Table 1.

Composite results of studies comparing outcome of dMMR CRC based on B2M mutation status

Study	Tumour stage	Recurrence/metastases
		B2M mutation/B2M loss	B2M‐proficient
Kloor et al. (2007) Case–control	58% stages I/II 30% stage III 12% stage IV	0/23	9/54
Tikidzhieva et al. (2012) Randomised trial	24% stages I/II 76% stage III	0/10	6/24
Koelzer et al. (2012) Case–control	53% stages I/II 47% stage III	0/19	14/79
Current study Randomised trial	95% stage II 5% stage III	0/39	14/77
Total		0/91	43/234

dMMR, mismatch repair‐deficient; CRC, colorectal cancer.