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Thin cutaneous malignant melanomas (≤1.5 mm)
Author(s) -
Massi Daniela,
Franchi Alessandro,
Borgogi Lorenzo,
Maria Reali Umberto,
Santucci Marco
Publication year - 1999
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/(sici)1097-0142(19990301)85:5<1067::aid-cncr9>3.0.co;2-t
Subject(s) - medicine , proportional hazards model , melanoma , acral lentiginous melanoma , univariate analysis , survival analysis , tumor progression , multivariate analysis , progression free survival , metastasis , log rank test , cancer , pathology , gastroenterology , oncology , overall survival , cancer research
BACKGROUND Although thin cutaneous melanomas generally have a favorable prognosis, in some cases they may undergo progression. The current study was undertaken to identify variables that may predict a more aggressive clinical outcome in these patients. In addition to classic clinicopathologic features, the authors tested the prognostic impact of three new morphometric quantitative parameters: 1) tumor thickness plus regression thickness (T+R), 2) percentage of skin thickness infiltrated by tumor cells (T/S ratio), and 3) percentage of skin thickness infiltrated by tumor cells and regression ([T+R]/S ratio). METHODS The authors retrospectively evaluated 287 patients with invasive cutaneous melanoma ≤ 1.5 mm in thickness. Disease free survival rates (Kaplan–Meier method) were compared by using the log rank test. A multivariate analysis (Cox proportional hazards model) was used to determine the independent effect of each variable on progression. Progression was defined as any documented cutaneous local and/or distant metastasis. RESULTS Thirty‐two of the 287 patients (11.1%) underwent disease progression. The overall 5‐year and 10‐year disease free survival rates were 89.3% and 84.6%, respectively. In the univariate analysis, the following factors were found to be significant predictors of progression: male gender ( P = 0.01), acral‐lentiginous histotype ( P = 0.02), tumor thickness ( P = 0.005), T+R ( P = 0.001), T/S ratio ≥ 50% ( P = 0.03), (T+R)/S ratio ≥ 50% ( P = 0.006), vertical growth phase ( P = 0.04), and absence of inflammatory response ( P < 0.0001). Conversely, age, site, and Clark's level did not affect the risk of recurrences and/or metastases significantly. In the multivariate analysis, only T+R ( P = 0.009) and inflammatory response ( P < 0.0001) were found to be independent predictors of progression. Five‐year disease free survival rates according to presence versus absence of inflammatory response were 93.4% and 63.8%, respectively ( P < 0.0001). CONCLUSIONS In the current study, peritumoral and intratumoral inflammatory infiltrate and T+R were found to be strong independent predictors of progression in thin cutaneous melanomas. Cancer 1999;85:1067–76. © 1999 American Cancer Society.