Prognostic classification of malignant melanomas by combining clinical, histological, and immunohistochemical parameters

In a retrospective study the prognostic relevance of clinical, histopathological, immunohistochemical, and flow-cytometric parameters in primary malignant melanomas was evaluated using both the receiver operating characteristic ROC procedure and the logistic regression model. The proteolytic enzymes collagenase IV, cathepsin B, and cathepsin D proved to be significant prognostic factors. Combining the results obtained with these enzymes with gender, anatomic site, tumour thickness, Clark's level, ulceration, pattern of invasive growth, and presence of large round cells resulted in greatly improved discrimination between metastasized and non-metastasized cases. It is anticipated that this method could allow for precise individual prognostic characterization and in particular for identification of high-risk patients for adjuvant therapy.     

Clinical, histological and quantitative prognostic factors in cutaneous malignant melanoma.

A retrospective study including 55 cutaneous melanoma patients with 9.5 years follow-up was carried out to assess the significance of various prognostic factors. The histological samples were evaluated according to Clark's and Breslow's classifications and six nuclear features were measured by interactive morphometry. Mitotic activity was assessed by two different methods: mitotic activity index (MAI) and volume corrected mitotic index (M/V index). The overall disease-related five-year survival of patients was 76.4%. TNM stage (p = 0.0001), sex (p = 0.0024), M/V index (p = 0.003), standard deviation of nuclear form factor (p = 0.023), MAI (p = 0.02), shortest nuclear axis (p = 0.023) and Breslow's classification (p = 0.044) predicted survival in univariate analysis. A multivariate analysis including clinical, histological and morphometric features pointed the Clark's classification as the most important predictor of survival (p = 0.002), while the other variables included had no independent prognostic value. The prognostic importance of mitotic indices and morphometric features is clearly a subject for further studies in superficial melanomas.     

Apolipoprotein D expression in cutaneous malignant melanoma

BACKGROUND AND OBJECTIVES: Apolipoprotein D (Apo D) is a protein component of the human plasma lipid transport system, and an androgen-regulated protein in both breast and prostate cancer cell lines. Our goal was to evaluate the expression of Apo D in malignant cutaneous melanomas, as well as to assess its possible relationship to clinical and pathological parameters. METHODS: Apo D expression was analyzed in 32 paraffin-embedded tissues from patients with invasive cutaneous malignant melanomas, in 8 samples from in situ melanoma, and in 10 samples from 10 benign lesions (4 dermal melanocytic nevi, 4 compound melanocytic nevi, and 2 dysplastic melanocytic nevi), using immunohistochemical techniques. RESULTS: The benign lesions were consistently negative for Apo D, whereas 3 of the 8 "in situ" melanomas (37.5%) and 12 of the 32 invasive melanomas (37.5%) showed positive immunostaining for Apo D. The percentage of Apo D-positive tumors was significantly higher in nodular than in superficial spreading melanomas (P = 0.011) and in melanomas with vertical growth phase than in melanomas with radial growth phase (P = 0.02). In addition, the percentage of Apo D-positive tumors was positively and significantly correlated with Clark's level of invasion (P = 0.046). CONCLUSIONS: Apo D may be a new prognostic factor of unfavorable evolution in cutaneous malignant melanoma.     

Loss of nuclear p16 protein expression correlates with increased tumor cell proliferation (Ki-67) and poor prognosis in patients with vertical growth phase melanoma.

