Microvessel proliferation by co-expression of endothelial nestin and Ki-67 is associated with a basal-like phenotype and aggressive features in breast cancer.

BACKGROUND: To quantify tumour angiogenesis, microvessel density (MVD) has been widely used. We here present a novel angiogenesis marker, microvessel proliferation (MVP), based on dual immunohistochemical staining of nestin and Ki-67. Immature endothelial cells express nestin, and when co-expressed with the proliferation marker Ki-67, the number of proliferating immature blood vessels can be measured. MATERIALS AND METHODS: Microvessel proliferation was evaluated in 178 breast cancer samples and estimated by vascular proliferation index (VPI), the ratio between the number of vessels containing proliferating endothelial cells and the total number of immature vessels. RESULTS: High VPI was strongly associated with several markers of aggressive breast cancer, such as negative oestrogen receptor (ER) status (p = 0.003), high tumour cell proliferation by Ki-67 (p = 0.004), high p53 expression (p = 0.001), and five profiles for the basal-like phenotype (odds ratios (OR); range 3.4-6.3). Also, high VPI was significantly associated with interval detected breast cancer compared with screening detected lesions (p < 0.0005), and adverse outcome in univariate and multivariate survival analysis (p = 0.034 and p = 0.022, respectively). CONCLUSION: Microvessel proliferation is a novel marker of ongoing angiogenesis and was associated with aggressive tumour features, basal-like phenotypes, interval presentation, and prognosis in this series of breast cancer.

Independent prognostic value of the basal-like phenotype of breast cancer and associations with EGFR and candidate stem cell marker BMI-1.

AIMS: To study the relationship between basal-like breast cancers, epidermal growth factor receptor (EGFR) and candidate stem cell markers (BMI-1, EZH2, Oct-4) in a population-based setting. METHODS AND RESULTS: Immunohistochemistry was evaluated in a series of 190 breast cancers. Basal-like phenotype (BLP) 1-5 was found in 4.3-14.3% of cases. EGFR was expressed in 9% of cases and associated with cytokeratin (CK) 5 and P-cadherin positivity, but not with survival; 28% of CK5+ cases were EGFR+. On multivariate analysis, basal-like differentiation and lymph node status were independent prognostic factors of comparable strength. BMI-1 positivity (42.6%) was associated with absence of basal-like features, oestrogen receptor positivity and low Ki67, but not related to survival. BMI was not associated with EZH2 expression, and these markers tended to show opposite associations with other variables, suggesting different roles in breast cancer. Oct-4 expression was not detected in this series. CONCLUSIONS: Basal-like features and lymph node status were strong and independent prognostic factors in this population-based series of breast cancer. Neither EGFR nor BMI-1 had significant prognostic impact, whereas EZH2 expression was associated with decreased survival. BMI-1 was inversely related to basal-like factors, and a stem cell phenotype of the basal-like subgroup could not be verified by this marker.

The prognostic contribution of estrogen and progesterone receptor status to a modified version of the Nottingham Prognostic Index.

The aim of this study was to test the prognostic contribution of estrogen (ER) and progesterone (PgR) receptor status to an index consisting of the number of positive lymph nodes, the mean nuclear area of the breast cancer cells (MNA), and tumour diameter. This index is compared with a Danish index, which includes the same factors but uses histological grade instead of MNA. The Danish index has been developed from the Nottingham Prognostic Index (NPI). In the present study of 1629 breast cancer patients the Cox proportional hazard method is used to examine the time-dependency of the index, and to test for interaction between the index and the hormone receptors. The index sorts the patients into groups with low, intermediate, and high risk of dying. Logistic regression analysis is used to report the sensitivity and specificity of the index with and without ER and PgR. Our index gave information comparable to that of the Danish group. However, the information given by our index is time-dependent, its strength being weaker after 5-year of follow-up. PgR and ER add information to high risk patients, but only in the first 5-year period. High risk patients with positive hormone receptors have a prognosis similar to intermediate risk ones. PgR increases the ability of the index to predict breast cancer deaths correctly by 5 percent in high risk patients. In conclusion, PgR and ER act differently in groups of patients with different risk levels when time-dependency is considered. This indicates biological differences in subgroups as defined by the index.

Prognostic role of oestrogen and progesterone receptors in patients with breast cancer: relation to age and lymph node status.

