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 Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht What does congenital Zika syndrome look like?
24.03.2017 | University of California - San Diego

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>