The CDKN2A (p16INK4alpha) cell cycle-inhibitory gene has been associated with development of familial melanoma. Additionally, recent studies indicate that p16 alterations occur frequently in sporadic melanomas. To investigate whether differences in p16 expression are associated with tumor cell proliferation, tumor progression, and patient survival, we examined the immunohistochemical staining of p16 protein in a consecutive series of 202 vertical growth phase melanomas and 68 corresponding metastases and compared the results with Ki-67 expression, p53 expression, clinicopathological variables, and survival data. Forty-five percent of the primary tumors showed absent or minimal nuclear staining for p16 protein. These cases were significantly associated with high Ki-67 expression (P < 0.0001), ulceration (P = 0.001), and vascular invasion (P = 0.03). Further loss of p16 expression was observed in metastatic lesions (77% were negative; P < 0.0001). Absent/minimal nuclear p16 staining significantly predicted poor patient survival (log-rank test, P = 0.0003), with 37% and 67% estimated 10-year survival rates for cases with absent or present p16 expression, respectively. In multivariate analysis, p16 staining was an independent prognostic factor (hazard ratio, 2.5; 95% confidence interval, 1.5-4.2; P = 0.0008), along with p53 expression, Ki-67 expression, anatomical site, Clark's level of invasion, and vascular invasion. Our findings indicate that loss of nuclear p16 protein expression in vertical growth phase melanomas is associated with increased tumor cell proliferation (Ki-67) and independently predicts decreased patient survival. Cases without p53 expression had improved survival.     

Expression of CD44s and CD44 splice variants in human melanoma.

The ability of tumor cells to adhere and detach from extracellular matrix and endothelial cells, is a crucial step in the metastatic process and may alter the clinical prognosis of some human tumors such as melanomas. CD44, the major cell surface receptor for hyaluronate, has been implicated in cell adhesion and in tumor progression. We studied the expression of standard CD44 molecule (CD44s) and its variants v3 and v6 in 57 human primary melanoma biopsies, without previous treatment. We analyzed the association between CD44 expression and the principal clinicopathological features, including survival. Fifty-six of 57 tumors expressed CD44s, associated to the cytoplasmic membrane. No expression of CD44v3 or CD44v6 was detected. No association between CD44s expression and prognostic factors such as tumor thickness, growth type, stage or anatomic site of the lesion was found. However, a positive correlation between CD44s expression and Clark level (Spearman, p<0.001) was found. While only 33.3% of melanomas Clark I + II showed high expression of CD44s (more than 50% of positive cells), 82.6% of melanomas Clark IV + V did so. Kaplan-Meier analysis revelead that patients whose melanomas had high expression of CD44s showed a reduced relapse free survival (RFS) rate, though without statistical significance. No difference between the level of CD44 expression and overall survival (OS) was found. We conclude that melanomas only expressed CD44s, and that its level was associated with Clark's stage. CD44s seems not to be useful as a tumor marker, because it does not predict either RFS or OS.     

Morphometric,DNA and PCNA in thin malignant melanomas

Morphometric assessment of nuclear area, shape and density, nucleolar area, analysis of DNA content and expression of proliferating cell nuclear antigen (PCNA) was performed in a case control study of 72 malignant melanomas, thickness ≤0.8 mm and Clark level II-IIL Twenty-four thin metastasizing melanomas (TMM) were individually compared to two thin non-metastasizing melanomas (TNM) after individual matching for site of primary tumor, tumor thickness, level of invasion, tumor regression and duration of follow-up. Conditional logistic regression analysis with maximum likelihood estimates showed significant differences between TMM and TNM with regard to the nuclear correlation coefficient (p = 0.005), standard deviation of nuclear shape NCI(p = 0.017), and nuclear density (p=0.030), indicating that thin melanomas with pleomorphic and possibly densely packed nuclei are associated with recurrence. No significant differences were found regarding nuclear or nucleolar area, mean nuclear shape NCI, nuclear DNA content or expression of PCNA.     

Prognostic significance of periodic acid-Schiff-positive patterns in primary cutaneous melanoma.

The patterns of periodic acid-Schiff (PAS) staining of extracellular matrix in histological sections of certain melanomas may be predictive of outcome. Recent in vitro and molecular genetic data suggest that the appearance of these patterns in both uveal and cutaneous melanoma is a function of aggressive tumor cells. We studied 96 patients with primary cutaneous melanomas treated at the University of Illinois at Chicago who were monitored for disease-free survival. Survival probabilities were determined by Kaplan-Meier estimates, and prognostic factors were evaluated by multivariate analysis. By univariate analysis, there was a significant decrease in disease-free survival among patients whose tumors contained parallel with cross-linking or network patterns (PXNs; P = 0.0070). Stepwise regression with Cox models that included the combinations of the PAS-positive patterns, tumor thickness, female gender, ulceration, and age yielded a model with thickness and the PAS-positive parallel with cross-linking or networks. Despite the relatively small sample size in this study, the detection of the PAS-positive parallel with cross-linking or networking in cutaneous melanoma was associated with a decrease in disease-free outcome. Additional studies of the prognostic significance of these patterns is warranted on larger data sets.     

