Tumor-Infiltrating CD8+ Lymphocytes Effect on Clinical Outcome of Muco-Cutaneous Melanoma

Recent data have changed our views of prognostic factors in cutaneous melanoma, while some newer methods have yielded better prognostic information. Tumor-infiltrating lymphocytes are believed to represent the immune reaction/response to melanoma cells which is often found in melanocytic cancer.

We carried out an analysis, aiming to establish pooled estimates for clinical outcomes based on the presence of CD8+ T cell in melanocytic cancer.

We have included 42 patients with primary cutaneous melanocytic cancer without preoperative treatments in our study. We next analyzed the proliferative activity of CD8+ T cells that infiltrated in tumor cell nests. The intratumoral and adjacent to invasive margin of tumor CD+ T-cell infiltration were analyzed which could also reflect antitumor immunity.

The total number of CD8+ cells especially adjacent to invasive margin of tumor was positively correlated with anatomical tumor thickness (P < .001) and not correlated with patient's age and sex. The stage of tumor which is related to vascular-neural invasion, regional lymph nodes involvement and tumor thickness shows positive correlation with CD8+ infiltration in tumor (P < .004, P < .005, P < .001), respectively. Acral melanoma shows more CD8 lymphocytes infiltration and also recurrence rate of tumor (P < .005).

We believe that CD8+ T-cell infiltration in primary cutaneous melanocytic cancer represents the immune reaction/response to melanoma which could be an important new therapy for melanoma although more research is needed on this treatment modality.