Neither routine chest x-ray (with or without sputum cytology) nor low-dose computed tomography (CT) have been proven to reduce mortality when used for lung cancer screening, although low-dose CT screening does identify lung cancer at an early stage in high-risk patients (strength of recommendation: B, based on heterogeneous cohort studies). Large studies of both imaging approaches are ongoing

Harper, Amy

Neher, Jon O.

Waldman, Michael J.

University of Missouri: MOspace

CliniCal InquIrIes From the Family Physicians Inquiries Network	 vol	57,	no	1	/	january	2008	 49www.jfponline.comMichael J. Waldman, MD and Jon O. neher, MDValley Medical Center,  Renton, Washamy Harper, MliSUniversity of Washington Health Sciences Libraries, Seattle  Does screening reduce  lung cancer mortality?It’s	not	clear.	neither	routine	chest	x-ray	(with	or	without	sputum	cytology)	nor	low-dose	computed	tomography	(CT)	have	been	proven	to	reduce	mortality	when	used	for	lung	cancer	screening,	although	low-dose	CT	screening	does	identify	lung	cancer	at	an	early	stage	in	high-risk	patients	(strength	of	recommendation:	B,	based	on	heterogeneous	cohort	studies).	large	studies	of	both	imaging	approaches	are	ongoing.Let’s prevent lung cancer so we don’t have to worry about screeningWhile	some	trials	suggest	possibly	useful	screening	tools,	and	myriad	other	trials	are	underway,	one	point	often	gets	short	shrift:	the	importance	of	preventing	cancer	from	occurring	in	the	first	place.	Most	family	physicians	already	screen	for	smoking	and	offer	counseling	and	pharmacologic	assistance	to	smokers.	We	should	also	be	aggressively	counseling	our	adolescent	and	young	adult	patients	against	starting	to	smoke.	Ideally,	we	would	help	people	reduce	their	exposure	to	secondhand	smoke,	as	well.	When	a	teachable	moment	comes	along,	we	should	take	the	time	to	educate	our	patients	about	their	specific	risk	factors	and	how	they	can	be	modified.	Preventing	the	problem	before	it	starts	is	our	patients’	best	defense	against	lung	cancer. Tim Huber, MDoroville	Hospital,	oroville,	Califz Evidence summaryChest x-ray and cytology:  A trend toward reduced mortalityA Cochrane review1 identified 6 ran-domized controlled trials (RCTs) and 1 non-RCT (with a total of 245,610 patients) that screened patients with se-rial chest x-rays, with or without sputum cytology. Most patients were current or ex-smokers or had significant exposure to industrial smoke. No studies included an unscreened control group, and only 1 included women. There was a trend toward reduced mortality with the combination of an-nual chest x-ray and sputum cytology compared with annual x-ray alone, but it was not statistically significant (relative risk [RR]=0.88; 95% confidence interval [CI], 0.74–1.03). However, more frequent screening with chest x-rays (2 or 3 times/year) was associated with an 11% increase in mortality compared with less frequent x-rays (RR=1.11; 95% CI, 1.00–1.23). The authors concluded that there was in-sufficient evidence to support screening with chest x-ray or sputum cytology. Low-dose CT: Studies reach  different conclusionsA 2006 study followed a cohort of at-risk patients using low-dose CT screening.2 Clinical commentaryEvidence-based answerfast trackLow-dose CT screening does identify lung  cancer at an early stage in high-risk patientsConT InueDLung carcinoma on CT scanfast trackCliniCal InquIrIes50 vol	57,	no	1	/	january	2008		ThE JournaL of famiLy PraCTiCEThere were 31,567 patients evaluated initially, of which 27,456 had an annual repeat screening. Most patients were cur-rent or former smokers (83%); patients with exposure to occupational and sec-ondhand smoke were also included. A positive initial screen was defined as a solid or partly solid noncalcified nodule ≥5 mm in diameter; a nonsolid, noncalci-fied nodule ≥8 mm in diameter; or a solid endobronchial nodule. A positive screen during follow-up was defined as any new noncalcified nodule, regardless of size. Positive tests occurred in 13% of baseline screens and 5% of annual screens. Biopsies were performed accord-ing to