ABSTRACT
RATIONALE: Screening for lung cancer with low-dose spiral computed tomography (LDCT) has been shown to reduce lung cancer mortality by 20% compared with screening with chest X-ray (CXR) in the National Lung Screening Trial, but uncertainty remains concerning the efficacy of LDCT screening in a community setting. OBJECTIVES: To explore the effect of LDCT screening on lung cancer mortality compared with no screening. Secondary endpoints included incidence, stage, and resectability rates. METHODS: Male smokers of 20+ pack-years, aged 60 to 74 years, underwent a baseline CXR and sputum cytology examination and received five screening rounds with LDCT or a yearly clinical review only in a randomized fashion. MEASUREMENTS AND MAIN RESULTS: A total of 1,264 subjects were enrolled in the LDCT arm and 1,186 in the control arm. Their median age was 64.0 years (interquartile range, 5), and median smoking exposure was 45.0 pack-years. The median follow-up was 8.35 years. One hundred four patients (8.23%) were diagnosed with lung cancer in the screening arm (66 by CT), 47 of whom (3.71%) had stage I disease; 72 control patients (6.07%) were diagnosed with lung cancer, with 16 (1.35%) being stage I cases. Lung cancer mortality was 543 per 100,000 person-years (95% confidence interval, 413-700) in the LDCT arm versus 544 per 100,000 person-years (95% CI, 410-709) in the control arm (hazard ratio, 0.993; 95% confidence interval, 0.688-1.433). CONCLUSIONS: Because of its limited statistical power, the results of the DANTE (Detection And screening of early lung cancer with Novel imaging TEchnology) trial do not allow us to make a definitive statement about the efficacy of LDCT screening. However, they underline the importance of obtaining additional data from randomized trials with intervention-free reference arms before the implementation of population screening.
Subject(s)
Early Detection of Cancer/methods , Lung Neoplasms/diagnosis , Smoking/epidemiology , Sputum/cytology , Tomography, Spiral Computed/methods , Aged , Cause of Death , Comorbidity , Cost-Benefit Analysis , Early Detection of Cancer/statistics & numerical data , Follow-Up Studies , Humans , Incidence , Italy , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/mortality , Male , Middle Aged , Neoplasm Staging , Outcome and Process Assessment, Health Care , Radiography, Thoracic , Smoking/adverse effectsABSTRACT
RATIONALE: Screening for lung cancer with modern imaging technology may decrease lung cancer mortality, but encouraging results have only been obtained in uncontrolled studies. OBJECTIVES: To explore the effect of screening with low-dose spiral computed tomography (LDCT) on lung cancer mortality. Secondary endpoints are incidence, stage at diagnosis, and resectability. METHODS: Male subjects, aged 60 to 75 years, smokers of 20 or more pack-years, were randomized to screening with LDCT or control groups. All participants underwent a baseline, once-only chest X-ray and sputum cytology examination. Screening-arm subjects had LDCT upon accrual to be repeated every year for 4 years, whereas controls had a yearly medical examination only. MEASUREMENTS AND MAIN RESULTS: A total of 2,811 subjects were randomized and 2,472 were enrolled (LDCT, 1,276; control, 1,196). After a median follow-up of 33 months, lung cancer was detected in 60 (4.7%) patients receiving LDCT and 34 (2.8%) control subjects (P = 0.016). Resectability rates were similar in both groups. More patients with stage I disease were detected by LDCT (54 vs. 34%; P = 0.06) and fewer cases were detected in the screening arm due to intercurrent symptoms. However, the number of advanced lung cancer cases was the same as in the control arm. Twenty patients in the LDCT group (1.6%) and 20 controls (1.7%) died of lung cancer, whereas 26 and 25 died of other causes, respectively. CONCLUSIONS: The mortality benefit from lung cancer screening by LDCT might be far smaller than anticipated.
Subject(s)
Lung Neoplasms/diagnostic imaging , Mass Screening/methods , Tomography, Spiral Computed , Aged , Cause of Death , Follow-Up Studies , Humans , Italy/epidemiology , Lung Neoplasms/mortality , Male , Middle Aged , Prospective Studies , Radiography, Thoracic , Survival RateABSTRACT
BACKGROUND: Despite the high survival rates reported for screening-detected cases, the potential of screening of high-risk subjects for reducing lung cancer mortality is still unproven. We herewith present the baseline results of a randomized trial comparing screening for lung cancer with annual spiral computed tomography (CT) versus a yearly clinical review. METHODS: Male subjects, 60-74 years old, and smokers of 20+ pack-years were enrolled. All participants received a baseline medical examination, chest X-rays (CXR) and sputum cytology upon accrual. Subjects randomized in the spiral CT group received a spiral CT scan at baseline, then yearly for the following 4 years. For controls, a yearly clinical examination was scheduled for the following 4 years. RESULTS: 2472 subjects were randomized (1276 spiral CT arm, 1196 controls). Age, smoking exposure and co-morbid conditions were similar in the two groups. In the spiral CT group, 28 lung cancers were detected, 13 of which were visible in the baseline chest X-rays (overall prevalence 2.2%). Sixteen out of 28 tumours (57%) were stage I, and 19 (68%) were resectable. In the control group, eight cases were detected by the baseline chest X-rays (prevalence rate 0.67%), four (50%) were stage I, and six (75%) were resectable. CONCLUSIONS: Baseline lung cancer detection rate in the spiral CT arm was higher than in most published studies. The stage I detection rate was increased four-fold by spiral CT versus chest X-rays. However, more tumours in an advanced stage were also detected by CT. The high resection rate of screening-detected patients suggests a possible increase in cure rate. However, longer follow-up is required for definitive conclusions. This trial has been registered at www.Clinicaltrials.gov, registration No. NCT00420862.
