Effects of treatment with megestrol acetate on the insulin-like growth factor system: time and dose dependency

Supportive care of female hormones in brain health: what and how?

Female hormones, functioning as neuroactive steroids, are utilized beyond menopausal hormone therapy. The rapid onset of allopregnanolone analogs, such as brexanolone and zuranolone, in treating depression, and the effectiveness of megestrol acetate in addressing appetite and weight gain, prompted the Food and Drug Administration to authorize the use of progesterone for treating postpartum depression and cancer-related cachexia. Progesterone has also been found to alleviate neuropathic pain in animal studies. These off-label applications offer a promising option for patients with advanced cancer who often experience various mood disorders such as depression, persistent pain, social isolation, and physical complications like cachexia. These patients have shown low tolerance to opioids and mood-regulating medications. However, the potential risks and uncertainties associated with hormone therapy treatment modalities can be daunting for both patients and medical professionals. This review aims to offer a comprehensive understanding of the non-reproductive functions and mechanisms of female hormones in brain health.

Megestrol acetate improves cardiac function in a model of cancer cachexia-induced cardiomyopathy by autophagic modulation

BACKGROUND

Cachexia is a complex metabolic syndrome associated with cancer. One of the features of cachexia is the loss of muscle mass, characterized by an imbalance between protein synthesis and protein degradation. Muscle atrophy is caused by the hyperactivation of some of the main cellular catabolic pathways, including autophagy. Cachexia also affects the cardiac muscle. As a consequence of the atrophy of the heart, cardiac function is impaired and mortality is increased. Anti-cachectic therapy in patients with cancer cachexia is so far limited to nutritional support and anabolic steroids. The use of the appetite stimulant megestrol acetate (MA) has been discussed as a treatment for cachexia.

METHODS

In this study the effects of MA were tested in cachectic tumour-bearing rats (Yoshida AH-130 ascites hepatoma). Rats were treated daily with 100 mg/kg of MA or placebo starting one day after tumour inoculation, and for a period of 16 days. Body weight and body composition were assessed at baseline and at the end of the study. Cardiac function was analysed by echocardiography at baseline and at day 11. Locomotor activity and food intake were assessed before tumour inoculation and at day 11. Autophagic markers were assessed in gastrocnemius muscle and heart by western blot analysis.

RESULTS

Treatment with 100 mg/kg/day MA significantly attenuated the loss of body weight (-9 ± 12%, P < 0.05) and the wasting of lean and fat mass (-7.0 ± 6% and -22.4 ± 3 %, P < 0.001 and P < 0.05, respectively). Administration of 100 mg/kg/day MA significantly protected the heart from general atrophy (633.8 ± 30 mg vs. placebo 474 ± 13 mg, P < 0.001). Tumour-bearing rats displayed cardiac dysfunction, as indicated by the significant impairment of the left ventricular ejection fraction, the left ventricular fractional shortening, the stroke volume, the end dyastolic volume, and the end systolic volume. In contrast, MA significantly improved left ventricular ejection fraction, left ventricular fractional shortening, and left ventricular end systolic volume. Western blotting analysis showed an upregulation of the autophagic pathway in the gastrocnemius and hearts of the placebo-treated tumour-bearing rats. Treatment with MA, however, was able to modulate the autophagic markers (e.g. Beclin-1, p62, TRAF6, and LC3) in the gastrocnemius and in the hearts of tumour-bearing rats. Most importantly, 100 mg/kg/day MA reduced mortality [hazard ratio (HR): 0.44; 95%CI: 0.20-1.00; P = 0.0486].

CONCLUSIONS

Megestrol acetate improved survival and reduced wasting through a marked downregulation of autophagy, occurring in both skeletal and heart muscle, the latter effect leading to a significant improvement of cardiac function. Our data suggest that MA might represent a valuable strategy to counteract the development of cancer cachexia-induced cardiomyopathy.

Tamoxifen and megestrol acetate for postmenopausal breast cancer: diverging effects on liver proteins, androgens, and glucocorticoids

AIM

To compare the effects of tamoxifen and megestrol acetate on liver proteins, androgens, and glucocorticoids during adjuvant treatment for postmenopausal breast cancer.

METHODS

A subgroup of women within a large prospective multicenter trial were followed with blood sampling every 3 mo during 2 yr. Women were randomized to receive either continuous tamoxifen 40 mg/d or repeated sequential treatment with tamoxifen and megestrol acetate (MA) 160 mg/d.

RESULTS

We found profound and distinct differences between the two regimens. Tamoxifen increased steroid-binding proteins (SHBG and CBG) and suppressed circulating androgens and IGF-I. In contrast, the metabolic effects of tamoxifen were clearly antagonized by MA. There was a rise in IGF-I and marked suppression of steroid-binding proteins. Levels of free testosterone were reduced by 70%. MA also caused apparent adrenal suppression.

CONCLUSION

The different effects on anabolic/catabolic balance and adrenal function may relate to certain clinical effects during treatment.

