IASLC 2017: Biopsy Specimen Found to Be Reliable for Evaluating DLL3 Expression in Small Cell Lung Cancer

Key Points

  • Biopsy specimen is a reliable material for evaluating DLL3 expression.
  • High DLL3 levels in SCLCs were correlated with patients’ history of smoking, TTF-1 (neuroendocrine differentiation), and poor survival trends.
  • These results may lead to further evaluation of the scoring system for predicting DLL3-targeted therapeutic efficacy and clinical significance of DLL3 expression in high-grade pulmonary neuroendocrine carcinomas.

Small cell lung cancer (SCLC) biopsy specimens were found to be reliable material for evaluating DLL3 expression, and high levels of DLL3 in SCLC are correlated with poor survival trends. Researchers from Guangdong General Hospital and Guangdong Academy of Medical Sciences in China presented findings from this study at the International Association for the Study of Lung Cancer (IASLC) 18th World Conference on Lung Cancer (WCLC) in Yokohama, Japan.

Study Background

Rovalpituzumab tesirine is a promising DLL3-targeted antibody-drug conjugate for the treatment of high-grade pulmonary neuroendocrine carcinomas. Biopsies are used often in clinical practice to determine high-grade neuroendocrine carcinoma diagnoses before treatment. The research team set out to determine the reliability of the scoring system used to assess the correlation between paired biopsy and surgical specimens and high-grade neuroendocrine carcinoma features and prognoses. They viewed this information as crucial to understanding whether DLL3 expression on small specimens could represent its expression level on the whole tumor.

Between 2006 and 2015, the researchers recruited patients with de novo high-grade neuroendocrine carcinomas, including 43 large-cell neuroendocrine carcinoma and 335 SCLC patients. One group, containing all of the large-cell neuroendocrine carcinoma patients and some of the SCLC patients, had paired biopsy and surgical specimens collected. The other group, containing the remainder of the SCLC patients, had only biopsy specimens collected. Using the anti–DLL3 antibody, the researchers evaluated and determined individuals' DLL3 expression levels using immunohistochemical H score (HS).

Findings

The results of the study provided evidence that biopsy specimen is a reliable material for evaluating DLL3 expression. Additionally, the researchers found that high DLL3 levels in SCLCs were correlated with patients’ history of smoking, TTF-1 (neuroendocrine differentiation), and poor survival trends. These results may lead to further evaluation of the scoring system for predicting DLL3-targeted therapeutic efficacy and clinical significance of DLL3 expression in high-grade pulmonary neuroendocrine carcinomas.

“Accurate diagnosis is the premise of accurate treatment,” said Dr. Li-Xu Yan. “To study the heterogeneity of molecular biomarkers is conducive to better guiding targeted treatments.”

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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