Molecular prognostic markers in intermediate-thickness cutaneous malignant melanoma

BACKGROUND: The limitations of morphologic criteria alone in determining the prognosis for a patient with a particular intermediate-thickness primary melanoma have prompted efforts to identify other markers. METHODS: In this study, the authors analyzed expression of p53, beta1 integrin, and beta3 integrin in primary tumors from 111 patients with intermediate-thickness malignant melanoma. RESULTS: Eighty-nine (80%) had detectable p53 protein, 58 (52%) expressed beta1 integrin, and 71 (64%) expressed beta3 integrin. Patients with beta3 positive melanomas were more likely to die of their disease (32 of 71 patients, 45%) than those with beta3 negative tumors (3 of 40 patients, 8%) (P < 0.0001). The number of involved lymph nodes, Clark's level, beta1 integrin expression, thickness, and mitotic rate also had prognostic significance. beta3 integrin was associated with subsequent lung metastases and beta1 integrin with lymph node involvement. CONCLUSIONS: Integrin expression, along with histopathologic criteria, is a prognostic marker for intermediate-thickness malignant melanoma and may indicate the site of subsequent metastasis. These observations may have clinical utility and suggest areas for future investigation.     

CEACAM1 expression in cutaneous malignant melanoma predicts the development of metastatic disease.

PURPOSE: The cell adhesion molecule CEACAM1 is involved in intercellular adhesion and subsequent signal transduction events in a number of epithelia. CEACAM1 downregulation has been demonstrated in colorectal and prostate carcinomas. This study sought to analyze whether its expression in malignant melanoma is associated with metastasis. PATIENTS AND METHODS: CEACAM1 expression was immunohistochemically evaluated in 100 primary cutaneous malignant melanomas and correlated with metastasis in a 10-year follow-up. Furthermore, CEACAM1 expression was analyzed in metastatic lesions (11 distant metastases and six sentinel lymph node metastases). Univariate Kaplan-Meier analysis and multivariate Cox proportional hazard regression analysis adjusted for standard prognostic indicators were performed to assess the prognostic relevance of CEACAM1 expression. RESULTS: A total of 28 of 40 patients with CEACAM1-positive primary melanomas developed metastatic disease, compared with only six of 60 patients with CEACAM1-negative melanomas. Often, the strongest CEACAM1 expression was observed at the invading front. In addition, CEACAM1 expression was preserved in the metastatic lesions. Kaplan-Meier analysis revealed a highly significant association between CEACAM1 expression and metastasis (P <.0001); multivariate Cox regression analysis, including CEACAM1 expression status adjusted for tumor thickness, presence of ulceration, and mitotic rate, confirmed that CEACAM1 is an independent factor for the risk of metastasis and demonstrated that the predictive value of CEACAM1 expression is superior to that of tumor thickness. CONCLUSION: Expression of the cell adhesion molecule CEACAM1 in the primary tumors in melanoma patients is associated with the subsequent development of metastatic disease. This raises the possibility of a functional role for this cell adhesion molecule in the metastatic spread it indicates.     

Invasive cutaneous malignant melanoma in Sweden, 1990-1999. A prospective, population-based study of survival and prognostic factors

