Table 2. Baseline and disease characteristics according to the presence of EGFR mutation by cfDNA analysis.
|
LUX-Lung 3 |
LUX-Lung 6 |
|||||
|---|---|---|---|---|---|---|
| Characteristics | Serum cfDNA+ (n=82) | Serum cfDNA− (n=205) | Association OR (95% CI); P valuea | Plasma cfDNA+ (n=202) | Plasma cfDNA− (n=132) | Association OR (95% CI); P valuea |
|
Gender,
n
(%) | ||||||
| Male | 27 (32.9) | 72 (35.1) | 1.10 (0.64–1.90); 0.7238 | 63 (31.2) | 57 (43.2) | 1.68 (1.06–2.64); 0.0260 |
| Female | 55 (67.1) | 133 (64.9) | 139 (68.8) | 75 (56.8) | ||
|
Age, years | ||||||
| Median (range) | 61 (38–83) | 61 (28–84) | 0.94 (0.73–1.22); 0.6487 | 58 (29–77) | 58 (27–78) | 1.00 (0.82–1.22); 0.9683 |
|
Race,
n
(%) | ||||||
| Asian | 58 (70.7) | 149 (72.7) | 1.10 (0.63–1.94); 0.7391 | 202 (100.0) | 132 (100.0) | – |
| Non-Asian | 24 (29.3) | 56 (27.3) | 0 | 0 | ||
|
ECOG PS,
n
(%) | ||||||
| 0 | 17 (20.7) | 81 (39.5) | 2.50 (1.37–4.56); 0.0029 | 36 (17.8) | 43 (32.6) | 2.23 (1.34–3.72); 0.0022 |
| 1 | 65 (79.3) | 124 (60.5)b | 166 (82.2) | 89 (67.4) | ||
|
Smoking status, n (%) | ||||||
| Current | 2 (2.4) | 4 (2.0) | 16 (7.9) | 10 (7.6) | ||
| Former | 23 (28.0) | 62 (30.2) | 1.08 (0.62–1.88); 0.7789c | 26 (12.9) | 28 (21.2) | 1.54 (0.93–2.56); 0.0953c |
| Never | 57 (69.5) | 139 (67.8) | 160 (79.2) | 94 (71.2) | ||
|
Adenocarcinoma stage, n (%) | ||||||
| IIIB with pleural effusion | 7 (8.5) | 24 (11.7) | 1.42 (0.59–3.44); 0.4364 | 7 (3.5) | 10 (7.6) | 2.28 (0.85–6.16); 0.1029 |
| IV | 75 (91.5) | 181 (88.3) | 195 (96.5) | 122 (92.4) | ||
|
Differentiation grade, n (%) | ||||||
| Well differentiated | 3 (3.7) | 27 (13.2) | 1.23 (0.67–2.26)d; 1.77 (0.87–3.60)e; 0.2825 | 10 (5.0) | 15 (11.4) | 1.56 (0.92–2.65)d; 2.23 (1.27–5.03)e; 0.0295 |
| Moderately differentiated | 19 (23.2) | 42 (20.5) | 30 (14.9) | 25 (18.9) | ||
| Poorly differentiated | 16 (19.5) | 28 (13.7) | 46 (22.8) | 17 (12.9) | ||
| Undifferentiated | 6 (7.3) | 11 (5.4) | 2 (1.0) | 2 (1.5) | ||
| Not specified | 38 (46.3) | 97 (47.3) | 114 (56.4) | 73 (55.3) | ||
|
Number of metastatic sites,
n
(%) | ||||||
| 0 | 0 (0.0) | 6 (2.9) | 1.81 (0.91–4.07)f; 3.94 (1.94–7.98)g; 0.0003 | 1 (0.5) | 3 (2.3) | 2.06 (1.22–3.48)f; 4.20 (2.32–7.61)g; <0.0001 |
| 1 | 12 (14.6) | 64 (31.2) | 50 (24.8) | 61 (46.2) | ||
| 2 | 18 (22.0) | 58 (28.3) | 74 (36.6) | 45 (34.1) | ||
| ⩾3 | 52 (63.4) | 77 (37.6) | 77 (38.1) | 23 (17.4) | ||
