Prognostic factors analysis of 17,600 melanoma patients: validation of the American Joint Committee on Cancer melanoma staging system

Prognostic factors for malignant melanoma of the squamous mucosa of the head and neck

Primary malignant melanomas of the squamous mucosa of the head and neck are rare. To learn more about the prognostic significance of various histologic parameters we examined the pathologic features of squamous mucosa from 40 patients seen at a single institution and correlated them with clinical outcome. Follow-up information was available on 37 patients. Thirty-five were treated with surgical resection and two were treated with radiotherapy. Twenty-six were dead at follow-up. Twenty-one of them died of disease. The interval between diagnosis and death ranged from 1 month to 16.5 years (median survival, 2.4 years). Eleven patients were alive at 4 months to 19.5 years after the diagnosis: six of them with disease and five of them free of disease (mean follow-up, 3.5 years). Predictors of poor survival by univariate analysis were the presence of vascular invasion (overall survival, p = 0.007; disease-specific survival, p = 0.01), a polymorphous tumor cell population (overall survival, p = 0.007; disease-specific survival, p = 0.008), and necrosis (overall survival, p = 0.007; disease-specific survival, p = 0.056). However, because these three parameters were associated with each other, none of them remained of independent predictive value for outcome by multivariate analysis. No prognostic significance was found for tumor thickness, level of invasion, ulceration, mitotic index, or nerve/nerve sheath involvement. Thus, the histologic parameters relevant for the prognosis of squamous mucosa differ significantly from those of cutaneous melanomas.

Metastatic pathways and time courses in the orderly progression of cutaneous melanoma

BACKGROUND

It is known that two-thirds of patients who develop clinical metastases following treatment of a primary cutaneous melanoma initially present with locoregional metastases and one-third initially present with distant metastases. However, few reports in the literature give detailed figures on different metastatic pathways in cutaneous melanoma.

OBJECTIVES

The aim of the present study was to perform a detailed analysis of the different metastatic pathways, the time course of the development of metastases and the factors influencing them.

METHODS

In a series of 3001 patients with primary cutaneous melanoma at first presentation, 466 subsequently developed metastasis and were followed-up over the long term at the University of Tuebingen, Germany between 1976 and 1996. Different pathways of metastatic spread were traced. Associated risk factors for the different pathways were assessed. Differences in survival probabilities were calculated by the Kaplan-Meier method and evaluated by the log-rank test.

RESULTS

In 50.2% of the patients the first metastasis after treatment of the primary tumour developed in the regional lymph nodes. In the remaining half of the patient sample the first metastasis developed in the lymphatic drainage area in front of the regional lymph nodes, as satellite or in-transit metastases (21.7%) or as direct distant metastases (28.1%). Anatomical location, sex and tumour thickness were significant risk factors for the development of metastasis by different pathways. The most important risk factor appeared to be the location of the primary tumour. The median intervals elapsing before the first metastasis differed significantly between the different metastatic pathways. The direct distant metastases became manifest after a median period of 25 months, thus later than the direct regional lymph node metastases (median latency period, 16 months) and the direct satellite and in-transit metastases (median latency period, 17 months). In patients who developed distant metastases the period of development was independent of the metastatic route. The time at which the distant metastases developed was roughly the same (between 24 and 30 months after the detection of the primary tumour), irrespective of whether satellite or in-transit metastases, lymph node metastases or distant metastases were the first to occur.

CONCLUSIONS

The time course of the development of distant metastasis was more or less the same irrespective of the metastatic pathway; this suggests that in patients with in-transit or satellite metastasis or regional lymph node metastasis, haematogenic metastatic spread had already taken place. Thus, the diagnostic value of sentinel lymph node biopsy and the therapeutic benefit of elective lymph node dissection may be limited, as satellite and in-transit metastases or direct distant metastases will not be detected and haematogenous spread may already have taken place when the intervention is performed.

Long-term survival in 2,505 patients with melanoma with regional lymph node metastasis

OBJECTIVE

To examine the long-term outcomes of patients with melanoma metastatic to regional lymph nodes.

SUMMARY BACKGROUND DATA

Regional lymph node metastasis is a major determinant of outcome for patients with melanoma, and the presence of regional lymph node metastasis has been commonly used as an indication for systemic, often intensive, adjuvant therapy. However, the risk of recurrence varies greatly within this heterogeneous group of patients.

METHODS

Database review identified 2,505 patients, referred to the Duke University Melanoma Clinic between 1970 and 1998, with histologic confirmation of regional lymph node metastasis before clinical evidence of distant metastasis and with documentation of full lymph node dissection. Recurrence and survival after lymph node dissection were analyzed.

