Efficacy of Metformin in Patients With Breast Cancer Receiving Chemotherapy or Endocrine Therapy: Systematic Review and Meta-analysis

BACKGROUND

Previous studies have suggested that metformin might improve survival outcomes in patients with breast cancer. However, findings on the efficacy of metformin with chemotherapy or endocrine therapy are inconsistent.

OBJECTIVE

To clarify the efficacy of metformin with chemotherapy or endocrine therapy in breast cancer patients according to the treatment setting, including neoadjuvant, adjuvant, and metastasis/recurrence.

METHODS

We systematically searched for randomized controlled trials (RCTs) in MEDLINE, CENTRAL, and EMBASE from inception through July 2020. Overall survival (OS), progression-free survival (PFS), and hypoglycemia rate were the primary outcomes. Secondary outcomes included severe adverse events (SAEs) and relapse-free survival. We used the Grading of Recommendations Assessment, Development, and Evaluation approach and performed a meta-analysis to evaluate the efficacy and safety of metformin with chemotherapy and endocrine therapy in patients with breast cancer.

RESULTS

Our systematic review included 412 participants from 5 trials. Metformin showed little to no difference in OS (hazard ratio [HR] = 1.13; 95% CI = 0.71-1.81; certainty of evidence [COE], moderate) and PFS (HR = 1.14; 95% CI = 0.86-1.50; COE, moderate) in patients with metastasis/recurrence. The evidence was very uncertain about the effect of metformin on survival outcomes in patients who received metformin with neoadjuvant or adjuvant treatment. Metformin showed little to no difference in hypoglycemia and SAEs.

CONCLUSION AND RELEVANCE

Metformin should be discouraged routinely in nondiabetic patients with metastatic/recurrent breast cancer. Further RCTs are needed to verify whether metformin with chemotherapy or endocrine therapy results in significant clinical benefits in the neoadjuvant or adjuvant setting.

Relationship Between Tramadol Response and Cancer Cachexia: A Retrospective Cohort Study

OBJECTIVE

It was reported that the administration of tramadol in patients with cancer pain who have a higher interleukin 6 (IL-6) serum level led to insufficient pain relief. Cytokines produced by tumors, including IL-6, are associated with cancer cachexia. However, whether nonresponse to tramadol is related to cancer cachexia is unknown. The purpose of this study was to examine the relationship between tramadol response and cancer cachexia in patients with cancer pain.

METHODS

We conducted a retrospective cohort study of patients with cancer who received tramadol treatment for mild to moderate pain from January 2016 to June 2019. Patients who experienced <20% pain reduction based on the numeric rating scale from baseline to day 7 after treatment with tramadol were defined as nonresponders. Univariate and multivariate logistic regression analyses were conducted to examine the relationships between tramadol response and various patient characteristics, including cancer cachexia.

RESULTS

Of 115 patients, 79 were included in the analysis. A total of 24 patients experienced cancer cachexia, and 22 patients were nonresponders. In the univariate logistic analysis, cancer cachexia (odds ratio [OR]: 6.04, 95% confidence interval [CI]: 2.06-17.7), higher white blood cell counts (× 10³/μL; OR: 1.28, 95% CI: 1.04-1.61), and lower body mass index (OR: 0.79, 95% CI: 0.66-0.96) were significantly associated with nonresponse to tramadol. The multivariate logistic analysis revealed that cancer cachexia (OR: 5.27, 95% CI: 1.75-15.9) was the only significant factor associated with nonresponse to tramadol.

CONCLUSIONS

Cancer cachexia in patients with cancer pain can be associated with nonresponse to tramadol.

Weight Loss Associated with Platinum-Based Chemotherapy in Patients with Advanced Lung Cancer

BACKGROUND

We examined whether the weight loss that occurs with platinum-based chemotherapy in lung cancer patients is associated with chemotherapy side effects, treatment completion rates and therapeutic effect.

