No abstract

To identify the risk factors of conjunctival malignant melanoma that predict local tumor recurrence, orbital exenteration, distant metastasis, and tumorrelated mortality. Design: The clinical parameters of the patient, tumor, and treatment were analyzed in a nonrandomized fashion for their relation to 4 main outcome measures using Cox proportional hazards regression models. Participants: One hundred fifty consecutive patients. Main Outcome Measures: Local tumor recurrence, orbital exenteration, distant metastasis, and death from conjunctival melanoma. Results: The Kaplan-Meier estimates of local tumor recurrence was 26% at 5 years, 51% at 10 years, and 65% at 15 years. The mean number of recurrences per patient was 1 (median, 0 recurrences). There was no recurrence in 98 patients (65%), 1 recurrence in 28 patients (19%), 2 recurrences in 11 patients (7%), 3 recurrences in 5 patients (3%), and 4 or more recurrences in 8 patients (5%). Using multivariate analysis, the factors correlated with local tumor recurrence were melanoma location (not touching the limbus) (P =.01) and pathological tumor margins (lateral margin involved) (P=.02). Multivariate analysis for features correlated with ultimate exenteration included initial visual acuity (20/40 OU or worse) (PϽ.001), melanoma color red (P =.01), and melanoma location (not touching the limbus) (P=.02). Tumor metastasis was present in 16% of patients at 5 years, 26% of patients at 10 years, and 32% of patients at 15 years. Metastasis was first located in the regional lymph nodes in 17 cases, the brain in 4 cases, the liver in 3 cases, the lung in 2 cases, and was disseminated in 1 case. The risks for metastases using multivariate analysis included pathological tumor margins (lateral margin involved) (P = .002) and melanoma location (not touching limbus) (P =.04). Tumor-related death occurred in 7% patients at 5 years' follow-up and 13% at 8 years' follow-up. The risk factors for death using multivariate analysis included initial symptoms (lump) (P = .004) and pathologic findings (de novo melanoma without primary acquired melanosis) (P=.05). The technique of initial surgery was shown to be an important factor in preventing eventual tumor recurrence (P=.07), metastasis (P=.03), and death (P=.006) in the univariate analysis, but did not reach significance in the multivariate analysis. Conclusions: Conjunctival malignant melanoma is a potentially deadly tumor. In the present study, metastasis was detected in 26% of patients, and death occurred in 13% of patients at 10 years. Extralimbal melanoma and tumor involvement of the surgical margins were especially poor prognostic factors. Meticulous surgical planning using wide microsurgical excisional biopsy working with the "no touch" technique and supplemental alcohol corneal epitheliectomy and conjunctival cryotherapy is advised.

The basis of extracorporeal photopheresis is the reinfusion of leukocytes previously exposed to 8-methoxypsoralen (8-MOP) and UVA radiation. It has been approved for the palliative treatment of cutaneous T cell lymphoma and has reported benefits in autoimmune diseases, transplant rejection, and graft-vs-host disease. However, the underlying mechanism of photopheresis remains unresolved. Because UVB radiation can cause immune tolerance via induction of regulatory T cells, we studied whether photopheresis exerts a similar effect extracorporeally. Therefore, we established a model of photopheresis using a murine model of contact hypersensitivity. Splenocytes and lymph node cells of mice that were sensitized with dinitrofluorobenzene were exposed to 8-MOP plus UVA in vitro. Intravenous injection of these cells into naive mice caused inhibition of a hapten immune response, which was lost upon depletion of CD11c+ cells but not T cells. Mice that received untreated cells or cells exposed to UVA or 8-MOP alone were not affected. Inhibition was cell-mediated and Ag-specific as demonstrated by transfer of tolerance from the primary recipients into naive animals, which could, however, properly respond to the unrelated hapten oxazolone. Transfer activity was lost when cells were depleted of CD4+ or CD25+ subpopulations. These data suggest that photopheresis exerts its immunomodulatory effects via the induction of Ag-specific regulatory T cells.

Epicutaneous application of haptens to UV-exposed skin induces hapten-specific tolerance. This is mediated via regulatory T cells (Tr), as i.v. injection of T cells from UV-tolerized mice into naive animals renders the recipients unresponsive to the respective hapten. However, when UV-induced Tr are injected i.v. into sensitized mice, contact hypersensitivity (CHS) is not suppressed, suggesting that Tr inhibit the induction, but not the elicitation, of CHS and are inferior to T effector cells. As sensitization takes place in the lymph nodes, but elicitation occurs in the area of challenge, we postulated that Tr injected i.v. locate to the lymph nodes and not to the periphery and therefore only suppress the induction, not the elicitation, of CHS. Indeed, i.v. injection of Tr into sensitized mice did not inhibit CHS, although injection of Tr into the ears of sensitized mice suppressed the challenge. Inhibition was hapten specific, as injection of dinitrofluorobenzene (DNFB)-specific Tr into the ears of oxazolone (OXA)-sensitized mice did not affect challenge with OXA. However, when ears of OXA-sensitized mice were injected with DNFB-specific Tr and painted with DNFB before OXA challenge, CHS was suppressed. Inhibition correlated with the local expression of IL-10. Depletion studies and FACS analysis revealed that Tr express the lymph node-homing receptor L-selectin, but not the ligands for the skin-homing receptors E- and P-selectin, suggesting that UV-induced Tr, although able to inhibit T effector cells, do not suppress the elicitation of CHS upon i.v. injection, because they obviously do not migrate into the skin.