Relationship between p53 gene abnormalities and other tumour characteristics in breast-cancer prognosis

Differential expression of senescence tumour markers and its implications on survival outcomes of breast cancer patients

Breast cancer is a heterogeneous disease displaying different histopathological characteristics, molecular profiling and clinical behavior. This study describes the expression patterns of senescence markers P53, DEC1 and DCR2 and assesses their significance on patient survival as a single or combined marker with P16 or P14 using breast cancer progression series. One thousand and eighty (1080) patients with primary invasive ductal carcinoma, no special type, were recruited through an 11-year retrospective study period. We constructed tissue microarrays of normal, benign hyperplasia, ductal carcinoma in situ and invasive ductal carcinoma from each patient and performed immunohistochemical staining to study the protein expression. Statistical analysis includes Pearson chi-square, Kaplan-Meier log ran test and Cox proportional hazard regression were undertaken to determine the associations and predict the survival outcomes. P53, DEC1 and DCR2 expression correlated significantly with normal, benign, premalignant and malignant tissues with (p<0.05). The expression profile of these genes increases from normal to benign to premalignant and plateaued from premalignant to malignant phenotype. There is a significant association between P53 protein expression and age, grade, staging, lymphovascular invasion, estrogen receptor, progesterone receptor and HER2 whereas DCR2 protein expression significantly correlated with tumour grade, hormone receptors status and HER2 (p<0.05 respectively). P53 overexpression correlated with increased risk of relapse (p = 0.002) specifically in patients who did not receive hormone therapy (p = 0.005) or chemotherapy (p<0.0001). The combination of P53+/P16+ is significantly correlated with poor overall and disease-free survival, whereas a combination of P53+/P14+ is associated with worse outcome in disease-free survival (p<0.05 respectively). P53 overexpression appears to be a univariate predictor of poor disease-free survival. The expression profiles of DEC1 and DCR2 do not appear to correlate with patient survival outcomes. The combination of P53 with P16, rather P53 expression alone, appears to provide more useful clinical information on patient survival outcomes in breast cancer.

Medullary Breast Carcinoma: Prognostic Implications of P53 Expression

Medullary breast carcinoma (MBC) is a rare pathological type of breast cancer. The rate of p53 protein accumulation is higher in MBC than in common invasive ductal carcinoma. Whether this particular feature of MBC influences the outcome after treatment is unknown. We retrospectively analyzed the characteristics, treatment and outcome of 71 patients with MBC treated between 1981 and 1996. The median age was 51 years (range 27–81) and the median clinical tumor size was 25 mm (range 0-70 mm). Breast-conserving treatment was offered when possible: 55 patients had undergone a tumorectomy and radiotherapy while 16 patients had undergone a mastectomy. p53 protein accumulation was determined by immunohistochemistry on paraffin-embedded tumor specimens from 58/71 samples available for this study. The median follow-up for the 56 survivors was 113 months (range 30–241). The 10-year survival and metastasis-free survival rates were 81% and 81.4%, respectively. The local recurrence rate was 16.4%. The two factors predicting outcome were pathological axillary node involvement in the 60 patients who underwent axillary dissection and adjuvant chemotherapy. p53 accumulation was found in 33/58 patients (57%). p53 status was not predictive of survival nor of distant or local recurrences. We confirm that medullary breast carcinoma has a favorable prognosis despite its aggressive pathological features. p53 protein accumulation, found in the majority of MBCs, was not related to outcome.

Invasive micropapillary carcinoma of the mammary gland in humans and canines: Clinicopathological, immunophenotypical and survival approaches

Invasive micropapillary carcinoma (IMPC) is a breast cancer with a proclivity for lymph node metastasis that affects women. In canines, this carcinoma has only recently been reported and appears to have similar histological aspects as its human counterpart. Thus, the aim of the present study was to compare clinicopathological, immunohistochemical and prognostic characteristics of mammary IMPC between humans and canines. In canines, regional metastasis was more frequently observed. Histopathologically, humans and canines predominantly showed a moderate histological grade. The pure subtype and neoplastic emboli were more frequently observed in canines. Regarding immunohistochemical evaluation, most canine and human IMPCs were positive for the estrogen and progesterone receptors. A reversed pattern of epithelial membrane antigen expression and a high proliferation index predominated in both species. The mortality due to the neoplastic disease was more frequently observed in canines (94%) than in humans (4%). Thus, canine IMPCs show a larger tumor size and higher rates of the pure subtype, regional metastasis and mortality than their human counterparts and appear to provide a good spontaneous model for achieving a better understanding of the biological behavior of human IMPCs.

The use of digital images improves reproducibility of the ki-67 labeling index as a proliferation marker in breast cancer

The proportion of Ki-67 immunostained cells (Ki-67 labeling index, LI) is one of the most commonly used histology methods for estimating proliferation of breast carcinomas. Although the Ki-67 LI is used in treatment decision making, its reproducibility shows variation in different studies, and is generally less then optimal. The aim of the present study was to investigate how the use of a standardized, partially digitalized counting method could affect reproducibility of determining the Ki-67 LI. Thirty breast cancer core-biopsy samples were stained with B-56, SP-6 and MIB-1 monoclonal Ki-67 antibodies. Each sample was represented by a single digital photograph taken with a x20 objective. Four investigators determined the Ki-67 LI on these digital images by estimation, then by counting with the help of a grid overlaid on the same images. Altogether 720 evaluations were made by 4 independent pathologists. Good to excellent correlation was found between estimations and calculations of each observer. Kappa values >0.6 suggest substantial inter-observer agreement when classifying the cases into a 15 % and 30 % cut-off determined three-tiered or a 4-quarter-based four-tiered categorization, which is better than the fair reproducibility gained on the real slides in a previous study. The results also suggest that the type of the antibody may also impact on the consistency of both estimating and calculating the Ki-67 LIs. The results indicate that counting on digital images may significantly improve reproducibility of determining the KI-67 LI. Interestingly, estimation on the same images is not worse, but is obviously faster and more convenient.

Ki-67 evaluation at the hottest spot predicts clinical outcome of patients with hormone receptor-positive/HER2-negative breast cancer treated with adjuvant tamoxifen monotherapy

BACKGROUND

The clinicopathological importance of Ki-67 in breast cancers has been intensely studied; however, there have been few systematic large studies of patients treated with predefined adjuvant therapy. Further, Ki-67 evaluation methodology differed among studies, which prevents Ki-67 from being used for clinical practice. We performed a large systematic study using routinely processed tissues and compared various scoring methods.

METHODS

Representative slides of archival tissue blocks of 442 consecutive invasive breast cancers from women treated with adjuvant tamoxifen monotherapy and having a long follow-up period were subjected to immunohistochemistry using anti-Ki-67 monoclonal antibody, Mib-1. Both the average score across the section and the score at the hottest spot were assessed.

RESULTS

Ki-67 evaluated at the hottest spot, not the average score across the section, independently predicted poor clinical outcomes of patients with hormone receptor-positive/HER2-negative cancer. Ki-67 was not a predictor of clinical outcome in patients with triple-negative breast cancer. Overall, high Ki-67 level significantly correlated with classic unfavorable clinicopathological factors, correlating negatively with the status of estrogen receptor (ER)-α and progesterone receptor (PR), and positively with HER2 status and grade. ER-β status positively correlated with the Ki-67 level.

CONCLUSIONS

Ki-67 evaluation at the hottest spot was superior to that determined by average score across the section as a predictor of outcome in patients with hormone receptor-positive/HER2-negative breast cancers treated with endocrine monotherapy. The different result obtained in patients with triple-negative carcinomas needs to be further investigated.

Clinical implication of p53 overexpression in breast cancer patients younger than 50 years with a triple-negative subtype who undergo a modified radical mastectomy

OBJECTIVE

The purpose of this study was to identify the clinicopathological characteristics and prognostic value of p53 overexpression in breast cancer patients treated with a modified radical mastectomy.

