Tumor thickness and prognosis in clinical stage I malignant melanoma

Clinicopathologic Features of Cutaneous Malignant Melanoma and Their Impact on Prognosis

Introduction: Melanoma ranks 19th among malignancies overall and second among cutaneous types. The incidence worldwide has been on the rise over the last seven decades. Various prognostic factors have been assessed and found to have a profound impact on patient outcome. However, no such studies have been attempted in our population. Our study aimed to have an insight into the behavior of malignant melanoma in our population.

Materials and Methods: Cases of cutaneous malignant melanoma treated and followed up at our institute were included in this study. Cases of mucosal and choroidal melanoma were excluded. The parameters noted were age, gender, tumor thickness, Clark level, and presence of ulceration. These parameters were individually correlated with development of distant metastasis, two-year survival, survival duration, and primary tumor and lymph node stage. Appropriate statistical analyses were done.

Results: Thirty patients of cutaneous malignant melanomas were treated and followed up at our institution. There was male predilection of 1:1.5. Mean age at diagnosis was 50.1 years. Two-year survival was significantly better in females. Sun-exposed areas of the skin were most commonly involved followed by anal canal that has an unusually high incidence in our society. Majority of our cases were pT4(25) on tumor, nodal status, metastasis (TNM) staging at time of diagnosis. Increasing tumor thickness in terms of primary tumor staging was not found to have any significant impact on two-year survival, distant metastasis, lymph node stage, or survival duration. Sixty percent of cases had ulceration. There was no statistically significant effect on two-year survival (78% in ulcerated group vs 75% in nonulcerated group) and distant metastasis (61% vs 58.3%). In terms of Clark level, 20 cases were level V, seven cases were level IV, two were level III, and one was level I. There was no statistically significant difference between the Clark levels in terms of two years survival, development of distant metastasis, and lymph node stages.

Conclusion: Melanoma is an aggressive malignancy that causes high morbidity and morality. It commonly presents at an advanced stage at time of diagnosis in our population. Broader studies are required with early-stage melanomas to compare the various prognostic factors and their impact on prognosis.

Discordance of histopathologic parameters in cutaneous melanoma: Clinical implications

BACKGROUND

Histopathologic analysis remains the gold standard for the diagnosis of melanoma, however previous studies have shown a substantial rate of interobserver variability in the evaluation of melanocytic lesions.

OBJECTIVE

We sought to evaluate discordance in the histopathological diagnosis and microstaging parameters of melanoma and subsequent impact on clinical management.

METHODS

This was a retrospective review of 588 cases of cutaneous melanoma and melanoma in situ from January 2009 to December 2014 that were referred to Emory University Hospital, Atlanta, GA, for treatment. Per institutional policy, all outside melanoma biopsy specimens were reviewed internally. Outside and institutional reports were compared.

RESULTS

Disagreement between outside and internal reports resulted in a change in American Joint Committee on Cancer pathologic stage in 114/588 (19%) cases, resulting in a change in management based on National Comprehensive Cancer Network guidelines in 105/588 (18%) cases.

LIMITATIONS

Given the retrospective nature of data collection and the bias of a tertiary care referral center, cases in this study may not be representative of all melanoma diagnoses.

CONCLUSION

These findings confirm consistent subjectivity in the histopathologic interpretation of melanoma. This study emphasizes that a review of the primary biopsy specimen may lead to significant changes in tumor classification, resulting in meaningful changes in clinical management.

Public health engagement: detection of suspicious skin lesions, screening and referral behaviour of UK based chiropractors

BACKGROUND

UK morbidity and mortality rates from skin cancer are increasing despite existing preventative strategies involving education and early detection. Manual therapists are ideally placed to support these goals as they see greater quantities of exposed patient skin more often than most other healthcare professionals. The purpose of this study therefore was to ascertain the ability of manual therapists to detect, screen and refer suspicious skin lesions.

METHOD

A web-based questionnaire and quiz was used in a sample of UK chiropractic student clinicians and registered chiropractors to gather data during 2011 concerning skin screening and referral behaviors for suspicious skin lesions.

RESULTS

A total of 120 questionnaires were included. Eighty one percent of participants agreed that screening for suspicious skin lesions was part of their clinical role, with nearly all (94%) assessing their patients for lesions during examination. Over 90% of the participants reported regularly having the opportunity for skin examination; with nearly all (98%) agreeing they would refer patients with suspicious skin lesions to a medical practitioner. A third of respondents had referred a total of 80 suspicious lesions within the last 12 months with 67% warranting further investigation.

CONCLUSIONS

Nearly all respondents agreed that screening patients for suspicious skin lesions was part of their clinical role, with a significant number already referring patients with lesions.

Melanoma prognostic factors found in the dermatopathology report

Significant prognostic information is available in a routine melanoma dermatopathology report. Features that are enumerated in the pathology report and that portend a potentially poorer prognosis are older age, site (acral, head, neck), male sex, increasing Breslow tumor thickness, increasing Clark's level, ulceration, increasing number of mitoses, vertical growth phase, regression, absence of a host inflammatory response, increased tumor vascularity, angiotropism, vascular invasion, neurotropism, marked atypia, and satellite metastasis.

