Molecular biology of breast tumors and prognosis

Clinicopathological and prognostic significance of programmed cell death ligand 1 expression in patients diagnosed with breast cancer: meta-analysis

BACKGROUND

Uncertainty exists regarding the clinical relevance of programmed cell death ligand 1 (PD-L1) expression in breast cancer.

METHODS

A systematic review was performed in accordance with PRISMA guidelines. Observational studies that compared high versus low expression of PD-L1 on breast cancer cells were identified. Log hazard ratios (HRs) for disease-free and overall survival and their standard errors were calculated from Kaplan-Meier curves or Cox regression analyses, and pooled using the inverse-variance method. Dichotomous variables were pooled as odds ratios (ORs) using the Mantel-Haenszel method.

RESULTS

Sixty-five studies with 19 870 patients were included; 14 404 patients were classified as having low and 4975 high PD-L1 expression. High PD-L1 was associated with achieving a pathological complete response following neoadjuvant chemotherapy (OR 3.30, 95 per cent confidence interval 1.19 to 9.16; P < 0.01; I2 = 85 per cent). Low PD-L1 expression was associated with human epidermal growth factor receptor 2 (OR 3.98, 1.81 to 8.75; P < 0.001; I2 = 96 per cent) and luminal (OR 14.93, 6.46 to 34.51; P < 0.001; I2 = 99 per cent) breast cancer subtypes. Those with low PD-L1 had favourable overall survival rates (HR 1.30, 1.05 to 1.61; P = 0.02; I2 = 85 per cent).

CONCLUSION

Breast cancers with high PD-L1 expression are associated with aggressive clinicopathological and immunohistochemical characteristics and are more likely to achieve a pathological complete response following neoadjuvant chemotherapy. These breast cancers are, however, associated with worse overall survival outcomes.

Morphological Evaluation of Tumor-Infiltrating Lymphocytes (TILs) to Investigate Invasive Breast Cancer Immunogenicity, Reveal Lymphocytic Networks and Help Relapse Prediction: A Retrospective Study

Tumor-infiltrating lymphocytes (TILs) in breast cancer are a key representative of the tumor immune microenvironment and have been shown to provide prognostic and predictive biomarkers. The extent of lymphocytic infiltration in tumor tissues can be assessed by evaluating hematoxylin and eosin (H&amp;E)-stained tumor sections. We investigated tissue microarrays of 31 invasive breast cancer patients, looking at quantity and topological distribution of CD3+, CD8+, CD20+, Ki67+, FoxP3+ TILs and CD3+/FoxP3+, CD8+/FoxP3+ cell ratios. We separately evaluated TILs at the invasive edge and at the center of the tumor, to find any clinical implications of tumor heterogeneity. No statistically significant difference was found in quantity and distribution of both TIL subsets and TIL ratios, by comparing patients who suffered from a local or distant recurrence of the tumor (relapse group: 13 patients) with patients not showing cancer relapse (non-relapse group: 18 patients). In the whole sample, we observed three main statistically significant positive correlations: (1) between CD3+ and CD8+ T-cells; (2) between FoxP3+ and Ki67+ lymphocyte infiltration; (3) between CD3+/FoxP3+ cell ratio (C3FR) and CD8+/FoxP3+ cell ratio (C8FR). Tumor heterogeneity and stronger positive TIL associations were found in the non-relapse group, where both CD3-CD8 and FoxP3-Ki67 inter-correlations were found to be significant at the center of the tumor, while the correlation between C3FR and C8FR was significant at the invasive edge. No correlations between TIL subsets were detected in the relapse group. Our findings suggest the existence of stronger inter-subtype lymphocytic networks in invasive breast cancer not showing recurrence. Further evaluations of clinical and topological correlations between and within TIL subsets are needed, in addition to the assessment of TIL quantification and distribution, in order to follow up on whether morphological evaluation of TILs might reveal the underlying lymphocytic functional connectivity and help relapse prediction.

In situ localization of tumor cells associated with the epithelial-mesenchymal transition marker Snail and the prognostic impact of lymphocytes in the tumor microenvironment in invasive ductal breast cancer

PURPOSE

Tumor surgery is aimed at complete resection of the lesion while ensuring a sufficient tumor-specific safety distance. Nevertheless, in many cases the most peripheral part - the invasion front - remains in situ. Tumor cells at the tumor margin have been reported to lose their epithelial properties and acquire features of mesenchymal cells. The process of epithelial-to-mesenchymal transition (EMT) is believed to be of prime importance for tissue and vessel invasion. Furthermore, the detection of tumor-infiltrating lymphocytes in the microenvironment of breast cancer might serve as a reliable prognostic marker.

METHODS

We investigated tissue microarrays of 352 breast cancer patients with regard to the presence and distribution of the EMT factor Snail, and the presence of FoxP3, CD3 and CD8 in the immune microenvironment.

RESULTS

The expression of the transcription factor Snail is strongly associated with longer disease-free and overall survival. The presence of CD3, CD8 or FoxP3 is associated with a better outcome, although statistically significant results were noted only for FoxP3. The prognostic significance of FoxP3 and Snail were also proven in multivariate analysis.

CONCLUSIONS

Based on previous studies concerning the intratumoral heterogeneity of EMT, our results suggest that Snail and FoxP3 are possible prognostic markers for breast cancer. The diverse presence of lymphocytes in the tumor microenvironment (CD3 and CD8) was confirmed. Although the importance of these markers is known, their specific role in tumor invasion and metastasis as well as their hierarchical organization in these tumors remain unclear.

Integration of advances in social media and mHealth technology are pivotal to successful cancer prevention and control

The successful prevention and treatment of cancer is dependent upon efficient and reliable communication between healthcare workers and patients. Advances in social media and mHealth platforms have provided new ways in which to enhance the sharing of cancer related information. Other benefits of embracing this technology include utilising its analytic capabilities which can process the vast quantity of information generated from genome exploration in a highly efficient manner. The aim of this review is to provide an overview of the rapidly evolving areas through which digital engagement is proving useful in the prevention and control of cancer.