According to the latest report from the International Early Lung Cancer Action Program (I-ELCAP) published online in the journal Radiology, lung cancers diagnosed in annual repeat rounds of CT screening are similar—both in volume doubling time and cell-type distribution— to those found in clinical practice.
"There was concern that cancers diagnosed in the screening context were somehow different than cancers found in routine practice, that they were not aggressive," said I-ELCAP principal investigator Claudia I. Henschke, Ph.D., M.D., professor of radiology at Mount Sinai School of Medicine in New York, N.Y. "We demonstrate here that they are quite similar."
The researchers reported that growth rates found in cancers detected in repeat rounds of annual CT screening are not significantly different from growth rates reported for cancers diagnosed in clinical practice in the absence of screening. Also, the frequencies of small-cell carcinoma and adenocarcinoma among all lung cancers have been reported to be approximately 20 percent and 50 percent, respectively, in the absence of screening. In repeat rounds of CT screening, these frequencies were nearly identical (19 percent and 50 percent).
Lung cancer is the leading cause of cancer death among men and women. The American Cancer Society estimates that in 2012, approximately 226,160 new cases of lung cancer will be diagnosed in the U.S. and 160,340 Americans will die from the disease.
CT screening has been found effective in detecting lung cancer at its earliest, most curable stage.
"This study shows that the cell types of cancer diagnosed in annual rounds of screening, as well as their growth rates, are quite similar to those that are found in clinical practice where it is well understood that lung cancer is highly lethal," Dr. Henschke said. The first, or baseline, round of screening for any cancer detects a higher proportion of slower-growing cancers than those detected in clinical practice, she noted. The subsequent, repeat rounds of screening, however, reflect what is found in clinical practice.
The study found that there is a difference in the growth rates of cancers in solid and sub-solid lesions and that the sub-solid ones tend to be less aggressive than solid ones.
"This suggests that a less aggressive approach is indicated for both diagnosis and treatment of sub-solid lesions," Dr. Henschke said.
The researchers reviewed results from the I-ELCAP database for 1993 to 2009, consisting of men and women at risk for lung cancer who underwent annual repeat rounds of CT screening. The research team identified 111 instances of first primary lung cancer diagnosed either through screening or between rounds after a negative result of the prior screening seven to 18 months earlier. Of the 111 cancers identified, 88 were clinical Stage I. The investigators then analyzed volume doubling time and cell-type distribution.
The results showed that the median volume doubling time was 98 days. Most of the cancers, 99 of the 111, manifested as solid nodules, while only 12 of the cancers manifested as sub-solid nodules. Solid nodule cancers had significantly faster volume doubling times than sub-solid nodule cancers. According to Dr. Henschke, identifying the volume doubling times for specific lesion types may lead to more tailored treatment for the patient.
Volume doubling times for lung cancers diagnosed in clinical practice in the absence of screening have been reported to range from 20 to 360 days. A recent study, based on a systematic medical literature review, reported a mean volume doubling time of 135 days for non-small-cell lung cancers diagnosed in the absence of screening.
Dr. Henschke recommends that people at high risk for lung cancer have a discussion with their health care provider to discuss the benefits and risks of screening so as to make an informed decision about enrolling in a screening program.
"Lung Cancers Diagnosed by Annual CT Screening: Volume Doubling Times." Collaborating with Dr. Henschke were David F. Yankelevitz, M.D., Rowena Yip, M.P.H., Anthony P. Reeves, Ph.D., Ali Farooqi, M.D., Dongming Xu, M.D., James P. Smith, M.D., Daniel M. Libby, M.D., Mark W. Pasmantier, M.D., and Olli S. Miettinen, M.D., Ph.D., as the writing committee for the I-ELCAP Investigators.
Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc. (http://radiology.rsna.org/)
RSNA is an association of more than 48,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)
For patient-friendly information on CT and lung cancer, visit RadiologyInfo.org
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
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...
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...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
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...
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...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
22.03.2017 | Materials Sciences
22.03.2017 | Physics and Astronomy
22.03.2017 | Materials Sciences