|
Location of metastatic sites,
n
(%) | ||||||
| Pleural effusion | 43 (52.4) | 82 (40.0) | 1.65 (0.99–2.77); 0.0558 | 63 (31.2) | 42 (31.8) | 0.97 (0.61–1.56); 0.9034 |
| Bone | 54 (65.9) | 76 (37.1) | 3.27 (1.91–5.60); <0.0001 | 119 (58.9) | 28 (21.2) | 5.33 (3.22–9.80); <0.0001 |
| Brain | 13 (15.9) | 27 (13.2) | 1.24 (0.61–2.55); 0.5538 | 24 (11.9) | 22 (16.7) | 0.67 (0.36–1.26); 0.2166 |
| Liver | 25 (30.5) | 18 (8.8) | 4.56 (2.32–8.95); <0.0001 | 37 (18.3) | 4 (3.0) | 7.18 (2.49–20.65); 0.0003 |
| Other | 60 (73.2) | 142 (69.3) | – | 164 (81.2) | 101 (76.5) | – |
| Median (range) SLD target lesions, mm | 60.5 (14.1–168.5) | 45.6 (10.6–167.0) | 1.14 (0.99–1.31); 0.0613 | 56.8 (16.1–175.8) | 46.2 (12.0–162.6) | 1.35 (1.16–1.58); 0.0001 |
|
Tissue
EGFR
mutation type,
n
(%) | ||||||
| Common mutations | 75 (91.5) | 183 (89.3) | 0.59 (0.34–1.02)h; 0.62(0.25–1.56)i; 0.1427 | 184 (91.1) | 114 (86.4) | 0.73 (0.46–1.17)h; 0.54 (0.26–1.12)i; 0.1732 |
| Del19 | 49 (59.8) | 96 (46.8) | 111 (55.0) | 60 (45.5) | ||
| L858R | 26 (31.7) | 87 (42.4) | 73 (36.1) | 54 (40.9) | ||
| Uncommon mutationsj | 7 (8.5) | 22 (10.7) | 18 (8.9) | 18 (13.6) | ||
|
Laboratory parameters, median (range) | ||||||
| WBC count, 109 l−1 | 7.8 (3.2–29.9) | 7.0 (2.4–24.4) | 1.09 (1.02–1.17); 0.0132 | 7.4 (2.9–18.6) | 6.8 (3.5–24.1) | 1.08 (1.00–1.17); 0.0599 |
| LDH, U l−1 | 287 (125–1706) | 245 (93–1160) | 1.06 (1.02–1.11); 0.0023 | 224 (89–1773) | 170 (54–431) | 1.16 (1.06–1.26); <0.0001 |
| ALP, U l−1 | 124 (40–973) | 125 (36–513) | 1.10 (1.04–1.17); 0.0025 | 98 (31–2463) | 83 (39–379) | 1.49 (1.28–1.74); 0.0006 |
Abbreviations: ALP=alkaline phosphatase; cfDNA=cell-free DNA; CI=confidence interval; ECOG PS=Eastern Cooperative Oncology Group performance status; EGFR=epidermal growth factor receptor; LDH=lactate dehydrogenase; OR=odds ratio; SLD=sum of longest diameter; WBC=white blood cell.
a
Two-sided Wald chi-square test from univariate logistic regression analysis.
b
Includes one patient with an ECOG PS of 2.
c
Never vs former/current smoker.
d
Not specified vs well/moderately differentiated.
e
Well/moderately differentiated vs poorly/undifferentiated.
f
0/1 vs 2 metastatic sites.
g
0/1 vs ⩾3 metastatic sites.
h
Del19 vs L858R mutations.
i
Del19 vs other mutations.
j
Including T790M, Ins20, G719X, S768I, and L861Q, alone or as complex mutations in two or more exons.