Susumu Owada

Intersite Variation of Estrogen Receptors in Human Breast Cancers and Response to Endocrine Therapy

Estrogen receptor (ER) assays were performed by sucrose gradient centrifugation method at multiple sites in large breast cancers. Intersite variation of ER in a tumor was observed in 24 out of 35 cases. 16 tumors with relatively low ER levels showed different ER status with multiple assays. The results suggest that an assay performed on a small random part of a large tumor may not yield the true ER status. ER value at the largest cross-section was almost the same as the average ER values in each tumor. In addition, 21 cases were examined in relation to ER values at multiple sites in the large tumors and response to endocrine therapy. As the ER value at the largest cross-section was highly correlated with the therapeutic response to endocrine therapy of breast cancer, it would represent true ER status and level. The results suggest that the ER assay at the largest cross-section of a large tumor is an appropriate method to predict response to endocrine therapy.

Anti-tumor effects of the oral administration of the streptococcal preparation OK-432 (PICIBANIL)--the inhibition of carcinogenesis and growth in rats with ENNG-induced gastrointestinal tumors.

We examined whether the Streptococcal preparation OK-432, an immunopotentiating agent, increases immunocompetence of the gut-associated lymphoid system (GALS), inhibits gastrointestinal carcinogenesis, and has an anti-tumor effect.14C-labelled OK-432 was orally and intraperitoneally administered to rats, and the distribution of the agent in various organs then serially evaluated. The concentration of OK-432 in Peyers patches and mesenteric lymph nodes was higher after oral administration than after intraperitoneal administration, and showed a biphasic pattern peaking at 30 minutes and 5 hours following administration, in the Peyers patches. With regard to immunocompetence, PHA- and PWM-stimulated blastogenesis of lymphocytes derived from the mesenteric lymph nodes and peripheral blood enhanced, and the helper/suppressor T-cell ratio was elevated after the oral administration of OK-432. Moreover, chemotactic activity of peritoneal macrophages was also increased. ENNG-induced gastrointestinal carcinogenesis was observed in 60 per cent of the rats orally administered OK-432 as compared with 88 per cent of the controls. The 13-month survival rate of the rats with gastrointestinal cancer was 50 per cent in those administered OK-432 as compared with 25 per cent in those administered OK-432 as compared with 25 per cent in the controls. When administered orally, the agent prevented reduction in immunocompetence in the course of carcinogenesis, suppressed carcinogenesis, and prolonged the survival of animals with cancer without any of the side effects associated with injection. The oral administration of OK-432 is thus considered to be an effective non-specific immunotherapy against gastrointestinal malignancies.