Epidemiology of malignant melanoma in central Europe: risk factors and prognostic predictors. Results of the Central Malignant Melanoma Registry of the German Dermatological Society

The Central Malignant Melanoma Registry (CMMR) of the German Dermatological Society was established in 1983, and 7789 cutaneous malignant melanomas (CMM) were registered by 35 dermatological departments in Germany, Austria and Switzerland until the end of 1989. Population-based incidence rates, risk factors for developing CMM and prognostic parameters for predicting the final outcome were investigated in separate multicenter studies performed by the CMMR. Among the 7789 CMM registered, there was a preponderance of females (57.7%) versus males (42.3%). The age distribution peaked in the 5th and 6th decade of life for both sexes with a mean age of 52 years. The mean detection age was 50 years for superficial spreading melanoma, 53 for nodular melanoma, and 65 for lentigo maligna melanoma. Mean tumor thickness decreased from 2 mm in 1983 to 1.5 mm in 1989, indicating better CMM-awareness of the population and the medical community in this area. 90% of the patients presented with clinical stage I CMM without detectable metastases at first diagnosis. The incidence of CMM in Berlin (West) was assessed based on 960 cases diagnosed between 1980 and 1986. The incidence increased by 49% between 1980-81 and 1985-86, and the age standardized-incidence rate (European standard population) was 9.8 for males and 7.8 for females per 100,000 inhabitants and year in 1985-86. Mortality rates decreased in this period from 3.5 to 2.6 for males and slightly increased for females from 1.2 to 1.6 per 100,000 inhabitants and year. A case control study on the relative risk (RR) for developing CMM revealed the total number of melanocytic nevi (MCN) to be the strongest risk predictor (15x -50x increased RR), followed by the presence of dysplastic MCN (7x increased RR) and the skin type I (2x increased RR). Interestingly, no differences between CMM-cases and controls were found with respect to the history of sunburns or other parameters of sun exposure in this study. Multivariate analysis of 5093 stage I CMM-patients from four departments with long-term follow-up revealed that tumor thickness is the strongest predictor of survival with an almost linear correlation to the risk of death for tumor thickness up to 6 mm with no further increase in mortality for higher tumor thickness. The best classification of tumor thickness for survival prediction was less than or equal to 1 mm, 1.01-2 mm, 2.01-4 mm and greater than 4 mm in our data set on 5093 patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Gender differences in skin: a review of the literature

BACKGROUND

There has been increasing interest in studying gender differences in skin to learn more about disease pathogenesis and to discover more effective treatments. Recent advances have been made in our understanding of these differences in skin histology, physiology, and immunology, and they have implications for diseases such as acne, eczema, alopecia, skin cancer, wound healing, and rheumatologic diseases with skin manifestations.

OBJECTIVE

This article reviews advances in our understanding of gender differences in skin.

METHODS

Using the PubMed database, broad searches for topics, with search terms such as gender differences in skin and sex differences in skin, as well as targeted searches for gender differences in specific dermatologic diseases, such as gender differences in melanoma, were performed. Additional articles were identified from cited references. Articles reporting gender differences in the following areas were reviewed: acne, skin cancer, wound healing, immunology, hair/alopecia, histology and skin physiology, disease-specific gender differences, and psychological responses to disease burden.

RESULTS

A recurring theme encountered in many of the articles reviewed referred to a delicate balance between normal and pathogenic conditions. This theme is highlighted by the complex interplay between estrogens and androgens in men and women, and how changes and adaptations with aging affect the disease process. Sex steroids modulate epidermal and dermal thickness as well as immune system function, and changes in these hormonal levels with aging and/or disease processes alter skin surface pH, quality of wound healing, and propensity to develop autoimmune disease, thereby significantly influencing potential for infection and other disease states. Gender differences in alopecia, acne, and skin cancers also distinguish hormonal interactions as a major target for which more research is needed to translate current findings to clinically significant diagnostic and therapeutic applications.

CONCLUSIONS

The published findings on gender differences in skin yielded many advances in our understanding of cancer, immunology, psychology, skin histology, and specific dermatologic diseases. These advances will enable us to learn more about disease pathogenesis, with the goal of offering better treatments. Although gender differences can help us to individually tailor clinical management of disease processes, it is important to remember that a patient's sex should not radically alter diagnostic or therapeutic efforts until clinically significant differences between males and females arise from these findings. Because many of the results reviewed did not originate from randomized controlled clinical trials, it is difficult to generalize the data to the general population. However, the pressing need for additional research in these areas becomes exceedingly clear, and there is already a strong foundation on which to base future investigations.

Gender-related differences in outcome for melanoma patients

OBJECTIVE

To better understand the factors associated with the well-established gender difference in survival for patients with melanoma.

SUMMARY BACKGROUND DATA

Gender is an important factor in patients with cutaneous melanoma. Male patients have a worse outcome when compared with females. The reasons for this difference are poorly understood.

METHODS

This prospective multi-institutional study included patients aged 18 to 70 years with melanomas > or =1.0 mm Breslow thickness. Wide excision and sentinel lymph node (SLN) biopsy was performed in all patients. Clinicopathologic factors, including gender, were assessed and correlated with disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS).

RESULTS

A total of 3324 patients were included in the covariate analyses; 1829 patients had follow-up data available and were included in the survival analyses. Median follow-up was 30 months. On univariate analysis, men (n = 1906) were more likely than women to be older than 60 years (P < 0.0001), have thicker melanomas (P < 0.0001), have primary tumor regression (P = 0.0054), ulceration (P < 0.0001), and axial primary tumor location (P < 0.0001). On multivariate analysis, age (P = 0.0002), thickness (P < 0.0001), ulceration (P = 0.015), and location (P < 0.0001) remained significant in the model. There was no difference in the rate of SLN metastasis between men and women (P = 0.37) on multivariate analysis. When factors affecting survival were considered, the prognosis was worse for men as validated by lower DFS (P = 0.0005), DDFS (P < 0.0001), and OS (P < 0.0001).

CONCLUSIONS

Male gender is associated with a greater incidence of unfavorable primary tumor characteristics without an increased risk for nodal metastasis. Nonetheless, gender is an independent factor affecting survival.

