Observational analysis of clinical and pathological characteristics and their prognostic impact in Mexican patients with breast cancer: A multi-center study.

Breast cancer is the most incidental and deadly neoplasm worldwide; in Mexico, very few epidemiologic reports have analyzed the pathological features and its impact on their clinical outcome. Here, we studied the relation between pathological features and the clinical presentation at diagnosis and their impact on the overall and progression-free survival of patients with breast cancer. For this purpose, we collected 199 clinical records of female patients, aged at least 18 years old (y/o), with breast cancer diagnosis confirmed by biopsy. We excluded patients with incomplete or conflicting clinical records. Afterward, we performed an analysis of overall and progression-free survival and associated risks. Our results showed an average age at diagnosis of 52 y/o (24-85), the most common features were: upper outer quadrant tumor (32%), invasive ductal carcinoma (76.8%), moderately differentiated (44.3%), early clinical stages (40.8%), asymptomatic patients (47.8%), luminal A subtype (47.8%). Median overall survival was not reached, but median progression-free survival was 32.2 months (29.75-34.64, CI 95%) associated risk were: clinical stage (p < 0.0001) symptomatic presentation (p = 0.009) and histologic grade (p = 0.02). Therefore, we concluded that symptom presence at diagnosis impacts progression-free survival, and palpable symptoms are related to an increased risk for mortality.

Expression of Programmed Death Ligand 1 in Breast Cancer in Mexican Women.

Background: Breast cancer is one of the most common malignant forms of neoplasia worldwide; programmed death protein 1 (PD-1), an inhibitory receptor of T lymphocytes, and its ligand programmed death ligand 1 (PD-L1), play an important role in the ability of tumor cells to evade the host's immune system. Methods: We conducted a descriptive, observational study using retrospective data and an open evaluation using immunohistochemistry to determine the general prevalence of PD-L1 expression in 63 women with breast cancer who underwent a modified radical mastectomy, or quadrantectomy, with axillary lymph node removal. Results: The prevalence of PD-L1 expression was 32% in patients with breast cancer treated with radical mastectomy. PD-L1 expression was higher in patients with large tumor size (19% for pT1, 37% for pT2, 50% for pT3, and 100% for pT4), metastasis in regional lymph nodes (25% for N0, 38% for N1, 75% for pN2, and 38% for pN3), and higher histological grade carcinoma (0% for grade 1, 23% for grade 2, and 50% for grade 3). Conclusions: These findings suggest that PD-L1 expression is heterogeneous in breast cancer tumors and that its expression varies highly in tumor regions over time. The evaluation of PD-L1 expression is significant, because of the therapeutical implications that could improve the outcomes and prognosis of these patients.