubtful that tradition will shift toward more sessions. Dialysis is a limited and expensive resource. It is also very time consuming, so patients may not welcome additional sessions.

Experts Call New Cholesterol Drug "Spectacular." Heart-health experts are excited about the results of tests on a new drug that may have a bigger effect on cholesterol than statin drugs. The drug, anacetrapib, lowered LDL (bad cholesterol) by more than a third in test patients, and it more than doubled HDL levels (the good cholesterol). These results were based on a study of 1,623 people who were at high risk for heart attack. Researchers randomly assigned half of the people to take anacetrapib and half to take a placebo pill for 18 months. Overall, during the study, the group getting the new drug had fewer clogged arteries that required balloon angioplasty or stents. People in this group also had fewer deaths. This study was too short and too small for these benefits to be certain, so the drug will need additional testing. Then the U.S. Food and Drug Administration will decide whether to approve the new drug to go on the market. The promising results of this study were published online by the New England Journal of Medicine November 17.

HPV Vaccine Can Prevent Genital Warts. The vaccine for human papilloma virus (HPV) was developed to prevent cervical cancer. And this has been the focus of vaccination campaigns. But at least one brand of the HPV vaccine is also helping to prevent genital warts, says an article published by The Lancet Infectious Diseases on November 8. In Australia, the government has been vaccinating girls and women between the ages of 12 and 26 for free since 2007. In that country, diagnosis of genital warts has already decreased by 59% among those vaccinated. Even among young men who have not received the vaccination, the diagnosis of genital warts has dropped by 28%. Experts are crediting this to "herd immunity:" Vaccinating part of the population has limited the spread of the HPV virus among the whole population. The brand of HPV vaccine used in Australia is Gardasil. This is the same brand commonly used in the United States.

Mary Pickett, M.D. is an Associate professor at Oregon Health & Science University where she is a primary care doctor for adults. She supervises and educates residents in the field of Internal Medicine, for outpatient and hospital care. She is a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications.