Circulating breast tumour antigen-sensitive T lymphocytes in early breast cancer and high risk benign breast disease

Incidence of de-novo breast cancer in women chronically immunosuppressed after organ transplantation

In mice, retrovirus-associated breast cancers are promoted by immune mechanisms, and immunosuppression during the premalignant phase reduces the incidence of breast cancer and prolongs life. If some women likewise have immune promotion of breast cancer, the incidence of breast cancer in patients receiving therapeutic immunosuppression should be lower than that in a comparable cohort of non-immunosuppressed women. We examined the incidence of de-novo breast cancer arising in women receiving immunosuppressive therapy after kidney or heart transplantation, comparing the figures with published rates. In 25,914 immunosuppressed women followed for 1-11 years there were 86 cases of breast cancer compared with 113.8 expected (p = 0.009). Incidence was particularly low in the first transplant year with relative risk 0.49, rising to 0.84 in subsequent years. For all other major cancers the incidence was higher in the immunosuppressed women. If, as in mice, the reduced incidence of breast cancer is a direct effect of immunosuppression, these observations raise the possibility of therapeutic manipulation of specific immune mechanisms that promote tumour growth.

Natural killer cell activity in women at "high risk" for breast cancer, with and without benign breast syndrome

This study is an analysis of natural killer cell (NK) function in 155 women repeatedly tested over a 5-year period while attending breast screening clinics because of one or more of the following risk factors: family history-breast cancer in a close female relative (relative risk = 1.2-9); personal history-early menarche, non-parity, late menopause, etc. (relative risk = 1.3-3); clinical benign breast syndrome-localized and diffuse (relative risk = 2-4). Contrary to expectations, the high-risk group as a whole had significantly higher than normal relative NK function vs K562 (1.21 +/- 0.06 vs 1.00 +/- 0.06) (p less than 0.02). Division into subgroups showed that the NK activities in patients with positive family histories, personal histories, or both, were exactly the same as normal values and that the increased NK function in the high-risk group as a whole was due to those donors with benign breast syndrome (BBS). This group was also subdivided and the results were compared with the high-risk patients with no BBS. The NK activity of the group having diffuse BBS (1.67 +/- 0.05, n = 32) was significantly higher than that of the "No BBS" group (1.07 +/- 0.07, n = 102) (p less than 0.025). A paired "t'-test performed on data from 7 patients who had no BBS and diffuse BBS at different times showed a significant difference of p less than 0.001, suggesting that the elevated NK activity is a reaction to the hormonal factors which cause this condition.