Cell kinetics of histologic variants of in situ breast carcinoma

Neu-protein overexpression in breast cancer. Association with comedo-type ductal carcinoma in situ and limited prognostic value in stage II breast cancer

Amplification of the neu proto-oncogene in breast cancer has been reported to correlate with the presence of lymph-node metastases and with a poor prognosis. We describe a method for the immunohistochemical detection of overexpression of neu protein on formalin-fixed paraffin-embedded tissue, with the use of two different monoclonal antibodies. In a group of tumors with a known neu-gene copy number, intense membrane staining of tumor cells was present in all tumors with neu-gene amplification. Of 189 tumors from patients with Stage II breast cancer, 27 (14 percent) had neu-membrane staining. Neu overexpression was associated with larger tumor size (P = 0.006) but not with lymph-node involvement. Neu-protein expression in lymph-node metastases was the same as its expression in primary tumors. Among the patients with neu overexpression (median follow-up, 37 months), disease-free survival was not significantly shorter; overall survival was reduced significantly in these patients (P = 0.042), but this reduction did not remain significant after adjustment for tumor size. Of 45 ductal carcinomas in situ, 19 (42 percent) had neu-membrane staining. These 19 were all of the large-cell, comedo growth type. None of 16 ductal carcinomas in situ of small-cell, papillary, or cribriform growth type had neu overexpression. We conclude that neu overexpression may be an early step in the development of a distinct histologic type of carcinoma of the breast, but we could find no association of overexpression with lymph-node status or tumor recurrence.

Comparative analysis of different approaches to investigate cell kinetics

The potential of different methods to investigate proliferative activity of cell populations was analysed for non-Hodgkin's lymphomas. Cells in S phase and all cycling cells were determined on cell suspensions obtained from fresh lymph node material by [3H]-thymidine autoradiography [( 3H]TdR LI), a monoclonal antibody to bromodeoxyuridine (BrdU LI), and the monoclonal antibody Ki67. A good correlation was observed between the values of [3H]TdR LI and BrdU LI (rs = 0.90; P less than 0.01), [3H]TdR LI and S phase (rs = 0.62; P less than 0.01) and [3H]TdR LI and Ki67 (rs = 0.64; P less than 0.01) in individual lymphomas. Using the median values obtained from the different approaches as cut-off points to define slowly and rapidly proliferating tumours, the best agreement was observed between [3H]TdR LI and BrdU LI (91%) and poorer agreements, even though statistically significant, were observed between [3H]TdR LI and S phase (73%) or Ki67 (76%). In conclusion, the kinetic information derived from different approaches was more or less concordant and newly proposed approaches should be directly and carefully verified for their prognostic relevance before using them as alternatives to conventional methods.