METHODS

The medical records of 197 patients who had undergone modified radical mastectomy between January 1991 and December 2008 were reviewed retrospectively. Breast cancer subtype and p53 overexpression were investigated using immunohistochemistry and/or fluorescent in situ hybridization analysis of surgical specimens.

RESULTS

The median follow-up after the modified radical mastectomy was 56.1 months (range, 14.7-232.7). The median age was 47 years (range, 31-72). p53 overexpression was noted in 73 patients (37.1%). Breast cancer-specific death rate (P = 0.011), cancer progression (P = 0.024), distant metastasis (P = 0.015), hormone receptor negativity (P < 0.001) and human epidermal growth factor receptor 2 positivity (P = 0.017) were detected more frequently in patients with p53 overexpression. The overall survival rates were significantly lower in the p53-overexpression group than in the non-p53-overexpression group (P = 0.021, log-rank test). In the multivariate analysis, p53 overexpression showed the strongest prognostic significance in patients aged <50 years (P = 0.039) and with the triple-negative subtype (P = 0.023).

CONCLUSIONS

p53 overexpression correlated with breast cancer-specific death rates and adverse prognostic factors in patients treated with modified radical mastectomy. p53 overexpression might be a more reliable prognosticator in patients aged <50 years and with the triple-negative subtype. More effective systemic treatments might be warranted for these patients exhibiting p53 overexpression. Further validation is required to make more definite conclusions.

Protein biomarkers for the early detection of breast cancer

Advances in breast cancer control will be greatly aided by early detection so as to diagnose and treat breast cancer in its preinvasive state prior to metastasis. For breast cancer, the second leading cause of cancer-related death among women in the United States, early detection does allow for increased treatment options, including surgical resection, with a corresponding better patient response. Unfortunately, however, many patients' tumors are diagnosed following metastasis, thus making it more difficult to successfully treat the malignancy. There are, at present, no existing validated plasma/serum biomarkers for breast cancer. Only a few biomarkers (such as HER-2/neu, estrogen receptor, and progesterone receptor) have utility for diagnosis and prognosis. Thus, there is a great need for new biomarkers for breast cancer. This paper will focus on the identification of new serum protein biomarkers with utility for the early detection of breast cancer.

Cell Cycle Control Related Proteins (p53,p21, and Rb) and Transforming Growth Factorβ(TGFβ) in Benign and Carcinomatous (In Situ and Infiltrating) Human Breast: Implications in Malignant Transformations

A comparative study of the products of the cell cycle control genes p53 (mutated form), p21, Rb (nonphosphorylated and phosphorylated form) and TGFbeta was performed by immunohistochemistry and Western blot, in benign breast disorders and breast cancer (in situ and infiltrating tumors). For the five proteins studied, the relative numbers of positively stained cells were higher in in situ carcinoma than in benign breast diseases. In infiltrating breast tumors, the relative numbers of positively stained cells were even higher than in in situ tumors except for the percentage of pRb immunostained cells, which decreased slightly in infiltrative tumors. For the other four proteins, the percentages of positively stained cases were similar to those found in in situ tumors. In the three groups of patients, TGFbeta immunoreaction appeared in the cytoplasm while immunoreactions to p53, p21, Rb, and pRb were found always in the nucleus except for p21 in in situ tumors, which showed cytoplasmic immunoreaction. Present results suggest that accumulation of mutated p53, cytoplasmic p21, and pRb in breast gland epithelium might be a crucial point in the development of in situ adenocarcinoma. In the infiltrating tumors, the expression of p21 in the nuclei and the decrease in pRb expression suggest an insufficient attempt to hinder cell proliferation.

MIB‐1 Proliferation Index in Ductal Carcinoma In Situ of the Breast: Relationship to the Expression of the Apoptosis‐Regulating Proteins bcl‐2 and p53

Tumor growth is the net result of cell proliferation and cell death. To investigate the relationship between these phenomena in ductal carcinoma in situ (DCIS), we studied proliferation index (PI) in DCIS in relation to the expression of two proteins involved in the regulation of cell death, bcl-2 and p53. Thirty-nine consecutive cases of DCIS were studied. PI was determined using immunolabeling with the monoclonal antibody MIB-1. The proportion of MIB-1-positive nuclei among 500 tumor cell nuclei was determined for each case and constituted the PI. All cases were also assessed immunohistochemically for bcl-2 and p53 protein expression. DCIS cases were graded using the criteria of Holland et al. PI ranged from 0 to 57% (mean 11.2%, median 4.6%). PI was significantly lower in well-differentiated and intermediately differentiated DCIS cases (mean 7.3% and 4.8%, respectively) than in poorly differentiated lesions (mean 24%, p = 0.01). PI was significantly lower in bcl-2-positive cases than in bcl-2-negative cases (mean PI for bcl-2-positive cases 6% and for bcl-2-negative cases 26%, p = 0.01). PI was higher in lesions expressing the p53 protein than in p53 negative cases (19% versus 8.3%), but this difference did not reach statistical significance. PI was also examined in relation to combinations of bcl-2 and p53 expression. Twenty-five of the DCIS lesions (64%) showed the bcl-2-positive/p53-negative phenotype which is similar to that seen in normal breast tissue and benign lesions and can be considered the "physiologic" combination. Among these cases the mean PI was 6.4%. In contrast, 14 cases showed "aberrant" combinations of bcl-2 and p53 expression suggesting dysregulated control of apoptosis. Among these cases the mean PI was 19.6% (p = 0.03). The highest mean PI was in cases with the bcl-2-negative/p53-positive phenotype (PI = 29.7%). DCIS lesions with the physiologic bcl-2-positive/p53-negative phenotype have low PI. In contrast, DCIS lesions with "aberrant" bcl-2/p53 phenotypes have high PI. This combination may favor tumor growth and progression in DCIS.

Proliferation markers and survival in early breast cancer: a systematic review and meta-analysis of 85 studies in 32,825 patients

We have performed a systematic review and meta-analysis of proliferation markers (Ki-67, mitotic index (MI), proliferating cell nuclear antigen (PCNA) and thymidine or bromodeoxyuridine labelling index (LI)) with respect to survival in early breast cancer. Eighty-five studies involving 32,825 patients were analysed. Ki-67 (43 studies, 15,790 patients), MI (20 studies, 7021 patients), and LI (11 studies, 7337 patients) were associated with significantly shorter overall and disease free survival, using results from univariate and multivariate analyses from the individual studies. PCNA (11 studies, 2677 patients) was associated with shorter overall survival by multivariate analysis only, because of lack of data. There was some evidence for publication bias, but all markers remained significant after allowing for this. Ki-67, MI, PCNA and LI are associated with worse survival outcomes in early breast cancer. However, whether these proliferation markers provide additional prognostic information to commonly used prognostic indices remains unclear.

Prognostic relevance of proliferative activity evaluated by Mib-1 immunostaining in node negative breast cancer

AIM

The purpose of this prospective observational study was to analyze the role of Mib-1 immunostaining as a proliferation index in breast cancer. Correlations between Mib-1 expression and clinico-pathological characteristics as well as its prognostic value have been studied in a series of 432 node negative breast cancers.

METHODS

Mib-1 expression was evaluated by immunohistochemistry. Tumor sections from highly cellular invasive areas of cancer were stained by monoclonal antibody Mib-1 (Dako) and cells whose nuclei stained positive were counted in 10 randomly chosen HPFs and expressed as percentages of all epithelial cells. A minimum of 400 cells were counted. Correlation between Mib-1 staining and clinico-pathological factors was investigated by means of univariate and multivariate analyses. The prognostic impact on actuarial disease free (DFS) and overall survival (OS) was evaluated by univariate analysis using the log-rank test and by multivariate analysis using Cox regression model.