Clinical significance of occult metastatic melanoma in sentinel lymph nodes and other high-risk factors based on long-term follow-up

Selective sentinel lymphadenectomy (SSL) following preoperative lymphoscintigraphy is the most significant recent advance in the management of patients with primary melanoma. This study evaluates the prognostic value of sentinel lymph node (SLN) status and other risk factors in predicting survival and recurrence in patients with primary cutaneous melanoma. From October 1993 to July 1998 a series of 412 patients with primary invasive melanoma underwent SSL at the UCSF/ Mt. Zion Melanoma Center. The outcome of 363 evaluable patients is summarized in this study. The factors related to survival and disease recurrence were analyzed by Cox proportional hazard regression models. The overall incidence of patients with positive SLNs was 18%. Over a median follow-up of 4.8 years, the overall mortality rate in patients with primary cutaneous melanoma was 18.7%, and 74 recurrences occurred (20.4%). Mortality was significantly related to SLN status [HR = 2.06; 95% Confidence interval (CI) 1.18, 3.58], angiolymphatic invasion (HR = 2.21; 95% CI 1.08, 4.55), ulceration (HR = 1.79; 95% CI 1.02, 3.15), mitotic index (HR =1.38; 95% CI 1.01, 1.90), and tumor thickness (HR = 2.20, 95% CI 1.21, 3.99). Factors significantly related to disease-free survival included SLN status (HR = 2.09; 95% CI 1.31, 3.34), tumor thickness (HR = 1.89; 95%. CI 1.20,2.98), and age (HR= 1.26 95% CI 1.08, 1.47). SLN status was the most significant factor for melanoma recurrence and death. Other important predictors include tumor thickness, ulceration, lymphatic invasion, and mitotic index.

Adjuvant therapies in the treatment of stage II and III malignant melanoma

BACKGROUND

The incidence of cutaneous melanoma has increased during the past three decades. The development of sentinel lymph node biopsy has facilitated better staging. Despite these improvements, 5-year survival rates for American Joint Committee on Cancer stage II and III disease range from 50%-90%.

METHODS

A review of the current literature concerning adjuvant therapies in patients with stage II and III malignant melanomas was undertaken.

RESULTS

The focus of adjuvant therapies has shifted from radiotherapy, BCG and levamisole to newer biological agents. Interferon, interleukin and vaccines have been evaluated but none of these agents have demonstrated an increase in overall survival in patients with stage II and III melanoma. Interferon can prolong disease-free interval.

CONCLUSION

At present, no adjuvant therapy improves overall survival in patients with stage II and III melanoma. New staging allows more accurate stratification of patients for clinical trials.

New TNM melanoma staging system: linking biology and natural history to clinical outcomes

The American Joint Committee on Cancer (AJCC) implemented major revisions of the melanoma TNM and stage grouping criteria in the recently published 6th edition of the Staging Manual. The new staging system better reflects independent prognostic factors that are used in clinical trials and in reporting the outcomes of various melanoma treatment modalities. Major revisions include: 1) melanoma thickness and ulceration but not level of invasion to be used in the T classification, 2) the number of metastatic lymph nodes rather than their gross dimensions and the delineation of microscopic vs. macroscopic nodal metastases to be used in the N classification, 3) the site of distant metastases and the presence of elevated serum lactic dehydrogenase (LDH) to be used in the M classification, 4) an upstaging of all patients with Stage I, II, and III disease when a primary melanoma is ulcerated, 5) a merging of satellite metastases around a primary melanoma and in transit metastases into a single staging entity that is grouped into Stage III disease, and 6) a new convention for defining clinical and pathological staging so as to take into account the new staging information gained from intraoperative lymphatic mapping and sentinel node biopsy.

Prognosis for patients with thin cutaneous melanoma: long-term survival data from New South Wales Central Cancer Registry and the Sydney Melanoma Unit

BACKGROUND

Estimates of long-term survival for patients with thin (< or = 1 mm) primary cutaneous melanomas vary widely. Two separate methods were used to study the survival of patients with melanoma from New South Wales (NSW), Australia, and from the Sydney Melanoma Unit (SMU).

METHODS

The NSW Central Cancer Registry (NSWCCR) provided data on all patients who were diagnosed with cutaneous melanomas that measured < or = 1 mm thick between 1983 and 1998, inclusive. Patients with metastases at the time of diagnosis were not included, leaving 18,088 patients for analysis. The SMU data base was analyzed to extract data for all patients with thin melanomas who met the same criteria from 1979 to 1998, inclusive. All patients who had their primary tumors treated definitively elsewhere were excluded, leaving 2746 patients for analysis. Ten-year Kaplan-Meier survival rates were calculated, and significant differences were determined using log-rank analysis. Prognostic factors were evaluated with Cox proportional hazards analysis.

RESULTS

The NSWCCR analysis revealed a 10-year survival rate of 96.4%. The 10-year survival rate for patients at SMU was 92.7%. Among the patients at SMU who died, the median time to recurrence was 49.8 months, and the median time to death was 65.9 months. The 10-year survival for patients at SMU who had lesions that measured < or = 0.75 mm was 96.9% compared with 84.3% for patients who had lesions that measured 0.76-1.0 mm. For patients who had ulcerated melanomas measuring < or = 1 mm thick, the 10-year survival rate was 83%, compared with 92.3% for patients who had nonulcerated melanomas.

CONCLUSIONS

The results of the current study confirmed the excellent survival rate for patients with thin melanomas. Higher-risk subsets of patients who may warrant consideration for aggressive investigation and treatment are identifiable.

The long-term clinical course of patients with cutaneous melanoma

BACKGROUND

The clinical course of cutaneous melanoma is associated with pathologic and clinical factors, such as thickness, ulceration, and location of tumor and gender of the patient. The authors used a parametric survival model that incorporated a cured fraction of patients to translate these factors into specific estimates of long-term outcome.

