Thirty women with breast masses were evaluated psychologically and endocrinologically ten years ago while they were awaiting breast biopsy (3). Eight of these women proved to have benign fibrocystic disease and 22 had breast cancer. A significant (p < 0.05) positive correlation was found between extent of failure of psychological "defenses" and cortisol metabolite excretion rate in these 30 women. On follow-up, 12 women had died (11 with cancer and one who had had benign disease); 7 women were lost to follow-up. Of the remaining 11, one refused to participate, leaving 10 women for follow-up study (7 who had had mastectomy for breast cancer and 3 with benign breast lesions). They were reevaluated using the same assessment techniques as 10 years before. The psychological parameters and cortisol metabolite excretion rates did not show a significant change over the span of ten years. These data support the hypothesis that these psychological parameters and cortisol metabolite excretion rates reflect relatively abiding characteristics and are not as much affected by a "psychosocial threat" as previous research has suggested.