An analysis of relapsed breast cancer in patients previously treated with breast conserving surgery

The Roles of MicroRNAs in Breast Cancer

MicroRNAs (miRNAs) constitute a large family of small, approximately 20–22 nucleotide, non-coding RNAs that regulate the expression of target genes, mainly at the post-transcriptional level. Accumulating lines of evidence have indicated that miRNAs play important roles in the maintenance of biological homeostasis and that aberrant expression levels of miRNAs are associated with the onset of many diseases, including cancer. In various cancers, miRNAs play important roles in tumor initiation, drug resistance and metastasis. Recent studies reported that miRNAs could also be secreted via small endosome-derived vesicles called exosomes, which are derived from multiple cell types, including dendritic cells, lymphocytes, and tumor cells. Exosomal miRNAs play an important role in cell-to-cell communication and have been investigated as prognostic and diagnostic biomarkers. In this review, we summarize the major findings related to the functions of miRNAs in breast cancer, which is the most frequent cancer in women, and discuss the potential clinical uses of miRNAs, including their roles as therapeutic targets and diagnostic markers.

Breast conservation: evolution of surgical strategies

The surgical strategy for breast cancer has changed considerably over the last decade. Breast-conserving therapy (BCT) is now standard treatment. Today, at least three out of four breast cancer patients are, in principle, eligible for BCT. However, several specific factors must be considered to choose the correct surgical strategy. This review provides a scientific overview of the history, surgical methodology, and specific aspects of BCT.

The management of elderly patients with T1–T2 breast cancer treated with or without radiotherapy

AIM

The aim of the current study is to identify a subgroup of patients with breast cancer who have a low risk of local recurrence after conservative surgery in order to avoid radiotherapy treatment.

METHODS

A group of 472 patients underwent conservative surgery without radiotherapy, and it was compared to a second group of 755 patients with similar characteristics, but who had received radiotherapy treatment (RT) after conservative surgery.

RESULTS

Breast relapse's univariate analysis demonstrated statistical significance for the following factors: radiotherapy treatment, clinical stage, pathological stage, positive axillary nodes and tumour grading. Different results were obtained studying breast relapse. In the no-RT group breast relapse was 10.6% while in the irradiated group it was 3.4%. The breast relapse incidence decreases as the age of the patients increases especially over 75 years of age.

CONCLUSIONS

In conclusion, there is clinical evidence of avoiding adjuvant radiotherapy for patients over 75 years with T1-T2 cancer treated with quadrantectomy with a clear excision margin.

Histological quantitation of tumour angiogenesis

Tumours establish their blood supply via a number of processes in addition to angiogenesis. These include vasculogenesis, vascular remodelling, intussusception and possibly vascular mimicry in certain tumours. The mainstay of the assessment of tumour vascularity has been counting the number of immunohistochemically identified microvessels in vascular hot spots. Nevertheless, several other techniques are available, including Chalkley counting, vascular grade and the use of image analysis systems. Angiogenic activity can furthermore be assessed in histological samples by measuring the molecules involved in the establishment of the tumour vasculature, including angiogenic growth factors and their receptors, cell adhesion molecules, proteases and markers of activated, proliferating, cytokine stimulated or angiogenic vessels, such as CD105. Measuring the maturity of vessels may give an indication of the proportion of the tumour vasculature that is functional. Other reagents that can identify hypoxia-activated pathways are also being developed. The histological assessment of tumour vascularity is mainly used in the research setting but may also have applications in the clinic if appropriate methodology and trained observers perform the studies. Gene arrays may be able to provide an angiogenesis profile. Continued study into the processes involved in generating a tumour blood supply is likely to identify new markers that may be more accurate measures.

Lack of prognostic significance of survivin, survivin-deltaEx3, survivin-2B, galectin-3, bag-1, bax-alpha and MRP-1 mRNAs in breast cancer

The expression of transcripts for anti-apoptotic (survivin, survivin-deltaEx3, survivin-2B, galectin-3, bag-1 and bcl-2) and pro-apoptotic (bax-alpha) genes, and for multiple drug resistance related protein-1 (MRP-1) gene were investigated, using RT-PCR, in 106 breast tumour biopsies. Normal breast tissue was also analysed for comparative purposes. Overall, survivin, survivin-deltaEx3, survivin-2B, bcl-2, bag-1, galectin-3, bax-alpha and MRP-1 mRNAs were detected in 68, 54.7, 9.4, 78.4, 80.9, 98.9, 97.8 and 72.8%, respectively, of tumour specimens. Uniquely among the mRNAs analysed, the expression of bcl-2 correlated significantly with disease outcome, with bcl-2 expression indicative of favourable outcome in terms of both relapse-free survival and overall survival. This suggests that bcl-2 mRNA expression may be a key prognostic marker for breast cancer and that routine analysis of expression of this transcript should be considered. The results from this study suggest, however, that the expression of survivin, survivin-deltaEx3, survivin-2B, bag-1, galectin-3, bax-alpha and MRP-1 mRNAs cannot be considered as prognostic indicators of disease outcome for patients with breast cancer.