A combination of HER-2 status and the St. Gallen classification provides useful information on prognosis in lymph node-negative breast carcinoma

Application of St Gallen Categories in Predicting Survival for Patients With Breast Cancer in Vietnam

Breast cancer is a heterogeneous disease with different tumor subtypes. Identifying risk categories will help make better treatment decisions. Hence, this study aimed to predict the survival outcomes of invasive breast cancer in Vietnam, using St Gallen 2007 classification. This study was conducted on 501 patients with breast cancer who had surgical operations, but had not received neoadjuvant chemotherapy, from 2011 to 2013. The clinicopathological characteristics were recorded. Immunohistochemistry staining was performed on ER, PR, HER2/neu, and Ki67 markers. For HER2/neu(2+), fluorescence in situ hybridization was used as the test. All patients with breast cancer were stratified according to 2007 St Gallen categories. Kaplan-Meier and log-rank models were used to analyze survival rates. There were 3.8% cases classified as low risk (LR), 72.1% as intermediate risk (IR1: 60.1% and IR2: 12.0%), and 24.1% as high risk (HR1: 11.8% and HR2: 12.3%). Patients who were LR had the best prognosis, with a 5-year overall survival (OS) rate of 100%. Intermediate-risk patients were at 92.3%. High-risk patients had the worst prognosis, with a 5-year OS proportion of 69.3% (P < .05). For disease-free survival (DFS), risk categories were categorized as LR: 100%, IR: 90.3%, and HR: 69.3% (P < .05). Three main risk categories of breast cancer had a distinct OS and DFS. These findings suggest that the 2007 St Gallen risk category could be used to stratify patients with breast cancer into different risk groups in Vietnam.

Activated HER-receptors in predicting outcome of ER-positive breast cancer patients treated with adjuvant endocrine therapy

The four human epidermal growth factor receptors (HER1-4) are involved in growth stimulation and may play a role in endocrine resistance. The receptors form dimers, leading to activation by mutual phosphorylation. Our purpose was to explore the role of the activated receptors (pHER1, pHER2, pHER3) in endocrine treated breast cancer in terms of co-expression and association with disease-free survival (DFS) in 1062 patients with ER-positive tumors. Furthermore, HER2 amplification was evaluated. We found positive associations between the phosphorylated receptors. pHER1 and pHER3 were co-expressed with one or two of the other activated receptors in 85% and 89% of tumors, respectively, whereas pHER2 was co-expressed with the other activated receptors in 54% of tumors. Except for HER2, which was associated with poor prognosis, none of the remaining markers were associated with DFS. However, frequent co-expression indicates a role of the other HER-family members in activation of HER2.

Development of novel breast cancer recurrence prediction model using support vector machine

Purpose

The prediction of breast cancer recurrence is a crucial factor for successful treatment and follow-up planning. The principal objective of this study was to construct a novel prognostic model based on support vector machine (SVM) for the prediction of breast cancer recurrence within 5 years after breast cancer surgery in the Korean population, and to compare the predictive performance of the model with the previously established models.

Methods

Data on 679 patients, who underwent breast cancer surgery between 1994 and 2002, were collected retrospectively from a Korean tertiary teaching hospital. The following variables were selected as independent variables for the prognostic model, by using the established medical knowledge and univariate analysis: histological grade, tumor size, number of metastatic lymph node, estrogen receptor, lymphovascular invasion, local invasion of tumor, and number of tumors. Three prediction algorithms, with each using SVM, artificial neural network and Cox-proportional hazard regression model, were constructed and compared with one another. The resultant and most effective model based on SVM was compared with previously established prognostic models, which included Adjuvant! Online, Nottingham prognostic index (NPI), and St. Gallen guidelines.

Results

The SVM-based prediction model, named 'breast cancer recurrence prediction based on SVM (BCRSVM),' proposed herein outperformed other prognostic models (area under the curve=0.85, 0.71, 0.70, respectively for the BCRSVM, Adjuvant! Online, and NPI). The BCRSVM evidenced substantially high sensitivity (0.89), specificity (0.73), positive predictive values (0.75), and negative predictive values (0.89).

