[Subrenal capsule assay for chemosensitivity test (II)--Sequential changes in the implanted tumor tissue and histological findings].

We carried out fundamental subrenal capsule assay methodology, using tumor specimens of human cancer xenografts (breast cancer and colon cancer) serially transplanted into nude mice. With regard to sequential changes in the tumor grafts implanted under the renal space of immunocompetent mice, tumor size was largest macroscopically around day 6 after inoculation, and later involuted gradually. Histological findings showed that implanted tumor tissues were preserved to a moderate extent until day 4 after inoculation, but leukocyte infiltration by host reaction had begun by day 4, and tumor tissues were almost replaced by host reactive tissues on day 6. Labeling index scoring did not indicate growth of implanted tumor cells. We found that macroscopic tumor size was largest around day 6 because we measured tumor size with involved leukocyte infiltration, and the macroscopic tumor did not represent the true extent of the tumor tissue.

Clinicopathologic characteristics and prognosis of breast cancer patients associated with pregnancy and lactation: analysis of case-control study in Japan.

Clinicopathologic characteristics and prognosis of breast cancer patients associated with pregnancy and lactation were clarified by means of a case-control study of matched non-pregnant and non-lactating patients with breast cancer. From 18 institutions in Japan, a total of 192 subjects with breast cancer diagnosed during pregnancy (72 cases) and lactation (120 cases) were collected between 1970 and 1988, accounting for 0.76% of all breast cancer patients. The duration of symptoms was longer and tumor size was larger in the study subjects. Although the disease-free interval was longer than that in the control patients, the survival time was shorter. There was no characteristic difference in histologic type. Vascular invasion and lymph node metastasis were found more frequently in the subjects. The positive rates of estrogen receptor and progesterone receptor were lower in the subjects. The 5- and 10-year survival rates of the study patients were 65% and 55%, respectively, and these survivals were significantly lower than those of the control (P < 0.001). The survival rates were poorer in the subjects, in accordance with stage and lymph node metastasis. The results suggest that most of the patients with breast cancer diagnosed during pregnancy and lactation are in a more advanced stage because of a delay in detection and diagnosis, and hence have unfavorable prognosis. Therefore, it is important to diagnose and treat early for improvement of prognosis in patients with breast cancer during pregnancy and lactation.