PURPOSE: Lymphangiogenesis has been reported to affect malignant phenotype and be involved in lymphatic metastasis. Recently, D2-40, a selective marker for lymphatic endothelium has been developed for clinical studies in human cancers but its expression and prognostic impact in SCLC still remains vague.This study aims to investigate the expression of D2-40 in SCLC by calculating intratumoral lymphatic microvessel density(ILMVD) and associate it with the presence of lymphatic invasion(L.I), clinical parameters and prognosis.
METHODS: Fifty five SCLC specimens were immunohistochemically stained for D2-40 (DBS California-Menarini Hellas). Calculation of ILMVD and assessment of L.I were performed and retrospective correlation with available clinical data followed.
RESULTS: Patients' mean age was 68.1 years (range 40-89) and 56.3% were male. All received chemotherapy and 37.8% radiation therapy. Regarding stage, 41.8% of patients were classified as extensive. D2-40 was expressed in all specimens with high expression (ILMVD≥36) in 38.3% and low (ILMVD<36) in 61.7%. L.I was present in 59.6% of specimens. ILMVD was significantly associated with patients' sex (p=0.00,x2=27.9), L.I (p=0.00,x2=14.7), stage at diagnosis (p=0.017,x2=6.01) and certain target organs for metastasis (liver:p=0.001,x2=11.51, adrenals: p=0.046,x2=4.1). L.I was associated with stage (p=0.00,x2=11.7), and all target organs for metastasis (p<0.05). No association was found between ILMVD, L.I and survival.
CONCLUSION: D2-40 and L.I were highly expressed in SCLC and independently associated with poor patient outcome, thus presenting as prognostic factors at the time of diagnosis.
CLINICAL IMPLICATIONS: In this context, defining subsets of patients with poor prognosis could present exciting possibilities for the future in developing new targeted therapeutic strategies.
DISCLOSURE: Georgia Hardavella, No Financial Disclosure Information; No Product/Research Disclosure Information