BACKGROUND: The objective of the current study was to compile prospective, population-based data on cutaneous invasive melanomas in Sweden during the period from 1990 to 1999, to describe and analyze survival data and prognostic factors, and to make comparisons with previously published Swedish and international data. METHODS: Twelve thousand five hundred thirty-three patients, which included 97% of all registered melanomas in Sweden, were included and described. Among these, 9515 patients with clinical Stage I and II melanoma were included in an analysis of survival and in a univariate analysis, and 6191 patients were included in a multivariate analysis of prognostic factors. RESULTS: There was no significant change in melanoma incidence during 1990-1999. Favorable prognostic factors were found, especially in younger and female patients, resulting in a relative 5-year survival rate of 91.5%. In the multivariate analysis, significant factors that had a negative effect on survival were Clark level of invasion, Breslow thickness, ulceration, older patient age, trunk location, greatest tumor dimension, nodular histogenetic type, and male gender. CONCLUSIONS: During the period from 1990 to 1999, the 5-year survival of patients with malignant melanoma in Sweden was better compared with the previously reported rates in published, population-based studies from Sweden, probably as a result of better secondary prevention due to better knowledge and awareness by both patients and the medical profession. The more favorable prognostic factors and the change in melanoma location found in younger patients, compared with earlier reports, may reflect changes in clothing as well as tanning habits; however, a decrease also was found in Clark Level II and thin melanomas for the same patient group. The authors concluded that further improvements can be achieved with better access to health care and with the use of early melanoma detection campaigns.     

Beclin-1 and LC3A expression in cutaneous malignant melanomas: a biphasic survival pattern for beclin-1

Autophagy is an intracellular pathway for the degradation of long-lived proteins and damaged organelles. It is, in essence, a recycling process allowing cells to survive oxygen and nutrient depletion. The expression of two autophagy-related proteins, beclin 1 and light chain 3A (LC3A) was investigated in 79 nodular cutaneous melanomas. The results were correlated with histopathological factors, vascular density, and hypoxia-related proteins [hypoxia-inducible factors (HIF1α and HIF2α) and lactate dehydrogenase 5]. The reactivity of both autophagy-related proteins was uniformly cytoplasmically diffused. High beclin 1 and LC3A reactivity was related to tumor hypoxia, as this was inferred from the intense expression of HIF1α and lactate dehydrogenase 5, whereas low beclin 1 and LC3A expression was linked with an increased vascular density. In addition, beclin 1 was related to disease-specific survival which, however, exposed a biphasic pattern. A strong beclin 1 expression extending over a tumor area of more than 50% (high) was associated with an increased rate of early deaths, whereas a similarly strong, but less-extensive cytoplasmic reactivity (<10% tumor area; low) defined a sharp fall in the survival 5 years after surgery. Furthermore, the low beclin 1 expression was associated with high Breslow's depth, high Clark's level, and ulceration. Low LC3A expression was also related to ulceration, but not to other histopathological features nor prognosis. In multivariate analysis, beclin 1 was an independent prognostic variable. It is concluded that extensive autophagic activity is generated by tumor hypoxia and anaerobic glycolysis, whereas angiogenesis maintains low autophagic activity. Atg6/beclin 1 was proved to be capable of deciphering the prognosis in cutaneous malignant melanoma, but the matter requires further investigation.     

Comparison between lentigo maligna melanoma and other histogenetic types of malignant melanoma of the head and neck. Scottish Melanoma Group.

A study of 953 invasive cutaneous malignant melanomas of the head and neck was performed to determine differences between lentigo maligna melanoma and other histogenetic types with regard to patients and sites affected; prognosis was analysed in 595 of these cases. The cases studied comprised all head and neck melanomas registered with the Scottish Melanoma Group between 1979 and 1992, apart from the 3% of cases that were unclassifiable or rare histogenetic types. The histogenetic types of melanoma were 498 (52%) lentigo maligna melanoma (LMM), 237 (25%) superficial spreading melanoma (SSM) and 218 (23%) nodular melanoma (NM). All types increased in incidence throughout the study period. Patients with LMM (mean age 73 years) and NM (mean 68 years) were significantly older than those with SSM (mean 57 years). There were significant anatomical subsite differences related to sex of patients and histogenetic type of melanoma; melanomas on the face were more frequent in females and 90% of LMM occurred at this site, whereas melanomas on the scalp, neck and ears were more frequent in men. Kaplan-Meier estimates of the probability of survival were produced for the 595 of these 953 patients with 5 year follow-up details. In this group of patients the prognostic significance of tumour thickness, Clark level of invasion, ulceration, histogenetic type of melanoma and number of mitoses were studied using stepwise variable selection of procedures. Each of these possible prognostic factors attained individual significance but the tumour thickness was the dominant risk factor in the proportional hazards analysis. When patients were divided into four sex/ulceration subgroups (male/ulcerated, female/ulcerated, male/non-ulcerated, female/non-ulcerated) and analysed by proportional hazards analysis, no variable other than the tumour thickness had any further prognostic effect. Histogenetic type did not remain an independent prognostic variable at this stage. Despite sex and subsite differences, the prognosis for invasive lentigo maligna melanoma does not differ from that for other histogenetic types after controlling for tumour thickness.     

