Among 2667 patients with nodules suspicious for lung cancer, a total of 1853 patients met inclusion criteria (Figure 1). All patients were Chinese. Baseline demographic and clinical characteristics of the cohort are summarized in Table 1.
Table.1 Baseline Demographic and Clinical Characteristics
|
variable
|
Overall Cohort
n (%)
|
Not abiding by the guildline
n (%)
|
abiding by the guildline
n (%)
|
P value*
|
Total, n
|
1853 (100)
|
689 (37.2)
|
1164(62.8)
|
|
Sex
|
<0.001
|
Male
|
816(44.0)
|
268 (32.8)
|
548 (67.2)
|
|
Female
|
1037 (56.0)
|
421 (40.6)
|
618 (59.4)
|
|
Age, y
|
<0.001
|
≤40
|
209 (11.3)
|
106 (50.7)
|
103 (49,3)
|
|
41~50
|
324 (17.5)
|
129 (39.8)
|
195 (60.2)
|
|
51~60
|
561 (30.3)
|
217 (38.7)
|
344 (61.3)
|
|
61~70
|
572 (30.9)
|
185 (32.3)
|
387 (67.7)
|
|
>70
|
187 (10.1)
|
52 (27.8)
|
135 (72.2)
|
|
Nodule density
|
<0.001
|
pGGO
|
478 (25.8)
|
275 (57.5)
|
203(42.5)
|
|
mGGO
|
759 (40.9)
|
314 (41.4)
|
445 (58.6)
|
|
Solid nodule
|
616(33.2)
|
100 (16.2)
|
516 (83.8)
|
|
Abbreviations:
pGGO: pure ground glass opacity.
mGGO: mixed ground glass opacity.
*Bold indicates statistically significant P values (P<0.05)
Overall, during the 12-months study period, around 37.2% of our patients underwent excessive CT. The proportion of females was 56.0%. 40.6% of them ignored the recommendation, while this rate changed to 32.8% among males. The percentage of patients ≤40 years, 41 to 50 years, 51 to 60 years, 61 to 70 years and >70 years were11.3%, 17.5%, 30.3%, 30.9% and 10.1%, and 50.7%, 39.8%, 38.7%, 32,3%, 27.8% of them received unnecessary examination.
As for density of nodules, 25.8% found pure ground glass opacity(pGGO), 40.9% found mixed ground glass opacity (mGGO), and 32.2% found solid nodules during their screening. 57.5%, 41.4%, and 16.2% of them did not abide by the guideline of NCCN.
Table 2. Required following-up times for different density of nodule
|
variable
|
Overall Cohort
n (%)
|
Not abiding by the guildline
n (%)
|
abiding by the guildline
n (%)
|
P value*
|
pGGO
|
<0.001
|
0
|
167 (34.9)
|
93 (55.7)
|
74 (44.3)
|
|
1
|
243 (50.8)
|
125 (51.4)
|
118 (48.6)
|
|
2
|
48 (10.0)
|
39 (81.3)
|
9 (18.8)
|
|
3
|
11 (2.3)
|
10 (90.9)
|
1 (9.1)
|
|
>3
|
9 (1.9)
|
8(88.9)
|
1 (10.1)
|
|
mGGO
|
<0.001
|
0
|
295 (37.3)
|
144 (50.9)
|
139 (49.1)
|
|
1
|
274 (33.9)
|
62(24.1)
|
195 (75.9)
|
|
2
|
84 (10.9)
|
49 (59.0)
|
34 (41.0)
|
|
3
|
71 (9.4)
|
29 (40.8)
|
42 (59.2)
|
|
>3
|
65 (8.6)
|
30 (46.2)
|
35 (53.8)
|
|
Solid nodule
|
<0.001
|
0
|
440 (56.6)
|
39 (11.2)
|
310(88.8)
|
|
1
|
182 (22.1)
|
16 (11.8)
|
120(88.2)
|
|
>1
|
152 (21.3)
|
45 (34.4)
|
86 (65.6)
|
|
Abbreviations:
pGGO: pure ground glass opacity.
mGGO: mixed ground glass opacity.
