Expression of cell adhesion molecules and tumour infiltrating leucocytes in conjunctival melanoma.

AIM: Very little is known about the immunology of conjunctival melanoma. We investigated the expression of cell adhesion molecules and the grade of tumour infiltration with lymphocytes and macrophages as important members for the communication between tumour cells and the immune system. METHODS: Archival material from 35 conjunctival melanomas was used for immunohistochemical detection of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), neural cell adhesion molecule (NCAM), CD3 and CD68 using monoclonal antibodies. Histological and clinical data for these tumours were assessed. RESULTS: ICAM-1 was expressed in 34 of 35 tumours; in 20 cases, more than 50% of the cells stained ICAM-1 positive. VCAM-1 was expressed in 21 of 34 tumours; in 17 cases, only a small proportion (1-25%) stained VCAM-1 positive. NCAM was expressed in 14 of 34 tumours; in 11 cases, only a small proportion (1-25%) stained NCAM positive. CD3-positive leucocytes were found in 26 of 32 tumours, whereas CD68-positive leucocytes were present in 33 of 34 tumours. Cox regression analysis revealed that patients with NCAM-positive tumours had a 6.4-fold higher risk of dying from conjunctival melanoma (P = 0.02). NCAM-positive tumours were preferentially (P = 0.03) located in prognostically 'unfavourable' areas (i.e. fornices, palpebral, caruncle) and had no or only a weak CD3-positive infiltrate (P = 0.03). CONCLUSIONS: ICAM-1, VCAM-1 and NCAM are differentially expressed in conjunctival melanoma. Leucocytes were present in almost every tumour. The association between NCAM expression and prognosis may be related to the differential anatomical tumour location of NCAM-positive and NCAM-negative tumours, and should be considered a preliminary observation due to the limited statistical power of this study.

Prognostic value of clinical and histopathological parameters in conjunctival melanomas: a retrospective study.

AIM: To determine prognostic factors for recurrence of disease and tumour related mortality in patients with conjunctival melanoma. METHODS: A retrospective analysis of clinical and histopathological data of 69 patients with histologically verified conjunctival melanoma. RESULTS: As univariate analysis showed, significant risk factors for the development of recurrence were: irregular pigmentation (RR = 2.0, p = 0.0007), incomplete surgical excision (RR = 3.5, p = 0.008), tumour invasion deeper than in substantia propria (RR = 3.9, p = 0.008), and presence of epithelioid tumour cells (RR = 2.9, p = 0.05). For tumour related mortality a significantly increased risk was found for tumour location in palpebral conjunctiva, caruncle, plica, or fornices (RR = 5.9, p = 0.001), for tumour infiltration deeper than the substantia propria (RR = 5.5, p = 0.001), for incomplete surgical excision (RR = 4.4, p = 0.05), and for nodular or mixed (nodular and superficial) growth pattern of the tumours (RR = 1.2, p = 0.002). The use of an adjuvant therapy for the surgical excision of the melanomas had no statistically significant influence upon the development of recurrent disease nor upon the tumour related mortality. CONCLUSION: These data present similar clinical and histopathological risk factors for patients with conjunctival melanoma as reported previously. The present study also addresses the failure of retrospective studies on conjunctival melanoma to prove the efficacy of a supplementary therapy to surgical excision.