RESULTS

Tumors were considered as positive for Mib-1 expression when more than 15% of cells counted were stained. Mib-1 positivity was found in 190/432 cases and resulted in being significantly related to tumor grade, tumor size and absence of estrogen receptors at multivariate analysis. With a median follow-up of 66 months, Mib-1 positivity resulted in being the only independent predictor of OS (RR 2.92), and an independent predictor of DFS (RR 2.01) together with absence of estrogen receptors (RR 2.15).

CONCLUSIONS

Mib-1 index of proliferative activity correlates well to other established prognostic factors of breast cancer. Mib-1 index may improve the tailoring of adjuvant therapy in early breast cancer, and our experience adds evidence to its effectiveness as prognostic factor. Efforts to reach uniformity in the methodology and in the scoring system should be done to warrant a standardized procedure and make Mib-1 determination definitively reliable in the current clinical practice.

Ki-67 as prognostic marker in early breast cancer: a meta-analysis of published studies involving 12,155 patients

The Ki-67 antigen is used to evaluate the proliferative activity of breast cancer (BC); however, Ki-67's role as a prognostic marker in BC is still undefined. In order to better define the prognostic value of Ki-67/MIB-1, we performed a meta-analysis of studies that evaluated the impact of Ki-67/MIB-1 on disease-free survival (DFS) and/or on overall survival (OS) in early BC. Sixty-eight studies were identified and 46 studies including 12 155 patients were evaluable for our meta-analysis; 38 studies were evaluable for the aggregation of results for DFS, and 35 studies for OS. Patients were considered to present positive tumours for the expression of Ki-67/MIB-1 according to the cut-off points defined by the authors. Ki-67/MIB-1 positivity is associated with higher probability of relapse in all patients (HR=1.93 (95% confidence interval (CI): 1.74–2.14); P<0.001), in node-negative patients (HR=2.31 (95% CI: 1.83–2.92); P<0.001) and in node-positive patients (HR=1.59 (95% CI: 1.35–1.87); P<0.001). Furthermore, Ki-67/MIB-1 positivity is associated with worse survival in all patients (HR=1.95 (95% CI: 1.70–2.24; P<0.001)), node-negative patients (HR=2.54 (95% CI: 1.65–3.91); P<0.001) and node-positive patients (HR=2.33 (95% CI: 1.83–2.95); P<0.001). Our meta-analysis suggests that Ki-67/MIB-1 positivity confers a higher risk of relapse and a worse survival in patients with early BC.

Proliferation marker Ki-67 in early breast cancer

Molecular markers have been extensively investigated with a view to providing early and accurate information on long-term outcome and prediction of response to treatment of early breast cancer. Proliferation is a key feature of the progression of tumors and is now widely estimated by the immunohistochemical assessment of the nuclear antigen Ki-67. The expression of Ki-67 correlates with other measurements of proliferation, including S-phase and bromodeoxyuridine uptake. High Ki-67 is a sign of poor prognosis associated with a good chance of clinical response to chemotherapy, but its independent significance is modest and does not merit measurements in most routine clinical scenarios. However, its application as a pharmacodynamic intermediate marker of the effectiveness of medical therapy holds great promise for rapid evaluation of new drugs.

Proliferative markers as prognostic and predictive tools in early breast cancer: where are we now?

In the last few decades, proliferative markers have been broadly evaluated as prognostic and predictive factors for early stage breast cancer patients. Several papers evaluating one or more markers have been published, often with contradictory results. As a consequence, there is still uncertainty about the role of these proliferative markers. The present paper critically reviews the current knowledge about the following markers: thymidine labeling index, S phase fraction/flow cytometry, Ki 67, thymidine kinase (TK), cyclins E, cyclin D, the cyclin inhibitors p27 and p21, and topoisomerase IIalpha. For each marker, the prognostic and predictive role was separately analyzed. Only papers published in English in peer-reviewed journals before June 2004 that include at least 100 evaluable patients were selected. In addition, the prognostic and predictive role of the proliferative markers had to be assessed through multivariate analyses. One hundred and thirty-two papers fulfilled these criteria and 159 516 patients were analyzed. Unfortunately, several methodological problems in the research to date prevent us from including any one of these proliferative markers among the standard prognostic and predictive factors. Early incorporation of translational research and new technologies with clinical trials are needed to prospectively validate biological markers and allow their use in clinical practice.

Predictive value of apoptosis, proliferation, HER-2, and topoisomerase IIα for anthracycline chemotherapy in locally advanced breast cancer

PURPOSE

Laboratory evidence indicates that tumor growth depends on the balance between cell proliferation and cell death, and many anticancer agents may exert their therapeutic effect by decreasing proliferation and increasing apoptosis. Additionally, clinical observations indicate that overexpression of HER-2 or topoisomerase IIalpha (topo IIalpha) may be predictors of better response to anthracyclines in breast cancer. The objective of this study was to determine if proliferation (Ki-67), apoptosis (TUNEL), and expression of HER-2 and topo IIalpha are affected by anthracycline treatment, and if these molecular markers predict anthracycline responsiveness.

EXPERIMENTAL DESIGN

Thirty-three women with primary breast tumors > or =3 cm received either doxorubicin (75 mg/m(2)) or epirubicin (120 mg/m(2)) for 4 cycles before surgery. Clinical response was evaluated after 4 cycles of treatment. Changes in molecular markers were assessed from core needle taken before treatment (D0), at 24-48 h (Dl) and on day 7 (D7) while on treatment, and from the surgical specimen excised on day 84 (D84) after the fourth cycle of chemotherapy.

RESULTS

The overall response rate was 51% (17 of 33 patients), with a 12% complete clinical response rate (4 of 33 patients). There were trends for tumors with higher apoptosis and topo IIalpha at baseline (D0) to be more responsive to anthracyclines, p = 0.1 and p = 0.08, respectively. Median apoptosis increased from D0 to Dl (p = 0.06) while median Ki-67 decreased (p = 0.07). Overall, expression of HER-2 remained stable throughout the chemotherapy administration. By Day 84, topo IIalpha had significantly decreased from baseline in responders, while it increased in non-responders, p = 0.03.

CONCLUSIONS

In human primary breast cancer, anthracycline treatment causes an early increase in apoptosis and a decrease in proliferation. In this pilot study, higher apoptosis and topo IIalphaa levels in primary tumors were associated with greater responsiveness to anthracyclines, and topo IIalpha levels declined in responsive tumors.

Utilizing prognostic and predictive factors in breast cancer

In order to make optimal treatment recommendations for patients with early-stage breast cancer, it is essential to accurately determine the patient's underlying risk of disease recurrence and choose a therapy to which the individual is most likely to respond. Lymph node status, tumor size, histopathologic features including tumor type and grade, and hormone receptor status are well-accepted prognostic factors related to breast cancer. In addition, hormone receptor status is a very strong predictor of response to hormonal therapy. However, our currently accepted prognostic and predictive factors fall short and there is a critical need to more accurately identify those most likely to require or benefit from particular therapies. Attention has therefore focused on the determination of novel prognostic and predictive factors. The most promising new factor is the level of urokinase plasminogen activator and its inhibitor plasminogen activator inhibitor. Other putative factors include proliferative rate, the presence of lymphatic or vascular invasion, human epidermal growth factor receptor 2 (HER-2/neu or erbB-2) positivity, the presence of micrometastases in lymph nodes or bone marrow, and gene expression profile by microarray analysis, and by RNA-based methodology. Data regarding potential new prognostic factors are constantly emerging. These studies are frequently challenging to interpret as they are often retrospective, based on relatively small numbers of patients, include a mix of treated and untreated women, and often do not control for other known prognostic factors. Therefore, new data must be interpreted with caution.

