Association of tumor CD73 expression with clinical outcomes in small cell lung cancer treated with first-line
Masafumi Saiki1, Tomohiro Inoue2, Kazuho Takusagawa1
1Department of Respiratory Medicine, Graduate School of Medicine, University of Yamanashi, Japan.
Background:
Small cell lung cancer (SCLC) is a highly aggressive malignancy with limited therapeutic options. Immune checkpoint inhibitors (ICIs) modestly improve outcomes, but predictive biomarkers are lacking. CD73, an ecto-5'-nucleotidase, generates immunosuppressive adenosine and may attenuate ICI efficacy.
Methods:
We conducted a single-center, retrospective study of 36 SCLC patients receiving first-line platinum-based chemo-immunotherapy. Tumor CD73 expression was assessed by immunohistochemistry and dichotomized as negative (H-score = 0) or positive (H-score ≥ 1). Molecular subtypes were determined based on dominant transcription factor expression (ASCL1, NEUROD1, POU2F3, YAP1). Associations between CD73 expression, progression-free survival (PFS), overall survival (OS), and transcriptional subtypes were analyzed. Public RNA-sequencing data (GSE69091) were used to contextualize immune-related gene expression patterns.
Results:
CD73 was positive in 75% of tumors. CD73-positive patients exhibited significantly shorter median PFS compared with CD73-negative patients (4.0 vs. 7.9 months; p = 0.048) and a trend toward reduced OS (8.5 vs. 29.1 months; p = 0.249). CD73 expression was not significantly associated with molecular subtypes. Public dataset analysis revealed CD73-high tumors with elevated T cell and immunosuppressive gene expression, but no OS difference in an ICI-naïve cohort, suggesting that CD73's impact is treatment-specific.
Conclusions:
Tumor CD73 expression is associated with inferior PFS in SCLC patients receiving chemo-immunotherapy and may serve as a predictive biomarker for ICI efficacy. Immunohistochemistry-based assessment of CD73 might facilitate treatment stratification, and prospective studies evaluating CD73-targeted therapies in combination with ICIs are warranted.
Insights
High CD73 expression in small cell lung cancer (SCLC) predicts shorter progression-free survival for patients receiving chemo-immunotherapy. This finding suggests CD73 may be a biomarker for immune checkpoint inhibitor efficacy.
Area of Science:
- Oncology
- Immunology
- Molecular Biology
Background:
- Small cell lung cancer (SCLC) is an aggressive cancer with limited treatment options.
- Immune checkpoint inhibitors (ICIs) offer modest benefits, but predictive biomarkers are needed.
- CD73, an enzyme generating immunosuppressive adenosine, may limit ICI effectiveness.
Purpose of the Study:
- To investigate the association between tumor CD73 expression and outcomes in SCLC patients treated with chemo-immunotherapy.
- To determine if CD73 expression can serve as a predictive biomarker for ICI efficacy in SCLC.
- To explore the relationship between CD73 expression, molecular subtypes, and immune gene expression.
Main Methods:
- Retrospective analysis of 36 SCLC patients receiving first-line chemo-immunotherapy.
- Immunohistochemistry to assess tumor CD73 expression (negative vs. positive).
- Analysis of associations between CD73, progression-free survival (PFS), overall survival (OS), and molecular subtypes; public data used for immune gene expression context.
Main Results:
- CD73 was expressed in 75% of SCLC tumors.
- CD73-positive tumors were linked to significantly shorter PFS (4.0 vs. 7.9 months) and a trend towards reduced OS (8.5 vs. 29.1 months).
- CD73 expression did not correlate with molecular subtypes, but high CD73 tumors showed increased immunosuppressive gene expression.
Conclusions:
- Tumor CD73 expression is associated with worse PFS in SCLC patients undergoing chemo-immunotherapy.
- CD73 may function as a predictive biomarker for ICI response in SCLC.
- Further research, including prospective trials of CD73-targeted therapies combined with ICIs, is warranted.
