Cutaneous melanoma: estimating survival and recurrence risk based on histopathologic features

Abstract

The prognosis of melanoma is best understood in terms of a model of tumor progression, in which most melanomas may evolve through two major phases of progression: from a lesion that is nontumorigenic and has little or no capacity for metastasis; to a more advanced lesion that is tumorigenic and may have capacity for metastasis. The likelihood of metastasis varies with a number of attributes of the primary melanoma, including the phase of progression, the Breslow tumor thickness, mitotic rate, and host response to the tumorigenic compartment of the lesion, Clark's level of invasion, and other factors. When distant metastasis has occurred, the prognosis for the patient is very poor. In this monograph, the focus will be the discussion of factors related to the prognosis of melanomas that at diagnosis are clinically localized to the primary site.

Predicting sentinel node status in AJCC stage I/II primary cutaneous melanoma

“…8,14,20 In the current study, we found in multivariate analysis that the presence of any mitoses (MR >0), as well as a high mitotic rate (MR >5), was associated with a higher odds of having a positive SLN. With our classification tree it is important to note that mitogenicity 41,42 (present when MR >0 or absent when MR ¼ 0) was prognostic only in thinner VGP lesions. Within the 2.0 mm thickness group, MR was selected to identify patients with lower and higher rates of SLN positivity.…”

“…15 Of note, melanomas of these acral sites have been found to have specific genetic abnormalities that distinguish them from those located elsewhere. 30 Because in situ and RGP lesions are apparently incapable of metastasis, [21][22][23][24] our study focused on lesions with VGP, a marker of dermal proliferation defined as the presence of tumor cell mitoses in the dermis and/or clusters or nests of melanoma cells in the dermis that are larger than those in the epidermis. [21][22][23] Candidate histopathologic prognostic factors were Breslow thickness (measured in millimeters), level, mitotic rate (MR: number of mitoses per square millimeter), TIL (measured as lymphocytes infiltrating the VGP and disrupting the melanoma cells, see Fig.…”

“…[21][22][23] Candidate histopathologic prognostic factors were Breslow thickness (measured in millimeters), level, mitotic rate (MR: number of mitoses per square millimeter), TIL (measured as lymphocytes infiltrating the VGP and disrupting the melanoma cells, see Fig. 1), ulceration, and regression in association with the adjacent RGP (as recently described in detail 23 ).…”

“…5,[7][8][9][10][11][12][13][14][15][16][17][18][19][20] Our group evaluated prognostic factors within the context of a biological model of melanoma progression in which melanomas are hypothesized to evolve from cell populations incapable of metastasis (the in situ and invasive radial growth phase [RGP]) to those with variable metastatic potential (the VGP). [21][22][23][24] Histologic features such as VGP (defined below) and dermal mitotic rate are taken to indicate that a lesion may have gained the capacity to metastasize. [21][22][23][24] These 2 factors have been shown to be associated with SLN metastasis in lesions 1.0 mm.…”

“…[21][22][23][24] Histologic features such as VGP (defined below) and dermal mitotic rate are taken to indicate that a lesion may have gained the capacity to metastasize. [21][22][23][24] These 2 factors have been shown to be associated with SLN metastasis in lesions 1.0 mm. 19,25 Clark et al, 21 as well as other investigators, [26][27][28][29] have also found that markers of antitumor immunity predict the likelihood of metastasis: the presence and density of tumor infiltrating lymphocytes (TIL) independently associate with survival.…”