Ki-67 expression in patients with uterine leiomyomas, uterine smooth muscle tumors of uncertain malignant potential (STUMP) and uterine leiomyosarcomas (LMS)

BACKGROUND

The aim of the current study was to evaluate the expression of Ki-67 in uterine smooth muscle tumors, comparing leiomyomas, uterine smooth muscle tumors of uncertain malignant potential (STUMP) and uterine leiomyosarcomas (LMS) and to prove the accuracy of a Ki-67 expression as a useful parameter in the diagnosis of LMS.

METHODS

Ki-67 was assessed using immunohistochemistry from paraffin-embedded tissue in 20 patients with uterine LMS, 22 cases of STUMP and 25 cases of leiomyomas.

RESULTS

Ki-67 was present in 10/20 (50%) LMS, in 0/22 (0%) STUMP and in 2/25 (8%) leiomyomas. Significant differences regarding the frequency of Ki-67 expression were observed between LMS and STUMP (p = 0.0001) as well as between LMS and leiomyomas (p = 0.002), but not between STUMP and leiomyomas (p = 0.491). Likewise, the staining intensity differed significantly between LMS and leiomyomas (p = 0.018) as well as between LMS and STUMP (p = 0.002), but not between STUMP and leiomyomas (p = 0.368).

CONCLUSIONS

Our results demonstrate that the significantly elevated Ki-67 antigen expression in LMS, which correlates well with the rapid growth of these malignant tumors, may be a useful immunohistochemical parameter to distinguish between cases of malignant smooth muscle tumors and those of uncertain or borderline histology.

Lipomatous hemangiopericytoma of the head and neck: immunohistochemical and DNA ploidy analyses

BACKGROUND

Lipomatous hemangiopericytoma (LHPC) is a newly described rare soft tissue tumor with unpredictable biologic behavior and is difficult to diagnose by conventional histologic parameters. The molecular analyses of this entity to date are sparse. Only a few cases of LHPC have been reported. Although one case of LHPC in the sinonasal region was briefly reported, this is the first case in the head and neck region with detailed clinicopathologic features and molecular analysis of this entity.

METHODS

We reported a case of LHPC in a 55-year-old woman with a slowly growing lesion in the occipital area that was diagnosed by CT and MRI and removed surgically. Immunohistochemical and DNA ploidy analyses were performed.

RESULTS

A panel of 16 markers was included for immunohistochemical analysis. Diffuse immunopositivity of CD57 in our case provides supportive evidence that LHPC is linked with HPC because this marker is also present in approximately 50% of conventional HPCs. CD57 should be used in the immunohistochemical panel in any lesion suspected to be LHPC. Furthermore, CD57 along with CD34 and XIIIa is thought to stain for primitive mesenchymal stem cells, suggesting a bimodal/multimodal differentiation of LHPC. By flow cytometry, we found that tumor cells were 100% diploid with the S-phase fraction (SPF) being 3.21%. A significant positive correlation was detected between nuclear proliferating index and SPF (p < 0.001, by Spearman analysis). These findings provide molecular evidence indicating a benign nature of LHPC.

CONCLUSIONS

Contrary to the old belief that HPC has an aggressive nature, this variant of tumor looks less aggressive. The patient was followed for 1 year without any evidence of recurrence, supporting our pathologic hypothesis.

Gene expression patterns as marker for 5-year postoperative prognosis of primary breast cancers

PURPOSE

To establish the novel prognostic markers for breast cancer, gene expression profile was examined genome-wide.

METHODS

We used cDNA microarray consisting of 18,432 human genes to compare genome-wide expression profiles of eight primary breast cancers, four from patients who died of breast cancer within 5 years after surgery (5D group) and four who survived disease-free for more than 5 years (5S group).

RESULTS

We identified 21 genes whose expression was greater in tumors from the 5D group than in 5S tumors, and 23 with higher expression in the 5S group than in the 5D group. We established a Prognostic Index (PI) for prediction of postoperative prognosis, based on the aberrant expression profiles of ten of those genes. Among 20 additional cases chosen blindly, ten presented with high prognostic scores (>7, good) according to the PI; the remaining ten cases revealed scores <7 (poor). The PI predicted the actual 5-year clinical outcomes of these 20 cases with 100% accuracy.

CONCLUSION

Our PI system is reliable in clinical settings for predicting postoperative risk for breast cancer. The extensive list of genes provides valuable information about progression of breast cancer and suggests potential target molecules for treating this disease.

Prognostic implication of p53 protein expression in relation to nuclear pleomorphism and the MIB-1 counts in breast cancer

BACKGROUND

A close correlation of the p53 protein expression to nuclear pleomorphism and proliferative activity in breast cancer has been reported. The prognostic implications of p53 protein expression, however, in relation to nuclear pleomorphism and proliferative activity in breast cancer remain controversial.

PATIENTS AND METHODS

Nuclear pleomorphism and immunohistochemical reactivity for p53 protein and MIB-1 were evaluated on formalin-fixed paraffin-stored sections from 250 patients with breast cancer for whom the median follow-up duration was 6.4 years.

RESULTS

p53 protein expression was positive in 66 (26.4%) of 250 cases. Nuclear pleomorphism was grade I or II in 169 (67.6%) cases and grade III in 81(32.4%)cases. The MIB-1 counts were more than 10% in 102 (40.8%) cases and less than 10% in 148 (59.2%) cases. There was a close correlation between p53 protein expression and nuclear pleomorphism (p<0.0001) and between p53 protein expression and MIB-1 counts (p<0.0001). Univariate analyses showed the 66 cases with positive p53 protein expression to have a significantly (p=0.0284) worse disease free survival (DFS) than the 184 cases with negative p53 protein expression. A multivariate analysis, however, on the variables including all of p53 protein expression, nuclear pleomorphism and MIB-1 counts indicated the MIB-1 counts (p=0.0041) as well as the lymph node status to be independently significant factors for DFS, while neither p53 protein expression nor nuclear pleomorphism were independently significant factors for DFS.

CONCLUSION

The present study demonstrated that the p53 protein expression, nuclear pleomorphism and MIB-1 counts all demonstrated prognostic significance for breast cancer, while the most significant prognostic indicator among these three biological parameters was the MIB-1 counts.

Invariant p53 immunostaining in primary and recurrent breast cancer

In animal models, acquired mutations of the p53 gene that result in increased p53 protein expression are associated with tumour recurrence following chemotherapy. The aim of this study was to test the hypothesis that breast cancer recurrences following adjuvant therapy exhibit aberrant p53 expression. We therefore evaluated p53 expression in paired primary and recurrent breast tumours: 48% of primary and 32% of recurrent tumours had abnormally increased p53 expression. Of the paired samples, 84% showed no change in p53 expression between the primary tumour and the metastasis. In fact, in no case was low (normal) p53 expression in the primary tumour followed by the development of high (aberrant) p53 expression in the recurrence. These results show that increased p53 expression is not selected for in the malignant cells emerging following adjuvant therapy, suggesting that p53 expression is unlikely to play a central role in breast cancer recurrences.

The prognostic relevance of estimates of proliferative activity in early breast cancer

AIMS

Immunohistochemical estimates of cell proliferation evaluated with MIB-1 antibody have been suggested as prognostic indicators in different types of carcinoma. This study investigates whether MIB-1 scores add additional prognostic impact when evaluated together with classical clinicopathological parameters at diagnosis in early breast cancer patients.

MATERIALS AND METHODS

Tumour specimens from 365 consecutively treated breast cancer patients were immunostained for MIB-1 and evaluated under the microscope using systematic random sampling accomplished by the CAST-grid system.

RESULTS

The systematic random sampling technique resulted in MIB-1 estimates with very high interobserver and intraobserver reproducibilities (P < 0.0001). Median MIB-1 was 16% (range 0-83%). Patients were stratified by MIB-1 in tertiles, and increasing MIB-1 was significantly associated with poor overall and disease-specific survival in node-positive patients, but not in node-negative patients. High MIB-1 was significantly related to large tumour size, and strongly associated with high grade, high mitotic score, negative oestrogen receptor status and young age. In multivariate analysis, both with and without malignancy grade and number of mitoses included in the analysis, MIB-1 estimates showed no independent prognostic impact.