METHODS

We retrospectively reviewed charts of advanced lung cancer patients treated with ≥2 cycles of platinum-based chemotherapy. Patients were divided into 2 groups based on ≥5 or <5% weight loss. Relationships between weight loss and other variables were investigated.

RESULTS

Among 114 patients, 18 (15.8%) experienced ≥5% weight loss. Significantly more patients with small-cell lung cancer (SCLC) than with non-SCLC were found to have ≥5% weight loss (30.8 vs. 11.4%, p = 0.023). Patients with ≥5% weight loss experienced higher incidences of grade 3-4 leukopenia (p = 0.008) and neutropenia (p = 0.005), and treatment completion rates were lower in this group (p = 0.035). Weight loss was not significantly associated with therapeutic effect.

CONCLUSION

The weight loss in patients with advanced lung cancer receiving platinum-based chemotherapy is associated with SCLC, grade 3-4 leukopenia, neutropenia and a decrease in treatment completion rate.

[Effect of the administration of zoledronic acid on life expectancy in patients with multiple myeloma with or without renal impairment]

Zoledronic acid(ZA)is believed to exert anticancer effects in patients with multiple myeloma(MM). For patients with impaired renal function, its dosage should be determined according to creatinine clearance(Ccr). However, there is no reported difference in life expectancy improvement between those with and without renal impairment. Therefore, we conducted a retrospective study to investigate this clinical question. Seventy-eight MM patients receiving ZA injections were selected and divided into 2 groups: (1)normal group(n=39), baseline Ccr≥60mL/min, and(2)impaired group(n=39), baseline Ccr<60mL/min. Patients in the normal group received a significantly higher initial dose(p<0.001), were of a younger age(p<0.001), had lower b2-microglobulin(b2-M)levels(p<0.001), and had higher rates of prior hematopoietic stem cell transplantation(p<0.001)than those in the impaired group. We then compared the survival rate between 31 patients in the normal group and 27 patients in the impaired group whose treatment outcome data were available and found no significant difference(p=0.251). Therefore, our results suggest that the survival rate on ZA administration may not differ between MM patients with and without renal impairment.

[Preliminary study of calculating cerebral arterial blood oxygen saturation using MRI]

To assess whether cerebral arterial blood oxygen saturation (SaO2) can be calculated by EPI, we examined the relationship between peripheral SaO2 and T2+ signal intensity (SI) changes in the brain in three normal subjects, using 1.5 Tesla MRI. To decrease SaO2, hypoxia was induced by 100% helium-gas inhalation (60 sec). SI declined as SaO2 decreased during helium inhalation, while rapid recovery of SI to the baseline was noted with recovery from hypoxia. The differential effective transverse relaxation rate was closely correlated with SaO2 (r > 0.94). Consequently, using MRI, we were able to calculate arterial SaO2.

Preparation and properties of 2',5'-linked oligonucleotide analogues containing 3'-O,4'-C-methyleneribonucleosides

Bicyclic nucleoside analogues, 3'-O,4'-C-methyleneuridine and -5-methyluridine, were successfully incorporated into oligonucleotides via connection with 2',5'-phosphodiester linkage, and hybridization behavior and nuclease stability of the modified oligonucleotides were investigated.

Ferric ammonium citrate-cellulose paste for opacification of the esophageal lumen on MRI

OBJECTIVE

A new ferric ammonium citrate-cellulose mixture for use in MRI of the esophagus was evaluated for its ability to opacify the esophageal lumen.

MATERIALS AND METHODS

Thirty-two patients with esophageal disorders and ten patients with normal esophagus undergoing MRI at 1.5 T were given approximately 100 ml of the newly developed high-viscosity esophageal contrast preparation. Moreover, six of the patients with esophageal cancer were subjected to a second examination after radiation therapy. A total of 48 MR imagings were performed.

