Pulmonary Nodule Screening in Smoker by Jeffrey Dach

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Mar 30, 2007, 9:34:28 AM3/30/07
to sci.med.diseases.cancer, alt.support.cancer, alt.smokers
A friend who has been a heavy smoker for many years underwent
screening Lung CAT scan and a small spiculated density in the upper
lobe was detected. The density was thought to represent either a small
spiculated cancer or perhaps merely inflammatory scarring about 12 x
16 mm in size.

There was no mediastinal adenopathy, and the lungs showed mild COPD.
A PET scan showed only very slight activity in the nodule, so there
was still some question about whether the nodule should be removed
surgically, or adopt a wait and see approach. The patient waited 12
weeks and had a follow up PET scan which showed again very slightly
increased activity in the nodule compared to the first PET scan.

I found this to be unusual to follow a nodule with serial PET scans as
the standard method is to follow with serial high resolution CAT scans
at 12 week intervals to assess change in size and growth. Although
the PET scan comes with an accompanying CAT scan, this is a non-
diagnostic CAT for anatomic localization of the PET findings and not
considered adequate for accurate assessment of change in size of the

On the basis of the second PET scan, the surgeon recommended
thoracotomy. The patient declined and insisted on a second high
resolution CAT scan to be performed instead at the 12 week follow up

Any Comments?

Jeffrey Dach MD www.drdach.com


http://radiology.rsnajnls.org/cgi/content/full/235/1/259 (full text)

CT screening for lung cancer: five-year prospective experience.
Radiology. 2005 Apr;235(1):259-65. Epub 2005 Feb 4.

Swensen SJ, Jett JR, Hartman TE, Midthun DE, Mandrekar SJ, Hillman SL,
Sykes AM, Aughenbaugh GL, Bungum AO, Allen KL.Department of Radiology,
Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.

PURPOSE: To report results of a 5-year prospective low-dose helical
chest computed tomographic (CT) study of a cohort at high risk for
lung cancer.

MATERIALS AND METHODS: After informed written consent was obtained,
1520 individuals were enrolled. Protocol was approved by institutional
review board and National Cancer Institute and was compliant with
Health Insurance Portability and Accountability Act, or HIPAA.
Participants were aged 50 years and older and had smoked for more than
20 pack-years. Participants underwent five annual (one initial and
four subsequent) CT examinations. A significant downward shift was
evaluated in non-small cell lung cancers detected initially from
advanced stage down to stage I by using a one-sided binomial test of
proportions. Poisson regression and Fisher exact tests were used for
comparisons with Mayo Lung Project.

RESULTS: In 788 (52%) men and 732 (48%) women, 61% (927 of 1520) were
current smokers, and 39% were former smokers. After five annual CT
examinations, 3356 uncalcified lung nodules were identified in 1118
(74%) participants. Sixty-eight lung cancers were diagnosed (31
initial, 34 subsequent, three interval cancers) in 66 participants.
Twenty-eight subsequent cases of non-small cell cancers were detected,
of which 17 (61%; 95% confidence interval: 41%, 79%) were stage I
tumors. Diameter of cancers detected subsequently was 5-50 mm (mean,
14.4 mm; median, 10.0 mm). Analysis for a more than 50% shift in
proportion of stage I non-small cell cancer detection did not show
statistical significance. Forty-eight participants died of various
causes since enrollment. Lung cancer mortality rate for incidence
portion of trial was 1.6 per 1000 person-years. There was no
significant difference in lung cancer mortality rates of cancers
detected in subsequent examinations between this trial and Mayo Lung
Project after separation of participants into subsets (2.8 vs 2.0 per
1000 person-years, P = .43).

CONCLUSION: CT allows detection of early-stage lung cancers. Benign
nodule detection rate is high. Results suggest no stage shift.

More References:

Evaluating Pulmonary Nodules, Radiology Rounds, Massachusetts General
Department of Radiology


The following articles are the basis for the belief that screening
with CXR and/or sputum cytology don't improve mortality. Many have
expressed concern about the quality of these studies.