CONCLUSIONS

High MIB-1 estimates did not add independent prognostic information at diagnosis when evaluated together with classical prognostic markers of early breast cancer.

Prognostic significance of Bcl-2 and p53 expression in gastric cancer

BACKGROUND AND AIMS

Apoptosis regulates cell death and influences cell proliferation and therefore may play an important role in development or growth of various malignant tumors. The Bcl-2 and p53 are closely linked in the regulation of apoptosis. We investigated the prognostic significance of Bcl-2 and p53 expression in patients with gastric cancer.

PATIENTS AND METHODS

Immunohistochemistry was used to study Bcl-2 and p53 expression in 308 consecutive patients with gastric cancer.

RESULTS

Bcl-2 expression was positive in 39 patients (12.7%) and showed a significant negative correlation with depth of invasion and lymph node metastasis. p53 expression was observed in 105 patients (34.1%) and was significantly associated with depth of invasion, lymph node metastasis, distant metastasis, and intestinal type. Patients with Bcl-2(+) tumors showed a trend to better 5-year survival rate (81%) than those with Bcl-2(-) negative tumors (71%). The 5-year survival rate in p53 positive cases (60%) was significantly lower than that in p53-negative cases (78%). In addition, p53 expression showed a significantly poorer prognosis in both diffuse and intestinal types. In multivariate analysis restricted to patients with R0 resection p53 expression was an independent prognostic factor (relative risk: 2.063). In combined assessment of p53 and Bcl-2 expression the group with p53(+)/Bcl-2(-) tumors showed significantly worse 5-year survival (57%) than the other groups, while best survival was seen in the group with p53(+)/Bcl-2(+) tumors (100%).

CONCLUSION

p53 expression is an unfavorable prognostic factor in gastric cancer. Bcl-2 expression may have possible prognostic value when combined with p53 expression.

Molecular evolutionary patterns in breast cancer

Geno-phenotypic patterns of pre-invasive and invasive lobular breast cancers and infiltrating ductal carcinomas of low, intermediate, and high grade are reviewed. One of the main differences between lobular breast cancers and ductal carcinomas is the presence of inactivating E-cadherin gene mutations in lobular breast cancers. In many other respects, lobular breast cancers and low-grade ductal carcinomas exhibit similar geno-phenotypic profiles. The development of p53 dysfunction may be a hallmark of infiltrating ductal cancers of intermediate and high grade. Sequential Her-2/neu and ras abnormalities define a subset of aggressive high-grade tumors, and the development of Rb dysfunction may define a separate subset of aggressive ductal cancers. Based on these observations, a branching molecular evolutionary model for the development and progression of breast cancer is proposed.

Prognostic value of p53 molecular status in high-risk primary breast cancer

BACKGROUND

Mutations in the p53 gene are the most common genetic alterations in human primary breast carcinoma and these mutations are often associated with worse prognosis and chemo/radioresistance.

PATIENTS AND METHODS

The analysis of the p53 gene was performed by fluorescence-assisted mismatch analysis in 13 consecutive high-risk primary breast cancer (HR-BC) patients with 10 or more involved axillary nodes to evaluate its prognostic value.

RESULTS

Three p53 mutations (23%) and four allelic variants were detected. After a median follow-up of 52 months the HR-BC disease-free survival (DFS) was 51% and overall survival 79%. All patients harboring a p53 mutation (p53(mut)) relapsed within 10 months of the median DFS while 67% of those showing a wild-type p53 status (p53(wt)) survive disease-free at a median follow-up of 43 months. One p53(mut) patient is still alive while all the p53(wt) patients survive at 56 months median follow-up. Two out of the four p53(wt) relapsing breast cancer patients showed the Arg72Pro allelic variant; one of these died at 75 months.

CONCLUSIONS

p53 mutations may help identify a subset of very high risk breast cancer patients (vHR-BC) with worse prognosis.

TP53 and breast cancer

The TP53 gene (p53) is found altered in breast carcinomas in approximately 20-40% of all cases depending on tumor size and stage of the disease. It seems to be an early event in breast tumorigenesis. Several polymorphisms in the TP53 gene have been detected and their possible roles in breast cancer risk and association to type of cancer developed are discussed. The different mutation spectra seen in geographical and ethnic populations may be used to identify environmental exposure contributing to breast cancer development. The role of TP53 mutation as a prognostic marker is reviewed as well as its role as a predictor for therapy response. All data available on TP53 mutation analyses of human breast carcinomas, as well data from transgenic animal studies and experimental cell studies, support an important role for TP53 in mammary carcinogenesis.

Inter-laboratory and inter-observer reproducibility of immunohistochemical assessment of the Ki-67 labelling index in a large multi-centre trial

Proliferative activity of tumour cells, as assessed by the Ki-67 labelling index, has been suggested as a potential prognostic indicator in many neoplastic diseases. Meaningful application of the immunohistochemically determined tumour cell growth fraction in clinical decision-making requires information about its inter-laboratory reproducibility. To assess the reproducibility of Ki-67 determined growth fraction, a multi-centre immunohistochemical trial was performed with 172 participating laboratories, each testing 30 different tissue samples. Evaluating 5160 Ki-67 labelling indices with a newly developed tissue microarray, good inter-observer reproducibility but high inter-laboratory variability was found. Reassessment of all stainings revealed considerable inter-laboratory differences in the intensity and frequency of labelled nuclei, suggesting that antigen retrieval or staining techniques are predominantly responsible for the inter-laboratory variability found in this trial. Consequently, cut-off levels for Ki-67, suggested to distinguish prognostic subgroups in tumours, appear to have limited reproducibility in a multi-centre approach. It is concluded that there is a need to standardize the immunohistochemical determination of the Ki-67 labelling index when it is used as a prognostic indicator in surgical pathology.

Increased incidence of ERBB2 overexpression and TP53 mutation in inflammatory breast cancer

Inflammatory breast cancer (IBC) is one of the most aggressive forms of breast cancer. We studied the biological characteristics of these tumours by comparing the overexpression of oncogenes ERBB2, MYC, CCND1 and RHOC and TP53 gene mutation rates in IBC with those found in locally advanced and not otherwise specified breast cancers. The prevalence of the TP53 mutation was much higher in IBC than in the two other types of cancer (57% vs 30). Unexpectedly, however, in IBC tumours, histological grade was independent of TP53 status. In addition, ERBB2 overexpression was twice as frequent in inflammatory as in non-inflammatory tumours, whereas the frequencies of MYC, CCND1 and RHOC overexpression did not vary significantly among the three types of breast cancer. These findings suggest that IBC tumours constitute a distinct subset with a specific pathogenesis. Given the importance of TP53 and ERBB2 in the response to treatments, our observations have important therapeutic implications for the clinical management of IBC patients.

Estradiol stabilizes p53 protein in breast cancer cell line, MCF-7

Overexpression of the oncoprotein MDM2, an important regulator of the p53 tumor suppressor protein, is often observed in breast cancer tissues and cell lines, particularly in those which express estrogen receptor alpha (ERalpha). In MCF-7 breast cancer cell line possessing wild-type p53, ERalpha, and overexpressing MDM2, p53 accumulation was stimulated by 17beta-estradiol (E2) in a concentration-dependent manner. On the other hand, E2 caused no change of the expression of p53 mRNA, indicating that E2 affects p53 at the post-transcriptional level. To analyze the mechanism of p53 accumulation by E2, the stability of p53, ERalpha and MDM2 proteins was analyzed in the presence of cycloheximide under an E2-supplemented or -depleted condition. E2 significantly extended the half-life of p53 protein, but shortened that of ERalpha in MCF-7 cells. E2 significantly decreased the stability of p90(MDM2) and p60(MDM2) in MCF-7. Interestingly, E2 increased the ratio p60(MDM2)/p90(MDM2) inversely proportionally to the degradation of p53. These results suggest that the ratio of the two MDM2 proteins, p90(MDM2) and p60(MDM2), may affect the accumulation of wild-type p53 protein in response to E2.