Sentinel node biopsy in cutaneous melanoma: correlations between melanoma prognostic factors and sentinel node status

This study aims to correlate the most important prognostic factors of primary melanoma with sentinel node (SN) positive for metastases. We have enrolled 84 patients subjected to sentinel node biopsies for cutaneous melanomas of Breslow's thickness > or = 0.75 mm by using an intra-operative gamma probe after lymphoscintigraphy, without blue dye support. SN metastases were reported in 27% of cases (14% by histology and 13% by immunohistochemistry). By chi-square test Breslow's thickness > 2mm (p= 0.004), IV and V Clark's level (p= 0.02), ulceration (p= 0.05) and high mitotic rate (p= 0.05) were statistically significant (p < 0.05) with reference to SN positive for metastases, unlike the site of cutaneous melanoma, vertical growth phase, tumour infiltrating lymphocytes, regression and vascular invasion. Breslow's thickness remains the first prognostic factor to be considered for sentinel node biopsy in cutaneous melanoma, but other markers must be carefully estimated.     

Stereologic estimates of nuclear volume in noninvasive bladder tumors (Ta) correlated with the recurrence pattern

The mean nuclear volume of cells in bladder tumors was estimated using the principle for estimation of the volume of particles of arbitrary shape. The study included three groups of patients: one group of 10 patients with only one nonrecurrent, noninvasive bladder tumor (Ta), another group of 11 patients with recurrent noninvasive bladder tumors, and a third group of 14 patients with recurrent primary noninvasive bladder tumors who ultimately developed an invasive tumor. After standard fixation, embedding, sectioning, and hematoxylin-eosin staining an unbiased estimate of the mean volume of nuclei sampled with a chance proportional to their volume was calculated: nu v = pi/3.l3(0). Here lo is the length of the intercept through a test point hitting a nucleus measured in a random direction through the test point. In the primary tumor the mean, nuclear volume of the cells in tumors from patients with a single bladder tumor is small (141 micrograms 3 geometric mean) with only one of ten above 165 microns 3. The mean nuclear volume of the primary tumor cells in patients with recurrent noninvasive bladder tumors was slightly larger (195 microns 3 geometric mean) with five of 11 above 165 microns 3. The mean nuclear volume of the primary tumor cells in patients who ended up with invasive tumors was higher (245 microns 3 geometric mean) with 12 of 14 above 165 microns 3. A large mean nuclear volume of cells in noninvasive bladder tumors (Ta) indicates recurrence and an invasive potential. Considering that nearly all primary tumors were classified as Bergkvist Grade II tumors, the prognostic precision of absolute mean nuclear volume is noticeable. This simple and fast estimate of mean nuclear volume seems to provide objective data with high prognostic value in primary noninvasive bladder tumors (Ta).     

Clinical and pathologic diagnosis, staging and prognostic factors of melanoma and management of primary disease.