METHODS

A cohort study was conducted of 5837 patients who were treated for localized cutaneous melanoma between 1978 and 1990 at the Duke Comprehensive Cancer Center. Of these, 495 patients were excluded because the survival status or one or more of the prognostic factors was unknown. Maximum follow-up was 22 years. The primary outcome measures examined were cured fraction (probability of cure), median tumor specific survival (i.e., median time to death from tumor), and the probability of tumor-related survival at fixed intervals after treatment.

RESULTS

For an example of a class of patients with a relatively good prognosis, consider women with nonulcerated lesions measuring 0.5 mm thick on an extremity. The probability of cure (+/- standard error) for these patients was estimated at 80.8% +/- 2.0%, and the median tumor specific survival was 10.0 years +/- 0.8 years. This suggests that, in these patients, half of the deaths from melanoma will occur more than 10 years after treatment, barring death from other causes. Conversely, men with ulcerated lesions measuring 8.00 mm thick on the trunk have a relatively poor prognosis. The probability of cure for these patients was 16.8% +/- 2.4%, and the median tumor specific survival was 2.7 years +/- 0.2 years. Despite this poor initial prognosis, the conditional probability of cure increased to 90%; after 15 years of recurrence free survival.

CONCLUSIONS

Parametric statistical analysis provides quantitative measures of long-term survival. These measures show that late recurrence-longer than a decade after treatment-is to be expected in a significant portion of patients, although the probability of cure increases with progressively longer recurrence free survival.

Testing a new staging system for cutaneous melanoma proposed by the American Joint Committee on Cancer

The American Joint Committee on Cancer (AJCC) recently proposed a new staging system for cutaneous melanoma. We tested its practicability and its prognostic value was compared with the currently used TNM classification. The data of 1976 melanoma patients were used for the testing. 1218 patients (61.6%) could be assigned to the proposed pT classification, 136 patients (90.1%) with lymph node metastases and/or in-transit metastases to the proposed pN classification and all 14 patients with distant metastases to the proposed pM classification. Proposed pathological staging was possible for 971 patients (49%). The number of pT1 patients (399 versus 230) and stage I patients (544 versus 393) was distinctly higher in the proposed classification. In proposed stage II and III groups, subgroups with different prognosis could be identified. The new staging system includes more detailed information on clinical and pathohistological findings. Nevertheless, it is practicable and enables more patients with excellent prognosis to be identified.

The new melanoma staging system

BACKGROUND

Classification schemas for cancers are useful for predicting overall survival and selecting patients for treatment. Historically, the most important factors in determining prognosis in patients with melanoma have been tumor thickness and lymph node status. Sentinel lymph node mapping defines a subset of patients with microscopic metastatic disease can be identified, offering greater accuracy in staging.

METHODS

The authors reviewed studies evaluating the prognostic factors that are significant in predicting survival in patients with melanoma. The newly revised American Joint Committee on Cancer (AJCC) staging system for melanoma is compared with the 1997 AJCC staging system currently in use.

RESULTS

The changes in the new AJCC melanoma staging system reflect the new prognostic factors that have been found to be important in predicting survival. These include primary tumor thickness (tumor depth in millimeters is more predictive than the level of invasion) and ulceration, number of metastatic lymph nodes, micrometastatic disease based on the sentinel lymph node biopsy technique or elective node dissection, the site(s) of distant metastatic disease and serum LDH levels.

CONCLUSIONS

Major revisions have been made to form a new AJCC staging system for melanoma, which will become official in 2002. This system will provide more accurate and precise information regarding patient prognosis. Validation studies are needed to confirm the accuracy of this revised staging system.

Compliance with follow-up and prognosis among patients with thin melanomas

The aim of this study was to report on the compliance with follow-up among patients with thin melanomas. We also examined the prognosis of patients with recurrent disease and whether there were any differences in prognosis associated with the time between the last follow-up examination and the onset of recurrence. A retrospective analysis of the records of 513 consecutive patients (50.3% males, mean age: 52.8+/-16.9 years) with thin melanomas (<1.5 mm Breslow thickness) was carried out. The estimated cumulative proportion of patients who still continued their follow-up examinations 5 years after diagnosis of the primary tumour was 55.3% (95% Confidence Interval (CI): 50.4--60.2%). The mean annual drop-out rate was 11.2%. The drop-out rate was similar for males and females and was not influenced by the patients' age or the tumour thickness. Among 263 patients who continued follow-up, 50.2% (n=132) were not compliant with the time schedule. 20 patients presented with recurrent disease after a median of 35.9 months (25--75% percentiles: 16.7--46.5 months). Six patients who did not have a follow-up examination within 1 year before the onset of recurrence presented with more advanced disease and had a worse prognosis (median survival: 12.5 months, hazard ratio: 3.5, 95% CI: 1.1--17.1, P=0.04), than those patients, who had a recent follow-up examination before the onset of recurrence (n=14, median survival: 22.3+ months). In the majority of recurrent cases with good prognosis, metastatic disease was confined to the regional lymph nodes and the presumptive diagnosis of metastatic disease was either made by palpation or by sonography of the regional lymph nodes. The observed drop-out rate of patients during the first 5 years of follow-up is substantial and does not depend on the patients' age, sex or on the tumour thickness. Although the frequency of recurrences among patients with thin melanomas is low, regular follow-up examinations including physical examination, as well as palpation and sonography of the regional lymph nodes, are essential.

Prognostic value of Ki-67 expression in localized cutaneous malignant melanoma

BACKGROUND

The proliferative activity of some tumors is related to the development of metastatic disease and survival. Thus it could be used as a potential prognostic variable.