Fontana RS, Sanderson DR, Taylor WF, et al.

Early lung cancer detection: results of the initial (prevalence)
radiologic and cytologic screening in the Mayo Clinic study.

Am Rev Respir Dis 1984;130:561-5.

Also includes a summary of the combined results of the Mayo, Sloan-
Kettering, and Johns Hopkins study sites on pp 565-70.


Melamed MR, Flehinger BJ, Zaman MB, et al.
Screening for lung cancer: results of the Memorial Sloan-Kettering
study in New York. CHEST 1984;86:44-53.


Frost JK, Ball WC, Levin ML, et al.

Early lung cancer detection: results of the initial (prevalence)
radiologic and cytologic screening in the Johns Hopkins study. Am Rev
Respir Dis 1984;130:549-54


Kubik A, Parkin DM, Khlat M, et al.

Lack of benefit from semi-annual screening for cancer of the lung:
follow-up of a randomized controlled trial on a population of high-
risk males in Czechoslavakia.

Int J Cancer1990;45:26-33.


The following articles address screening with chest CT scans.

Henschke CI, McCauley DI, Yankelevitz DF, et al.
Early lung cancer action project: overall design and findings from
baseline screening.
Lancet 1999;354:99-105.

Study of annual low dose CT in detecting lung cancer in 1000 heavy
smokers identified noncalcified nodules in 23% of patients and 12% of
nodules were malignant. The yield was extraordinarily high, as 27 of
28 biopsies were positive for malignancy, and 87% of these were stage
I. Large scale study to confirm findings and assess long-term survival
benefit and costs is in progress.


Swenson SJ, Jett JR, Hartman TE, et al. CT screening for lung cancer:
Five-year prospective experience.

Radiology 2005;235:259-65.

Full Text of article:


Updated results from Mayo's screening study of 1,520 subjects age > 50
with tobacco use > 20 pack-years. After 5 years, 74% of subjects had
at least 1 uncalcified nodule and 2.6% were diagnosed with stage I non-
small cell cancer. Compared to previous studies, adenocarcinoma
(including bronchioloalveolar carcinoma) was over-represented, which
raises the possibility of earlier diagnosis without reduction in
mortality. 96% of nodules identified on the prevalence scan and 96% of
nodules identified on an incidence scan proved to be benign based on
observation or resection. 69% of all participants had at least 1 of
these "false-positive" nodules.

Evaluation of the Solitary pulmonary nodule

Ost D, Fein AM, Feinsilver SH. The solitary pulmonary nodule. NEJM

Concise review of risks and yield of the currently used diagnostic
modalities, including PET scans. Unlike some recently published
guidelines, the authors consider both clinical suspicion for
malignancy and operative risk in making management recommendations.
The authors advocate the use of serial CT scans in patients with low
probability of cancer as well as patients with intermediate
probability with negative additional workup.


Torrington KG, Kern JD.

The utility of fiberoptic bronchoscopy in the evaluation of the
solitary pulmonary nodule.
CHEST 1993;104; 1021-4.

Study found low yield for use of FOB in the work-up of radiographic
Stage I lung cancer. FOB confirmed the diagnosis of cancer in 30% of
cases (no higher yield with use of fluoroscopic guidance), but this
did not affect surgical management. Unsuspected synchronous tumor
found in only 1% of cases. Study population skewed in that a high
proportion (87%) of SPNs were malignant.


Henschke CI, Yankelevitz DF, Naidich DP, et al. CT screening for lung
cancer: suspiciousness of nodules by size. Radiology 2004;231:164-8.
Based on data from 2897 high-risk subjects in the ELCAP study, non-
calcified nodules < 5mm diameter should be followed with a repeat scan
in 12 months rather than shorter-term follow-up.


Risk factors

Tockman MS, Anthonisen NR, Wright EC, et al.Airways obstruction and
the risk for lung cancer. Annals Intern Med 1987;106:512-8. This study
found smokers with COPD had about a 5-fold risk of developing lung
cancer compared to smokers without COPD. The more severe the COPD, the
greater the risk.


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