Endocrine therapy for hormone receptor-positive breast cancer in non-surgery elderly patients aged 75 or above

The treatment of breast cancer in elderly patients is usually surgery, and in the Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer, the use of only drug therapy is limited to cases of co-morbidities or refusal of surgery. However, there are many cases in which surgery is not performed due to co-morbidities and in which the patient or patient's family declines surgery. We retrospectively analyzed the cases of 19 elderly patients aged 75 or above with hormone receptor-positive breast cancer who selected endocrine therapy as early treatment at our hospital or Yamakawa Breast Clinic during the period from December 2009 to December 2019. We determined the treatment effects, changes in the patients' quality of life (QOL), co-morbidities, medication compliance, and more. Six patients died due to causes other than breast cancer, and one case of death due to breast cancer was confirmed. These results indicate that endocrine therapy can contribute to good progress and QOL maintenance. We suggest that selecting only endocrine therapy as early treatment can be an appropriate option for elderly patients with hormone receptor-positive breast cancer when their daily life can be monitored by their family members

Effects of guanidino compounds on monoamine oxidase and catechol-O-methyltransferase activity

In the central nervous system (CNS)of mammals, monoamine oxidase (EC 1.4.3.4)(MAO), which have been divided into two functional forms (MAO-A and MAO-B), and catechol-O-methyltransferase (EC 2.1.1.6)(COMT) act as catabolic enzymes of catecholamines and serotonin regulating their concentrations. In this study, the effects of guanidino compounds (5mM) on MAO-A, MAO-B and COMT were examined to invastigate the role of guanidino compounds in CNS function. MAO-A activity was decreased by α-guanidinoglutaric acid (GGA) and guanidinoethanesulfonic acid, and increased by arginine (Arg) and N-acetylarginine at a low substrate concentration (4.33μM). MAO-B activity was decreased by creatinine (CRN), δ-guanidinovaleric acid (GVA) and methylguanidine (MGua) at a high substrate concentration (3.125mM), and decreased by CRN, GVA, MGua, Arg, guanidine, 2-guanidinoethanol, β-guanidinopropionic acid, guanidinosuccinic acid and homoarginine at a low substrate concentration (62.5μM). GVA, CRN and MGua acted as competitive inhibitors on MAO-B and their calculated Ki values were 9.47mM, 14.5mM and 29.4mM, respectively. Although the guanidino compounds tested had no effect on COMT activity at a high substrate concentration (600μM), GSA and GVA inhibited COMT activity at a low substrate concentration (75μM). These results suggest that some guanidino compounds influence catabolic enzymes of indoleamine and catecholamines to control CNS function