OBJECTIVE

The purpose of this study was to determine the prognostic value of the Ki-67 index and of a "proliferation-based prognostic index" (PBPI, derived as tumor thickness x Ki-67 index/100) in localized cutaneous malignant melanoma (CMM).

METHODS

The Ki-67 index (percent of total tumor nuclei) was determined in a series of 84 localized CMMs, with the use of the alkaline phosphatase-antialkaline phosphatase labeling method in formalin-fixed, paraffin-embedded material, and was correlated with other prognostic variables. Survival analysis was performed to determine whether the Ki-67 index and the PBPI could be predictive of metastatic spread or recurrent disease. A stratified analysis of these two parameters according to the tumor thickness was done.

RESULTS

An association among the Ki-67 index and location, Clark level, tumor thickness and stage, and prognostic index was detected. Increased Ki-67 index and PBPI were associated with poorer overall survival (P =.03 and P <.0001, respectively) and disease-free survival (P =.01 and P <.0001, respectively). However, after stratification for thickness, only the PBPI showed independent prognostic significance, restricted to tumors thicker than 4 mm (P =. 03).

CONCLUSION

The determination of the PBPI in CMM conveys prognostic information for localized thick (>4 mm) CMM, identifying two groups of patients with distinct outcome.

A new American Joint Committee on Cancer staging system for cutaneous melanoma

The Melanoma Staging Committee of the AJCC has proposed major revisions of the melanoma TNM and stage grouping criteria. The committee members represent most of the major cooperative groups and cancer centers worldwide with a special interest in melanoma; the committee also collectively has had clinical experience with over 40,000 patients. The new staging system better reflects independent prognostic factors that are used in clinical trials and in reporting the outcomes of various melanoma treatment modalities. Major revisions include 1) melanoma thickness and ulceration, but not level of invasion, to be used in the T classification; 2) the number of metastatic lymph nodes, rather than their gross dimensions, the delineation of microscopic versus macroscopic lymph node metastases, and presence of ulceration of the primary melanoma to be used in the N classification; 3) the site of distant metastases and the presence of elevated serum LDH, to be used in the M classification; 4) an upstaging of all patients with Stage I,II, and III disease when a primary melanoma is ulcerated; 5) a merging of satellite metastases around a primary melanoma and in-transit metastases into a single staging entity that is grouped into Stage III disease; and 6) a new convention for defining clinical and pathologic staging so as to take into account the new staging information gained from intraoperative lymphatic mapping and sentinel lymph node biopsy. The AJC Melanoma Staging Committee invites comments and suggestions regarding this proposed staging system before a final recommendation is made.

Prognosis in malignant melanoma

A uniform and practical classification and staging system for melanoma must exist and be widely adopted if useful comparisons between different treatment centers and databases are to be made. This article reviews the 1992 American Joint Committee on Cancer pTNM staging system. In this classification, localized disease without regional nodal involvement is defined as stage I or II, depending on the tumor thickness of the primary melanoma. Regional lymph node involvement and/or in-transit metastasis is defined as stage III, and systemic metastatic disease is defined as stage IV.

Therapeutic node dissections in malignant melanoma

In the absence of distant disease, therapeutic node dissections in malignant melanoma, i.e., dissections of regional nodal basins for palpable suspicious or biopsy-proven positive nodes, offer the chance of cure. The 5-year survival rates after therapeutic lymphadenectomy closely correlate with expected cure rates. Although they varied greatly in the literature, from 19% to 38%, the currently obtainable survival rates are in the upper ranges of this spectrum because patients now are closely followed-up and operated for early palpable nodal disease. Properly done, these procedures carry a low morbidity, but they should be done thoroughly to completely eradicate regional disease and avoid recurrences in the same nodal basin to achieve the maximum survival that is surgically attainable.

Skin melanoma in Italy: a population-based study on survival and prognostic factors

Survival and prognostic factors of invasive cutaneous melanoma patients diagnosed in the province of Florence, Italy, were studied using a regression analysis of relative survival rates. The case series consisted of 428 patients reported by the Tuscany Cancer Registry between 1985 and 1989. The effect of gender, age, anatomical site, histological type and microstaging parameters upon relative survival were evaluated using an extension of the Cox proportional hazard model. Five-year relative survival was 70%; 8-year relative survival, referring to a subset of patients, was 67%. In univariate analysis, the following variables were significantly associated with better prognosis: female gender, age younger than 60 years, superficial spreading melanoma (SSM) compared with nodular melanoma (NM), location on the limbs, a thinner lesion according to Breslow, a shallower Clark level. Females had a clear-cut prognostic advantage over males in each category of the variables considered above. After simultaneous adjustment for all other variables, three factors continued to show an independent prognostic effect: age, gender and microstaging parameters (Breslow thickness and Clark level, separately fitted in the model). In the multivariate analysis, the prognostic advantage of females over males was specifically seen for lesions located on the trunk and for both SSM and NM histotype.

Problems in defining cutoff points of continuous prognostic factors: example of tumor thickness in primary cutaneous melanoma

Continuous prognostic factors are often categorized by defining optimized cutoff points. One component of criticism of this approach is the problem of multiple testing that leads to an overestimation of the true prognostic impact of the variable. The present study focuses on another crucial point by investigating the dependence of optimized cutoff points on the observed distribution of the continuous variable. The continuous variable investigated was the vertical tumor thickness according to Breslow, which is known to be the most important prognostic factor in primary melanoma. Based on the data of 5093 patients, stratified random samples were drawn out of six artificially created distributions of tumor thickness. For each of these samples, Cox models were calculated to explore optimized cutoff points for tumor thickness together with other prognostic variables. The optimized cutoff points for tumour thickness varied considerably with the underlying distribution. Even in samples from the same distribution, the range of cutoff points was amazingly broad and, for some of the distributions, covered the whole region of possible values. The results of the present study demonstrate that optimized cutoff points are extremely data dependent and vary notably even if prerequisites are constant. Therefore, if the classification of a continuous prognostic factor is necessary, it should not be based on the results of one single study, but on consensus discussions including the findings of several investigations.