Prognostic factors in node-negative breast cancer: a review of studies with sample size more than 200 and follow-up more than 5 years

OBJECTIVE

To review the published literature on prognostic factors in patients with node-negative breast cancer, focusing principally on recent studies with large sample sizes and extended follow-up periods.

SUMMARY BACKGROUND DATA

Although numerous studies have examined prognostic factors in patients with breast cancer, relatively few have dealt specifically with node-negative disease, and interpretation has been limited by small sample size and limited follow-up times.

METHODS

A review of the Medline database from 1996 to 2000 was undertaken, with additional papers published before 1996 identified through review articles. For inclusion in the analysis, papers needed to meet the following core criteria: 200 or more node-negative patients with invasive breast carcinoma; median follow-up time at least 5 years; method of testing and cut-off points specified; overall survival and/or disease-free survival specified; and relative risk or statistical probability values given for comparisons.

RESULTS

Three or more papers that met the core criteria were retrieved for each of 11 potential prognostic factors. Of these, tumor size, tumor grade, cathepsin-D, Ki-67, S-phase fraction, mitotic index, and vascular invasion showed a significant association with survival outcomes; HER2/neu and DNA ploidy showed no significant association; and estrogen receptor status and p53 showed mixed results. Lack of standardization in measurement techniques for many of the markers, including cathepsin-D, Ki-67, HER2/neu, and p53, limited their current clinical usefulness.

CONCLUSIONS

In large studies with extended follow-up periods, tumor size, tumor grade, cathepsin-D, Ki-67, S-phase fraction, mitotic index, and vascular invasion showed a significant association with survival outcome measures in patients with early-stage node-negative breast cancer. Because of technical difficulties and variations in the measurement of many of these factors, tumor size and tumor grade remain the only markers that currently have broad clinical usefulness for this patient group.

Prognostic value of TP53 gene mutation in adjuvant treated breast cancer patients

We investigated the prognostic significance of mutation to the TP53 tumor suppressor gene in a series of 908 breast cancer patients treated with or without adjuvant therapies. The frequency of TP53 mutation detected by single strand conformation polymorphism (SSCP) was 19.4% (176/908) in the overall tumor series. In multivariate analysis, TP53 mutation was independently associated with worse survival in the overall (HR = 2.1, 95% CI [1.5-3.1], P<0.0001), non-adjuvant treated (HR=2.2, 95% CI [1.2-4.2], P=0.017) and adjuvant treated (HR= 2.0, 95% CI [1.3-3.1], P = 0.0009) patients.

Value of epidermal growth factor receptor, HER2, p53, and steroid receptors in predicting the efficacy of tamoxifen in high-risk postmenopausal breast cancer patients

PURPOSE

Few studies have examined the possible importance of biologic prognostic factors in breast cancer connected with differentiation and growth in predicting response to a specific adjuvant treatment. HER2, epidermal growth factor receptor (EGFR), and p53 have all been suggested as possible markers of tamoxifen resistance. The aim of this study was to investigate interactions between adjuvant treatment with tamoxifen and the content of EGFR, HER2, and p53 in steroid receptor-positive patients.

PATIENTS AND METHODS

A total of 1,716 high-risk postmenopausal breast cancer patients were randomly assigned to treatment with tamoxifen (868 women) or to observation (848 women) in a prospective trial (Danish Breast Cancer Cooperative Group's 77c protocol). The content of the steroid receptors and expression of p53, EGFR, and HER2 were determined by immunohistochemical analysis of paraffin-embedded tissue. The length of follow-up was 10 years. The end point for this analysis was disease-free survival.

RESULTS

Multivariate analysis demonstrated no increased risk of recurrence after treatment with tamoxifen for HER2-, EGFR-, and p53-positive, high-risk, steroid receptor-positive patients. Patients with steroid receptor-positive tumors and positive immunohistochemical staining for HER2, EGFR or p53 benefited from treatment with tamoxifen for 1 year, although the latter variable contained independent prognostic information by itself.

CONCLUSION

With the statistical power of the present randomized study, we did not find support for the hypothesis that HER2/EGFR or p53 status predicts benefit from tamoxifen treatment in estrogen receptor-positive patients with early-stage breast cancer. Thus, neither HER2, EGFR, nor p53 overexpression/accumulation should be used as a contraindication for giving tamoxifen.

Concurrent overexpression of p53 and c-erbB-2 correlates with accelerated cycling and concomitant poor prognosis in node-negative breast cancer

Simultaneous overexpression of c-erbB-2 and p53 has been reported to be prognostically unfavorable in breast cancer. Herein, we show that concurrent overexpression of these 2 proteins is associated with a marked reduction in the relative fraction of cells in G(1) phase of the cell cycle, indicating an accelerated cell cycle progression. Using an immunohistochemical approach, we examined 261 cases of node-negative infiltrating ductal carcinomas of the breast with respect to c-erbB-2 and p53 expression and to the proliferative activity measured by the Ki-67 index. By means of a novel monoclonal antibody, Ki-S2, which exclusively recognizes proliferating cells in the S, G(2), and M phases of the reproductive cycle, we were further able to calculate the relative fraction of the cells having passed the restriction point at the G(1)/S boundary, thus defining a cycling ratio (CR). The results were correlated with clinical outcome; median follow-up time was 96 months. Tumors that simultaneously overexpressed c-erbB-2 and p53 had a high median CR and followed an unfavorable course. However, increased CRs were also observed independently of c-erbB-2 and p53 overexpression, suggesting that other molecular mechanisms may contribute to acceleration of cell cycle progression. In a multivariate analysis that included patient age, tumor size, hormone receptor status, c-erbB-2 and p53 expression, and the Ki-67 index, CR emerged as the most significant independent predictor of overall and disease-free survival (P <.0001). It is concluded that the CR is a gauge of cell cycle deregulation and therefore may be a powerful indicator of the biologic behavior of cancers. HUM PATHOL 32:311-319.

p53 and Ki-67 as predictive markers for radiosensitivity in squamous cell carcinoma of the oral cavity? an immunohistochemical and clinicopathologic study

PURPOSE

Previously published data relating the expression of p53 and Ki-67 to radiation response in head and neck cancer are conflicting. This may be due to differences in patient selection and treatment modalities. In this study of a homogenous population of patients with oral cavity cancer, Ki-67 and p53 indices were correlated with histopathologically assessed tumor regression after preoperative radiochemotherapy and longterm outcome.

METHODS AND MATERIALS

Eighty-eight patients with squamous cell carcinoma of the oral cavity and treated between September 1985 and November 1995 by preoperative radiochemotherapy and definitive surgery were included in this analysis. By immunohistochemistry (IHC) the pre-irradiation expression of p53 and of Ki-67 were analyzed and correlated with the histopathologically proven tumor regression, overall survival and local control.

RESULTS

The overall 2- and 5-year survival rates were 76.5% and 63%, the locoregional control rates were 84% and 79%, respectively. After preoperative radiochemotherapy 29 patients (33%) showed complete tumor regression (ypT(0) classification). Survival and local control rates were significantly higher for patients showing ypT(0) classification than ypT(1-4) classification (p < 0.01). This effect was independent of pretreatment tumor classification in multivariate analysis. Pre-irradiation p53 status and Ki-67 index had no influence on tumor regression and clinical outcome in these patients.

CONCLUSION

Complete tumor regression after preoperative treatment is related to an improved outcome in combined modality treatment of oral cavity cancer. The presented study could not demonstrate an influence of p53 and Ki-67 status as detected by immunohistochemical staining on survival, local control, or tumor regression after radiochemotherapy.

