Showing papers by "Cheryl Gillett published in 1998"

Cyclin D1 in breast cancer.

Abstract: Cyclin D1 protein plays an important part in regulating the progress of the cell during the G1 phase of the cell cycle. The cyclin D1 gene, CCND1, is amplified in approximately 20% of mammary carcinomas, and the protein is over-expressed in approximately 50% of cases. This has led to intensive study to ascertain whether cyclin D1 is a biological marker in breast cancer; however, the clinical work has produced unexpected results. Work in cell lines and in transgenic mice indicate that CCND1 is a weak oncogene and it was expected that, like c-erbB-2, over-expression of cyclin D1 protein would be associated with a poor prognosis. Early immunohistochemical prognostic studies produced equivocal results but we, and others, have recently shown that strong staining for cyclin D1 is more likely to be seen in well differentiated, estrogen receptor positive carcinomas. Furthermore, we have found that over-expression of cyclin D1 is actually associated with a good outcome, both in terms of prognosis and response to endocrine treatment. Cyclin D1 is frequently over-expressed in ductal carcinoma in situ but not in benign breast disease, including atypical ductal hyperplasia; hence its expression appears to be closely linked with carcinogenesis. In order to help explain the apparent beneficial effects of cyclin D1 over-expression, a number of closely associated cell cycle proteins have also been evaluated, including the cyclin dependent kinase inhibitor p27, which blocks the activating effects of cyclin D1. Initial reports show that high levels of p27 are associated with a good prognosis and we have shown a positive association between p27 and cyclin D1 expression. These clinical results of cyclin D1 are an example of how information obtained from basic cell biology studies needs to be complemented by clinical studies to ascertain the true worth of a prognostic marker.

Retinoblastoma and p16 proteins in mammary carcinoma: Their relationship to cyclin D1 and histopathological parameters

Abstract: The cell cycle-associated retinoblastoma protein (pRb) and p16 protein were demonstrated using immuno-histochemistry on paraffin sections from 192 cases of invasive breast carcinoma. Abnormal expression of pRb was defined as negative staining and was seen in 17% of tumours. Such abnormal expression was significantly more frequent in tumours with negative oestrogen receptor (ER) status. There was also a trend for tumours which were negative for pRb to be grade III ductal carcinomas. There was no association between p16 staining and any histopathological parameter, though, surprisingly, log-rank analysis showed that strong staining was associated with a poor outcome. There was a significant inverse relationship between pRb and p16 expression and a significant positive association between pRb and cyclin D1. In a Cox multivariate analysis, which included cyclin D1, neither pRb nor p16 was an independent predictor of patient outcome.

Cyclin D1 and associated proteins in mammary ductal carcinoma in situ and atypical ductal hyperplasia.

Abstract: Experimental studies suggest that cyclin D1 is a potential oncogene but in clinical studies of invasive breast cancer, overexpression of cyclin D1 is found to be associated with oestrogen receptor (ER) expression and low histological grade, both markers of good prognosis. Immunohistochemistry has been used to examine the relationship between cyclin D1 expression and differentiation in 36 cases of ductal carcinoma in situ (DCIS) and the interrelationship between expression of cyclin D1, its associated protein product of the retinoblastoma gene (pRb), and ER, in this group of cases. The expression of these markers has also been examined in nine cases of atypical ductal hyperplasia (ADH) and these results have been compared with the levels of expression seen in DCIS. Cyclin D1 overexpression was found in 23/36 (64 per cent) cases of DCIS and, in contrast to invasive carcinoma, there was no relationship with either differentiation or ER expression. The level of pRb expression was significantly associated with cyclin D1 expression (rS=0·49, P=0·001) and only two cases (6 per cent) were pRb-negative. There was no association between pRb and differentiation of DCIS or ER status. In contrast to DCIS, only one case of ADH showed overexpression of cyclin D1 (Mann–Whitney U-test, P=0·02). All cases of ADH were ER-positive and showed moderate pRb staining, similar to that seen in well-differentiated DCIS. These results provide further evidence that overexpression of cyclin D1 plays a role early in carcinogenesis. © 1998 John Wiley & Sons, Ltd.

Immunohistochemical expression of BRCA2 protein and allelic loss at the BRCA2 locus in prostate cancer

Abstract: Many epidemiological studies have reported an association between breast and prostate cancer. BRCA2 functions as a tumour-suppressor gene in about 35% of large familial breast-cancer clusters; its role in the pathogenesis of sporadic breast cancer is less clear. We have evaluated immunohistochemical expression of BRCA2 protein and allelic loss of markers at the BRCA2 locus in tissue derived both from sporadic and from familial cases of prostate cancer. Immunohistochemical analysis was performed in 167 paraffin-embedded archival specimens. Normal prostate and 75% (120/160) of prostate-cancer tissue did not express BRCA2 protein. However, 25% (40/160) of cancer cases did express patchy staining; of these, 17% (27/160) expressed positive nuclear staining in normal glandular tissue adjacent to tumour (either in addition to, or, independent of tumour). Allelic loss is the hallmark of a tumour-suppressor gene. Markers flanking (D13S267, D13S260) and within (D13S171) the BRCA2 gene indicated allelic loss in at least one locus in 23% (17/73) of tumours analyzed. There was no difference in the rates of allelic loss between sporadic and familial tumours, nor was there any association between immunohistochemical staining and allelic loss. Although immunohistochemical staining provided no useful prognostic information, allelic loss at BRCA2 was shown in univariate analysis to be associated with poorer survival (log-rank test, p = 0.046).

Cell proliferation measured by MIB1 and timing of surgery for breast cancer

Abstract: We have investigated the use of the antibody MIB1 as a proliferative and prognostic marker in breast cancer and whether changes in proliferative activity could account for differences in prognosis of premenopausal women operated on during different phases of the menstrual cycle. MIB1 expression was strongly correlated with S-phase fraction and histological grade. There was no difference in MIB1 scores between different phases of the menstrual cycle. Both MIB1 score and timing of surgery correlated significantly with duration of survival, while the two together were even stronger predictors of overall survival. Women with slowly proliferating tumours surgically removed in the luteal phase had a very good prognosis, whereas women with rapidly proliferating tumours excised at other times of the cycle had a worse prognosis.