The study population
In the period 2018–2022, 17,410 patients were identified with a primary lung cancer diagnosis (ICD-10: C34) at the CRN. Of these, 24.9% (n = 4,335) were excluded since the examination notifications were missing or information on one or more of the following factors was missing: multidisciplinary team meeting (MDT), positron-emission tomography computer-tomography (PET-CT), endobronchial ultrasound fine needle aspiration cytology (EBUS), results from epidermal growth factor receptor (EGFR) analysis or staging by cTNM (n = 2,549). Patients with unknown morphology (n = 305) or side information (n = 468) were also excluded. Finally, we excluded patients with tumours in the main bronchus (C34.0) (n = 824) and those with either overlapping lesions (C34.8) or unknown tumour location (C34.9) (n = 627). As a result, 10,849 patients were eligible for analysis. The data by lobe are listed in Table 1. Tables with the same data but arranged by side and by upper and lower lobes can be found in Supplementary Tables 1 and 2, respectively. There was no indication of a shift in the distribution of tumours between the lung lobes during the period (data not shown).
Table 1
Patient characteristics per side and lobe among patients diagnosed with lung cancer in 2018–2022 in Norway
|
Lobe
|
|
RUL
|
LUL
|
RML
|
RLL
|
LLL
|
Total
|
All
|
3,381
|
(31.2%)
|
2,796
|
(25.8%)
|
587
|
(5.4%)
|
2,328
|
(21.5%)
|
1,757
|
(16.2%)
|
10,849
|
(100.0%)
|
Age
|
70.2
|
(8.9)
|
70.8
|
(8.9)
|
69.7
|
(10.2)
|
70.6
|
(9.6)
|
71.0
|
(9.3)
|
70.5
|
(9.2)
|
Sex
|
|
|
|
|
|
|
|
|
|
|
|
|
Female
|
1,564
|
(46.3%)
|
1,325
|
(47.4%)
|
329
|
(56.0%)
|
1,187
|
(51.0%)
|
884
|
(50.3%)
|
5,289
|
(48.8%)
|
Male
|
1,817
|
(53.7%)
|
1,471
|
(52.6%)
|
258
|
(44.0%)
|
1,141
|
(49.0%)
|
873
|
(49.7%)
|
5,560
|
(51.2%)
|
Histology
|
|
|
|
|
|
|
|
|
|
|
|
|
AC
|
1,796
|
(53.1%)
|
1,397
|
(50.0%)
|
287
|
(48.9%)
|
1,199
|
(51.5%)
|
899
|
(51.2%)
|
5,578
|
(51.4%)
|
SCC
|
752
|
(22.2%)
|
668
|
(23.9%)
|
99
|
(16.9%)
|
577
|
(24.8%)
|
427
|
(24.3%)
|
2,523
|
(23.3%)
|
NSCLC, NOS
|
270
|
(8.0%)
|
201
|
(7.2%)
|
27
|
(4.6%)
|
148
|
(6.4%)
|
95
|
(5.4%)
|
741
|
(6.8%)
|
Large-cell
|
45
|
(1.3%)
|
33
|
(1.2%)
|
8
|
(1.4%)
|
30
|
(1.3%)
|
20
|
(1.1%)
|
136
|
(1.3%)
|
SCLC
|
411
|
(12.2%)
|
398
|
(14.2%)
|
91
|
(15.5%)
|
270
|
(11.6%)
|
218
|
(12.4%)
|
1,388
|
(12.8%)
|
Carsinoid
|
44
|
(1.3%)
|
36
|
(1.3%)
|
62
|
(10.6%)
|
61
|
(2.6%)
|
65
|
(3.7%)
|
268
|
(2.5%)
|
Other
|
63
|
(1.9%)
|
63
|
(2.3%)
|
13
|
(2.2%)
|
43
|
(1.8%)
|
33
|
(1.9%)
|
215
|
(2.0%)
|
cTNM
|
|
|
|
|
|
|
|
|
|
|
|
|
I
|
959
|
(28.4%)
|
768
|
(27.5%)
|
213
|
(36.3%)
|
716
|
(30.8%)
|
551
|
(31.4%)
|
3,207
|
(29.6%)
|
II
|
283
|
(8.4%)
|
233
|
(8.3%)
|
39
|
(6.6%)
|
222
|
(9.5%)
|
195
|
(11.1%)
|
972
|
(9.0%)
|
III
|
708
|
(20.9%)
|
539
|
(19.3%)
|
91
|
(15.5%)
|
434
|
(18.6%)
|
309
|
(17.6%)
|
2,081
|
(19.2%)
|
IV
|
1,431
|
(42.3%)
|
