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Consolidation radiotherapy for patients with extended disease small cell lung cancer in a single tertiary institution: impact of dose and perspectives in the era of immunotherapy


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Figure 1

Diagram of patients’ selection process.
Diagram of patients’ selection process.

Figure 2

Overall survival of patients treated with chemotherapy (Cht only) vs. chemotherapy and consolidation radiotherapy (ChT + cRT).
Overall survival of patients treated with chemotherapy (Cht only) vs. chemotherapy and consolidation radiotherapy (ChT + cRT).

Figure 3

Overall survival of patients treated with higher (45 Gy) vs. lower (30-36 Gy) dose of irradiation.
Overall survival of patients treated with higher (45 Gy) vs. lower (30-36 Gy) dose of irradiation.

Univariate and multivariate analysis of overall survival for patients with cRT vs no cRT (n = 187)

pUnivariate analysispMultivariate analysis
HR (95% CI)HR (95% CI)
cRT< 0.0011.73 (1.27–2.34)0.011.52 (1.10–2.09)
    no
    yes
Gender0.0421.17 (1.00–1.37)0.681.03 (0.87–1.21)
    Male
    Female
Age0.251.19 (0.88–1.62)
    > 65
    < 65
Number received of cycles< 0.0013.23 (2.33–4.47)< 0.0013.11 (2.22–4.35)
    < 4
    > 4
T stage0.981.00 (0.67–1.50)
    T1, 2
    T3, 4
N stage0.161.08 (0.96–1.22)
    N0-2
    N3
Metastases location
    Brain no/yes0.610.91 (0.64–1.29)
    Liver no/yes0.401.13 (0.84–1.52)
    Bone no/yes0.750.94 (0.67-1.33)
    Adrenal no/yes gland0.621.09 (0.76–1.57)
    Other no/yes0.181.21 (0.90–1.63)
Number of metastatic locations0.681.06 (0.79–1.42)
    1
    > 2
PCI< 0.0010.49 (CI 0.32–0.76)0.0151.59 (1.09–2.32)
    No
    Yes

Patients’ characteristics: higher vs. lower dose of radiotherapy

All45 Gy30-36 Gyp
n (%)n (%)n (%)
Gender591544
    Male35 (60)6 (40)29 (65.9)0.078
    Female24 (40)9 (60)15 (34.1)
Age
    median62 (42–76)60 (54–73)62 (42–76)0.12
    < 6542 (71.2)13 (68.7)29 ( 65.9)
    > 6517 (28.8)2 (13.3)15 (34.1)
Number of ChT cycles
    < 412 (20.3)2 (13.3)10 (22.7)0.37
    > 444 (74.6)13 (68.7)31 (70.5)
    unknown3 (5.1)0 (0)3 (6.8)
PS before RT0.66
    0-122 (37.3)5 (33.3)17 (38.6)
    2–37 (11.8))1 (6.67)6 (13.6)
    unknown30 (50.9)9 (0.6)21 (47.8)
T stage0.15
    T1–28 (13.6)4 (26.7)4 (9.1)
    T3–442 (71.2)8 (53.3)34 (77.3)
    Tx9 (15.3)3 (20)6 (13.6)
N stage0.69
    N0–224 (40.7)7 (46.7)17 (38.6)
    N329 (49.2)6 (40)23 (52.3)
    Nx6 (10.1)2 (13.3)4 (9.1)
Metastases location*
    Brain14 (23.7)5 (33.3)9 (20.5)0.31
    Liver27 (45.7)6 (40)21 (47.7)0.60
    Bone13 (22)3 (30)10 ( 22.7)0.82
    Adrenal gland15 (25.4)3 (30)12 (27.3)0.57
    Other21 (35.6)3 (30)19 (43.2)0.10
Number of metastatic locations
    134 (57.6)10 (66.7)24 (54.5)0.41
    > 225 (42.4)5 (33.3)20 (45.4)
Timing of RT**0.15
    < 4 weeks after ChT17 (53.1)6 (75)11 (45.9)
    > 4 weeks after ChT15 (46.9)2 (25)13 (54.1)
PCI
    Yes17 (28.8)5 (33.3)12 (27.3)0.65

Trials of consolidation radiotherapy (cRT) in extended disease small cell lung cancer (ED-SCLC)