a study protocol based on a nod-ule’s size and behavior over time. Out of a total of 5646 positive screens, there were 535 biopsies, and a diagnosis of cancer in 492 patients. Of those with cancer, 412 (84%) had clinical stage I lung cancer; the authors estimated their 10-year survival rate was 88% (95% CI, 84%–91%). If patients with stage I disease underwent surgical resection within 1 month of di-agnosis, their estimated 10-year survival increased to 92% (95% CI, 88%–95%).However, a cohort study using an-nual CT scanning to screen 3246 pa-tients for lung cancer came to a different conclusion.3 The authors compared the observed number of lung cancer cases, re-sections, advanced lung cancer diagnoses, and deaths in screened patients with the expected rates based on validated predic-tion models. Lung cancer was diagnosed in 144 patients compared with 44 expect-ed cases (RR=3.2; 95% CI, 2.7–3.8). Sub-sequently, 109 patients underwent lung resection compared with 11 expected (RR=10.0; 95% CI, 8.2–11.9). However, there was no decline in advanced cancers (42 actual vs 33 expected; P=.14) and no difference in deaths due to lung cancer (38 actual vs 38.8 expected; P=.9). The 81 patients diagnosed in this study with stage I disease who underwent surgical resection had 4-year estimated survival rates of 94% (95% CI, 85%–97%), matching the prior low-dose CT study.Major studies of both methods  are ongoingOther major studies are in progress. There is an RCT involving 154,942 male and female patients using annual chest x-ray screening vs no screening that will involve 14 years of follow-up.4 Another RCT is evaluating annual low-dose CT vs annual chest x-ray for 3 years in 50,000 at-risk men and women.5 Finally, investi-gators are conducting an RCT with 4000 at-risk patients comparing annual CT screening with no screening.6Recommendations from others The US Preventive Services Task Force gives an “I” recommendation (data in-sufficient) to screening for lung cancer with cytology, chest x-ray, or CT scan-ning.7 The American College of Chest Physicians stated in 2003 that the early studies of low-dose CT appeared prom-ising; however, they recommended that individuals should only be screened with low-dose CT in the context of well- designed clinical trials.8   nreferences	 1.	 	Manser	rl,	Irving	lB,	stone	C,	Byrnes	G,	abramson	M,	Campbell	D.	screening	for	lung	cancer.	Cochrane Database System Rev	2004;	(1):CD001991.	 2.	 	The	International	early	lung	Cancer	action	Program	Investigators;	 Henschke	 CI,	 yankelevitz	 DF,	 libby	DM,	Pasmantier	MW,	smith	jP,	Miettinen	os.	sur-vival	of	patients	with	stage	I	lung	cancer	detected	on	CT	screening.	N Engl J Med	2006;	355:1763–1771.		 3.	 	Bach	 PB,	 jett	 jr,	 Pastorino	 u,	 Tockman	 Ms,	swensen	 sj,	 Begg	 CB.	 Computed	 tomography	screening	and	lung	cancer	outcomes.	JAMA	2007;	279;	953–961.		 4.	 	oken	MM,	Marcus	PM,	Hu	P,	et	 al;	PlCo	Project	Team.	Baseline	chest	radiograph	for	lung	cancer	de-tection	in	the	randomized	Prostate,	lung,	Colorec-tal,	and	ovarian	Cancer	screening	Trial.	J Natl Can-cer Inst 2005;	97:1832–1839.	 5.	 	national	lung	screening	Trial	(nlsT).	national	Can-cer	Institute	Web	site.	available	at:	www.cancer.gov/nlst.	accessed	on	December	7,	2007.	 6.	 	van	 Iersel	 Ca,	 de	 Koning	 Hj,	 Draisma	 G,	 et	 al.	risk-based	 selection	 from	 the	 general	 population	in	 a	 screening	 trial:	 selection	 criteria,	 recruitment	and	power	 for	 the	Dutch-Belgian	randomised	 lung	cancer	multi-slice	CT	screening	trial	(nelson).	Int J Cancer	2007;	120:868-874.	 7.	 	recommendation	 statement.	 lung	cancer	 screen-ing.	 us	 Preventive	 services	 Task	 Force	Web	 site.	available	 at:	 www.ahrq.gov/clinic/3rduspstf/lung-cancer/lungcanrs.htm.	 accessed	 on	 December	 7,	2007.	 8.	 	Bach	PB,	niewoehner,	Black	WC.	screening	for	lung	cancer:	the	guidelines. Chest	2003;	123:83–88.Screening for lung cancer with x-ray, cytology, or CT scan is rated  “I” for insufficient data by the USPSTF 

Does screening reduce lung cancer mortality?

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