1,256
|
(44.9%)
|
244
|
(41.6%)
|
956
|
(41.1%)
|
702
|
(40.0%)
|
4,589
|
(42.3%)
|
MDT
|
|
|
|
|
|
|
|
|
|
|
|
|
No
|
797
|
(23.6%)
|
664
|
(23.7%)
|
125
|
(21.3%)
|
554
|
(23.8%)
|
417
|
(23.7%)
|
2,557
|
(23.6%)
|
Yes
|
2,584
|
(76.4%)
|
2,132
|
(76.3%)
|
462
|
(78.7%)
|
1,774
|
(76.2%)
|
1,340
|
(76.3%)
|
8,292
|
(76.4%)
|
PET-CT
|
|
|
|
|
|
|
|
|
|
|
|
|
No
|
1,174
|
(34.7%)
|
991
|
(35.4%)
|
204
|
(34.8%)
|
789
|
(33.9%)
|
585
|
(33.3%)
|
3,743
|
(34.5%)
|
Yes
|
2,207
|
(65.3%)
|
1,805
|
(64.6%)
|
383
|
(65.2%)
|
1,539
|
(66.1%)
|
1,172
|
(66.7%)
|
7,106
|
(65.5%)
|
EBUS
|
|
|
|
|
|
|
|
|
|
|
|
|
No
|
2,419
|
(71.5%)
|
2,192
|
(78.4%)
|
430
|
(73.3%)
|
1,711
|
(73.5%)
|
1,342
|
(76.4%)
|
8,094
|
(74.6%)
|
Yes
|
962
|
(28.5%)
|
604
|
(21.6%)
|
157
|
(26.7%)
|
617
|
(26.5%)
|
415
|
(23.6%)
|
2,755
|
(25.4%)
|
EGFR-test
|
|
|
|
|
|
|
|
|
|
|
|
|
Not tested
|
1,432
|
(42.4%)
|
1,316
|
(47.1%)
|
294
|
(50.1%)
|
1,068
|
(45.9%)
|
809
|
(46.0%)
|
4,919
|
(45.3%)
|
Positive
|
199
|
(5.9%)
|
170
|
(6.1%)
|
31
|
(5.3%)
|
111
|
(4.8%)
|
91
|
(5.2%)
|
602
|
(5.5%)
|
Negative
|
1,692
|
(50.0%)
|
1,255
|
(44.9%)
|
255
|
(43.4%)
|
1,118
|
(48.0%)
|
825
|
(47.0%)
|
5,145
|
(47.4%)
|
Unknown
|
58
|
(3.0%)
|
55
|
(3.7%)
|
7
|
(2.4%)
|
31
|
(2.5%)
|
32
|
(3.4%)
|
183
|
(3.1%)
|
First treatment
|
|
|
|
|
|
|
|
|
|
|
|
|
Resected
|
871
|
(25.8%)
|
721
|
(25.8%)
|
196
|
(33.4%)
|
693
|
(29.8%)
|
532
|
(30.3%)
|
3,013
|
(27.8%)
|
SBRT
|
294
|
(8.7%)
|
211
|
(7.5%)
|
30
|
(5.1%)
|
197
|
(8.5%)
|
145
|
(8.3%)
|
877
|
(8.1%)
|
Curative RT
|
435
|
(12.9%)
|
337
|
(12.1%)
|
56
|
(9.5%)
|
227
|
(9.8%)
|
177
|
(10.1%)
|
1,232
|
(11.4%)
|
Palliative RT
|
703
|
(20.8%)
|
585
|
(20.9%)
|
90
|
(15.3%)
|
430
|
(18.5%)
|
313
|
(17.8%)
|
2,121
|
(19.6%)
|
Unknown RT
|
22
|
(0.7%)
|
19
|
(0.7%)
|
2
|
(0.3%)
|
9
|
(0.4%)
|
16
|
(0.9%)
|
68
|
(0.6%)
|
No treatment reported
|
1,056
|
(31.2%)
|
923
|
(33.0%)
|
213
|
(36.3%)
|
772
|
(33.2%)
|
574
|
(32.7%)
|
3,538
|
(32.6%)
|
Abbreviations: AC: adenocarcinoma, EBUS: endobronchial ultrasound fine needle aspiration cytology, EGFR: epidermal growth factor receptor, LLL: left lower lobe, LUL: left upper lobe, MDT: multidisciplinary team meeting, NSCLC NOS: non-small cell lung cancer not otherwise specified, RLL: right lower lobe, RML: right middle lobe, RT: radiotherapy, RUL: right upper lobe, SBRT: stereotactic body radiation therapy, SCC: squamous cell cancer, SCLC: small cell lung cancer. |
Proportions of tumours
The relative proportion of tumours in the lobes ranged from 0.64 in RML to 1.77 in the RUL (Fig. 1). The RUL has comparable volumes as the LUL, RLL and LLL, and the number of tumours in the RUL was increased (p < 0.001) compared to each of these lobes. In 62.3% (n = 6,764) of the patients, the tumour was in the upper lobes (Table 1), representing an increased relative proportion of 1.28 compared to the lower lobes with 0.73 (p < 0.001).
