New study looks at growth rates of lung cancers found by CT screening

March 27, 2012, Radiological Society of North America

Growth rates of lung cancers found by annual rounds of computed tomography (CT) screening are important for determining the usefulness and frequency of screening, as well as for determining the treatment. 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 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 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 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 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 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.

Explore further: Study finds that annual screening with chest x-ray does not reduce rate of lung cancer deaths

More information: "Lung Cancers Diagnosed by Annual CT Screening: Volume Doubling Times." radiology.rsna.org/

Related Stories

Study finds that annual screening with chest x-ray does not reduce rate of lung cancer deaths

October 26, 2011
In a trial that included more than 150,000 participants, those who underwent annual chest radiographic screening for up to 4 years did not have a significantly lower rate of death from lung cancer compared to participants ...

Asymptomatic often sent for lung cancer screening tests

March 13, 2012
(HealthDay) -- A majority of primary care physicians report ordering lung cancer screening tests for asymptomatic patients, according to research published in the March/April issue of the Annals of Family Medicine.

Recommended for you

Boosting cancer therapy with cross-dressed immune cells

January 22, 2018
Researchers at EPFL have created artificial molecules that can help the immune system to recognize and attack cancer tumors. The study is published in Nature Methods.

Workouts may boost life span after breast cancer

January 22, 2018
(HealthDay)—Longer survival after breast cancer may be as simple as staying fit, new research shows.

Cancer patients who tell their life story find more peace, less depression

January 22, 2018
Fifteen years ago, University of Wisconsin–Madison researcher Meg Wise began interviewing cancer patients nearing the end of life about how they were living with their diagnosis. She was surprised to find that many asked ...

Single blood test screens for eight cancer types

January 18, 2018
Johns Hopkins Kimmel Cancer Center researchers developed a single blood test that screens for eight common cancer types and helps identify the location of the cancer.

Researchers find a way to 'starve' cancer

January 18, 2018
Researchers at Vanderbilt University Medical Center (VUMC) have demonstrated for the first time that it is possible to starve a tumor and stop its growth with a newly discovered small compound that blocks uptake of the vital ...

How cancer metastasis happens: Researchers reveal a key mechanism

January 18, 2018
Cancer metastasis, the migration of cells from a primary tumor to form distant tumors in the body, can be triggered by a chronic leakage of DNA within tumor cells, according to a team led by Weill Cornell Medicine and Memorial ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.