Abstract P1-07-16: Triple-negative breast cancer: A single-centre retrospective cohort study of 408 TNBC cases with a focus on elderly patients
Authors: Svoboda M , Navrátil J , Palácová M , Fabian P , Bareková L , Kabut T , Coufal O , Fait V , Jurácek J , Selingerová I 
Published: May 2016

Background: TNBC represents a heterogeneous group of breast cancers that do not express ER-α, PgR and Her-2 receptors. Generally, these tumors are aggressive and more common in younger women. The aim of our study was to create a representative set of patients with TNBC, which could be analyzed and the data gathered to build basic epidemiological, molecular and clinical characteristics of Czech patients with TNBC. In particular, we focused on older patients (≥70 and ≥75 y.o.). Methods: We retrospectively studied a consecutive cohort of 408 patients diagnosed and/or treated for TNBC at the Masaryk Memorial Cancer Institute between 2004 and 2010. Some clinical-pathologic/molecular correlations were performed to identify prognostically different groups of patients.

Results: The median age of patients was 56 years (25–88). A total of 9.3% of TNBC cases were diagnosed in patients under the age of 34, another 15,2% and 15,0% of cases were in the age group of 35 to 44 years and ≥70 years, respectively. In the group of patients aged ≥70 years (61), 59 % (36) were ≥75 y.o. Incidence of CK5/6+ and BRCA1 mutated tumors decreased with increasing age of patients, while the number of AR+ tumors increased (Chi-square test for trends: p=0,0245, p=0,0049 and p=0,0047, respectively). We confirmed the aggressive nature of this disease: in the follow-up period (median 77,2 months) we observed a relapse in 27,2 % (111) of patients: 71 % of deaths due to disease progression occured within 2 years after diagnosis of the disease. Patients ≥70 and especially ≥75 years of age had, together with patients ≤30 y.o., the highest risk of death due to tumor progression. DFS and OS of patients ≥75 y.o. was significantly worse in comparison with other patients (OS: p=0,035, HR 0,515; DFS: p=0,0077, HR 0,475). Simultaneously, adjuvant chemotherapy and anthracyclines were much less frequently administered in this age group (p&lt;0,0001), despite the fact that the distribution of clinical stages did not differ among the age groups. In the whole cohort, the most important negative prognostic factors in relation to disease specific OS were: higher clinical stage and pT (both p&lt;0.0001), pN–positive status (p&lt;0.0001), absence or early withholding of chemotherapy (p&lt;0.0001) and minimal disease response to neoadjuvant treatment (TRG4-TRG5) (p=0.005). High levels of BCL2 expression predicted poor OS in basal-like TNBC patients treated with adjuvant anthracycline-based regimens (p=0.033, HR 3.04). Contrariwise, longer OS was associated with the presence of tumor infiltrating lymphocytes (p=0,0004, HR 2,40).

Conclusion: TNBC is an aggressive form of breast cancer, which may occur in patients of all ages, but more frequently in younger patients. Early detection and intensive treatment od these tumors gives a high chance of cure. Patients ≥70 and especially ≥75 years of age, together with patients ≤30 y.o., are at the highest risk of death due to tumor progression. While in younger patients it is likely due to the aggressiveness of disease, in older patients, in particular, because of an absence of adjuvant systemic therapy. The introduction of targeted therapies could potentially improve prognosis in both groups of patients (eg. PARP inhibitors, antiandrogens).

Supported by IGA MZ CR: NT14599-3.

Citation Format: Svoboda M, Navrátil J, Palácová M, Fabian P, Bareková L, Kabut T, Coufal O, Fait V, Jurácek J, Selingerová I. Triple-negative breast cancer: A single-centre retrospective cohort study of 408 TNBC cases with a focus on elderly patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-07-16.