Does surgical removal of primary melanoma trigger growth of occult metastases? An analytical epidemiological approach

BACKGROUND

In several human tumor systems a potential role of surgical removal of the primary tumor upon metastatic tumor growth has been evaluated, as it has been in experimental models. The present study addresses the question of whether the removal of primary melanomas disinhibits growth of metastatic disease and results in more rapid progression.

METHODS

In a data set of 1224 primary cutaneous melanomas the risk of "thin" melanomas to develop metastases within 1 year was compared with the risk of matched pairs of "thick" melanomas to present metastases at the time of diagnosis. For this purpose, a pairwise matching procedure based on certain assumptions as to tumor volume and tumor doubling time has been applied.

RESULTS

When a long tumor doubling time is assumed (200, 400, or 800 days), the tumors removed seem to have a significantly higher risk of metastases to become clinically apparent within 1 year than the matched pairs of tumors to present metastatic disease at the time of diagnosis (chi-square < 0.01). When short tumor doubling time is assumed (50 or 100 days), the difference is not significant, but there also seems to be no benefit for the operated patients.

CONCLUSION

In the present data set there is evidence that surgery of primary melanoma may enhance tumor growth at metastatic sites.

Surgical treatment of malignant melanoma

The surgical treatment of the primary melanoma site has been made more rational through correlations of rates of local control with various margins of resection in the context of the dominant prognostic indicator for localized melanoma, the thickness of the primary lesion. It is now known that for lesions less than 1 mm in thickness, a 1-cm margin is satisfactory. For lesions 1 to 4 mm thick, a 2-cm margin is adequate according to the results of a multi-institutional, randomized, surgical trial. Lesions thicker than 4 mm should be treated with a margin larger than 2 cm where the anatomy permits, although the main concern for these lesions is their high propensity for distant dissemination. Elective dissection has not been shown to alter survival significantly in prospective randomized trials. Surgical treatment of distant metastases is indicated for the palliation of a symptomatic lesion, for example, solitary brain metastasis or gastrointestinal metastases.

Surgical management of melanoma

The incidence of melanoma is rising more rapidly than any other malignancy. More conservative margins of excision have been established and the role of elective node dissection awaits determination by prospective randomized trials. Lymphoscintigraphy has clarified lymphatic drainage from watershed areas. Lymphatic mapping and sentinel node biopsy may lead to acceptance of selective lymphadenectomy, and also allows for more sensitive staging. Further advances in outcome require the development of effective systemic adjuvant therapies. Until such time, surgery continues to play a pivotal role in all stages.

Primary cutaneous melanoma. Optimized cutoff points of tumor thickness and importance of Clark's level for prognostic classification

BACKGROUND

Maximum tumor thickness and level of invasion are known to be the most important prognostic factors for patients with primary cutaneous melanoma. However, the classification of tumor thickness and the question of whether the combination of tumor thickness and level of invasion provides a better prognostic classification than tumor thickness alone are still matters of debate. The present study examined the relationship between tumor thickness and survival probability to define cutoff points of tumor thickness. Secondly, it investigated the prognostic value of the combination of tumor thickness and level of invasion as proposed in the current TNM classification system.

METHODS

A series of 5093 patients with invasive primary cutaneous melanoma followed from 1970 to 1988 at four University centers in Germany (Departments of Dermatology in Tübingen, Würzburg, Berlin-Steglitz, and at the Fachklinik) were analyzed by multivariate Cox models.

RESULTS

The relationship between tumor thickness and relative risk of death caused by melanoma was found to be almost linear to a tumor thickness of 6 mm. For tumors greater than 6 mm, no further marked increase in relative risk was observed. The stratification of tumor thickness with endpoints at 1, 2, and 4 mm resulted in the best fit to the authors' data among all classifications with three endpoints, but differences were only slight. By multivariate analysis, the combination of tumor thickness and level of invasion as proposed by the current TNM classification were found to be prognostically less significant than tumor thickness alone. The prognostic influence of level of invasion was proved statistically only for tumor thickness less than or equal to 1 mm.

CONCLUSIONS

The proposed stratification of tumor thickness with cutoff points at 1, 2, and 4 mm was supported by multivariate statistical analysis. The analysis of the current TNM staging system indicates the precedence of tumor thickness for the staging of patients with primary cutaneous melanoma in the case of discordance between tumor thickness and level of invasion.

Primary cutaneous melanoma. Identification of prognostic groups and estimation of individual prognosis for 5093 patients

BACKGROUND

Numerous investigations have examined prognostic factors for patients with primary cutaneous melanoma. However, only a few studies have been published on the definition of prognostic groups. The first aim of the present study was to determine the relative importance of different prognostic factors in a large collective study. The second aim was to define prognostic groups of patients based on combinations of prognostic factors and to define a model that allows the estimation of individual survival probability.

METHODS

Long term follow-up of 5264 patients with invasive primary cutaneous melanoma was performed from 1970 to 1988 at four German University Departments of Dermatology (Berlin-Steglitz, Münster-Hornheide, Tübingen, and Würzburg). The multivariate Cox model was used to analyze 5093 patients, and 4371 patients with complete information were included in a classification and regression tree analysis (CART).