Author/Trial, referencePublication yearType of studyPatients -years enrolledNumber of patientsPatient selectionThoracic irradiation dose schememOS1-year OS2-year OS
Jeremic181999P1988–1993109ED-SCLC with CR at metastatic sites and at least PR in thorax54 Gy in 36 fractions, BID17 m vs. 11 m* P = 0.04165% vs. 46% P ≤ 0.0538% vs. 28% P ≤ 0.05
Slotman (CREST)82015P2009–2012495ED-SCLC with any response to ChT30 Gy in 10 fractions8 m vs. 8 m33% vs. 28% P = 0.06613% vs. 3% P = 0.004
Gore (RTOG 0937)92017P2010–201697ED-SCLC (1-4 extracranial m., any response to ChT40 Gy in 15 fractions15.8 m vs. 13.8 m P = 0.2150.8% vs. 60.1% P = 0.21NR
Zhu102011R2003–2006119ED-SCLC40–60 Gy17 m P = vs. 0.014 9.3 mNR35% vs. 17%
Giuliani122011R2005–200919ED-SCLC with metastatic minimal disease36–45 Gy14 m58%14%
Yee112012R2008–200932ED-SCLC40 fractions Gy in 158.3 mNRNR
Zhan13 (SEER database)2018R2010–20126812ED-SCLC from SEER databaseDifferent, not reported9 m vs. 7 m; P < 0.001 8 m vs. 6 m for polymetastases P < 0.05NRNR
Stanic2020R2010–2014187ED-SCLC30–45 Gy11.1 7.6 m m vs. P < 0.00144% vs. 23% P = 0.002510% vs. 5% P = 0.19

Patients’ characteristics: chemotherapy only vs. chemotherapy with consolidation radiotherapy

ChT onlyChT with cRTp
n (%)n (%)
Gender187 (100)113 (60.4)74 (39.6)
    Male126 (67.4)81 (71.1)45 (60.1)0.12
    Female61 (32.6)32 (28.9)29 (39.9)
Age
    median (range)63 (42-80)61 (42-80)63 (47-80)0.24
    < 65122 (65.2)70 (61.9)52 (70.3)
    > 6565 (34.8)43 (38.1)22 (29.7)
Number of ChT cycles*
    < 466 (35.3)51 (47.2)15 (20)<0.001
    > 4113 (60.4)57 (52.8)56 (80)
T stage0.23
    T1–232 (17.1)20(17.7)12 (16.2)
    T3-4122 (65.2)69 (61)53 (71.6)
    Tx33 (17.7)24 (21.3)9 (12.2)
N stage0.56
    N0–271 (38)40 (35.4)31(41.9)
    N391(48.7)56 (49.6)35 (47.3)
    Nx25 (13.3)17 (15)8 (10.8)
Metastases location**
    Brain44 (23.5)28 (24.8)16 (21.6)0.61
    Liver86 (46)57 (50.4)29 (39.2)0.13
    Bone42 (22.5)28 (24.8)14 (18.9)0.34
    Adrenal gland38 (20.3)23 (20.4)15 (20.3)0.98
    Other92 (49.2)62 (54.9)30 (40.5)0.06
Number of metastatic locations
    1105 (56.1)55 (48.7)50 (67.6)0.01
    > 282 (43.9)58 (51.3)24 (23.4)
PCI
    Yes41 (21.9)20 (17.6)21 (28.4)0.08
    no146 (78.1)93 (82.4)53 (71.6)

Univariate and multivariate analysis of overall survival for higher vs. lower dose of consolidation radiotherapy

pUnivariate analysispMultivariate analysis
HR (95% CI)HR (95% CI)
Dose0.0230.49 (0.27–0.90)0.0180.47 (0.25–0.87)
    45 Gy
    30-36 Gy
Gender0.171.4 (0.86–2.27)
    Male
    Female
Age0.381.25 (0.75–2.09)
    > 65
    < 65
PS before RT0.0891.94 (0.90–4.18)
    2–3
    0–1
Number of ChT cycles0.0651.78 (0.96–3.31)
    < 4
    > 4
T stage0.340.72 (0.37–1.40)
    T1–2
    T3–4
N stage0.281.32 (0.79–2.20)
    N0–2
    N3
Metastases location
    Brain da/ne0.521.2 (0.68–2.11)
    Liver da/ne0.391.22 (0.76–1.92)
    Bone da/ne0.461.24 (0.70–2.21)
    Adrenal gland da/ne0.980.99 (0.59–1.67)
    Other0.840.95 (0.58–1.56)
Number locations of metastatic0.430.82 (0.51–1.33)
    1
    > 2
Timing of RT0.711.13 (0.59–2.16)
    < 4 weeks after ChT
    > 4 weeks after ChT
PCI0.040.56 (CI 0.32–0.97)0.0370.51 (0.27–0.95)
    Yes
    No
eISSN:
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Journal Subjects:
Medicine, Clinical Medicine, Internal Medicine, Haematology, Oncology, Radiology