Department of Oncology, Rigshospitalet, 9 Blegdamsvej, 2100, Copenhagen, Denmark,
Cancer Chemother Pharmacol. 2014 Jan;73(1):131-7. doi: 10.1007/s00280-013-2329-0. Epub 2013 Dec 11.
Antibodies targeting epidermal growth factor receptor (EGFR), such as cetuximab, may potentially improve outcome in non-small cell lung cancer (NSCLC) patients with high EGFR expression. The EGFR expression may be heterogeneously distributed within tumors, and small biopsies may thus not accurately reveal the EGFR expression. In addition, EGFR expression may also change during chemotherapy. The current study investigates the magnitude of these two issues.
EGFR expression in diagnostic biopsies and resection specimen was compared in 53 NSCLC patients stage T1-4N0-1M0 treated with surgery without preceding chemotherapy (OP group), and 65 NSCLC patients stage T1-3N0-2M0 (NAC group) treated with preoperative carboplatin and paclitaxel in order to evaluate the discordance of EGFR expression between samples.
Discordance between tumors dichotomized according to EGFR expression (high: H-score ≥200; low: H-score <200) in diagnostic biopsies and immediate resection specimens was 25 % in the OP group and 33 % in the NAC group (p = 0.628). Five (9 %) of primary tumors in the OP group and 4 (13 %) in the NAC group had increased EGFR expression in the resection specimens as compared to the diagnostic biopsies (p = 0.583). A decrease in EGFR expression was observed in 6 (11 %) in the OP group and 7 (23 %) in the NAC group (p = 0.148).
EGFR expression in 25 % of diagnostic biopsies may potentially not be accurate compared to the prevailing pattern in the whole tumor based on the larger resection specimens. This may potentially be an obstacle for proper use of antibodies targeting the EGFR in NSCLC. EGFR expression does, however, not change significantly during paclitaxel and carboplatin and rebiopsies in order to decide on anti-EGFR antibody therapy following chemotherapy do not seem warranted.
针对表皮生长因子受体（EGFR）的抗体，如西妥昔单抗，可能会改善高 EGFR 表达的非小细胞肺癌（NSCLC）患者的预后。EGFR 的表达可能在肿瘤内呈异质性分布，因此小活检可能无法准确揭示 EGFR 的表达情况。此外，EGFR 的表达也可能在化疗过程中发生变化。本研究旨在调查这两个问题的严重程度。
对 53 例未经化疗（OP 组）和 65 例接受术前卡铂和紫杉醇治疗的 NSCLC 患者（NAC 组）的手术标本进行了 EGFR 表达比较。OP 组患者的 T1-4N0-1M0 期，NAC 组患者的 T1-3N0-2M0 期。以评估诊断活检和即刻切除标本中 EGFR 表达的不一致性。
OP 组和 NAC 组中，根据 EGFR 表达（高：H 评分≥200；低：H 评分<200）对肿瘤进行二分法时，诊断活检和即刻切除标本之间的不一致率分别为 25%和 33%（p=0.628）。OP 组中有 5（9%）例原发性肿瘤的 EGFR 表达在切除标本中较诊断活检升高，NAC 组中有 4（13%）例升高（p=0.583）。OP 组中有 6（11%）例和 NAC 组中有 7（23%）例 EGFR 表达降低（p=0.148）。
与较大的切除标本相比，25%的诊断性活检中 EGFR 的表达可能不够准确，这可能是正确使用针对 EGFR 的抗体治疗 NSCLC 的障碍。然而，在紫杉醇和卡铂化疗期间，EGFR 表达没有显著变化，并且不需要进行再活检以决定是否进行抗 EGFR 抗体治疗。
