John K. MacFarlane

Studies on estrogen receptors and regression in human breast cancer

Estradiol receptors were studied both qualitatively and quantitatively in 650 cases of breast cancer to obtain information on molecular forms and relationship with response to endocrine therapy. Cytosol estradiol receptor (ERC) was assayed by a charcoal method following incubations with 3H‐estradiol and also by chromatography on Sephacryl columns. Results were classified as positive (10 fmoles/mg P and up), borderline (3–10 fmoles) and negative (0–3 fmoles). It was found that 44.6% of tumors were positive, 14.15% were borderline, and 41.2% were negative. Qualitatively, two major molecular forms of ERC were identified with molecular weights 31,000 and ∼250,000. ERC level and response to endocrine therapy were correlated in a group of 52 patients. Response rate to hormonal therapy only was 59% in the ERC‐positive, 28% in the borderline, and 9% in the ERC‐negative group. Combination therapy, including endocrine manipulation, chemotherapy, and/or radiation improved response rates to 66% in the ERC‐positive, 40% in the borderline, and 33% in the ERC‐negative group. Defects in the translocation of the cytosol estradiol receptor (ERC)‐estradiol complex to the nucleus could partly explain the failure of endocrine therapy in 40% of patients with significant ERC. To examine this possibility, 98 cases of breast cancer were examined for both ERC and nuclear translocation of estradiol (ERN). Nuclei were isolated from the low speed sediment and incubated with the ERC‐3H‐estradiol complex in the presence and absence of an estrogen competitor. After incubation, ERN was extracted from the nuclei and expressed as specifically bound estradiol, fmoles/mg DNA. Of 44 cases with significant ERC, nine had no ERN (20%). In the borderline group of 23 cases, eight had no ERN (34%), and of the 31 cases with zero or negligible ERC 27 had no ERN (87%). Results indicate that ERC‐negative cases should be excluded from hormonal therapy and appear to benefit most from chemo‐ and/or radiation therapy. The absence of ERN in a significant proportion of ERC‐positive cases probably contributes to the failure of hormonal manipulation in such patients. The results indicate that the determination of both ERC and ERN could improve the selection of patients for endocrine therapy.

Predictive value of tube leukocyte adherence inhibition (LAI) assay for breast, colorectal, stomach and pancreatic cancer

The tube LAI assay measures accurately antitumor immunity in patients with early cancer but fails to detect up to 75% of patients with advanced cancer due to excess circulating organ‐specific neoantigen (OSN). Substances such as prostaglandin E2 (PGE2) or aminophylline which increase intracellular nucleotides in leukocytes of patients with advanced cancer reversed this nonreactivity and greatly increased the sensitivity of the assay without any loss of specificity. Antitumor immunity can now be detected in advanced cancer, and a combination of the two assays gives prognostic potential to the assay: a positive test with PGE2 and negative test without indicates the patient has a large tumor burden. The specificity of the assay for each cancer was high and in most instances was < 95%. The PGE2 stimulated assay retained the high specificity. The sensitivity of the regular tube assay was often low, 33–56% because of the many advanced cancer patients tested, whereas the PGE2 stimulated assay showed almost a two‐fold increase in sensitivity, 67‐93%. The diagnostic value of the assay was estimated by calculating the predictive value for different prevalences of cancer. It was found that at low prevalances of cancer as found in the general population, the assay had a low diagnostic value since few patients with a positive test would have the cancer tested for. With prevalences of cancer of 5% or greater as might be found in a tertiary care clinical setting, the assay would seem to have diagnostic value since one half or more patients with a positive test would have the cancer tested for. Most false positives, but not all, are found in patients who have lesions that are often considered to increase their risk for cancer: severe dysplasia of the breast, colon adenomas, chronic atrophic gastritis and chronic pancreatitis, suggesting that the assay predicts oncogenesis.

Studies on cytosol and nuclear binding of estradiol in human breast cancer

Abstract Defects in the translocation of the cytosol estradiol receptor (ERC)-estradiol complex to the nucleus could partly explain the failure of endocrine therapy in 40% of breast cancer patients with significant ERC. To examine this possibility, 98 cases of human breast cancer were investigated for cytoplasmic and nuclear (ERN) estradiol receptors. ERC was assayed by a charcoal method following incubation with [ 3 H]-estradiol. Nuclei were isolated from the low speed sediment and incubated at 30°C with the ERC-[ 3 H]-estradiol complex in the presence and absence of an estrogen competitor. ERN was extracted from the nuclei with 0.4 M KCl and expressed as specifically bound estradiol, fmol/mg DNA. The quantity of ERN ranged between 0–746 fmol/mg DNA. Of 50 cases with significant ERC activity, 11 had no ERN (24%). In the borderline ERC group of 17 tumors, 5 had no ERN (29%), while of the 31 cases with zero or negligible ERC, 27 eases had no ERN (87%). Characteristics of ERC are different from the classical model. Chromatography of ERC on Sephacryl-S-200 columns and sucrose gradient sedimentation values indicate that the original form has an approximate molecular weight of 35,600, which on warming is transformed into an even smaller form (mol. wt — 22,700). The larger form of ERC (mol. wt ∼- 250,000) is produced by aggregation in low ionic strength media. The major form of the ERN complex has a molecular weight of 35,600, the same as that of the cytosolic receptor complex. It appears that the absence of ERN in a significant proportion of ERC positive tumors could contribute to the failure of endocrine therapy in such patients. Results indicate that the determination of both ERC and ERN could improve the selection of patients for endocrine therapy.

Anaesthesia for cardiopulmonary bypass in calves

SummaryA safe and convenient method of anaesthesia, utilizing standard laboratory apparatus, has been described for use in cardiopulmonary bypass procedures in calves. The technique evolved during early work on aortic valve xenograft replacements. The long-term results of the series will be reported in a subsequent publication.RésuméPour plusieurs raisons, le veau est l’animal de choix pour les expériences sur la chirurgie cardiovasculaire. Les auteurs décrivent en détail l’évolution de la technique d’anesthésie par inhalation au cours de 25 cas de remplacements de valves aortiques pratiques ces dernières années. On préfère le méthoxyflurane (Penthrane) pour sa marge de sécurité et ses propriétés d’induction lente. En n’utilisant que le matériel de laboratoire standard, on a trouvé sûre et efficace la technique décrite. Dans cette série d’expériences, une seule mort a été attribuée directement à l’anesthésie.

Cortisol binding in human breast cancer: Correlation with antitumor immunity

SummaryThe intensity of cortisol binding was measured in the cytosol fraction of the primary tumor obtained from 50 patients with stage I and II breast cancer. The state of cellular antitumor immunity of the same patients was investigated by the tube leucocyte adherence inhibition (LAI) test, performed with peripheral blood leucocytes 1–2 days preoperatively. It was found that the intensity of tumor cortisol binding correlates negatively with LAI values. Patients with high cortisol binding in their tumors have low LAI values, while low tumor cortisol binding is associated with higher antitumor immunity. The results suggest that high cortisol binding in the tumor might inhibit the tumor recognition process and/or the cellular immune defense mechanism and thus facilitate cancer development.