Takeo Kumaki

The significance of regional lymph node dissection in the surgical management of breast cancer

The results of an analysis done on the regional lymph node metastases of 300 patients with operable breast cancer, who were treated in the Department of Surgery (II), Kanazawa University Hospital from 1973 to early 1988 are reported herein. It was found that the metastases of the axillary and internal mammary lymph nodes were closely related to the survival of patients, but they were hardly diagnosed before the operation. Only the dissection of these lymph nodes proved useful for providing the prognostic information. Moreover, in a retrospective study comparing theen bloc extended radical mastectomyversus the other types of mastectomy, the extended radical mastectomy was seen to greatly improve the survival of patients with 3 or less than 3 metastatic axillary lymph nodes. Thus, the extended radical mastectomy provides the maximum diagnostic and prognostic information, and gives the best chance of loco-regional control of the disease. The anterior chest deformity created by the extended radical mastectomy, however, should be avoided in those patients without internal mammary involvement. We therefore propose the modified extended mastectomy as a staging operation.

A retrospective study on the efficacy of cervical lymph node dissection in well-differentiated carcinoma of the thyroid

The management of cervical lymph node metastases in well-differentiated carcinoma of the thyroid is controversial. In our department, from 1963 to 1972, node plucking was performed only in patients with cervical lymphadenopathy whereas, from 1973 to 1983, modified radical neck dissection was therapeutically or electively performed. In order to determine whether the more extensive dissection is adequate, a retrospective analysis was performed using two groups of patients who were managed differently with regard to the treatment of cervical lymph node metastases. From this series of 206 patients with more than five years follow-up, it was found that the rates of survival and lymph node recurrence did not differ between the two groups. However, since the well-differentiated carcinoma of the thyroid has relatively indolent biological behaviour, further long-term follow-up seems to be necessary for demonstrating the efficacy of neck dissection.

Effects of High Dietary Fat on the Total DNA and Receptor Contents in Rats with 7,12-Dimethylbenz[a]anthracene-Induced Mammary Carcinoma

The influence of high dietary fat on the malignant intensity and the hormone receptors of 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary carcinoma in female Sprague-Dawley rats were analyzed by the tumor incidence and growth, the DNA histogram type, the DNA index, the S-phase fraction, and the estrogen receptor (ER) and progesterone receptor (PgR) assays. The rats were fed either a low-fat (0.5% corn oil) diet or a high-fat (20% corn oil) diet after the DMBA administration. Tumor incidences in the low-fat and the high-fat diet groups were 46 and 86%, respectively (p less than 0.01). Tumors in the high-fat diet group were also significantly larger than those in the low-fat group. Average tumor latent period was significantly shorter in the high-fat diet group, comparing with that in the low-fat diet group (p less than 0.01). Sixty-nine percent of the tumors in the high-fat diet group had aneuploid type, while only 8% of those in the low-fat diet group had aneuploid type. The DNA index and S-phase fraction also were significantly higher in the high-fat diet group (p less than 0.01). But the ER and PgR contents were not different between both groups. Therefore, these results suggest that a high dietary fat could increase the malignant intensity of the tumor but does not influence the hormonal responsiveness of these tumors.

Influence of Hormones on Proliferation of ER-Positive Cells and ER-Negative Cells of Human Breast Cancer (MCF-7)

The influence of endocrine therapy on the proliferation of estrogen receptor (ER)-positive cells and ER-negative cells of human breast cancer (MFC-7) serially transplanted into nude mice was analyzed by tumor growth, dextran-coated charcoal (DCC) method, ER-immunocytochemical assay (ER-ICA) and ER-immunocytochemically stained 3H-thymidine autoradiography. In the tamoxifen (TAM) group and the medroxyprogesterone acetate (MPA) group, tumor growth was inhibited, but it was promoted in the 17-beta-estradiol dipropionate (E2) group. The ER level by the DCC method was significantly decreased in the TMA, the MPA and the E2 groups. The ER-ICA showed that the percentage of ER-positive cells was decreased in the TAM and the MPA group, but it was increased in E2 group. However, the ER-immunocytochemically stained 3H-thymidine autoradiography showed that not only the labelling index of ER-positive cells but also that of ER-negative cells was significantly decreased in the TAM and the MPA groups, while the labelling index was significantly increased in the E2 groups. Therefore, it was concluded that endocrine therapy affected the proliferation of both ER-positive cells and ER-negative cells of ER-positive breast cancer.