Age
The mean age at diagnosis for all patients was 70.5 years (Table 1). Those with tumours on the right side had a mean age of 70.3 years and were younger than those with left-sided tumour (70.9 years, p < 0.001). Those with tumours in the upper lobes had a mean age of 70.4 years and were younger than those with tumours in the lower lobes (70.8 years, p < 0.028). Patients with tumours in the RML had the lowest mean age at 69.7 years, and those with tumours in the LLL had the highest mean age, 71.0 years (p = 0.002).
Sex
Females comprised 48.8%. The proportion of females with tumours in the upper lobes was 47.6%, which is lower than the proportion in the lower lobes (50.7%, p = 0.002). The lobes with the lowest and highest proportions of females were the RUL and RML, with 46.3% and 56.0%, respectively (p < 0.001).
Endobronchial ultrasound fine needle aspiration cytology
Endobronchial ultrasound fine needle aspiration cytology (EBUS) was performed in 25.4%, with 22.4% and 27.6% of patients with tumours in the left and right lung, respectively (p < 0.001).
Epidermal growth factor receptor
The results from epidermal growth factor receptor (EGFR) mutation analyses were available in 87.8% (n = 4,897) of the patients with AC.
A positive EGFR mutation was reported in 12.5% (n = 379) of the patients with AC in the upper lobes and 10.5% (n = 196) in the lower lobes (p = 0.042). The lobes with the lowest and highest proportions of mutated EGFR were RLL and LUL, with 10.2% (n = 108) and 13.5% (n = 162) respectively (p = 0.013).
Histology
AC was diagnosed in 51.4% of patients, and there were small differences in the proportions between the lung lobes (Table 1).
Squamous cell carcinoma (SCC) was diagnosed in 23.3%, and 22.5% of patients with tumours the upper lobes and 24.6% in the lower lobes (p = 0.011). SCC was found in 16.9% of the RMLs compared to 23.6% in the four other lobes combined (p < 0.001).
Small cell lung cancer (SCLC) was diagnosed in 12.8%, and 11.9% of patients, with tumours in the lower lobes and 13.3% in the upper lobes (p = 0.040). The lobes with the lowest and highest proportions of SCLC were RLL and RML with 11.6% and 15.5%, respectively (p = 0.010).
Carcinoid tumours were diagnosed in 2.5%, and 2.1% of patients with tumours in the upper lobes and 3.1% in the lower lobes (p = 0.001). The lobes with the lowest and highest proportions of carcinoid tumours were LUL and RML with 1.3% and 10.6%, respectively (p < 0.001). Of all carcinoid tumours reported, 23.1% (n = 62) were in the RML.
Due to their common cellular origin, SCLC and carcinoids are grouped as neuroendocrine tumours (NETs) and were diagnosed in 15.3%, with 26.1% in the RML and 14.6% in the rest of the lung (p < 0.001) (Fig. 1).
Tumour diameter, lymph node metastases, and stage
The mean tumour diameter was 43.9 (SD = 32.4) mm, with the smallest at 38.0 (SD = 25.2) mm in RML and the largest at 45.6 (SD = 38.8) mm in LUL (p < 0.001).