RESULTS

Tumor thickness, sex, anatomic location, and level of invasion were highly significant prognostic factors according to the multivariate analysis (P < 0.0001). However, histologic subtype and age influenced prognosis less significantly (P < 0.05). The CART analysis resulted in 12 groups defined mainly by tumor thickness, sex, and anatomic location, which were combined into five prognostic groups. The prognostic stratification defined by the five groups was superior compared with the standard TNM model. Ten-year survival rates of the five groups ranged from 97% to 14% (P < 0.0001), and an equation was used to calculate individual survival probabilities based on the significant factors of the Cox model.

CONCLUSIONS

Consideration of all significant prognostic factors of patients with primary cutaneous melanoma investigated in the present study allows for the definition of prognostic groups with a more reliable estimation of prognosis than by previous staging systems and also enables calculation of individual survival probabilities.

Prognostic parameters in localised melanoma: gender versus anatomical location

Extremity location and female gender are both considered favourable prognostic parameters in primary melanoma, but since they cluster in the same group of patients, the question remains as to whether they are both independent variables. Multivariate analysis of 695 patients with primary, localised melanoma was used. The effects of gender and anatomical location were compared directly by sequentially controlling one factor while the other remained free. Following multivariate analysis, significant prognostic factors related to survival were the thickness of the primary lesion (P < 0.0001), the age of the patient at diagnosis (P < 0.0001), the gender of the patient (P = 0.0008) and the anatomical location of the primary lesion (P = 0.005). Thicker lesions, patients older than 50 years, males, and trunk, head and neck locations had poorer prognoses. There was a significant difference in survival according to gender within each location, extremity (P = 0.002) or trunk, head and neck (P = 0.0004); however, there was no significant difference in survival according to anatomical location within each gender, male (P = 0.11) or female (P = 0.29). The thickness of the primary lesion, the age of the patient at diagnosis, the gender and the anatomical location of the melanoma are all significant prognostic parameters in localised melanoma. Gender appears to have a more pronounced effect on survival than anatomical location.

Survival of patients with stage IA malignant melanoma

There is ongoing clinical research on prognostic parameters relevant to stage IA melanoma. The object is to identify those factors associated with an increased risk of recurrence. The charts of 197 patients first treated at our Institute between 1980 and 1992 along with 62 patients referred for follow-up or treatment of recurrent disease, all having been initially diagnosed with stage IA disease, were reviewed. Only one patient (0.5%) of those first treated at our Institute manifested recurrence and this was a local recurrence. No statistically significant differences were found between patients who relapsed and those who did not with regard to lesion thickness, level of invasion, evidence of ulceration, location of the primary lesion, gender, or age. Generally, stage IA melanomas have excellent prognosis. However, there are patients who experience recurrent and metastatic disease. At the present time, there are no reliable indicators available for use in predicting which patients are at risk.

Prognostic factors in thin cutaneous malignant melanoma

BACKGROUND

Thin melanomas can metastasize and be lethal. The predictive importance of tumor thickness in thin melanomas and the specific features identifying the patients at risk have not been investigated fully.

METHODS

Prognostic factors were analyzed in 585 patients with clinical Stage I invasive cutaneous malignant melanoma with a thickness of less than or equal to 0.8 mm. The patients were included in a population-based cancer registry in Stockholm county during 1976-1987. They constituted about 64% of all patients with thin melanomas who were diagnosed in the region during the study period. Information was available on age, sex, anatomic site of the tumor, histologic type of melanoma, level of invasion, tumor thickness, and tumor regression. In a Cox regression analysis, the prognostic importance of each factor was studied. By a case-control technique with individual matching for the identified independent predictors of recurrence, the additional prognostic information given by type and grade of inflammatory response, presence of vertical growth phase, mitotic rate/mm2, and histologic ulceration of the tumor was assessed.

RESULTS

After a median follow-up time of 50 months, recurrent disease developed in 26 patients (4%). There was no difference in recurrence rate between patients treated with narrow (1-2 cm) or wide (5 cm) excision. Anatomic site, tumor thickness, level of invasion, and tumor regression were found to be independent prognostic factors in the multivariate analysis. In the case-control study, only grade of inflammatory reaction added significant prognostic information. No subgroup could be identified that was without risk of recurrent disease.

CONCLUSIONS

Thin melanomas do not seem to constitute a separate form of melanoma, but compose one end of a continuous spectrum of biologic behavior.

The pathology of melanoma as a basis for prognostic models: the UCSF experience

A patient survival model is proposed which allows visualization of a data base, and which includes only routine and commonly recorded attributes in most melanoma clinics. It is proposed that a network of such data be collected for meta-analysis (MELNET), which could make stratification within the individual subsets more significant by virtue of the large numbers. Such a network could then be fully tested in various melanoma clinics for clinical usefulness.

Malignant melanoma of the scrotum: report of 2 cases

Primary melanoma of the scrotum is a rare entity, with only 4 cases reported previously. Of about 2,000 patients with malignant melanoma treated in the last 15 years at our hospital only 2 had primary melanoma of the scrotum. The treatment and outcome of these patients are presented.

Profile of the malignant melanoma excised in general practice

An analysis of 27 malignant melanomas diagnosed in a Dutch laboratory specializing in the provision of a cytology and pathology service to general practitioners is reported. The median age of the patients was 39 years, and was lower in women (30 years) than in men (54 years). In the national data the mean age was 52 years for both sexes. There were twice as many women as men. There were no tumours from the head and neck region. The ratio of tumours on the limbs to those on the trunk was 3:2. The melanomas were very small (74% with a diameter of < or = 6.0 mm), and they were also very thin (74% with a Breslow thickness < or = 1.0 mm), compared with the national data in which 62% were < or = 1.0 mm. Not surprisingly, the estimated mean 5-year survival was favourable (95% for women and 76% for men). After a period of follow-up ranging from 2 to 32 months, none of the patients had any evidence of residual disease. This study demonstrates that in skin biopsies performed by general practitioners melanomas are mainly detected by chance, and have a very good prognosis.

