Purpose: Young age is associated with poor prognosis in ductal carcinoma in situ (DCIS) of female breast and controversy exists regarding the optimal treatment modality for young patients. We aimed to compare treatment outcomes among breast conserving surgery (BCS), BCS with adjuvant radiotherapy (BCS + RT), and total mastectomy (MT) for young DCIS women. Methods: PubMed, Cochrane, and Embase were searched for studies reporting comparative results among BCS, BCS + RT, or MT in ≤50 years old (y/o) DCIS females. Study quality was assessed and meta-analysis with subgroup analysis was performed to pool the effect sizes of the outcomes-of-interest. Results: We included 3 randomized control trials and 18 observational studies. For DCIS women ≤50 y/o, RT following BCS significantly reduced the risk for ipsilateral breast tumor recurrence (IBTR) (HR = 0.66, 95% CI 0.50–0.87). However, the benefit was less robust in extremely young patients and with long follow-ups. RT revealed no statistically significant preventive effect on ipsilateral invasive recurrence (HR = 1.38, 95% CI 0.98–1.94). On the other hand, MT yielded the lowest IBTR (BCS + RT vs MT: HR = 4.4, 95% CI 2.06–9.40), both in ipsilateral DCIS recurrence and ipsilateral invasive recurrence. There was great heterogeneity and could not reach an evident conclusion concerning survival outcomes. Conclusion: This study highlighted the varying effect of RT for young DCIS females. The local control benefit of MT was definite without survival differences observed. Our study provided a moderate certainty of evidence to guide the treatment for young DCIS women. Further age-specific prospective trial is warranted.