The effect of delayed treatment in breast cancer patients: How much is too late? An experience of a single-center study effect of surgery delay in survival.

BACKGROUND AND OBJECTIVES: Proper treatment is critical for control and curative intent in breast cancer. Delays in receiving treatment can influence patients' prognoses. METHODS: Retrospective, observational, single-center study based on data from medical records of 747 patients with non-metastatic invasive ductal breast carcinoma (I-III) in the initial analysis, comprising 554 patients undergoing adjuvant and 193 neoadjuvant treatment. Kaplan-Meier, Cox regression and time-dependent Cox regression were performed to obtain the predictive value of time to surgery and time to first treatment. Immortal time bias was managed and only 721 patients were included in the multivariable analysis. RESULTS: During a median observation of 64.4 months, there were 140 death events and 177 disease progression events. Time to surgery (TTS) and time from completion of neoadjuvant chemotherapy to surgery (TNS) showed a significant impact on overall survival, associated with a 6% increased chance of death [HR: 1.06 (1.03-1.09), p < 0.001] and 4% [HR: 1.04 (1.00-1.09), p = 0.048] with a one-month increment, respectively. By multivariable analysis, continuous TTS had a different weight as a prognostic factor in stage IIIA/IIIB [adjusted HR: 1.249 (1.072-1.454), p = 0.004] compared to stage I/II [adjusted HR: 1.093 (1.048-1.141), p < 0.0005]. Likewise, TNS was significant after adjusting for other factors [adjusted HR: 1.092 (1.038-1.148), p = 0.001]. CONCLUSION: Delay in receiving surgery with curative intent impairs the survival of patients with breast cancer.

The effectiveness of radiotherapy in preventing disease recurrence after breast cancer surgery.

BACKGROUND AND OBJECTIVES: The locoregional management of breast cancer has a critical impact on prognosis. This study aimed to analyze the effectiveness of radiotherapy against the deleterious effect of positive surgical margins on disease outcomes. METHODS: Retrospective, single-center study enrolled 721 breast cancer patients with a median follow-up of approximately 64.50 months (3.67-247.40). Analyses were performed considering the end of adjuvant therapy, except endocrine therapy. Kaplan-Meier and Cox regression were performed to obtain the predictive value of treatments. RESULTS: The minimally adequate radiotherapy (≥45 cGy) was associated with improved outcomes in breast cancer patients compared to inadequate radiotherapy (<45 cGy/no) by controlling locoregional relapses and distant metastasis. In patients with positive surgical margins (n = 53), radiotherapy was associated with an approximate decrease of 90% in locoregional relapse risk [adjusted HR: 0.108 (0.012-0.932), p = 0.043]. Radiotherapy did not alter the adverse effect of positive surgical margins, especially in patients with a higher risk of poorly differentiated tumors (n = 146), presence of lymphovascular invasion (n = 163), and triple-negative subtype (n = 113). Notwithstanding, radiotherapy was associated with respective decreases of distant metastasis risk of 75.2% [adjusted HR: 0.248 (0.081-0.762), p = 0.015] and 67.8% [adjusted HR: 0.322 (0.101-1.029), p = 0.056] in patients with triple-negative tumors or with lymphovascular invasion. CONCLUSION: Adequate radiotherapy is associated with better outcomes in breast cancer. Despite improving locoregional relapse-free survival, radiotherapy does not ablate positive surgical margins, a factor of poorer prognosis that prevails mainly in patients with factors of higher relapse risk.

Pentachloropseudilin impairs angiogenesis by disrupting the actin cytoskeleton, integrin trafficking and the cell cycle

Class 1 myosins (Myo1s) were the first unconventional myosins identified and humans have eight known Myo1 isoforms. The Myo1 family is involved in the regulation of gene expression, cytoskeletal rearrangements, delivery of proteins to the cell surface, cell migration and spreading. Thus, the important role of Myo1s in different biological processes is evident. In this study, we have investigated the effects of pentachloropseudilin (PClP), a reversible and allosteric potent inhibitor of Myo1s, on angiogenesis. We demonstrated that treatment of cells with PClP promoted a decrease in the number of vessels. The observed inhibition of angiogenesis is likely to be related to the inhibition of cell proliferation, migration and adhesion, as well as to alteration of the actin cytoskeleton pattern, as shown on a PClP‐treated HUVEC cell line. Moreover, we also demonstrated that PClP treatment partially prevented the delivery of integrins to the plasma membrane. Finally, we showed that PClP caused DNA strand breaks, which are probably repaired during the cell cycle arrest in the G1 phase. Taken together, our results suggest that Myo1s participate directly in the angiogenesis process.

Mechanistic insights into the anti-angiogenic activity of Trypanosoma cruzi protein 21 and its potential impact on the onset of chagasic cardiomyopathy

Chronic chagasic cardiomyopathy (CCC) is arguably the most important form of the Chagas Disease, caused by the intracellular protozoan Trypanosoma cruzi; it is estimated that 10-30% of chronic patients develop this clinical manifestation. The most common and severe form of CCC can be related to ventricular abnormalities, such as heart failure, arrhythmias, heart blocks, thromboembolic events and sudden death. Therefore, in this study, we proposed to evaluate the anti-angiogenic activity of a recombinant protein from T. cruzi named P21 (rP21) and the potential impact of the native protein on CCC. Our data suggest that the anti-angiogenic activity of rP21 depends on the protein's direct interaction with the CXCR4 receptor. This capacity is likely related to the modulation of the expression of actin and angiogenesis-associated genes. Thus, our results indicate that T. cruzi P21 is an attractive target for the development of innovative therapeutic agents against CCC.