The insulin-like growth factor system in advanced breast cancer

Despite improvements in therapy, the prognosis for advanced breast cancer is poor and a search for new treatment targets and key regulators of tumour growth is warranted. Extensive data are available on the importance of the insulin-like growth factor (IGF) system in growth regulation of breast cancer cell lines in vitro, indicating that the IGF-I receptor (IGF-IR), IGF-I (and IGF-II) function as survival factors, while IGF binding protein (IGFBP)-3 may act as a growth inhibitor. There is a tight link between the growth regulatory pathways of IGFs and oestrogens in oestrogen-receptor(OR)-positive breast cancer cells. In vivo studies indicate a role of IGF-I and IGF-IR in breast cancer development. However, the importance of the IGF system in metastatic and highly aggressive breast tumours in vivo is not clear, and therapeutic strategies designed to interrupt IGF signalling have not yet proved to be an effective treatment modality in patients with metastatic breast cancer.

Expression of estrogen receptors (alpha, beta) and insulin-like growth factor-I in breast tissue from surgically postmenopausal cynomolgus macaques after long-term treatment with HRT and tamoxifen

The novel estrogen receptor ERbeta could be a key factor for proliferation and breast cancer risk. In a primate model for long-term HRT, surgically postmenopausal cynomolgus macaques were treated for 35 months with conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), CEE+MPA and tamoxifen (n=5 in all groups). The immunohistochemical expression of ERalpha, ERbeta and IGF-I in breast tissue was quantified by image analysis. Overall the levels of ERbeta were higher than for ERalpha. In untreated animals, the median area of positive cells was 58% and 21%. The lowest levels for ERbeta were seen during treatment with CEE/MPA (3%) and in this group the expression of ERbeta was lower than for ERalpha. Tamoxifen had effects similar to estrogen. ERbeta may have a role to modulate the proliferative response following activation of ERalpha. The results suggest that hormonal treatments have a different influence on the balance ERbeta/ERalpha in breast tissue.

The IGF-system in healthy pre- and postmenopausal women: relations to demographic variables and sex-steroids

Plasma insulin-like growth factor (IGF)-I, free IGF-I and -II, IGF-binding protein (IGFBP)-1, -2, and -3 together with IGFBP-3 protease activity were measured in 114 postmenopausal and 39 premenopausal healthy women. For each parameter, the mathematical distribution was characterised, and the normal range for pre- and postmenopausal women described, together with correlations to demographic variables and sex-steroids (postmenopausal women). Postmenopausal women had lower levels of plasma IGF-I (P<0.001) and free IGF-I (P<0.001) compared to premenopausal women, while plasma IGFBP-2 (P<0.05) and immunoreactive IGFBP-3 (P<0.001) were higher in postmenopausal women. Free IGF-I (but none of the other parameters) was significantly lower in postmenopausal smokers compared to non-smokers (P<0.05).IGF-I and -II both correlated positively to height (r=0.203, P<0.05 and r=0.198, P<0.05, respectively), while IGF-II correlated positively to weight (r=0.250, P<0.01). Plasma IGF-I correlated positively to androstenedione (r=0.292, P<0.01) and dehydroepiandrosterone sulphate (DHEAS, r=0.202, P<0.05), while a significant positive correlation was observed between IGF-II on the one side and oestradiol (E(2), r=0.227), oestrone sulphate (E(1)S, r=0.238) and androstenedione (r=0.213) on the other side (P<0.05 for all). Our results support a relation between sex-steroids and IGF-I and -II in healthy postmenopausal women. The lower levels of total and free IGF-I in postmenopausal compared to premenopausal women indicate lower bioavailability of this growth factor in elderly females.

Effects of megestrol acetate on weight gain, body composition, and pulmonary function in patients with cystic fibrosis

OBJECTIVES

Malnutrition is a negative prognostic indicator in patients with cystic fibrosis (CF) and may accentuate pulmonary decline. We tested whether megestrol acetate would have beneficial effects on growth in patients with CF and pancreatic insufficiency.

STUDY DESIGN

We performed a randomized, double-blind, placebo controlled study. All patients were taking replacement enzymes to compensate for pancreatic insufficiency. Patients (n = 17) were randomly assigned to receive either megestrol acetate or placebo.

RESULTS

The treatment group had a significant increase in weight-for-age z scores compared with placebo and reached 100% of their ideal body weight within 3 months of initiating therapy. Weight gain included both fat and fat-free mass. Improved pulmonary function (forced vital capacity and forced expiratory volume in 1 second) was noted in the treatment group compared with placebo (P <.04). Reversible adrenal suppression was observed in the majority of patients who received megestrol acetate.

CONCLUSIONS

Short-term use of megestrol acetate results in significant weight gain and improved pulmonary function in malnourished subjects with CF. Our study provides a controlled basis for this intervention, identifies important side effects, and provides the foundation for multiyear, longitudinal trials in a larger number of patients with CF.