Breast cancer is the leading cause of cancer death in women worldwide. Trastuzumab, the main HER2-targeted treatment, faces limitations due to potential cardiotoxicity. The management of patients with mild cardiotoxicity on trastuzumab remains uncertain, resulting in treatment discontinuation and negative oncological outcomes. This retrospective study analyzed 23 patients who experienced decreased left ventricular function during trastuzumab treatment. During the 18-month follow-up period, two patients (9%) had severe declines in function, leading to treatment cessation, and one patient (4%) developed heart failure symptoms. However, 21 patients showed mild, reversible myocardial dysfunction without significant differences in final ventricular function compared to a control group (58.4% vs. 61.7%, respectively; p = 0.059). The declines in function were most pronounced at nine months but improved at twelve and eighteen months. Various echocardiographic parameters changed significantly over time. As predictors of severe cardiotoxicity, we identified the following: LVEF before initial chemotherapy (p = 0.022), as well as baseline LVEF before treatment with trastuzumab (p = 0.007); initial left ventricular end systolic volume (p = 0.027); and the initial global longitudinal strain (p = 0.021) and initial velocity time integral in the left ventricular outflow track (p = 0.027). In conclusion, the continuation of trastuzumab should be considered for most patients with mild cardiotoxicity, with close cardiac monitoring and cardioprotective measures. However, identifying the patients at risk of developing severe cardiotoxicity is necessary. According to our data, the initial LVEF and GLS levels appear to be reliable predictors.

Background: Many studies recognize a close link between inflammation, cardiovascular disease (CVD), and oncological diseases. High-sensitivity C-reactive protein (hs-CRP), a marker of low-grade systemic inflammation, is a shared feature of these conditions. This retrospective study aims to assess the predictive value of hs-CRP for the development of cancer in patients with CVD. Methods: Analyzing data from 174 patients undergoing coronary angiography, we assessed hs-CRP levels and collected demographic, biological, and therapeutic data that could influence the studied parameters. Results: Only smoking and dyslipidemia correlated significantly with CRP levels (p = 0.018 and 0.049, respectively). However, hs-CRP did not predict cancer development (p = 0.52) but correlated with 1-year and follow-up mortality (p = 0.011 and 0.021, respectively). Antiplatelet and statin use was higher in the cancer-free group and associated with a lower probability of developing cancer (p < 0.001 and p = 0.009, respectively). Conclusions: While hs-CRP did not prove effective as a cancer predictor in our study, it correlated with all-cause mortality. Our findings suggest a potential protective effect of antiplatelet and statin treatments against cancer development, prompting further research to understand underlying processes and identify key factors in the pathophysiology of these diseases.