Table 1.
Clinical Characteristics (N = 50)
| Characteristics | n (%) |
|---|---|
| Age | |
| Median years (range) | 68 (49-83) |
| Sex | |
| Female | 22 (44) |
| Male | 28 (56) |
| PS, ECOG | |
| 0 | 4 (8) |
| 1 | 36 (72) |
| 2 | 10 (20) |
| Smoking status | |
| Never | 1 (2) |
| Former⁎ | 38 (73) |
| Current | 12 (23) |
| Unknown | 1 (1) |
| Stage | |
| IIIa | 2 (4) |
| IIIb | 2 (4) |
| IV | 46 (92) |
| Brain metastases | |
| Yes | 7 (14) |
| No | 45 (86) |
| Histology | |
| Adenocarcinoma | 42 (84) |
| Squamous cell | 8 (16) |
| EML4-ALK gene fusion† | |
| Positive | 0 |
| Negative | 27 (54) |
| Unknown | 23 (44) |
| Erlotinib treatment | |
| 2nd line | 41 (79) |
| 3rd line | 9 (17) |
| Prior treatment | |
| 1st line | |
| Carboplatin/vinorelbine‡ | 27 (54) |
| Carboplatin/vinorelbine /bevacizumab§ | 23 (46) |
| 2nd line¶ | |
| Pemetrexed | 5 (56) |
| Docetaxel | 4 (44) |
| Timing of PET scans | |
| Days from pretreatment PET to erlotinib start, median (range) | 1 (0-21) |
| Days from erlotinib start to follow-up PET, median (range)# | 8 (2-23) |
| Timing of CT scans | |
| Days from pretreatment CT to erlotinib start, median (range) | 14 (4-120) |
| Days from erlotinib start to evaluation CT, median (range)⁎⁎ | 72 (20-92) |
| Timing of blood samples | |
| Days from pretreatment sample to erlotinib start, median (range) | 3 (0-24) |
| Days from erlotinib start to follow-up sample, median (range)†† | 26 (6-58) |
PS, performance status; ECOG, Eastern Cooperative Oncology Group; EML4-ALK, echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase.
Former smoker was defined as having stopped smoking at time of diagnosis.
Only patients with adenocarcinoma were tested.
Carboplatin day 1 (AUC 5) and vinorelbine day 1 and day 8 (60-80 mg/m2 [PO]) every 3 weeks for a maximum of four cycles.
Bevacizumab (7.5 mg/m2 IV day 1) was given in combination with chemotherapy. Patients with disease control received subsequent maintenance therapy every 3 weeks until progression or toxicity.
Only including patients treated with erlotinib in third line.
Four patients were not scanned between 7 and 10 days after initiation of erlotinib but instead after 2, 5, 14, and 23 days, respectively.
Four patients were scanned later than 9 to 11 weeks of treatment (3 patients 12 weeks after and 1 patient 13 weeks after). Thirteen patients had their CT scan performed earlier because of suspicion of progression.
One patient had the follow-up sample collected before 1 week of erlotinib treatment (after 6 days) and 7 patients later than 4 weeks (30, 31, 32, 35, 40, 48, and 58 days, respectively).