Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Benefits of lung cancer screening with CT questioned

24.03.2005


Annual screening with helical computed tomography (CT) can help radiologists detect lung cancers at their earliest, most curable stage, but has not been shown to reduce mortality from the disease, according to a study published in the April issue of the journal Radiology.



"What we’re finding with CT screening are more early-stage cancers. That could be good news--finding cancers that we’d otherwise find at a late stage," said the study’s lead author, Stephen J. Swensen, M.D., professor and chair of the Department of Radiology at Mayo Clinic in Rochester, Minn. "However, a number of these are probably non-lethal or slow-growing cancers that the patient would likely have died with and not from. Other cancers were so aggressive that early detection with CT did not make a difference."

Lung cancer is the leading cause of cancer death in both men and women in the United States, killing more people than breast, prostate and colon cancers combined, according to the American Cancer Society (ACS). ACS estimates that in 2005 there will be approximately 172,570 new cases of lung cancer diagnosed in the United States and 163,510 people will die from the disease.


While recent studies have focused on the benefits of early detection, the Mayo researchers looked more closely at the negative impact of CT screening, including over-diagnosis, expense, changes to quality of life, unnecessary surgical procedures and mortality. The study, funded in part by the National Cancer Institute, represents the most complete follow-up of the same group of patients of any published CT lung screening research.

Between January 1999 and May 2004, Dr. Swensen and colleagues studied 1,520 current and former smokers at high risk for lung cancer. The patient group contained 788 men and 732 women, age 50 or older (median age 59). All patients received an initial low-dose, helical CT examination, with annual screenings over the next four years. CT depicted 3,356 nodules in 1,118 (73.6 percent) of the patients. The researchers documented 68 primary lung cancers in 66 patients. Thirty-one of the tumors were detected at the initial screening and 34 at subsequent screenings. Three cancers were diagnosed by other means between screenings.

Approximately 69 percent of patients had at least one false-positive finding. False-positives are uncalcified lung nodules proved benign by observation or biopsy. Among the cancers identified through CT screening, false-positive rates ranged from 92.4 percent among nodules 4 millimeters or larger to 96.0 percent among all nodules. "Currently, half of lung nodules suspected of being cancerous that go to surgery outside of research study centers turn out to be benign," Dr. Swensen said.

Surgical intervention to diagnose these nodules is expensive and may impact quality of life and mortality. According to Dr. Swensen, a small percentage of patients will have chronic pain as a result of surgery, and the average mortality rate from lung cancer surgery ranges from 3 to 5 percent. "That’s a big price to pay if it’s a benign nodule," he said.

The researchers found no significant difference when comparing mortality rates demonstrated by this study to those of the Mayo Lung Project, a lung cancer screening trial conducted in the 1970s using chest radiography, lending support to their suggestion that while CT helps radiologists find more early-stage cancers, many of these are slow-growing tumors that probably would not have been lethal over the patient’s lifetime. "While there is still reason to hope that early detection of lung cancer with CT may save lives, our results lead us to be very cautious, because there’s a chance that we may be doing more harm than good," Dr. Swensen said.

No professional health organizations currently recommend CT screening for lung cancer.

Doug Dusik | EurekAlert!
Further information:
http://www.rsna.org

More articles from Health and Medicine:

nachricht Millions through license revenues
27.04.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Millions through license revenues

27.04.2017 | Health and Medicine

The TU Ilmenau develops tomorrow’s chip technology today

27.04.2017 | Information Technology

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>