RESULTS

Of the patients examined, successful esophageal opacification, graded as excellent, was obtained in 84.2, 78.9, and 57.9%, of the sagittal, axial, and coronal images, respectively. In cases of extrinsic disease involving the esophagus the contrast medium administration allowed the easy differentiation of the esophagus from adjacent mass lesions and proved very useful in identifying displacement and compression. In cases of esophageal carcinoma the contrast medium administration assisted in the measurement of wall thickness and length of the lesion as well as in the identification of the site of origin of the tumor.

CONCLUSION

The results indicate that this product effectively opacifies the esophageal lumen in the majority of patients. We found that it is easy to use, is well tolerated, and does not produce artifacts.

[A hemodialysis patient with HTLV-1-associated myelopathy (HAM)]

We report here a case of maintenance hemodialysis with HTLV-1 associated myelopathy (HAM). A 53-year-old female hemodialysis patient was admitted to Teikyo University Ichihara hospital because of paralytic ileus. She had a history of blood transfusion and had been under dialysis treatment for 8 years. She had experienced gait disturbance and sensory disturbance in her lower extremities for 8 years. Neurological examination revealed myelopathy and neuropathy. Laboratory data revealed that serum anti-HTLV-1-antibody was over 1260 x (PA) and liquor HTLV-1-antibody was over 160 x (PA). Her liquor revealed a cell count of 4/3 cmm, protein 22 mg/dl, glucose 45 mg/dl, chloride 125 mEq/l and no atypical cells. To the best of our knowledge this is a rare case in Japan. Our findings suggest that HAM should be taken into consideration when we diagnose a maintenance hemodialysis patient showing neuropathy and myelopathy.

[Secondary hyperparathyroidism and tertiary hyperparathyroidism chronic renal failure, uremia]

The bone histology of renal osteodystrophy is classified into osteitis fibrosa, osteomalacia, those of mixed, osteoporosis and low turnover bone. Osteitis fibrosa is the most frequent skeletal abnormality and is caused by various degrees of hyperparathyroidism. The main factors inducing hyperparathyroidism which is a well known complication in patients with renal failure include (a) phosphorus retention: 1) hypocalcemia and 2) decreased levels of 1 alpha, 25(OH)2 Vitamin D3, (b) reduced number of 1 alpha, 25(OH)2 Vitamin D3 receptors in parathyroid tissue, (c) skeletal resistance to set-point for calcium-regulated parathyroid hormone secretion. Serum or plasma levels of calcium, phosphorus, alkaline phosphatase, parathyroid hormone, calcitonin and tartrate resistant acid phosphatase are measured to evaluate hyperparathyroidism and metabolic bone disease. Dietary phosphorus restriction in chronic renal insufficiency prevents secondary hyperparathyroidism and renal osteodystrophy. Other treatment of phosphorus binders, Vitamin D metabolites or analogues, carcitonin and bisphosphonate are useful for the management of renal bone disease.

[An adult case of hemolytic uremic syndrome (HUS) after pathogenic Escherichia coli (E. coli) infection]

In recent years, it has been revealed that verocytotoxin-producing E. coli (VTEC) infection is one of the leading causes of HUS and the molecular aspects of its pathophysiology have also been studied extensively. We report a case of a 56-year-old man who developed HUS after E. coli (O 26 strain) infection with diarrhea. The characteristic laboratory findings in this case included hypergammaglobulinemia, hypocomplementemia and a high level of immune complex in addition to the common findings of HUS. The light microscopic findings of the first renal biopsy performed before treatment revealed extensive interstitial changes with remarkable mononuclear cell infiltrations as well as mild mesangial proliferation with crescent formation. Subendothelial electron-dense deposits within the glomerular capillary walls and mesangial area were also detected by electron microscopic examination. The diagnostic possibilities of infectious endocarditis and collagen diseases, such as Sjögren syndrome, were reasonably ruled out by the appropriate examinations. After 2-month prednisolone therapy, proteinuria and deteriorated renal functions as well as the abnormal immunological parameters described above were remarkably improved. The second renal biopsy after treatments showed clearly diminished subendothelial deposits and interstitial mononuclear cell infiltrations. This case report might provide information on the unique features of renal interstitial damage and immunological abnormalities in VTEC-induced adult HUS.

