Abstract Objective: The aim of the study was to investigate the localization, amount and type of lymphocytic infiltrate, found in different molecular subtypes of breast cancer (BC). Methods: Retrospectively, 100 cases of invasive BC were analyzed and immunohistochemicaly (IHC) stratified in four subtypes (Luminal A and Luminal B-like, HER2-positive, and triple negative (TN). The percentage of stromal areas occupied by tumor-infiltrating lymphocytes (TILs) was assessed for H&E slides. The samples were IHC-stained for CD3, CD4, CD8, CD20 and FoxP3. The immunophenotyped lymphocytes - intratumoural and stromal, were separately counted, semi-quantitatively graded and further analyzed. Results: A total of 10% of all tumors were lymphocyte-predominant BC. Intratumoral and stromal TILs were predominantly CD3+T-lymphocytes. High counts of all subtypes TILs - intratumoral and stromal, were most common for TNBC and HER2-positive BC. In TNBC, the intratumoral CD3+TILs are significantly related to CD8+ (p=0.002) and FoxP3+ phenotype (p=0.010). In HER2 BC, the intratumoral and stromal CD3+ TILs were significantly related to FoxP3+ phenotype (p = 0,035 and p= 0.011, respectively). Conclusion:CD3+T-cell mediated immunity, especially the one related to CD8+ and FoxP3+ lymphocytes was the leading one in antitumor response in BC, and high count of intratumoral and stromal lymphocytes predominated in TN and HER2-positive BC. Key words: Breast cancer, tumor-infiltrating lymphocytes, CD3, CD4, CD8, CD20, FoxP3. Citation Format: Popovska SL, Dimitrova PD, Dineva TB. A study on amount, localization and immune phenotype of tumor-infiltrating lymphocytes in different subtypes of breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-20.
The breast is an extremely rare target organ for metastasis of extramammary neoplasms. The occurence varies between 1.7% to 6.6% in autopsies; between 1.2% and 2% in clinical cases; and around 2.7% in sputum series. In accordance with the primary tumor localization, it is more common to find metastases of lymphoma, melanoma, rhabdomyosarcoma, tumors of the lung and ovarian tumors. Breast metastasis of the uterine cervix is a very seldomly found. According to the published literature so far there have been around 30 documented cases with such pathology. This study presents the case of a 48-year-old female with a squamous cell carcinoma of the uterine cervix, which was histologically verified in 2010. Three years after the initial tumor diagnosis, radiotherapy and chemotherapy, the patient was found to have a cystic tumor formation in one of her breasts. The formation was painful to pressure. Quadrantectomy with an open bisopsy was performed to the patient. Histological and immunohistochemical diagnosis rejected primary squamous cell carcinoma of the breast. The differential diagnosis of metastatic lesions in the breast is problematic and requires careful clinical history, immunohistochemical study and multidisciplinary approach in the management. Mammary metastases are a bad predictor and they serve as an indicator of generalized dissemination of the primary tumor process.