To increase detection of melanoma, medical practitioners and the general public should know the signs of early invasive melanoma. The Scottish Melanoma Group recently presented a revised checklist of the major and minor signs. The validity of the reported clinical and histopathologic criteria for the dysplastic nevus, a precursor to cutaneous melanoma, is not fully established. However, expert pathologists agreed on the use of major and minor criteria. The differential diagnosis between spindle-epitheloid cell nevi and melanoma remains problematic, because the former lesions often show cellular atypia. Other lesions that can cause considerable diagnostic difficulties are melanoma in situ and minimal-deviation melanoma. Immunohistochemical studies of human melanocytic lesions have contributed to the diagnosis of poorly differentiated tumors but, so far, have not helped in the discrimination among benign, premalignant, and malignant lesions. They have provided additional prognostic information in cases of primary melanoma and locoregional melanoma metastasis. Quality control of antibody reagents continues to be a problem. Microstaging of primary melanoma using Breslow depth and Clark's level of invasion may be subject to considerable intra- and interobserver variation. To improve the accuracy of the measurements, using a vernier scale is recommended. The type of melanoma is relevant in considering clinicopathologic prognostic factors. Acral melanoma (for example, that arise from glabrous skin) has been reported to carry a grave prognosis. Polypoid melanoma may have a less unfavorable outlook than previously thought. DNA cytophotometry provides prognostic information in case of primary melanoma but loses significance when stratified for tumor thickness. In patients with lymph node-positive melanoma, however, DNA ploidy analysis appears to yield additional prognostic information. In the management of primary disease, the width of the surgical excision and whether to approach the regional lymph nodes remain the main issues. A multicenter study conducted by the World Health Organization Melanoma Programme has found that a "narrow" excision is a safe procedure for primary melanomas not thicker than 1 mm. Several investigators underline the need for continued annual follow-up for all melanoma patients; recurrence may occur late. Currently, elective lymph node dissection is not recommended in the management of "thick" primary melanoma. Because data from randomized trials conducted in patients with a tumor of intermediate thickness are not yet available, only guidelines on management offered by experienced surgeons can be given. Patients with the dysplastic nevus syndrome should be closely followed so that melanomas can be diagnosed as early as possible.     

The changing importance of prognostic factors in breast cancer during long-term follow-up.

A cohort of 464 breast-cancer patients were followed up for over 10 years and the clinical, histological and morphometric factors were related to survival within different time periods during follow-up. Tumor diameter, axillary lymph-node status (pN), tubule formation and the fraction of intraductal growth as determined from the primary tumor biopsy specimen had prognostic value up to 5 years. Histological grade, morphometric nuclear factors and the M/V index had only short-term prognostic value immediately after the primary therapy. In axillary lymph-node-negative (ANN) tumors tubule formation, intraductal growth, tumor necrosis and tumor diameter had prognostic value during the first 3 postoperative years. In axillary lymph-node-positive (ANP) tumors, tumor diameter, intraductal growth and tubule formation had long-term prognostic value whereas the M/V index had prognostic value only for 1 postoperative year. Tumor diameter, axillary lymph-node status, tubule formation and the proportion of intraductal growth also had independent long-term prognostic value in a multivariate analysis and accordingly these factors can categorize breast-cancer patients into prognostic groups after several years of follow-up. In contrast, mitotic frequency loses its prognostic power within 2 postoperative years, while morphometric nuclear factors and histological grade have no practical prognostic value after 1 year of follow-up.     

Interrelationship between histopathologic characteristics of melanoma and estrogen receptor status

To evaluate whether the increase in disease-free survival and survival previously reported for women with melanomas with estrogen receptors (ER) was a reflection of the histopathology of the primary melanoma, the interrelationship of histopathologic characteristics of 143 patients with such tumors was examined. The ER was assayed in the primary tumor from 44 patients and in 99 metastatic deposits from the other patients. Tumor thickness, level of invasion, prognostic index, mitoses/mm2, ulceration, vascular invasion, necrosis, histologic grade, preexisting nevus, and predominant malignant cell type were examined. There was no relationship between ER presence and any histopathologic characteristic examined, irrespective of the tumor source (primary or metastatic). Examination of histopathologic characteristics as a function of sex and receptor status showed a slight but insignificant predominance of more well-differentiated, thinner tumors in women whose lesions were positive for the ER. These results suggest that the increased disease-free survival in patients with ER-positive lesions is not attributable to the pathologic characteristics of the primary tumor examined during this study.     

Thin cutaneous malignant melanomas (< or =1.5 mm): identification of risk factors indicative of progression

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 < or = 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 > or = 50% (P = 0.03), (T+R)/S ratio > or = 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.