[New development of cellulose-ferric ammonium citrate solution as a contrast-enhancement agent for magnetic resonance imaging of esophageal diseases]

For magnetic resonance imaging (MRI) of esophageal diseases, we have developed a new contrast-enhancement agent, cellulose-ferric ammonium citrate solution. Using this agent, the esophageal lumen is easily identified. This agent is expected to play a role in the MRI diagnosis of esophageal cancer and to help determine the indications for radical surgery and/or intracavitary irradiation.

[Thrombotic thrombocytopenic purpura (TTP) with a low level of apolipoprotein A-I (Apo A-I) which responded to combination of vincristine and beraprost]

A 51-year-old man was admitted to the psychiatric ward because of increasing confusion and irrational behavior. He was later transferred to our department due to anemia and thrombocytopenia. A diagnosis of thrombotic thrombocytopenic purpura (TTP) was made based on the presence of thrombocytopenic purpura, microangiopathic hemolytic anemia, neurological symptoms and fever. Corticosteroids, plasma exchange (PE), dextrans, dipyridamole and vincristine (VCR) were given without satisfactory response. Beraprost sodium was prescribed followed by a dramatic improvement and complete remission. A number of reports indicated that prostacyclin metabolism was involved in the pathogenesis of TTP. Recently Apo A-I was identified to be a prostacyclin-stabilizing factor, which was initially low in this patient. If patients do not respond to either PE or VCR, consideration should be given to treatment with beraprost, especially when the level of Apo A-I is low.

Percutaneous treatments for biliary diseases

Percutaneous treatment of biliary disease was administered in 173 cases, mainly among high-risk or elderly patients. Diagnosis was acute cholecystitis in 32 cases, acute cholangitis in 16, hepatic abscess in five, gallbladder stones in 28, common bile duct stones in 11, intrahepatic stones in five, malignant obstructive jaundice in 61, and benign biliary stenosis in 15. The treatment was successful in 158 of 173 cases (91.3%). Complications were encountered in 17 (9.8%). Most of these occurred during the initial period and were mild and controllable with conservative treatments. There were two deaths (1.2% of patients); one was not related to the procedure. These data suggest that percutaneous treatments are safe and effective even among elderly or high-risk patients with biliary diseases.

Role of endogenous arginine vasopressin in potentiating corticotropin-releasing hormone-stimulated corticotropin secretion in man

Exogenously administered vasopressin (VP) augments ACTH secretion stimulated by CRH. This study was performed to elucidate the role of endogenous VP in potentiating CRH-induced ACTH secretion in man. Synthetic human CRH (100 micrograms) was injected iv into seven normal men after they had been water loaded (20 mL/kg; 60 and 30 min before CRH injection; WL-CRH test) and water deprived (water restriction for 18 h before CRH injection; WD-CRH test). Blood samples were obtained before and 5, 15, 30, 60, 90, and 120 min after CRH injection at 0900 h for determination of plasma ACTH, cortisol, arginine vasopressin (AVP), CRH, and catecholamine levels and osmolality. Urine was obtained immediately before and 120 min after CRH injection for determination of osmolality. The mean plasma AVP levels were significantly higher during the WD-CRH test [1.8 +/- 0.4 (+/- SE) to 1.9 +/- 0.4 pmol/L] than during the WL-CRH test (0.6 +/- 0.1 to 0.9 +/- 0.1 pmol/L). The mean plasma ACTH and cortisol levels rose significantly from basal (4.5 +/- 0.6 pmol/L and 320 +/- 20 nmol/L, respectively) to peak values of 14.0 +/- 2.1 pmol/L at 30 min and 700 +/- 50 nmol/L at 60 min, respectively, during the WD-CRH test. During the WL-CRH test, mean basal plasma ACTH and cortisol levels were 3.5 +/- 0.7 pmol/L and 420 +/- 50 nmol/L, respectively, and reached peak values of 7.7 +/- 1.1 pmol/L at 60 min and 550 +/- 40 nmol/L at 30 min, respectively. Both the mean peak levels and integrated ACTH and cortisol responses were significantly higher during the WD-CRH than during the WL-CRH test. There was no significant difference between the plasma CRH and catecholamine concentrations in both tests. These results suggest that endogenous AVP potentiates CRH-stimulated ACTH secretion and, thus, plays a physiologically significant role in regulating CRH-stimulated ACTH and cortisol secretion in man.