Assessment of methods for tissue-based detection of the HER-2/neu alteration in human breast cancer: a direct comparison of fluorescence in situ hybridization and immunohistochemistry

PURPOSE

To compare the efficacy of fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) in detecting the HER-2/neu alteration in human breast cancer.

PATIENTS AND METHODS

Unselected stage I, II, and III breast cancer patients (N = 900) were tested for HER-2/neu gene amplification by FISH in paraffin-embedded, formalin-fixed archival material. Of these samples, 856 were tested for HER-2/neu overexpression by non-antigen-retrieval IHC with the polyclonal antibody R60, the sensitivity and specificity of which was preliminarily compared with the United States Food and Drug Administration-approved HercepTest (Dako Corp, Carpinteria, CA). Patient survival was analyzed in relation to the presence of the HER-2/neu alteration as determined by these two methodologies.

RESULTS

A total of 189 (21%) of 900 patients were positive by FISH and 147 (17.2%) of 856 were positive by IHC. This discrepancy is consistent with expected loss of IHC sensitivity associated with tissue fixation/embedding. The HercepTest did not improve sensitivity and introduced false positives. Comparison of R60-based IHC with FISH demonstrates that patient survival is associated progressively to gene amplification level as determined by FISH, whereas for IHC an association is found only in the highest (3+) immunostaining group. Among FISH-negative tumors, 45 (6.6%) of 678 were IHC-positive, with a survival probability similar to that of FISH-negative/IHC-negative cases; FISH-positive/IHC-negative patients have a survival probability similar to that of FISH-positive/IHC-positive cases.

CONCLUSION

IHC does not consistently discriminate patients likely to have a poor prognosis, whereas FISH provides superior prognostic information in segregating high-risk from lower-risk beast cancers. HER-2/neu protein overexpression in the absence of gene amplification occurs infrequently in breast cancer, in which case, patient outcome is similar to that of patients without the alteration.

Abnormal expression of cell cycle regulatory proteins in ductal and lobular carcinomas of the breast

In a previous study, we demonstrated that the G1 cell cycle checkpoint in carcinomas of the breast is frequently abrogated by loss of p16, the product of the CDKN2/INK4A gene, and, to a lesser extent, by loss of pRB, the product of the retinoblastoma gene. The purpose of the present study was to determine whether other mechanisms of cell cycle deregulation exist in breast cancers which have retained RB and p16 function. Paraffin sections of 81 invasive breast carcinomas (49 ductal, 26 lobular, 6 mixed) were reacted with monoclonal antibodies against cyclin D1 and p53, using optimized immunohistochemical staining protocols. The staining results were correlated with the expression of p16 and pRB, and with a variety of pathological parameters and DNA ploidy. Twenty-five tumors (31%) accumulated (presumably mutant) p53 and 28 (35%) overexpressed cyclin D1; 7 carcinomas (not including any pure lobular cancers) abnormally expressed both proteins. p53 accumulation correlated with nuclear, mitotic, and overall grade, but not with tumor size, lymph node involvement, or DNA ploidy. Overexpression of cyclin D1 was not associated with any of the patho-biological variables. There was an inverse correlation between loss of p16 and high levels of p53, but not cyclin D1. The G1 cell cycle checkpoint, which is controlled by RB, cyclin D1, and p16, was abrogated in 65% of carcinomas, and only p53 was abnormal in an additional 17%. The number of abnormally expressed genes correlated with mitotic activity and overall tumor grade, but not with tumor histology, size, or nodal status, suggesting that cell cycle deregulation is an early event in breast tumorigenesis. Only 18% of the carcinomas showed a normal level of expression of the four genes tested, and p16 appeared to be the most common target of cell cycle deregulation. These data point to the importance of cell cycle regulatory protein abnormalities in human breast cancer.

P53 determination alongside classical prognostic factors in node-negative breast cancer: an evaluation at more than 10-year follow-up

BACKGROUND

There is heterogeneity of methods and conflicting results concerning the prognostic value of p53 in node-negative breast cancer. The clinical value of a quantitative method for measuring tumoralp53 content still needs to be evaluated.

PATIENTS AND METHODS

A long-term retrospective study was conducted on 297 node-negative patients with a median follow-up greater than 10 years (11 years, 101-172 months). Classic prognostic factors were considered including age, tumor size, histoprognostic grade and estradiol (ER) and progesterone receptors (PR). In addition, the value of p53 determination (immunoluminometric assay in tumor cytosol) was assessed for this long follow-up period.

RESULTS

p53 concentrations were significantly linked to the histological grade (P = 0.001), to tumor size (P = 0.02) and ER status (P = 0.01). Higher p53 tumoral concentrations were found in tumors with large size, pejorative histological grade and negative ER status. In contrast, p53 tumoral concentrations were not influenced by menopausal or PR status. Multivariate Cox analysis demonstrates that tumor size was the only significant predictor of disease-free survival (P = 0.049) with a risk factor at 1.38. As regards specific survival, univariate Cox analysis indicates that p53 taken as a continuous variable is a significant predictor (P = 0.024) together with histological grade, tumor size and ER status. In a multivariate Cox analysis there were two significant and independent variables for predicting overall survival: tumor size (P = 0.031) and, ER status (P = 0.015) with the highest risk factor (RR = 2.14).

CONCLUSIONS

The present investigation points out that the prognostic power of p53 tumor determination evaluated at more than 10 years median survival is not higher than the well-recognized classic prognostic factors in node-negative breast cancer. The present data highlight the need to assess the prognostic value of potentially new biological factors in node-negative breast cancer on cohorts of patients followed over periods in excess of 10 years.

Routine analysis of p53 mutation in clinical breast tumor specimens using fluorescence-based polymerase chain reaction and single strand conformation polymorphism

Improved prognostic and predictive markers in breast cancer management would help considerably in therapeutic decision making, particularly in patients with early-stage breast cancer. Tumor factors currently used for prognostication and management decisions are tumor size, histologic type and grade, axillary lymph node status, and estrogen receptor content. The discovery of various somatic genetic alterations in breast cancer has raised the possibility that these may provide additional and independent prognostic and predictive information. Alterations of the p53 tumor suppressor gene in particular have received the most attention as potential prognostic and predictive factors. In multivariate analysis, p53 gene mutation is consistently associated with a two- to threefold increased risk of relapse and death from breast cancer. One of the major reasons preventing the introduction of p53 mutation as a routine marker to assist in therapeutic decision making is the lack of a simple, reproducible, and inexpensive assay. In the present study the authors optimized a polymerase chain reaction-based mutation screening method, fluorescence-single strand conformation polymorphism (F-SSCP), that allows p53 status to be assessed accurately and reproducibly in routinely handled, formalin-fixed and paraffin-embedded tumor specimens. The frequency of p53 mutation observed using F-SSCP in a consecutive series of invasive ductal breast carcinomas was 17% (28/164). The authors propose that the prognostic and predictive values of p53 mutation in breast cancer should be further evaluated in prospective, randomized studies using this standardized technique.

The Ki-67 protein: from the known and the unknown

The expression of the human Ki-67 protein is strictly associated with cell proliferation. During interphase, the antigen can be exclusively detected within the nucleus, whereas in mitosis most of the protein is relocated to the surface of the chromosomes. The fact that the Ki-67 protein is present during all active phases of the cell cycle (G(1), S, G(2), and mitosis), but is absent from resting cells (G(0)), makes it an excellent marker for determining the so-called growth fraction of a given cell population. In the first part of this study, the term proliferation marker is discussed and examples of the applications of anti-Ki-67 protein antibodies in diagnostics of human tumors are given. The fraction of Ki-67-positive tumor cells (the Ki-67 labeling index) is often correlated with the clinical course of the disease. The best-studied examples in this context are carcinomas of the prostate and the breast. For these types of tumors, the prognostic value for survival and tumor recurrence has repeatedly been proven in uni- and multivariate analysis. The preparation of new monoclonal antibodies that react with the Ki-67 equivalent protein from rodents now extends the use of the Ki-67 protein as a proliferation marker to laboratory animals that are routinely used in basic research. The second part of this review focuses on the biology of the Ki-67 protein. Our current knowledge of the Ki-67 gene and protein structure, mRNA splicing, expression, and cellular localization during the cell-division cycle is summarized and discussed. Although the Ki-67 protein is well characterized on the molecular level and extensively used as a proliferation marker, the functional significance still remains unclear. There are indications, however, that Ki-67 protein expression is an absolute requirement for progression through the cell-division cycle.