Metastases to mediastinal lymph nodes (cN2 or cN3) were reported in 43.6% (n = 4,693) of the patients. The lowest proportion of positive cN2 or cN3 nodes was reported in LLL with 37.8% (n = 658) and the highest in RUL with 46.7% (n = 1,571) (p < 0.001). The proportions of tumours with mediastinal lymph node metastases in the upper and lower lobes were 45.8% (n = 3,074) and 40.1% (n = 1,619), respectively (p < 0.001). In the right and left lungs there were 44.6% (n = 2,782) and 42.3% (n = 1,911) mediastinal nodes, respectively (p = 0.02).
The proportions diagnosed in cTNM- stages I, II, III and IV were 29.6%, 9.0%, 19.2%, and 42.3% respectively (Table 2). In patients with tumours in the upper and lower lobes, the proportions of patients with stage I and II disease were 36.9% (n = 2495) and 41.2% (n = 1,684), respectively (p < 0.001).
Table 2
The probability of having a surgical resection of a malign lung tumour, logistic regression for patients diagnosed with lung cancer in 2018–2022 in Norway
|
Univariable
|
Multivariable
|
|
Odds Ratio (95%CI)
|
Odds Ratio (95%CI)
|
Lobe
|
|
|
RUL
|
1.00
|
1.00
|
LUL
|
0.98 (0.88–1.09)
|
1.01 (0.88–1.16)
|
RML
|
1.40 (1.17–1.67)
|
1.19 (0.93–1.54)
|
RLL
|
1.22 (1.10–1.36)
|
1.21 (1.06–1.41)
|
LLL
|
1.19 (1.06–1.34)
|
1.14 (0.97–1.34)
|
p-value
|
0.00
|
0.04
|
Sex
|
|
|
Female
|
1.00
|
1.00
|
Male
|
0.84 (0.78–0.90)
|
1.08 (0.98–1.20)
|
p-value
|
0.00
|
0.13
|
Age
|
0.96 (0.95–0.96)
|
0.92 (0.92–0.93)
|
p-value
|
0.00
|
0.00
|
cTNM
|
|
|
I
|
1.00
|
1.00
|
II
|
0.91 (0.80–1.04)
|
1.15 (0.99–1.33)
|
III
|
0.13 (0.12–0.15)
|
0.14 (0.12–0.16)
|
IV
|
0.01 (0.01–0.01)
|
0.01 (0.01–0.01)
|
p-value
|
0.00
|
0.00
|
Histology
|
|
|
AC
|
1.00
|
1.00
|
SCC
|
0.79 (0.72–0.87)
|
0.66 (0.58–0.74)
|
NSCLC, NOS
|
0.11 (0.08–0.15)
|
0.17 (0.11–0.24)
|
Large-cell
|
1.24 (0.91–1.70)
|
2.10 (1.32–3.35)
|
SCLC
|
0.06 (0.04–0.08)
|
0.14 (0.11–0.20)
|
Carsinoid
|
6,36 (4.96–8.16)
|
1.57 (1.16–2.12)
|
Other
|
2.03 (1.60–2.58)
|
2.49 (1.72–3.59)
|
p-value
|
0.00
|
0.00
|
EGFR
|
|
|
Not tested
|
|
1.58 (1.22–2.05)
|
Positive
|
|
1.00
|
Negative
|
|
3.01 (2.51–3.62)
|
p-value
|
|
0.00
|
Abbreviations: AC: adenocarcinoma, CI: confidence interval, EGFR: epidermal growth factor receptor, LLL: left lower lobe, LUL: left upper lobe, NSCLC NOS: non-small cell lung cancer not otherwise specified, RLL: right lower lobe, RML: right middle lobe, RUL: right upper lobe, SCC: squamous cell cancer, SCLC: small cell lung cancer. |
The lobes with the lowest and highest proportions of patients diagnosed in stages I and II were LUL and RML, with 35.8% and 42.9%, respectively (p = 0.001).
Treatment
Surgical resection was performed in 27.8%, and 30.4% of patients with tumours in the upper and lower lobes, respectively (p < 0.001). The highest resection rate was 33.4% in the RML, while 27.5% of the patients with tumours in the other four lobes were resected (p = 0.002). Both by uni- and multivariable regression analysis, tumour in the RLL was a significant predictor for resection.