RESULTS

Estimated overall survival rates at 5, 10, 15, and 20 years were 43%, 35%, 28%, and 23%, respectively. This population included 792 actual 5-year survivors, 350 10-year survivors, and 137 15-year survivors. The number of positive lymph nodes was the most powerful predictor of both overall survival and recurrence-free survival; 5-year overall survival rates ranged from 53% for one positive node to 25% for greater than four nodes. Primary tumor ulceration and thickness were also powerful predictors of both overall and recurrence-free survival in multivariate analyses. The most common site of first recurrence after lymph node dissection was distant (44% of all patients).

CONCLUSIONS

Patients with regional lymph node metastasis can enjoy significant long-term survival after lymph node dissection. Therefore, aggressive surgical therapy of regional lymph node metastases is warranted, and each individual's risk of recurrence should be weighed against the potential risks of adjuvant therapy.

Incisional biopsy and melanoma prognosis

BACKGROUND

There are many circumstances in clinical practice in which it is helpful to have a definitive diagnosis of melanoma before subjecting a patient to mutilating surgery. Previous studies on the effect of incisional biopsy on melanoma prognosis were conflicting and lacked a matched control group to account for the other prognostic indicators.

OBJECTIVE

We set up this study to investigate the effect of incisional biopsy on melanoma prognosis.

METHODS

The design was of a retrospective case control. Data were obtained from the database of the Scottish Melanoma Group; the database was set up in 1979 to collect detailed clinical, pathologic, and follow-up data on all patients diagnosed with melanoma in Scotland. Each incisional case was matched against 2 excision cases controlling for age, sex, sites, and Breslow thickness. The main outcome measures were time from initial biopsy to recurrence and to melanoma-related death.

RESULTS

Two hundred sixty-five patients who had incisional biopsy before definitive excision of melanoma were included in the study; these were matched with 496 cases of excisional biopsy specimens. Cox's proportional hazard model for survival analysis showed that biopsy type had no significant effect on recurrence (P =.30) or melanoma-related death (P =.34).

CONCLUSIONS

This study is the largest series on the effect of incisional biopsy on melanoma prognosis to date and the first to include matched controls. Melanoma prognosis is not influenced by incisional biopsy,. before definitive excision.

Implications of microscopic satellites of the primary and extracapsular lymph node spread in patients with high-risk melanoma: pathologic corollary of Eastern Cooperative Oncology Group Trial E1690

PURPOSE

To correlate the presence of extracapsular spread (ECS) of regional nodal metastases, and micrometastasis near the primary tumor, with disease outcome in the intergroup study E1690 in relation to the impact of recombinant interferon-alfa (rIFN alpha)-2b.

PATIENTS AND METHODS

E1690 included 642 patients with American Joint Committee on Cancer stage IIB or III cutaneous melanoma. Patients were randomized into high- and low-dose rIFN alpha-2b treatment arms and an observation arm. Pathologic slides were reviewed for selected parameters from at least half of the subjects in all three arms. Evaluation of the primary tumor included notations regarding ulceration, mitotic activity, thickness, microscopic satellites (MS), and nodal ECS on a standardized pathology form. These data were collated in relation to relapse-free survival (RFS) and overall survival (OS) at 50 months' follow-up and studied using Cox regression analysis.

RESULTS

Ulceration, mitotic activity, thickness, and size of tumor-bearing lymph nodes did not show a statistically significant correlation with either OS or RFS across all treatment arms. The presence of MS was correlated with RFS (P =.0008) and OS (P =.05). ECS correlated with RFS (hazard ratio = 1.44, P =.032) but not OS (P =.11).

CONCLUSION

The presence of MS (in 6% [18 of 308 patients]) had a significant adverse impact on both RFS (P =.0008) and OS (P =.053). Ulceration, mitotic activity, thickness, and number of positive lymph nodes had no significant effect on OS in this subset study (univariate or multivariate Cox analysis). The presence of ECS in lymph nodes had a significant adverse effect on RFS (P =.032) but not on OS.

Interferon-alpha in tumor immunity and immunotherapy

Interferon-alpha (IFN-alpha) is a pleiotropic cytokine belonging to type I IFN, currently used in cancer patients. Early studies in mouse tumor models have shown the importance of host immune mechanisms in the generation of a long-lasting antitumor response to type I IFN. Recent studies have underscored new immunomodulatory effects of IFN-alpha, including activities on T and dendritic cells, which may explain IFN-induced tumor immunity. Reports on new immune correlates in cancer patients responding to IFN-alpha represent additional evidence on the importance of the interactions of IFN-alpha with the immune system for the generation of durable antitumor response. This knowledge, together with results from studies on genetically modified tumor cells expressing IFN-alpha, suggest novel strategies for using these cytokines in cancer immunotherapy and in particular the use of IFN-alpha as an immune adjuvant for the development of cancer vaccines.