*Bold indicates statistically significant P values (P<0.05)
Since different density of nodules need different screening strategies, we grouped patients by their density of nodules and assessed how many patients who need different follow-up time were inconsistent with NCCN (Table 2). As a result, for patients with pGGO, 55.7% of patients who need 0 follow-up violated the recommendation, and this rate ranged into 51.4%, 81.3%, 90.9%, 88.9% for who need 1, 2, 3 and more than 3 follow-ups. As for patients with mGGO, 50.9%, 24.1%, 59.0%, 40.8%, 46.2% patients who need 0, 1, 2, 3 and more than 3 follow-ups were not adhere to the guideline, and 11.2%, 11.8%, 34.4% patients with solid nodules who need 0, 1, 2 follow-ups underwent unnecessary Chest CT for screening.
In univariable analysis, factors associated with greater use of CT included younger age (odds ratios [ORs] of 0.64 for 41–50 years, P=.014; 0.62 for 51–60 years, P=.003; 0.47 for 61–70 years, P<.001; and 0.37 for ≥71 years, P<.0001; vs ≤40 years), female sex (OR, 1.40; P<.001) and lower nodule density(ORs of 0.52 for mGGO, P<.001; 0.14 for solid nodule, P<.001)(Table 3). In terms of the following-up time, patients tended to abide by the guideline when the first follow-up was recommended (ORs of 0.84 for patients with pure GGO, P=.040; 0.30 for mGGO, P<.001).
Correlations among patients’ unnecessary CT scan with clinical features were further evaluated by multivariable analysis using logistic regression analysis (Table 4). The result suggested that density of the nodules were independent predictors of overusing Chest CT (ORs of 0.53 for mGGO, P<.0001; 0.15 for solid nodule, P<.0001, vs patients with pGGO).
Table 3. Univariable analysis of Associations with Chest CT
|
Characteristic
|
OR
|
P value*
|
Age, y
|
≤40
|
Ref
|
|
41~50
|
0.64 (0.45 – 0.91)
|
0.014
|
51~60
|
0.62 (0.45 – 0.85)
|
0.003
|
61~70
|
0.47 (0.34 – 0.64)
|
<0.001
|
≥71
|
0.37 (0.25 – 0.57)
|
<0.001
|
Sex
|
Male
|
Ref
|
|
Female
|
1.40 (1.15 - 1.70)
|
<0.001
|
Nodule density
|
pGGO
|
Ref
|
|
mGGO
|
0.52 (0.41 – 0.65)
|
<0.001
|
Solid nodule
|
0.14 (0.11 – 0.19)
|
<0.001
|
Required following-up times for different density of nodule
|
pGGO
|
0
|
Ref
|
|
1
|
0.84 (0.39 – 0.91)
|
0.40
|
2
|
3.45 (2.27 – 8.63)
|
0.002
|
3
|
7.96 (1.82 – 21.82)
|
0.050
|
>3
|
6..37(0.78-52.04)
|
0.084
|
mGGO
|
0
|
Ref
|
|
1
|
0.30 (0.21 – 0.44)
|
<0.001
|
2
|
1.39 (0.85 – 2.28)
|
0.192
|
3
|
0.67 (0.39 – 1.13)
|
0.132
|
>3
|
0.83 (0.48 – 1.42)
|
0.492
|
Solid nodule
|
0
|
Ref
|
|
1
|
1.12 (0.61 – 2.07)
|
0.70
|
>1
|
4.16 (2.55 – 6.80)
|
<0.001
|
Abbreviations:
OR: odds ratio.
pGGO: pure ground glass opacity.
mGGO: mixed ground glass opacity.
*Bold indicates statistically significant P values (P<0.05)
Table 4. Multivariable analysis of Associations with Chest CT
|
Characteristic
|
OR
|
P value*
|
Age, y
|
|
41~50
|
0.83 (0.57 – 1.20)
|
0.320
|
51~60
|
0.93 (0.66 – 1.31)
|
0.658
|
61~70
|
0.83 (0.59 – 1.19)
|
0.318
|
≥71
|
0.80 (0.50 – 1.26)
|
0.328
|
Sex
|
Female
|
0.99 (0.81 - 1.22)
|
0.941
|
Nodule density
|
mGGO
|
0.53 (0.42 – 0.68)
|
<0.001
|
Solid nodule
|
0.15 (0.11 – 0.20)
|
<0.001
|
Abbreviations:
OR: odds ratio.
mGGO: mixed ground glass opacity.
*Bold indicates statistically significant P values (P<0.05)