[Rebound regression after additional hormonal treatment with ethinyl oestradiol of metastasising carcinoma of the breast in females: frequency and clinical significance (author's transl)].

Rebound regression occurred in 13 of 42 females (30.9% with metastasising carcinoma of the breast in the postmenopausal period in whom additional hormonal treatment with ethinyl oestradiol had brought about a remission. Duration of the rebound response ranged from 3 to 44 months (average 11.2 months; mean 8 months). There was a significantly longer duration of remission (18.7 months compared with 12.0 months; P = 0.01) in patients with than those without a rebound response. There was also a significant correlation between the duration of the preceding remission under additional hormonal treatment and the duration of the subsequent rebound response (P less than 0.01). On the other hand, there was a negative but not significant correlation between the free interval duration which preceded the metastasisation and the duration of the rebound regression.