1Tanin Titipungul M.D., 2Nipon Chaisuriya M.D., 2Emorn Phanomsri M.Sc., 2Sakda Waraasawapati M.D., 2Supinda Koonmee M.D., 2Suwit Balthaisong B.Sc., 2Chawalit Pairojkul M.D., 2Yaovalux Chamgramol Ph.D.
1Department of Pathology, Mahasarakham Hospital, Mahasarakham, Thailand 2Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand Correspondence: Yaovalux Chamgramol, Ph.D. Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
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Received : 30 March 2014; Accepted : 12 May 2014


Objective : To determine the prognostic significance of the immunophenotype, density and distribution of tumor-infiltrating lymphocytes (TILs) in breast cancer samples. 

Materials and methods : This was a retrospective study, using paraffin-embedded samples obtained from 43 breast cancer patients, treated at Mahasarakham Hospital between 2012 and 2013. TILs and prognostic markers were evaluated by immunohistochemical staining of tissue microarray cores, employing monoclonal antibodies to lymphocyte markers (i.e., CD3, CD4, CD8 and CD20) and markers for breast cancer (i.e., ER, PR, HER2 and Ki-67). TILs were separated into 2 groups: 1) intratumoral lymphocytes (when found within tumor cell nests), and peritumoral lymphocytes (when infiltrating into the stroma, adjacent to the invasive front of tumor). The results of low- or high-density lymphocyte subtype infiltration of TILs in the intratumoral and peritumoral regions were compared with clinicopathological data.
Results : A positive correlation was found between high density peritumoral infiltrating CD8+ lymphocytes and breast carcinoma without lymph node metastasis (p=0.044), and an inverse correlation was found between the density of peritumoral infiltrated CD4+ lymphocytes and estrogen receptor expression (p=0.027). The density of peritumoral infiltrating CD8+ lymphocytes as well as the number of intratumoral CD20+ lympho- cytes were independently, positively correlated with tumor size < 5 cm (p=0.027 and 0.004, respectively).
Conclusion : Pathology assessment of TILs subtyping in breast cancer sections could have implications for patient prognosis.