bcl-2 protein in invasive ductal breast carcinomas.
The bcl-2 gene encodes a protein which inhibits programmed cell death (apoptosis). This protein was detected by immunohistochemical techniques in 48% of invasive ductal carcinomas of the breast. It was present in well-differentiated carcinomas with hormonal receptors, and proteins synthesized under the control of oestrogens: pS2, cathepsin D and ERD5. In contrast, bcl-2+ carcinomas are less frequently positive for p53 and have a Ki67 score under the mean. bcl-2 protects cells against apoptosis. Accumulation of p53 protein, which is indicative of p53 mutation, would have the same effect; however, these two proteins seem inversely related, an inverse correlation observed by others in breast cancer cell lines and in lymphomas. Tumours positive for bcl-2 escape apoptosis and have worse prognosis but this is not what is found; survival at 5 years, and particularly the absence of recurrence during the first 5 years after surgery, seem to be associated with bcl-2 positivity. The bcl-2 protein seems only to be an important prognostic factor in women over 54 years of age. Moreover, p53-bcl-2+ tumours have a better response to hormonal therapy than p53-bcl-2-tumours.
Hurlimann
J
J
University Institute of Pathology, Lausanne, Switzerland.
Larrinaga
B
B
Vala
D L
DL
D001943:Breast Neoplasms / Q000737:chemistry* / Q000401:mortality; D018270:Carcinoma, Ductal, Breast / Q000737:chemistry* / Q000401:mortality; D005260:Female; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D019253:Proto-Oncogene Proteins c-bcl-2
D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2