Breast Surgery
Introduction
PThis Division is working on operative and adjuvant chemohormonal therapies for primary breast cancer patients. Since the opening of the National Cancer Center Hospital East in July 1992, more than 900 primary breast cancer patients have undergone surgery in this Division.
Routine Activities
One hundred sixty-one primary breast cancer patients were treated in 1998. Most patients had undergone modified radical mastectomy (69.6%) or breast-conserving surgery (BCS) (29.8%). BCS is considered the standard surgical treatment, but the local recurrence rate and overall survival rate based on the long-term follow-up have not been reported in Japan. In this hospital, patients who are eligible for BCS are informed of the method, benefits and risk of BCS, after which they choose BCS or mastectomy. Magnetic resonance imaging can help us diagnose the extent of the intraductal spread of breast cancer.
A recent meta-analysis indicated that adjuvant chemohormonal therapy for early breast cancer can prolong disease-free survival and overall survival. In Western countries, adjuvant polychemotherapy given intravenously is recommended for node-negative high-risk, or node-positive breast cancer patients. In contrast, monochemotherapy of oral fluoropyrimidine compounds (OFP) is widely used in Japan, because OFP is believed to be less toxic than polychemotherapy. The most important issue is whether OFP has a greater survival benefit than polychemotherapy. To answer this question, clinical randomized trials of Japan Clinical Oncology Group (JCOG) and National Surgical Adjuvant Study of Breast Cancer (NSAS) are ongoing.
Of the 552 breast cancer patients who underwent radical mastectomy or BCS between June 1992 and December 1996, 86 patients (15.6%) had a relapse and 42 (7.6%) had died of breast cancer by December 1998. As to the clinicopathological findings of these patients, 10 or more nodal metastases were found to be the most powerful prognostic factor to predict relapse.
Research Activities
Ongoing Phase III Study
1. JCOG 9208: CAF+TAM vs. CAF+ high-dose of CPA and thioTEPA with ABMT+TAM for patients with 10 or more positive nodes. (1993-)
2. JCOG 9401: AC+TAM vs. TAM for postmenopausal women with one to nine positive nodes. (1995-)
3. JCOG 9404: AC+TAM vs. UFT+TAM for premenopausal women with one to nine positive nodes. (1995-)
4. NSAS-BC 01: CMFｱTAM vs. UFTｱTAM for node negative, high-risk patients. (1996-)
[Note: A, adriamycin; ABMT, autologous bone marrow transplantation; C or CPA, cyclophosphamide; F, 5-fluorouracil; M, methotrexate; TAM, tamoxifen; UFT, tegaful+uracil]
New Developments
Human proto-oncogene erbB-2 is a prognostic factor of breast cancer, and it was also reported to be a factor predicting the response to chemo-hormonal therapies. In this Division, the levels of cytosol and serum erbB-2 protein are measured, and overexpression of cytosol erbB-2 was found more frequently in advanced breast cancer than in early breast cancer. The prognosis of breast cancer patients who had overexpression of erbB-2 in cytosol or sera is currently under investigation.
Tamoxifen is the standard hormonal therapy for breast cancer. From a retrospective analysis in this hospital, tamoxifen had the potential benefit of reducing serum cholesterol levels, which may be closely related to cardiovascular risk, in Japanese postmenopausal women.
Another retrospective analysis revealed the limitation of detection of the first recurrence of breast cancer diagnosed by intensive follow-up, including tumor markers, chest X-ray, mammography, liver echography, and bone scans.
Sentinel node biopsy (SNB) is a promising surgical technique applied to many kinds of malignant neoplasms. In this Division, SNB with a dye (indigo carmine) began in January 1998, and our initial experience indicates it to be feasible and reliable. In addition, lymphatic mapping and SNB with radioisotope are also being investigated. In the near future, this surgical technique is expected to be performed as a standard practice in patients with clinically node-negative breast cancer.
Statistics
| Operation | No. of pts | (%) |
| Standard radical mastectomy | 0 | (0) |
| Modified radical mastectomy | 112 | (69) |
| Breast-conserving surgery | 48 | (30) |
| Others | 1 | (1) |
| No. of nodal meta. | No. of pts | DS (%) | OS (%) |
| 0 | 236 | 93 | 97 |
| 1 to 9 | 135 | 68 | 85 |
| 10 or more | 45 | 41 | 59 |
(S. Imoto)
