Male-origin microchimerism and risk of cancer: a systematic review and meta‑analysis.

BACKGROUND

Many women carry male cells of presumed fetal origin-so-called male-origin microchimerism (MOM) in their circulation and tissues. The association between MOM and cancer risk remains unclear. We aim to evaluate the effect of MOM on cancer risk among postpartum women.

METHODS

A comprehensive literature search was conducted to identify relevant articles in databases of PubMed, EMBASE, and Web of Science. The data were extracted from eligible studies on the relationship between MOM and cancer risk. A random-effects model was applied to obtain the pooled relative risks (RRs) with 95% confidence intervals (95%CIs). Subgroup analysis, sensitivity analysis and publication bias and were also conducted.

RESULTS

Twelve studies involving 3078 participants were enrolled in the pooled analysis. Data on the risk of breast, colon, ovarian, endometrial, thyroid, and brain cancer were collected for quantitative analysis. Pooled analysis showed a significantly reduced rate of cancer (pooled RR = 0.51, 95%CI 0.32-0.82) among MOM-positive women.

CONCLUSIONS

Individuals harboring MOM exhibits a significantly low risk of cancer.