Metastatic pattern and survival in disseminated conjunctival melanoma: implications for sentinel lymph node biopsy.
OBJECTIVE
To study the pattern of metastasis and overall survival in patients with disseminated conjunctival melanoma.


METHODS
Population-based, retrospective cross-sectional study.


METHODS
Eighty-five Caucasian patients with primary malignant conjunctival melanoma diagnosed between 1967 and 2000.


METHODS
Data were collected from the Finnish Cancer and Population Registries and all involved hospitals. The pattern (regional or systemic) and site of first metastasis were recorded. The time to first metastasis and survival by pattern were estimated by cumulative incidence analysis, which takes competing risks into account, and by Kaplan-Meier analysis, respectively.


METHODS
Metastatic pattern, time to metastasis by pattern, overall survival.


RESULTS
In 45% (95% confidence interval, 23%-68%) of 20 patients with metastasis, regional lymph node metastases were detected before systemic ones. Median times to initial regional and systemic metastasis were 2.3 and 3.4 years, respectively, and the median time from regional to systemic metastasis, 1.0 year. The 10-year cumulative incidence of initial regional metastasis was 0.11, and it tended to be higher for tumors more than 2 mm thick (0.18 vs. 0.05, P = 0.062). The corresponding incidence of initial systemic metastasis was 0.18, and it was higher for nonlimbal tumors (0.38 vs. 0.07, P = 0.00023) and for tumors more than 2 mm thick (0.28 vs. 0.06, P = 0.026). Overall survival was longer after initial regional metastasis than after systemic metastasis (30 vs. 8 months, P = 0.012).


CONCLUSIONS
Initial regional lymph node metastasis was as common as systemic metastasis, but initial lymph node metastasis was associated with better prognosis. Metastasis, especially initial regional lymph node metastasis, from limbal tumors and tumors less than 2 mm thick was rare. These patients may have less benefit from sentinel lymph node biopsy, a method that is currently under evaluation regarding its potential to improve survival.
Tuomaala
Seppo
S
Ocular Oncology Service, Department of Ophthalmology, Helsinki University Central Hospital, Haartmaninkatu 4C, PL 220, FIN-00029 HUS, Helsinki, Finland. seppo.tuomaala@hus.fi
Kivelä
Tero
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003230:Conjunctival Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D003430:Cross-Sectional Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000401:mortality* / Q000556:secondary* / Q000601:surgery; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D015996:Survival Rate; D013997:Time Factors