Benefit of elective lymph node dissection in subgroups of melanoma patients. Results of a multicenter study of 3616 patients

BACKGROUND

The benefit of elective lymph node dissection (ELND) for the treatment of the nonmetastasized malignant melanoma has been assessed differently until today.

METHODS

Nine medical centers with a different ELND practice but comparable standards regarding diagnosis, excision of the primary tumors, classification, and follow-up, have collected their data (primarily ascertained prospectively) of 3616 patients of the tumor categories pT2 to pT4N0M0 to produce an unbiased analysis of the prognostic benefit of ELND, and to find the indications for its application. The data are based on patients 70 years of age and younger with a primary melanoma of the skin, who have been followed for at least 4 years (median, 9.6 years). The stratification (according to pT category [alternatively, tumor thickness], sex, anatomic site) was in accordance with the results of the multivariate risk analysis (Cox hazard model). Imbalances of other criteria such as ulceration, type, and age were excluded by chi-square tests of the individual strata. The results are based on the observed survival rates according to Kaplan-Meier analysis of the different strata.

RESULTS

A prognostic benefit of the ELND group (improvement of the 5-year survival rate of about 20%) can be claimed for male patients with axial and acral melanomas (excluding lentigo maligna melanoma [LMM] and ulcerated tumors) of the categories pT3a up to pT4a (tumor thickness of > 1.5-4.5 mm, respectively) (P < 0.001). As to the rest of the nonulcerated tumors of male patients, only those of the categories pT3b and 4a benefited from ELND (P < 0.01). A benefit from ELND for women was statistically verified (improvement of the 5-year survival rate of about 5%-10%) only for the subgroup with a tumor thickness > 2.5-5 mm, excluding LMM) (P = 0.016).

CONCLUSIONS

This retrospective study strongly suggests the efficacy of ELND in subgroups of melanoma patients.

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

The prognostic value of the TNM classifications of the UICC dated 1978 and 1987, was investigated in a population of 2,495 patients who were followed up over the long term. In the case of primary melanoma, Breslow's tumour thickness proved to be the most powerful predictor of patient survival in multivariate analysis, while the significance of Clark's level ranged after that of both localisation of the primary tumour and the sex of the patient. The continuous proportional relationship between tumour thickness and risk of death makes it possible to regrade thickness groups. Grading cutoffs at 1, 2 and 4 millimetres, with no account being taken of depth of invasion, proved to be particularly favourable for a classification in accordance with prognostic criteria. In advanced stages of the disease, the outcome of locoregional and distant metastasis is significantly different; and furthermore in the case of locoregional metastasis, in-transit and satellite metastases exert a significantly better prognosis than regional lymph node involvement. Isolated juxtaregional lymph node metastases occurred primarily or during the course of the observation period in only 19 patients of our group, and, in comparison with visceral metastases, proved to have only an insignificantly better prognosis. For this reason, it would appear meaningful to assign them to a common stage. On the basis of these results, proposals are made for modifications of the TNM classification.

Is poor prognosis really related to HLA-DR expression by malignant melanoma cells?

HLA-DR expression was examined in 50 consecutive primary cutaneous malignant melanomas with a Breslow depth greater than 2 mm using two well-characterized monoclonal antibodies which detect fixation-resistant epitopes. In 31 of these cases (62%) a subpopulation of tumour cells was reactive, although there was considerable heterogeneity. Positive labelling did not correlate with depth but was associated with a reduced likelihood of developing early metastatic disease and a tendency for better overall survival, particularly in male patients. These findings contrast with earlier studies using cryostat sections and one study on paraffin-embedded tissue in which HLA-DR expression was shown to be a poor prognostic factor, but are consistent with the findings in other malignant tumours studied. The significance of HLA-DR expression as a marker of prognosis may depend on the type of tissue preparation, the sensitivity of the immunocytochemical techniques used and the method of assessment.

Attributes and survival patterns of multiple primary cutaneous malignant melanoma

From a series of 1495 patients with primary cutaneous malignant melanoma (PCMM), 26 patients (1.73%) had multiple primary cutaneous malignant melanoma (MPCMM). This report describes the attributes and survival patterns in this small, but important, subgroup of patients with PCMM. Of 26 patients, 23 had two primaries, two had three primaries, and one had six primaries. Five patients had synchronous and 21 patients had metachronous MPCMM. The median interval between the occurrence of the first and subsequent PCMM in these patients was 1.93 years. The estimated 5-year survival rate from the first melanoma was 83.5%; that from the last melanoma was 53.1%. In summary, MPCMM is a distinct biologic phenomenon. A second or subsequent malignant melanoma should be treated like a primary melanoma.

Observer variation in the measurement of Breslow depth and Clark's level in thin cutaneous malignant melanoma

We have assessed the degree of observer variation of both Breslow depth and Clark's level in a series of 50 thin malignant melanomas. Our findings are similar to those of previous international studies in the Breslow depth is the more reproducible measure. Significant intra- and inter-observer variation exists and in some cases it was up to +/- 0.86 mm. Even small differences will potentially affect patient management at our centre and this was analysed using kappa statistics. Good agreement was found between observers and this could be improved by comparing the mean of two or more measurements. This removes larger errors, but smaller observer errors and differences in subjective interpretation of the deepest malignant cell mean that agreement will never be more than 90 per cent. This is high compared with studies of observer variation in other pathological conditions, e.g., dysplasia of the cervix, but where surgical management is potentially disfiguring it is not high enough. We conclude that Breslow depth and Clark's level should not be the sole basis of wide excision protocols.