A prospective trial of midwest breast cancer patients: a p53 gene mutation is the most important predictor of adverse outcome

Several retrospective studies have suggested p53 gene mutation as an adverse prognostic indicator in breast cancer patients, based on a selective growth advantage of p53 mutant cancer cells and their presumed resistance to current adjuvant therapy regimens. A cohort of 90 Caucasian midwestern breast cancer patients was analyzed prospectively (60 months of follow-up) with a rigorous mutation detection methodology. The presence of a p53 gene mutation was the single most adverse prognostic indicator for recurrence (p = 0.0032) and death (p = 0.0001), and was associated with poor response to both adjuvant (p = 0.0001) and palliative (p = 0.006) therapy. Analysis of the p53 gene with appropriate mutation detection methodology markedly improves the prediction of early recurrence, treatment failure, and death in breast cancer patients.

TP53 status and gene amplification in human colorectal carcinomas

Gene amplification is one of the characteristics of cancer cells. In vitro studies suggested that alterations of the TP53 gene might be responsible for gene amplification. We have examined the presence of TP53 mutations and looked for cytogenetic evidence of gene amplification in a series of 79 primary colorectal carcinomas. Other parameters such as the pattern of cytogenetic alterations, microsatellite instability, tumor site, and histological staging were also considered. A multiparametric study supported by statistical analyses suggests the existence of two major pathways of colorectal carcinogenesis. No relationships could be established between the presence of TP53 alterations and gene amplification.

Genetic alterations in early-onset invasive breast carcinomas: correlation of c-erbB-2 amplification detected by fluorescence in situ hybridization with p53 accumulation and tumor phenotype

p53 tumor-suppressor gene mutation and p53 protein over-expression have been reported with higher frequency in early-onset breast carcinomas (EOBC). Given the role attributed to normal p53 protein in DNA-repair mechanisms, other somatic genomic alterations would be expected to be associated with this abnormality. Amplification of the c-erbB-2 (HER-2/neu) oncogene and over-expression of the corresponding p185erbB-2 protein have been linked to prognosis and response to therapy in breast cancer. In a retrospective study of 62 formalin-fixed paraffin-embedded invasive EOBC (diagnosed at 35 years or less), the amplification status of the c-erbB-2 gene detected by fluorescence in situ hybridization (FISH) using a unique sequence probe was compared with p53 protein accumulation measured by immunohistochemistry (IHC) and phenotypic features. p185erbB2-protein expression was also detected by immunohistochemistry, together with estrogen-receptor (ER) and progesterone-receptor (PR) expression. The data for a sub-set of 33 node-negative EOBC cases were compared with 70 node-negative tumors diagnosed in women above 36 years of age. Compared with node-negative BC in older women, node-negative EOBC was significantly more likely to feature high grade, high proliferation rate, negative ER and/or PR and p53 over-expression (p < 0.05). A trend toward a higher incidence of c-erbB-2 amplification in EOBC (21% vs. 9%) reached near-significance (p = 0.07). In EOBC, c-erbB-2 amplification and p53 over-expression were not associated with high tumor grade or high cell-proliferation rate, in contrast to the significant associations of these markers in tumors in older women. Abnormalities in tumor markers, including c-erbB-2 gene amplification and p53-protein over-expression, occur at different rates in women with EOBC as compared with BC developing in older women. This finding may reflect a different pathogenesis for EOBC, and warrants further investigation.

Somatic mutations in the p53 gene and prognosis in breast cancer: a meta-analysis

Many studies have investigated the association between alterations in the p53 gene and clinical outcome of breast cancer, and most investigators have reported poorer overall and disease-free survival (as indicated by a relative hazard (RH) greater than one) in breast cancer cases with somatic mutations in p53. However, different studies have produced widely differing RH estimates, ranging from no risk (RH = 1) to a relative hazard of 23, and not all of these results have been statistically significant. We have therefore reviewed all the published studies that have investigated the association between somatic mutations in the p53 gene and breast cancer prognosis and used standard techniques of meta-analysis to combine the results of these studies to produce a more precise estimate of the prognostic significance of p53 mutations. Eleven studies investigated overall survival in a total of 2319 unselected cases. The RH estimates from these ranged from 1 to 23.4 with a combined RH estimate of 2.0 (confidence interval 1.7-2.5). Three studies investigated the role of p53 in node-negative patients and in these, the combined estimate of RH was 1.7 (1.2-2.3). For three studies of node-positive breast cancer the combined risk estimate was 2.6 (1.7-3.9). The inclusion of p53 mutation screening in large breast cancer clinical trials seems warranted in the light of these results. Analysis of large numbers of cases matched for stage and therapy will allow definitive clarification of the value of p53 mutational status in prognostication, and possibly choice of therapy.

p53 and survival in early onset breast cancer: analysis of gene mutations, loss of heterozygosity and protein accumulation

The p53 protein has proven to be central in tumorigenesis by its cell cycle regulatory properties and both gene mutations and protein accumulation have been associated with poor prognosis in breast cancer. The present study was undertaken to investigate the prognostic significance of gene mutations, p53 protein accumulation and of loss of heterozygosity (LOH) at the TP53 locus in young (age < 37 years) breast cancer patients. In total, gene mutations were found in 21 of the 123 patients (17%), LOH in 20 of the 47 informative cases (43%) and protein accumulation in 47 of the 102 available cases (46%). Log rank analysis revealed no significant association between survival and TP53 mutations (in general), p53 protein accumulation or LOH. However, missense mutations localised to the zinc binding domain were significantly (P = 0.0007) associated with poorer prognosis. As indicated in this as well as other studies, p53 protein accumulation is frequently found in young breast cancer patients, but this protein overexpression appears to be of minor significance for survival. Nevertheless, the present report also suggests that specific mutations contribute substantially to tumour aggressiveness.

A simple index using video image analysis to predict disease outcome in primary breast cancer

Image analysis was used to investigate the prognostic significance of immunostaining for oestrogen receptor (ER), p53 tumour-suppressor protein and tumour cell proliferation (MIB-1) in a random cohort of 200 primary breast cancer patients with between 4 and 7 years of clinical follow-up. Image measurements of the percentage of immunopositive cancer cell nuclei (% positive nuclear area) were recorded for the above tumour features for each patient. Assessment of relative risk using Cox's univariate analysis indicated that tumour size, number of cancer-involved nodes, MIB-1 and ER % positive nuclear area were significantly associated with breast cancer disease outcome, i.e., relapse-free survival and overall survival. In multivariate analysis, tumour size, number of involved nodes, ER and MIB-1 % positive nuclear area were retained as independent predictors of prognosis, depending on the image measurement cut-point used. A prognostic model, which can be used without reference to nodal involvement, was constructed for tumour size, ER cut-point of 30% positive nuclear area and MIB-1 cut-point of 10% positive nuclear area. Kaplan-Meier analysis of this image-based prognostic index identified 4 risk groups with predicted 5-year overall survival rates of 93%, 83%, 76.7% and 61.5%. We conclude that image measurements of ER and proliferative rate can be combined with tumour size to construct a prognostic index which reliably predicts disease outcome in primary breast cancer without knowledge of the nodal status of the patient.