The Relationship Of The Expression Of PD-L1, BRAF^V600E, And CD68 With Malignant Melanoma

Objectives:Detection of the expression of programmed death ligand-1 (PD-L1), BRAFV600E and CD68 (the marker of TAMs) in the tissue from primary malignant melanoma. Meanwhile, the percentage of lymphocytes which infiltrated into the tumor was counted. The co-relationship among those parameters, combined with the pathological features and some selective prognostic indicators for the malignant melanoma, were analyzed.Methods:The tumor tissues from 60 patients suffered from malignant melanoma,20 patients with metastasis among them. All of the patients were in-patients in from 2007. 1-2011.12 in the Cancer Hospital of Chinese Academy of Medical Sciences. All of the patients didn’t get any radiotherapy or chemotherapy before going to surgery and also kept complete clinical and pathological information. The grading of malignant melanoma was decided by the standard of AJCC for melanoma (7th edition). The information for each patient contained the gender, age, degree of the depth of tumor invasion, T-stage, the location of tumor, its clinical stages with/without ulceration or necrosis, the metastatic situation of local lymph node and overall survival (OS). The technology of high-throughput tissue microarray combined with immunohistochemistry was used to detect the expression of PD-L1, BRAFV600E and CD68. The variation of their expression was analyzed using semi-quantitative method by assessing their staining strength. The relationship of the expression of PD-L1, BRAFV600E and CD68, together with the clinicopathological features, some selective prognostic indicators of the patients, was analyzed. Meanwhile, the percentage of lymphocytes which infiltrated in the tumor tissue was counted and evaluated with the clinicopathologic parameters of the patients.Results： 1. The overall survival time of 60 patients with primary MM patients was 1-104 months. The age of patients was from 19 to 80 year-old. The age with high percentage of MM was from 50-65 year-old. The overall survival time for those patients in 1-year,3-year,5-year,7-year was 96.7%,85%,46.7% and 23.3%, respectively.2. The percentage of patients with PD-L1 positive reactivity was 43.3% (26/60), the positivity didn’t show any significant correlation with the survival time (P>0.05). Also, the expression of PD-L1 was no significant difference from the age and gender of patients, the location of tumor, the clinical grading and the invasive depth of tumor, the metastasis of lymph nodes, with/without ulceration or necrosis. Only the expression of PD-L1 was correlated with T-stage statistically (P<0.05).3. The 60%(36/60) of patients was BRAFV600E positive in their tumor tissue. The expression of BRAFV600E was not correlated with overall survival time (P>0.05). The positivity of BRAFV600E was also not related to the gender, the location of tumor, T-stage, invasive depth of tumor, with or without ulceration/necrosis, and lymph node metastasis. But the expression of BRAFV600E was only related to the age of patients and clinical stages statistically (P<0.05).4. Among 60 MM cases,6 cases of tumor tissues contained a large number of lymphocyte infiltration (TIL≥50 lymphocytes/100 tumor cells), which account for 10%(6/60). The number of lymphocyte infiltration was related to the lymph node metastasis (P<0.05), Otherwise, the infiltration of lymphocytes was not found to be related to age, gender, invasive depth of tumor, T-stage, clinical stages (P>0.05).5. Positive rate of CD68 expression was 26.7%(16/60), which was not found to be correlated with overall survival time (P>0.05). Also it was not found to be related to age, gender, the invasive depth of tumor, with/ without ulceration or necrosis and lymph node metastasis (P>0.05). CD68 expression was only statistical significant related to the clinical stage of patients and T-stage (P<0.05).6. In 22 MM cases with metastasis, the positive rate of PD-L1 was 59.1% (13/22), BRAFV600E was 50%(11/22) and the CD68 was 27.3%(6/22). Based on the above, the positive rate of PD-L1 in metastatic melanoma is higher than that in primary malignant melanoma. The negative expression of, PD-L1 seemed to indicate a relative better prognosis for the patients. But the difference is not statistically significant upon the data (P>0.05).Conclusions:1. During the development of MM, the expression of PD-L1 was related to T-stage closely.2. BRAFV600E protein expression was relevant to the age, clinical stages of MM.3. CD68 expression was related to T-stage, clinical stages in primary malignant melanoma.4. The number of TIL was closely elated with lymph node metastasis in primary malignant melanoma, which hinted that metastasis had possible developed if there was a large number of TIL in the tumor tissue. The attention will benefit to avoid the misdiagnosis in the future.