Table 1.
Baseline Patient Characteristics
| Lung Metastases (group 1A) n=100 | No Known Lung Metastases (group 1B) n=100 | Controls (group 2) n=200 | P value | |
|---|---|---|---|---|
|
| ||||
| N (%) | N (%) | N (%) | ||
|
| ||||
| Age (years), Median (Range) | 62 (33–88) | 57 (24–85) | 56 (30–87) | 0.006 |
|
| ||||
| BMI, Median (Range) | 26.8 (16.9–54.6) | 26.8 (16.0–41.7) | 25.4 (17.3–51.4) | 0.035 |
|
| ||||
| Time from Diagnosis to Participation1 (months), Median (Range) | 109 (1–423) | 75 (0–371) | 39 (5–299) | <0.001 |
|
| ||||
| Sites of Metastatic Disease | ||||
|
| ||||
| Lung | 100 (100) | 0 (0) | 0 (0) | <0.001 |
| Bone | 49 (49) | 69 (69) | 0 (0) | 0.006 |
| Lymph Node | 36 (36) | 23 (23) | 0 (0) | 0.06 |
| Liver | 17 (17) | 20 (20) | 0 (0) | 0.72 |
| Brain | 5 (5) | 2 (2) | 0 (0) | 0.45 |
| Other2 | 11 (11) | 12 (12) | 0 (0) | 1 |
|
| ||||
| Number of Sites of Metastatic Disease | <0.001 | |||
|
| ||||
| 0 | 0 (0) | 0 (0) | 200 (100) | |
| 1 | 21 (21) | 77 (77) | 0 (0) | |
| 2 | 43 (43) | 20 (20) | 0 (0) | |
| 3 | 33 (33) | 3 (3) | 0 (0) | |
| 4 | 3 (3) | 0 (0) | 0 (0) | |
|
| ||||
| Tumor Phenotype | 0.02 | |||
|
| ||||
| ER/PR Positive HER23 Negative | 71 (71) | 82 (82) | 141 (70) | |
| HER2 Positive | 22 (22) | 12 (12) | 23 (12) | |
| Triple4 Negative | 6 (6) | 3 (3) | 21 (11) | |
| Unknown (missing HER2 status) | 1 (1) | 3 (3) | 15 (8) | |
|
| ||||
| Received Breast/Chest Radiotherapy | 53 (53) | 35 (35) | 133 (77) | <0.001 |
|
| ||||
| Inflammatory Conditions of the Lung | ||||
|
| ||||
| Asthma | 12 (12) | 13 (13) | 22 (11) | 0.88 |
| COPD | 6 (6) | 6 (6) | 7 (4) | 0.50 |
| Other5 | 9 (9) | 9 (9) | 11 (6) | 0.40 |
|
| ||||
| Breast Cancer Treatment in Last Month | 83 (83) | 88 | 120 | |
|
| ||||
| Time Since Last Treatment | <0.001 | |||
|
| ||||
| Day of Study | 56 (56) | 58 (58) | 119 (60) | |
| Within One Month | 31 (31) | 32 (32) | 3 (20) | |
| None Recent | 13 (13) | 10 (10) | 78 (39) | |
|
| ||||
| Treatment Received | ||||
|
| ||||
| Chemotherapy/Targeted Therapy | 44 (44) | 31 (31) | 0 | <0.001 |
| Endocrine Therapy | 44 (44) | 66 (66) | 120 (60) | 0.004 |
|
| ||||
| Smoking History | 0.42 | |||
|
| ||||
| Current | 3 (3) | 8 (8) | 20 (10) | |
| Former | 41 (41) | 40 (40) | 84 (42) | |
| Ever | 44 (44) | 48 (48) | 104 (52) | |
| Never | 56 (56) | 52 (52) | 96 (48) | |
|
| ||||
| Smoking Exposure6, Median (Range) | 24 (1–126) | 27 (1–150) | 20 (1–150) | 0.98 |
|
| ||||
| Second Hand Smoking Exposure | 0.38 | |||
|
| ||||
| Ever | 54 (54) | 63 (63) | 122 (61) | |
| Never | 46 (46) | 37 (37) | 78 (39) | |
|
| ||||
| NSAID Use | 0.94 | |||
|
| ||||
| Regular | 33 (33) | 31 (31) | 65 (33) | |
| Occasional | 66 (66) | 69 (69) | 135 (68) | |
| Missing Data | 1 (1) | 0 (0) | 0 (0) | |
|
| ||||
| Time since NSAID (days) Median (Range) | 2.5 (0–713) n= 68 | 1 (0–1008) n=69 | 1 (0–4309) N = 142 | 0.77 |
|
| ||||
| NSAID Exposure within Seven Days | 50 (50) | 47(47) | 95 (48) | 0.90 |
BMI: Body Mass Index
1
Defined as time from first invasive breast cancer to day of study consent
2
Include soft tissue, adrenal and peritoneum
3
HER2= human epidermal growth factor receptor 2
4
Defined as ER=0%, PR=0% and HER2 Negative (Immunohistochemistry 0/1+ or FISH <2.0)
5
Including bronchiectasis, interstitial lung disease, granulomatous disease, pulmonary fibrosis and sarcoidosis
6
Defined in Pack Years among ever smokers