Emerging roles of N6-methyladenosine (m6A) modification in breast cancer

N6-Methyladenosine (m6A) is the most abundant, dynamic, and reversible epigenetic RNA modification that is found in coding and non-coding RNAs. Emerging studies have shown that m6A and its regulators affect multiple steps in RNA metabolism and play broad roles in various cancers. Worldwide, breast cancer is the most prevalent cancer in female. It is a very heterogeneous disease characterized by genetic and epigenetic variations in tumor cells. Increasing evidence has shown that the dysregulation of m6A-related effectors, as methyltransferases, demethylases, and m6A binding proteins, is pivotal in breast cancer pathogenesis. In this review, we have summarized the most up-to-date research on the biological functions of m6A modification in breast cancer and have discussed the potential clinical applications and future directions of m6A modification as a biomarker as well as a therapeutic target of breast cancer.

Comparison of Treatment Outcomes With Breast-conserving Surgery Plus Radiotherapy Versus Mastectomy for Patients With Stage I Breast Cancer: A Propensity Score-matched Analysis

BACKGROUND

To investigate the superiority of breast-conserving surgery (BCS) plus radiotherapy (RT) compared with mastectomy alone for patients with stage I breast cancer in a real-world setting.

PATIENTS AND METHODS

The data from patients with histologically confirmed stage I breast cancer treated from 1999 to 2014 were retrospectively reviewed. The association of outcomes with the choice of treatment (BCS plus RT vs. mastectomy) was evaluated using multivariable proportional hazards regression and further confirmed using propensity score matching methods.

RESULTS

Of 6137 eligible patients in the present study, 1296 underwent BCS plus RT and 4841 underwent mastectomy plus axillary lymph node dissection without RT (mastectomy group). Multivariate analysis revealed that BCS plus RT was related to similar locoregional recurrence-free survival but greater distant metastasis-free survival (P = .003) and overall survival (P = .036) compared with mastectomy. For the 1252 pairs of patients matched using propensity score matching, the BCS plus RT groups enjoyed significantly greater 5-year overall survival (99.1% vs. 96.1%; P = .001), distant metastasis-free survival (97.0% vs. 92.2%; P < .001), and disease-free survival (95.3% vs. 90.2%; P = .001) compared with the mastectomy group.

CONCLUSION

BCS plus RT provided better outcomes than mastectomy for eligible patients with stage I breast cancer and should be offered as a preferred treatment option.