Conclusion

As the selected prognostic factors can be easily obtained in clinical practice, the proposed model might prove useful in the prediction of breast cancer recurrence. The prediction model is freely available in the website (http://ami.ajou.ac.kr/bcr/).

Use of ER/PR/HER2 subtypes in conjunction with the 2007 St Gallen Consensus Statement for early breast cancer

Background

The 2007 St Gallen international expert consensus statement describes three risk categories and provides recommendations for treatment of early breast cancer. The set of recommendations on how to best treat primary breast cancer is recognized and used by clinicians worldwide. We now examine the variability of five-year survival of the 2007 St Gallen Risk Classifications utilizing the ER/PR/HER2 subtypes.

Methods

Using the population-based California Cancer Registry, 114,786 incident cases of Stages 1-3 invasive breast cancer diagnosed between 2000 and 2006 were identified. Cases were assigned to Low, Intermediate, or High Risk categories. Five-year-relative survival was computed for the three St Gallen risk categories and for the ER/PR/HER2 subtypes for further differentiation.

Results and Discussion

There were 9,124 (13%) cases classified as Low Risk, 44,234 (65%) cases as Intermediate Risk, and 14,340 (21%) as High Risk. Within the Intermediate Risk group, 33,735 (76%) were node-negative (Intermediate Risk 2) and 10,499 (24%) were node-positive (Intermediate Risk 3). For the High Risk group, 6,149 (43%) had 1 to 3 positive axillary lymph nodes (High Risk 4) and 8,191 (57%) had four or more positive lymph nodes (High Risk 5).

Using five-year relative survival as the principal criterion, we found the following: a) There was very little difference between the Low Risk and Intermediate Risk categories; b) Use of the ER/PR/HER2 subtypes within the Intermediate and High Risk categories separated each into a group with better five-year survival (ER-positive) and a group with worse survival (ER-negative), irrespective of HER2-status; c) The heterogeneity of the High Risk category was most evident when one examined the ER/PR/HER2 subtypes with four or more positive axillary lymph nodes; (d) HER2-positivity did not always translate to worse survival, as noted when one compared the triple positive subtype (ER+/PR+/HER2+) to the triple negative subtype (ER-/PR-/HER2-); and (e) ER-negativity appeared to be a stronger predictor of poor survival than HER2-positivity.

Conclusion

The use of ER/PR/HER2 subtype highlights the marked heterogeneity of the Intermediate and High Risk categories of the 2007 St Gallen statements. The use of ER/PR/HER2 subtypes and correlation with molecular classification of breast cancer is recommended.

Tissue microarray-based study of patients with lymph node-negative breast cancer shows that HER2/neu overexpression is an important predictive marker of poor prognosis

BACKGROUND

Despite good prognosis in most cases of lymph node (LN)-negative breast cancer, individual patients may have markedly different clinical outcomes. Here, we investigated the prognostic significance of HER2/neu overexpression in these tumors.

MATERIALS AND METHODS

We employed a tissue microarray to examine HER2/neu overexpression by immunohistochemical staining in 359 consecutive patients diagnosed with LN-negative breast cancer, who underwent surgery from January 1993 to December 1998.

RESULTS

HER2/neu overexpression was detected in 81 of 359 (23.1%) patients. The 10-year disease-free survival (DFS) values (81.2% versus 61.8%, P value 0.000) and overall survival (OS) rates (85.7% versus 63.9%, P value 0.000) were significantly different between cases with HER2/neu-negative or HER2/neu-positive tumors. After multivariate analysis, HER2/neu status and tumor size were identified as independent prognostic factors for 10-year OS. Moreover, HER2/neu overexpression was significantly associated with poorer clinical outcomes in an intermediate-risk group identified by the St Gallen classification (10-year DFS, 79.6% versus 61.8%, P value 0.000; 10-year OS, 84.7% versus 63.9%, P value 0.000).

