A Comparison of Prognostic Factors and Surgical Results in 1,786 Patients with Localized (Stage I) Melanoma Treated in Alabama, USA, and New South Wales, Australia

Abstract

Twelve clinical and pathologic parameters were compared in two series of Stage I melanoma patients treated at the University of Alabama in Birmingham, USA (676 patients) and at the University of Sydney in New South Wales, Australia (1,110 patients). Actuarial survival rates were virtually the same at the two institutions over a 25-year follow-up period. The incidence of thin melanomas (less than 0.76 mm) was also similar at both geographic locations (25% vs. 26%). Other similarities of these two patient populations included the following: 1) tumor thickness (Breslow Microstaging). 2) level of invasion (Clark Microstaging), 3) surgical results, 4) sex distribution, and 5) age distribution. The greatest differences between the two patient populations were their 1) anatomic distribution, 2) growth pattern, and 3) incidence of ulceration. The trunk was the most common site of melanoma, and occurred more frequently among Australian patients (37% vs. 28%). A multifactorial analysis (Cox's regression model) was then performed that included a comparison of the two institutions as a variable (Alabama vs. Australia). The dominant prognostic factors (p less than 0.0001) were 1) ulceration, 2) tumor thickness, 3) initial surgical management (wide excision +/- node dissection), 4) anatomic location, 5) pathologic stage (I vs. II), and 6) level of invasion. The benefit of elective lymph node dissection was demonstrated in both series for patients with intermediate thickness melanoma (0.76 to 3.99 mm.) For melanomas ranging from 0.76 to 1.5 mm in thickness, the benefit of node dissection was primarily in male patients. Survival rates for melanoma at the two institutions were not significantly different in the multifactorial analysis, even after adjusting for all other variable. Thus, the biologic behavior of melanoma in these two different parts of the world was virtually the same, with only minor differences that did not significantly influence survival rates. Long-term follow-up exceeding eight to ten years after surgery is critical in the interpretation of these prognostic factors and the surgical results.

The prognosis of primary and metastasising melanoma. An evaluation of the TNM classification in 2,495 patients

“…This was in agreement with the results of the majority of previously performed studies that differed considerably both with respect to the choice of parameters investigated, and in the size of the patient populations involved (Balch et al, 1982;Day et al, 1982;Garbe et al, 1990).…”

Histological Characteristics of Metastasizing Thin Melanomas

“…1 There is ample evidence that tumor thickness is directly proportional to the development of metastasis and to the overall patient survival. 2 In general, melanomas with a Breslow thickness of less than 1 mm have a good prognosis, with a low incidence of metastasis. However, thin melanomas may develop metastasis.…”

Anatomic Site of Primary Melanoma Is Associated With Depth of Invasion

“…However, since the introduction of microstaging methods by Clark et al 1 and Breslow, 2 more accurate predictions can be made regarding prognosis. [3][4][5][6] Numerous studies have shown that while thin (Ͻ1.25 mm) melanomas are considered curable by simple excision alone, deeply invasive lesions have probably metastasized by the time of diagnosis. 7 The high curability rate of early melanoma has increased public awareness to the issue of their early detection, and although the incidence of melanoma is rising faster than that of any other cancer, 8,9 an increasing number of patients are being diagnosed at an early stage.…”