To investigate the carrier rate of PALB2 gene germline mutations in Chinese female breast cancer patients, assess their pathogenic risk, and explore the correlation between these mutations and clinical pathological characteristics.

Systematic searches were conducted in both Chinese and English databases to collect studies on PALB2 gene mutations in the Chinese population published before 2024. A total of 12 studies were included, involving 15 824 female Chinese breast cancer patients and 13 505 female control subjects. The literature data were subjected to meta-analysis to calculate the pooled mutation carrier rate, risk ratio, and the strength of association with clinical characteristics. The primary effect indicators were the PALB2 mutation carrier rate and its risk ratio, both of which were calculated with 95%CI. The I² statistic was used to evaluate the heterogeneity among studies. P<0.05 was considered statistically significant

The pooled analysis showed that the total carrier rate of pathogenic/likely pathogenic mutations (PV/LPV) of PALB2 in Chinese female breast cancer patients was 1.3% (95%CI: 1.09%-1.44%), significantly higher than that of the control group of healthy individuals (0.2% (95%CI: 0.15%-0.32%)), and the combined risk ratio for developing breast cancer among carriers was as high as 6.8 (95%CI: 4.210-11.120, P<0.001). In the familial/early-onset breast cancer subgroup, the carrier rate increased to 2.2%. Compared with non-carriers, the proportions of grade 11 histological grading and high Ki-67 expression (>20%) were significantly higher in PALB2 mutation carriers (P<0.05); the average diagnosis age was significantly lower than that of non-carriers and the proportion of first-degree relatives with a history of breast cancer was higher (P<0.05); in PALB2 mutation carriers, there was a trend of higher proportion of triple-negative breast cancer compared to non-carriers, but the difference was not statistically significant (P>0.05).

PALB2 is an important breast cancer susceptibility gene with a high penetrance in Chinese women. Its germline mutations can significantly increase the risk of breast cancer and are associated with some invasive clinical pathological features.