Non-small Cell Lung Carcinoma With Neuroendocrine Differentiation—An Entity of No Clinicalor Prognostic Significance

American Journal of Surgical Pathology Volume 31, Number 1, January 2007

指導 : 鄭建睿 醫師Intern 許文彥

Diana N. Ionescu, MD, Diana Treaba, MD, Cyril B. Gilks, MD, Samuel Leung, BSc, Daniel Renouf, MD, Janessa Laskin, MD, Richard Wood-Baker, MD, and Allen M. Gown, MD

Pathology and Laboratory Medicine, Vancouver General Hospital

Introduction

LCNEC (large cell NE carcinoma) showed architectural and/or cytologic features of NE differentia

tion on routine HE. (organoid nesting, palisading or rosette-like structures)

well-recognized aggressive behavior and poor prognosis

NSCLC-ND (neuroendocrine differentiation) A minority of NSCLCs (10 to 30%) show NE differentiation. they

show no evidence of this differentiation on routine light microscopic examination.

The prognosic and treatment purpose are controversial.

Chromogranin, synaptophysin, and N-CAM (neural cell adhesion molecule) were most sensitive and specific.

Neuron-specific enolase (NSE) are now considered insufficiently specific as a marker of NE differentiation.

Chromogranin: major proteins in peptide containing dense core neurosecretory granules.

Synaptophysin: membrane glycoprotein of presnyaptic vesicles

N-CAM: membrane glycoprotein

MATERIALS AND METHODS

Case Selection

609 patients of primary NSCLCs, 1978-2002 588 cases met the criteria (exclude carcinoid

s, atypical carcinoids, LCNECS, and metastatic tumors)

533 cases were available for survival analysis

TMA (tissue microarray) Construction

Duplicate 0.6-mm tissue cores Serial 4-mm sections The 1st section was stained with H&E to assess adequa

cy. The remaining sections were stored at room temperature

for 3 weeks before immunostaining.

IHC (Immunohistochemistry)

Sections were deparaffinized and 10mM citrate solution was added inside a microwave pressure cooker.

Ch (clone PHE 5, 1:80; PhenoPath Lab Inc, Seattle, USA) SNP (clone SNP88, 1:100, Biogenex cat No. MU363-UC) N-CAM (1:100, Lab Vision cat No. MS-204-P).

Positive controls (normal colon, tonsil, NE carcinoma), Negative controls (with antibody omitted)

Scoring

All samples were evaluated and scored by 2 pathologists (A.G. and D.T.) without knowledge of the patient’s outcome information.

Staining in non-tumor cells was not considered to be positive

Scoring system 0, <1% of cells positive; 1, 1 to 25% of cells positive; 2, 26 to 75% of cells positive; 3, >75% of cells positive.

Data Analysis and Statistics

Excel spreadsheet format using the TMA-Deconvoluter program

Kaplan-Meier curves and survival estimates were calculated for each outcome, and a log-rank statistic was used to test for differences between groups.

A significant difference was declared if the P-value from a 2-tailed test was < 0.05.

Pearson χ2 test was used to evaluate the correlation between immunohistochemical staining and tumor cell type

RESULTS

Case Series Description

366 men and 192 women, median age: 63 years (range 35 to 82 y) median survival: 3.32 years (average 5.57 y).

106 patients (19.8%) were alive at the last time of last follow-up (June 2005) and 429 died (80.18%).

286 patients died of lung cancer (53.5%), 117 patients died of other known causes (21.9%) and in 26 cases

(4.9%) the cause of death was not available.--excluded

NE Expression by IHC

•ACA were more frequently positive for SNP and Ch(23/209, 11%) as compared with SCC (11/242, 4.5%) (P=0.012).

•SNP is more likely to be expressed in ACA (P=0.01) and N-CAM in SCC (P=0.008)

Chromogranin

Snyaptophysin

N-CAM

Correlation of NE Expression With Survival

Patients who died within 1 month after the surgical resection of their tumor (5.9%, 36/609 cases) -- excluded

Disease-specific survival in NSCLC

Not influenced by NE differentiation

Disease-specific survival in Adenocarcinoma

Not influenced by NE differentiation

Disease-specific survival in SCC

Not influenced by NE differentiation

These analyses, based on up to 26-year follow-up data, showed no prognostic significance of single NE marker expression, coexpression of 2 or more NE markers.

The survival analysis based on intensity of expression of any endocrine marker (ie, negative, weak vs. intermediate vs. strong) also did not show prognostic significance

DISCUSSION

Previous studies have identified NE differentiation in NSCLC in 10 to 70% of cases.

Studies with more specific NE markers, such as Ch, SNP, and N-CAM, positivity typically ranges between 10 to 30%.

→results of earlier studies should be interpreted with caution

Even when similar antibody panels have been used, what is considered positive in different studies has varied.

Schleusener et al NE differentiation in NSCLC has been shown in different studies

to be associated with either:1. improved survival (mostly in chemotherapy-treated patients)2. decreased survival (mostly in surgically-treated patients), 3. have no bearing at all on survival.

Why ? A small number of patients or had a short survival analysis time. By incorporation of the same cases into a larger study, the same

authors showed no prognostic significance for NE differentiation.

SNP was more likely to be expressed in ACA (P=0.01) and N-CAM in SCC (P=0.08).

In our study, NE expression of a single, or 2 or 3 NE markers had no significant impact on the disease-specific survival or the overall survival of either ACA or SCC subgroups.

Correlation with chemosensitivity was not attempted in this study.

1. management varied on the basis of the year of diagnosis (1978 to 2002),

2. detailed treatment information was not obtained because of to the major changes between chemotherapy protocols

The use of 0.6-mm cores for TMA construction may have decreased the number of cases with scattered focal expression of NE markers that would be identified as NE positive.

On the basis of our previous experience in other type of cancers with NE expression, we would not anticipate missing any cases with strong NE marker expression with this approach.

In this study

SNP staining was observed in a significant minority of NSCLC (7.5%, 39/521),

Ch, the most specific NE marker, was very uncommon (0.4%, 2/524).

N-CAM was encountered in a higher proportion of cases, 8.6% (44/511).

No significant correlation between positivity for SNP and Ch (P=0.35).

NE differentiation was found in 13.6% of cases (76/558). Coexpression of SNP and Ch, the most commonly used NE ma

rkers accounted for only 0.2% (1/517, ACA) Positivity for all 3 NE markers was not seen.

Conclusion

Therefore, we consider the assessment of NE differentiation in NSCLC as unnecessary and expensive and with no clinical or prognostic significance.

Thanks for your attention