[Neuroendocrine differentiation is not a malignant index of non-small cell lung cancer]

A debate has been ongoing whether non-small cell lung cancer(NSCLC) with neuroendocrine(NE) differentiation likely indicates malignant behavior, poor prognosis, and sensitivity to chemotherapy. In response to this issue, we retrospectively investigated NE differentiation in NSCLC patients who underwent anatomical pulmonary surgery.

A total of 274 patients who met the inclusion criteria through January 2000 to December 2008 were enrolled in this study because they had the detailed material and enough paraffin tumor samples for tissue microarray. The recommended antibody panel consisted of CgA, Syn, NCAM, Leu-7, PGP9.5, and MAP-2. We also counted Ki-67 in the tissues to present the nuclear proliferation index. The Kaplan-Meier estimator and the Cox proportional hazard model multivariate analysis were applied to observe the relationship between NE differentiation and postoperative survival of the patients.

The Cox analysis of different NE score combinations on the prognosis of NSCLC after surgical treatment did not reach statistical significance (score 1, score 2, and score≥3 vs score 0, P=0.527; score 0 vs score ≥1, P=0.791; score<2 vs score≥2, P=0.163; score<3 vs score≥3, P=0.293). The Kaplan-Meier estimator did not give significant difference in the survival of NE score combinations in each pTNM layer. In the perioperative chemotherapy group, we also did not find a positive correlation for the survival analysis of NE score combinations (score 1, score 2, and score≥3 vs score 0, P=0.692; score 0 vs score≥1, P=0.922; score<2 vs score ≥2, P=0.264; score<3 vs score≥3, P=0.484).

The NE differentiation of NSCLC reflects some structure and functional characteristics of NELT, although it cannot be used as an independent factor of biological behavior and survival for NSCLC patients who underwent surgery in our group.