Stereotactic body radiation therapy (SBRT), or curative radiotherapy, was given to 20.1% of the patients with tumours in the upper lobes and 18.3% in the lower lobes (p = 0.016). Palliative radiotherapy was performed in 1378 (20.4%) in the upper- and in 743 (18.2%) in the lower lobes (p = 0.005). Lobe, sex, age, cTNM stage, histologic type, and EGFR status were found to be independent predictors for resection (Table 2).
Survival
The 5-year relative survival in the study group was 33.7% (Table 3). The numerically reduced survival in patients with tumours in the LUL (Table 3) was not significant in multivariable analysis (Table 4). Independent predictors for survival in multivariable analysis were age, sex, cTNM stage, histology, EGFR status, and type of treatment (p < 0.001). The location in the lung lobes was not a significant predictor of survival.
Table 3
1-year, 5-year relative survival, and median survival by groups for patients diagnosed with lung cancer in 2018–2022 in Norway.
|
1-year RS (95%CI)
|
5-year RS (95%CI)
|
Median survival (95%CI)
|
All
|
61.2 (60.4–62.1)
|
33.7 (32.7–34.7)
|
20.1 (19.1–21.0)
|
Side
|
|
|
|
Right
|
61.2 (60.1–62.4)
|
34.6 (33.2–35.9)
|
20.6 (19.1–22.0)
|
Left
|
61.2 (59.9–62.5)
|
32.5 (31.0-34.1)
|
19.6 (18.4–20.8)
|
Lobe
|
|
|
|
RUL
|
61.1 (59.6–62.7)
|
34.1 (32.3–35.9)
|
20.8 (18.5–22.6)
|
LUL
|
60.4 (58.7–62.1)
|
31.6 (29.8–33.6)
|
18.8 (17.1–20.3)
|
RML
|
62.7 (59.0-66.6)
|
36.5 (32.0-41.5)
|
20.4 (16.3–25.5)
|
RLL
|
61.2 (59.3–63.1)
|
34.9 (32.7–37.2)
|
20.5 (18.6–22.6)
|
LLL
|
62.5 (60.4–64.7)
|
33.9 (31.5–36.5)
|
20.8 (18.8–23.0)
|
Over/Under
|
|
|
|
Over
|
60.8 (59.7–61.9)
|
33.0 (31.7–34.3)
|
19.5 (18.4–20.9)
|
Under
|
61.9 (60.6–63.2)
|
34.7 (33.2–36.4)
|
20.7 (19.1–22.0)
|
Sex
|
|
|
|
Female
|
65.3 (64.1–66.5)
|
37.7 (36.3–39.2)
|
25.3 (23.7–27.0)
|
Male
|
57.3 (56.1–58.5)
|
29.7 (28.4–31.1)
|
15.9 (14.9–16.8)
|
cTNM
|
|
|
|
I
|
93.4 (92.4–94.4)
|
68.5 (66.1–71.0)
|
82.7 (77.3–87.3)
|
II
|
82.6 (80.2–85.1)
|
49.9 (46.0-54.2)
|
47.0 (40.8–53.4)
|
III
|
65.2 (63.1–67.2)
|
25.2 (23.0-27.6)
|
18.9 (17.8–20.1)
|
IV
|
31.4 (30.1–32.7)
|
7.8 (6.8-9.0)
|
6.1 (5.7–6.4)
|
Unknown
|
57.0 (51.2–63.4)
|
27.1 (21.6–34.0)
|
12.0 (9.3–15.6)
|
Histology
|
|
|
|
AC
|
69.4 (68.2–70.7)
|
41.5 (39.9–43.3)
|
31.3 (29.4–33.6)
|
SCC
|
64.2 (62.3–66.1)
|
34.8 (32.7–37.0)
|
21.5 (19.3–23.5)
|
NSCLC, NOS
|
42.4 (39.0-46.1)
|
18.4 (15.2–22.1)
|
7.8 (6.9–9.5)
|
Large-cell
|
49.6 (41.4–59.3)
|
25.8 (19.2–34.7)
|
12.0 (7.8–17.6)
|
SCLC
|
36.9 (34.5–39.6)
|
8.9 (7.4–10.7)
|
8.3 (7.7-9.0)
|
Carsinoid
|
97.9 (95.0-100.9)
|
90.7 (82.1-100.1)
|
NA
|
Other
|
60.3 (53.5–68.0)
|
34.7 (26.4–45.7)
|
27.4 (16.3–38.0)
|
EGFR
|
|
|
|
Not tested
|
59.9 (55.8–64.2)
|
43.6 (39.3–48.3)
|
15.3 (14.1–16.2)
|
Positive
|
84.4 (81.3–87.7)
|
46.8 (41.1–53.2)
|
42.4 (36.0-49.4)
|
Negative
|
69.0 (67.6–70.5)
|
40.2 (38.2–42.2)
|
26.8 (25.4–28.8)
|
Unknown
|
67.9 (60.0-76.8)
|
44.6 (36.0-55.4)
|
30.4 (17.4–44.5)
|
Abbreviations: AC: adenocarcinoma, CI: confidence interval, EGFR: epidermal growth factor receptor, LLL: left lower lobe, LUL: left upper lobe, NA: not available, NSCLC NOS: non-small cell lung cancer not otherwise specified, RLL: right lower lobe, RML: right middle lobe, RS: relative survival, RUL: right upper lobe, SCC: squamous cell cancer, SCLC: small cell lung cancer.
