Do platinum salts fit all triple negative breast cancers?

Triple-negative breast cancer (TNBC) is an aggressive disease with limited treatment options and poor prognosis once metastatic. Pre-clinical and clinical data suggest that TNBC could be more sensitive to platinum-based chemotherapy, especially among BRCA1/2-mutated patients. In recent years, several randomised trials have been conducted to evaluate platinum efficacy in both early-stage and advanced TNBC, with conflicting results especially for long-term outcomes. Experimental studies are now focusing on identifying biomarkers of response to help selecting patients who may benefit most from platinum-based therapies, including BRCA1/2 mutational status and genomic instability signatures (such as HRD-LOH or HRD-LST scores). A standard therapy for TNBC is still missing and platinum-based regimens represent an emerging therapeutic option for selected patients with a defect in the homologous recombination repair system. The identification of these patients through validated biomarker assays will be crucial to optimize the use of currently approved agents in TNBC.

Pattern of metastasis and outcome in patients with breast cancer.

There is growing evidence about differences in metastatic spread among breast cancer (BC) biologic subtypes (BS). Aim of this study was to analyze the pattern of metastasization according to BS and to explore the corresponding prognosis. A series of 544 consecutive patients receiving anticancer therapy for metastatic BC from 2004 to 2013, was analyzed. BS were defined by immunohistochemistry according to St Gallen 2013 criteria. Association between BS and the different distant localizations was analyzed. Prognosis was described in terms of overall survival (OS), progression free survival (PFS) and post progression survival (PPS). Results were reported taking luminal A BC as reference. Triple negative BC showed a higher tropism for lung (OR 4.30 95% CI 1.41-13.1), while non luminal HER2 subtype was associated with a higher rate of liver metastases (OR 3.61 95% CI 1.36-9.58). All subtypes were associated with a lower risk of bone-only localization. Central nervous system (CNS) involvement was more common in HER2 positive BC (OR 6.3, 95% CI 1.08-36.66). Liver, lung and CNS involvement influenced negatively OS (HR 1.64, 95% CI 1.29-2.07; HR 1.49, 95% CI 1.18-1.90; HR 2.891, 95% CI 1.85-4.51, respectively) and PFS (HR 1.39, 95% CI 1.13-1.71; HR 1.26, 95% CI 1.02-1.55; HR 1.75, 95% CI 1.12-2.71, respectively). Multivariate analysis confirmed liver involvement as independent predictor of worse OS (HR 1.64, 95% CI 1.15-2.34). Stratification by metastatic pattern showed significant differences in terms of PPS but not in terms of PFS. The study suggests that BS may be characterized by typical patterns of metastatic spread and have different impact on clinical outcome.