Apoptosis and Bcl-2 expression in relation to age, tumor characteristics and prognosis in breast cancer. South-East Sweden Breast Cancer Group.
The extent of apoptosis and the expression of Bcl-2 was investigated in tumor samples from 165 women who underwent surgery for primary breast carcinoma between 1989 and 1990 in South-East Sweden. Apoptosis was assessed by a DNA fragmentation assay for flow cytometry. Bcl-2 protein expression was analyzed with immunocytochemistry. Bcl-2 immunoreactivity correlated with estrogen receptor (ER) and progesterone receptor (PgR) positivity and was inversely correlated with p53 accumulation. Apoptosis increased with patient age and a high degree of apoptosis was negatively associated with Bcl-2 immunostaining. Apoptosis showed no significant correlation with any of the other variables studied, including prognosis. The group with Bcl-2-positive tumors tended to have a lower risk of distant recurrence than others, but the association of Bcl-2 with recurrence was different in groups divided by ER and PgR status. Whereas Bcl-2 positivity indicated a low recurrence rate among PgR-negative patients, in the PgR-positive group, those with Bcl-2-positive tumors showed a non significantly higher recurrence rate than Bcl-2-negative cases. In the PgR-positive group, Bcl-2-positive tumors also appeared more frequently to be lymph node positive and DNA aneuploid. The results suggest that hormone receptor status is of importance for the prognostic role of Bcl-2. Likewise, patient age merits consideration when apoptosis is studied in human cancer.
Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, Sweden.
P
P
Holmqvist
M
M
Lundström
O
O
Stål
D000328:Adult; D000367:Age Factors; D000368:Aged; D017209:Apoptosis; D001943:Breast Neoplasms / Q000378:metabolism* / Q000503:physiopathology; D053938:DNA Fragmentation; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D019253:Proto-Oncogene Proteins c-bcl-2; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D016159:Tumor Suppressor Protein p53