Excised breast cancer specimens from patients previously enrolled in an ongoing , prospective , randomised trial ( NCT00418457 ) investigating the effect of anaesthetic technique on long-term breast cancer outcome were immunohistochemically stained to enable a colour deconvolution technique to summate marked immune cell infiltration : CD56 ( NK cells ) , CD4 ( T helper cells ) , CD8 ( T suppressor cells ) and CD68 ( macrophages ) .