CONCLUSIONS

Our results show that HER2/neu overexpression is an important independent prognostic factor for LN-negative breast cancer cases and support the theory that more intensive adjuvant chemotherapy is required in the population with HER2/neu overexpression.

Ki-67 expression gives additional prognostic information on St. Gallen 2007 and Adjuvant! Online risk categories in early breast cancer

BACKGROUND

We sought to determine the significance of Ki-67, one of the tumor cell proliferation markers, as a useful prognostic factor in early breast cancer.

METHODS

A total of 1080 consecutive patients with stage I or II breast cancer that underwent surgery between 1998 and 2003 were enrolled. Patients were categorized on the basis of the 2007 St. Gallen consensus and Adjuvant! Online. The expression of Ki-67 in the tumor was assayed by immunohistochemistry (cutoff value, 10%).

RESULTS

Univariate analysis determined that tumor size, lymph node involvement, histologic grade, estrogen receptor, progesterone receptor, bcl-2, and Ki-67 (> or =10%) were statistically significant for both overall survival (OS) and distant metastasis-free survival (DFS). Of these factors, lymph node involvement and high Ki-67 expression were identified as independent prognostic factors for OS and DFS on the basis of multivariate analysis. The survivals of intermediate- and high-risk groups according to 2007 St. Gallen consensus were further separated by Ki-67 expression level (5-year DFS rate = 91.9% vs. 86.3% for Ki-67 < 10% and > or = 10%, respectively in intermediate-risk group (P = .01); 5-year DFS rate = 82.5% vs. 61.4% for Ki-67 < 10% and > or = 10%, respectively in high-risk group (P = .01)). The survivals of low- and high-risk groups according to Adjuvant! Online were further separated by Ki-67 expression level (5-year DFS rate = 97.8% vs. 89.5% for Ki-67 < 10% and > or = 10%, respectively in low-risk group (P = .02); 5-year DFS rate = 9.4% vs. 82.6% for Ki-67 < 10% and > or = 10% in high-risk group (P = .005)).

CONCLUSIONS

Ki-67 is an independent prognostic factor for DFS and OS in early breast cancer and can provide additional prognostic information on the risk stratification with the use of the 2007 St. Gallen consensus and Adjuvant! Online.

Adjuvant therapy for breast cancer in Kyushu

BACKGROUND

There is lack of information on the present status of adjuvant therapy for breast cancer in Kyushu. Therefore, the Kyushu Breast Cancer Study Group (KBC-SG) started registering newly diagnosed breast cancer patients who were to receive adjuvant therapy.

METHODS

During a period from 2001 to 2003, institutions participating in KBC-SG registered new patients who underwent curative surgical treatment for breast cancer to the registration office. One year later, the office sent them inquiries to gather any missing information.

RESULTS

A total of 2284 patients were registered from 49 institutions. The mean age was 55, ranging from 30 to 93 years, and 46% had stage I disease. Estrogen and/or progesterone receptor was positive in 71% by immunoperoxidase staining, and HER2 was expressed in 297 (33%) of 906 patients. Twenty percent of the patients underwent adjuvant radiation therapy with or without antineoplastic agents. Overall, 98% received hormonal and/or cytotoxic agents. Anthracycline-containing regimens were given to 628 of 1285 (49%) patients with chemotherapy, while 360 (28%) received oral 5-fluorouracil derivatives with or without oral cyclophosphamide.

CONCLUSIONS

Anthracycline combination chemotherapy was commonly used as adjuvant therapy, but there were over a quarter of patients only given oral 5-FU derivatives, which might not be recommended by worldwide consensus. Adjuvant radiation therapy was also given to only 20% of the patients in Kyushu, which might be fewer than the report by the Japanese Breast Cancer Society. Based on these data, the KBC-SG will continue cooperative studies to improve the quality of adjuvant treatment for early breast cancer.