Effect of subcutaneous injection of a long-acting analogue of somatostatin (SMS 201-995) on plasma thyroid-stimulating hormone in normal human subjects

SMS 201-995 (SMS), a synthetic analogue of somatostatin (SRIF) has been shown to be effective in the treatment of the hypersecretion of hormones such as in acromegaly. However, little is known about the effects of SMS on the secretion of thyroid-stimulating hormone (TSH) in normal subjects. In this study, plasma TSH was determined with a highly sensitive immunoradiometric assay, in addition to the concentration of SMS in plasma and urine with a radioimmunoassay, following subcutaneous injection of 25, 50, 100 micrograms of SMS (4 subjects/dose) or a placebo (6 subjects) to normal male subjects, at 0900 h after an overnight fast. The plasma concentrations of SMS were dose-responsive and the peak levels were 1.61 +/- 0.09, 4.91 +/- 0.30 and 8.52 +/- 1.18 ng/ml, which were observed at 30, 15 and 45 min after the injection of 25, 50 and 100 micrograms of SMS, respectively. Mean plasma disappearance half-time of SMS was estimated to be 110 +/- 3 min. Plasma TSH was suppressed in a dose dependent manner and the suppression lasted for at least 8 hours. At 8 hours after the injection of 25, 50 and 100 micrograms of SMS, the plasma TSH levels were 43.8 +/- 19.4, 33.9 +/- 9.4 and 24.9 +/- 3.2%, respectively, of the basal values. The results suggest that SMS suppresses secretion of TSH from the normal thyrotrophs in man and thus also that attention should be paid to possible hypothyroidism during the long-term treatment of patients such as those with acromegaly with this potent analogue of SRIF.

Hormonal responses to insulin-induced hypoglycemia in man

Insulin-induced hypoglycemia is a potent stress stimulating ACTH release, but the factors responsible for this ACTH secretion are not known. In this study, several ACTH-stimulating factors, such as CRH, arginine vasopressin (AVP), epinephrine (E), norepinephrine (NE), and dopamine, in addition to ACTH, cortisol, and glucose, were simultaneously measured in plasma before and 15, 30, 60, 90, and 120 min after iv administration of 0.1 U/kg BW regular insulin to seven normal subjects. Insulin administration resulted in significant rises in the mean plasma ACTH level from 4.6 +/- 1.1 (+/- SEM) to 21.6 +/- 4.8 pmol/L at 30 min (P less than 0.01) and in plasma cortisol from 330 +/- 60 to 720 +/- 50 nmol/L at 60 min (P less than 0.01). These increases were preceded by a 41.0 +/- 1.9% (P less than 0.001) fall in blood glucose levels. The mean plasma CRH level rose significantly from 1.0 +/- 0.1 to 1.2 +/- 0.1 pmol/L (P less than 0.01) at 30 min and remained elevated until 120 min. In addition, concomitant and significant rises in plasma AVP levels (basal, 1.5 +/- 0.01; peak, 4.5 +/- 1.1 pmol/L at 30 min; P less than 0.01), E (basal, less than 50; peak, 640 +/- 130 pmol/L at 30 min; P less than 0.01), and NE (basal, 0.07 +/- 0.01; peak, 0.17 +/- 0.03 nmol/L at 60 min; P less than 0.05), but not dopamine, also occurred. These results suggest that multiple ACTH-releasing factors, such as CRH, AVP, E, and NE, are involved in ACTH secretion induced by insulin-induced hypoglycemia in man.