Update on the use of sentinel node biopsy in patients with melanoma: who and how

This review highlights the utility of sentinel lymph node biopsy for melanoma. The histopathologic status of the sentinel lymph node is acknowledged as the most powerful indicator of prognosis. Changes by the American Joint Committee for Cancer have not only incorporated the importance of ulceration in cutaneous melanoma, but have focused on the number of metastatic lymph nodes as well as whether the disease is macro- or micrometastatic. Specific technical aspects of the sentinel lymph node procedure are discussed, with emphasis on practical guidelines to minimize incorrect nodal staging.

Melanoma

The presentations at the American Society of Clinical Oncology 2001 meeting reported or updated the results of phase I, II, and III randomized trials and also reported important meta-analyses and retrospective studies impacting on the management of patients with melanoma. In the treatment of early stage melanoma, the prognostic significance of pathologic status of sentinel lymph nodes was affirmed. With respect to regional nodal involvement (American Joint Committee on Cancer [AJCC] stage III), investigators presented the interim results of the United Kingdom randomized low-dose interferon (IFN) trial, and up-to-date meta-analyses of several IFN trials including a pooled analysis of the Eastern Cooperative Oncology Group trials evaluating interferon in the adjuvant setting. In the advanced disease setting (AJCC stage IV), several studies elucidated the pros and cons of biochemotherapy in patients with metastatic melanoma, with an emphasis on seeking to improve response in the central nervous system and durability of response in general. Thought provoking was new data regarding the potential for lovastatin to act as a chemopreventive agent for melanoma. Translational studies were presented, one supporting the importance of HLA-typing in developing targeted vaccine therapy. Finally, the results of a novel experimental melanoma vaccine were presented using autologous tumor-derived heat-shock protein peptide complex-96 (HSPPC-96).

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.

Final version of the American Joint Committee on Cancer staging system for cutaneous melanoma

PURPOSE

To revise the staging system for cutaneous melanoma under the auspices of the American Joint Committee on Cancer (AJCC).

MATERIALS AND METHODS

The prognostic factors analysis described in the companion publication (this issue), as well as evidence from the published literature, was used to assemble the tumor-node-metastasis criteria and stage grouping for the melanoma staging system.

RESULTS

Major changes include (1) melanoma thickness and ulceration but not level of invasion to be used in the T category (except for T1 melanomas); (2) the number of metastatic lymph nodes rather than their gross dimensions and the delineation of clinically occult (ie, microscopic) versus clinically apparent (ie, macroscopic) nodal metastases to be used in the N category; (3) the site of distant metastases and the presence of elevated serum lactic dehydrogenase to be used in the M category; (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 staging information gained from intraoperative lymphatic mapping and sentinel node biopsy.

CONCLUSION

This revision will become official with publication of the sixth edition of the AJCC Cancer Staging Manual in the year 2002.

Review of the 2001 AJCC staging system for cutaneous malignant melanoma

The American Joint Committee on Cancer (AJCC) staging system for melanoma has recently been revised and published. The previous staging system had not been substantially modified since the late 1980s. In a series of papers, the staging system for melanoma was critically analyzed, and many shortcomings were identified. Many well-established prognostic factors were not used in the staging system. This assessment has led to a substantially modified staging system for cutaneous melanoma in 2001 that is a considerable improvement over past staging systems, albeit more complex. The following modifications are the most important: 1) The primary determinant of tumor (T) staging is tumor thickness as measured in millimeters. The Clark level of invasion is now used only for defining T1 (< or = 1mm) melanomas; 2) The cutpoints for tumor thickness are less than or equal to 1 mm, 1 to 2 mm, 2 to 4 mm, and greater than 4 mm; 3) Ulceration has been added in describing the primary tumor; 4) Local recurrence, satellite disease, and in-transit metastases have similar prognosis and are now all classified together as regional stage III disease; 5) Size of lymph node as prognostic factor has been eliminated and replaced with the number of positive nodes; 6) The presence of an elevated serum lactic dehyrogenase level is used in the metastasis (M) category. This revised staging system more precisely defines prognosis and will improve the stratification of patients in future clinical trials.