AIMS: To consider the prognostic role of oestrogen receptor and progesterone receptor status in relation to the age at surgery, length of follow up and lymph node status. METHODS: The study population comprised 977 patients with histologically confirmed breast carcinoma, with a median follow up of nine years. The actuarial life table method was used to test for survival differences. The Cox proportional hazard model was used to test for interaction effects between each hormone receptor and age, lymph node status and length of follow up. As the analysis involved multiple subgroups, significance was set at the 1% level (p < 0.01). RESULTS: When the patients were subdivided into groups according to lymph node status and age, progesterone and oestrogen receptor status predicted prognosis in middle aged (46-60 years) patients with lymph node positive breast cancer. Their prognostic effect in this subgroup, however, was restricted to the first five years after surgery. Progesterone receptor status was the strongest predictor of outcome. CONCLUSION: The prognostic power of oestrogen and progesterone receptor status varies depending on age, lymph node status and length of follow up after surgery.

Lymph node-negative breast cancer: the prognostic role and time dependency of age, tumor diameter and mean nuclear area.

This study of 786 node-negative breast cancer patients demonstrates that the prognostic effect of age at operation, tumor diameter and mean nuclear area (MNA) changed over time. Identifying patients at higher risk of dying after 5 years may be of clinical importance. These are patients who may have had a low metastatic tumor burden at the time of operation and in whom cytostatic adjuvant treatment could be of value. When estimating 10-year survival, a significant loss of strength was found for age. A near significant loss of effect was also found for MNA, while tumor diameter was the variable best maintaining prognostic power during the observation period. Due to the loss of strength for MNA and age when estimating 10-year survival, the observation period was divided into two periods. When estimating 5-year survival, MNA was the strongest variable, while tumor diameter and age gave additional significant information. When estimating the next 5 years, excluding patients who died before 5 years, only tumor diameter gave significant prognostic information (573 cases). This again stresses the importance of tumor diameter in assessing prognosis in node-negative patients.

Estrogen receptor in breast cancer; its relation to mean nuclear area, age and lymph node status.

A study of 378 patients with infiltrating breast carcinoma using linear logistic regression and ANOVA analysis demonstrated a different relation between age at operation and estrogen-receptor (ER) concentration in the lymph-node negative and the lymph-node positive groups. Tumours from patients between 51 and 70 years old had lower median ER concentration in the lymph-node negative group than in the lymph-node positive group. In the group older than 70 years, however, tumours from lymph-node negative patients had higher median ER concentrations than those from the lymph-node positive patients. Patients 50 years and younger had similar median ER concentrations in both lymph-node groups. Low mean nuclear area (MNA) of the tumour cells was associated with high frequency of tumours able to produce ER. No such association was found for age. Independent of age and lymph-node status tumours with low MNA also had high ER concentration. These findings suggest that tumours from different lymph-node/age groups may have different biological properties. The relationship between ER and nuclear size point to a key function of the nucleus, both as regards the ability to produce ER and its level of production.

The prognostic role of progesterone receptor status and age in relation to axillary node status in breast cancer patients.

The prognostic role of axillary lymph node status, progesterone receptor (PgR) status, age of the patient at operation, oestrogen receptor (ER) status and tumour diameter was studied in 443 breast cancer patients treated by modified radical mastectomy. Logistic and proportional hazard regression analyses were used to estimate the prognosis from the time of operation up to 60 months. We also estimated the prognosis from 36 to 60 months for those who had survived 36 months (conditional analysis). PgR and age gave significant information in each node class, old age and PgR negativity being disadvantages. PgR status relative to node status was more important for estimating early (24 months) prognosis, while age was of more importance later (60 months). Node status and age were the only variables giving significant information in the conditional analyses. It is thus of importance to consider the time dependency of the prognostic variables when predicting survival in breast cancer patients. No effect was found for ER status or tumour diameter.

Prognosis in node negative breast cancer patients: the importance of tumour diameter and mean nuclear area.

In node negative breast cancer patients, tumour size and mean nuclear area (MNA) as single variables have significant impact on prognosis. Combination of the two variables gives additional information on survival, and makes it possible to predict the outcome of the disease correctly in 70% of the patients both early (82 months) and late (154 months). MNA contributes relatively more to prediction of late prognosis than tumour diameter and vice versa for early prognosis. Thus a long follow-up is needed for node negative patients, and more so for patients with favourable prognostic criteria.