Table 4
The risk of death for lung cancer patients, Cox regression for patients diagnosed with lung cancer in 2018–2022 in Norway
|
Univariable
|
Multivariable
|
|
Hazard Ratio (95%CI)
|
Hazard Ratio (95%CI)
|
Lobe
|
|
|
RUL
|
1.00
|
1.00
|
LUL
|
1.04 (0.98–1.10)
|
1.01 (0.95–1.07)
|
RML
|
0.97 (0.87–1.09)
|
1.09 (0.97–1.22)
|
RLL
|
0.99 (0.92–1.05)
|
0.99 (0.92–1.06)
|
LLL
|
0.99 (0.92–1.07)
|
1.02 (0.95–1.10)
|
p-value
|
0.55
|
0.56
|
Age
|
1.03 (1.03–1.03)
|
1.03 (1.02–1.03)
|
p-value
|
0.00
|
0.00
|
Sex
|
|
|
Female
|
1.00
|
1.00
|
Male
|
1.28 (1.23–1.34)
|
1.21 (1.16–1.27)
|
p-value
|
0.00
|
0.00
|
cTNM
|
|
|
I
|
1.00
|
1.00
|
II
|
1.94 (1.73–2.18)
|
1.48 (1.31–1.68)
|
III
|
3.72 (3.41–4.05)
|
1.98 (1.79–2.19)
|
IV
|
8.74 (8.11–9.42)
|
3.46 (3.13–3.81)
|
p-value
|
0.00
|
0.00
|
Histology
|
|
|
AC
|
1.00
|
1.00
|
SCC
|
1.24 (1.17–1.31)
|
1.40 (1.32–1.49)
|
NSCLC- NOS
|
2.05 (1.89–2.23)
|
1.44 (1.33–1.57)
|
Large-cell
|
1.50 (1.24–1.80)
|
1.54 (1.28–1.86)
|
SCLC
|
2.46 (2.32–2.60)
|
1.62 (1.52–1.71)
|
Carsinoid
|
0.14 (0.10–0.20)
|
0.35 (0.25–0.49)
|
Other
|
1.13 (0.96–1.32)
|
1.45 (1.23–1.70)
|
p-value
|
0.00
|
0.00
|
EGFR
|
|
|
Not tested
|
|
1.50 (1.33–1.69)
|
Positive
|
|
1.00
|
Negative
|
|
0.93 (0.55–1.02)
|
p-value
|
|
0.00
|
First treatment
|
|
|
Resected
|
1.00
|
1.00
|
SBRT
|
2.07 (1.82–2.35)
|
1.74 (1.52–1.98)
|
Cur rad
|
3.73 (3.34–4.17)
|
1.95 (1.73–2.20)
|
Pall rad
|
11.05 (10.05–12.15)
|
4.14 (3.70–4.63)
|
Unknown rad
|
8.51 (6.85–10.57)
|
2.94 (2.34–3.69)
|
No treatment reported
|
12.50 (11.42–13.69)
|
4.97 (4.47–5.54)
|
p-value
|
0.00
|
0.00
|
Abbreviations: AC: adenocarcinoma, CI: confidence interval, LLL: left lower lobe, LUL: left upper lobe, NSCLC NOS: non-small cell lung cancer not otherwise specified, RLL: right lower lobe, RML: right middle lobe, RUL: right upper lobe, SBRT: stereotactic body radiation therapy, SCC: squamous cell cancer, SCLC: small cell lung cancer. |