Relative hyperestrogenism in Klinefelter Syndrome: results from a meta-analysis

Oncological diseases in Klinefelter Syndrome: an overview

Epidemiological studies have highlighted a higher incidence of morbidity and mortality among individuals with Klinefelter's Syndrome (KS), however, the relative impact of oncological diseases on KS subjects is still uncertain. While some malignancies (e.g., hematological and lung cancers) may show an increased prevalence in the KS population, only a few rare tumors (i.e., extragonadal germ cell tumors [GCTs] and male breast cancer [MBC]) seem to follow this trend. Additionally, hormonal and genetic determinants may be involved in the pathogenesis of neoplasia in KS, even if subjects affected by this syndrome generally show lower incidence of prostate cancer along with lower disease-specific mortality despite testosterone replacement therapy (TRT). This review deals with the pathophysiological and clinical aspects of neoplastic diseases occurring in KS.

Machine learning based prediction models in male reproductive health: Development of a proof-of-concept model for Klinefelter Syndrome in azoospermic patients

BACKGROUND

Due to the highly variable clinical phenotype, Klinefelter Syndrome is underdiagnosed.

OBJECTIVE

Assessment of supervised machine learning based prediction models for identification of Klinefelter Syndrome among azoospermic patients, and comparison to expert clinical evaluation.

MATERIALS AND METHODS

Retrospective patient data (karyotype, age, height, weight, testis volume, follicle-stimulating hormone, luteinizing hormone, testosterone, estradiol, prolactin, semen pH and semen volume) collected between January 2005 and June 2019 were retrieved from a patient data bank of a University Centre. Models were trained, validated and benchmarked based on different supervised machine learning algorithms. Models were then tested on an independent, prospectively acquired set of patient data (between July 2019 and July 2020). Benchmarking against physicians was performed in addition.

RESULTS

Based on average performance, support vector machines and CatBoost were particularly well-suited models, with 100% sensitivity and >93% specificity on the test dataset. Compared to a group of 18 expert clinicians, the machine learning models had significantly better median sensitivity (100% vs. 87.5%, p = 0.0455) and fared comparably with regards to specificity (90% vs. 89.9%, p = 0.4795), thereby possibly improving diagnosis rate. A Klinefelter Syndrome Score Calculator based on the prediction models is available on http://klinefelter-score-calculator.uni-muenster.de.

DISCUSSION

Differentiating Klinefelter Syndrome patients from azoospermic patients with normal karyotype (46,XY) is a problem that can be solved with supervised machine learning techniques, improving patient care.

CONCLUSIONS

Machine learning could improve the diagnostic rate of Klinefelter Syndrome among azoospermic patients, even more for less-experienced physicians.

Obesity and Breast Cancer Risk in Men: A National Case-Control Study in England and Wales

Background

Breast cancer is rare in men, and information on its causes is very limited from studies that have generally been small. Adult obesity has been shown as a risk factor, but more detailed anthropometric relations have not been investigated.

Methods

We conducted an interview population-based case-control study of breast cancer in men in England and Wales including 1998 cases incident during 2005-2017 at ages younger than 80 years and 1597 male controls, with questions asked about a range of anthropometric variables at several ages. All tests of statistical significance were 2-sided.

Results

Risk of breast cancer statistically significantly increased with increasing body mass index (BMI) at ages 20 (odds ratio [OR] = 1.07, 95% confidence interval [CI] = 1.02 to 1.12 per 2-unit change in BMI), 40 (OR = 1.11, 95% CI = 1.07 to 1.16), and 60 (OR = 1.14, 95% CI = 1.09 to 1.19) years, but there was also an indication of raised risk for the lowest BMIs. Large waist circumference 5 years before interview was more strongly associated than was BMI with risk, and each showed independent associations. Associations were similar for invasive and in situ tumors separately and stronger for HER2-positive than HER2-negative tumors. Of the tumors, 99% were estrogen receptor positive.

Conclusions

Obesity at all adult ages, particularly recent abdominal obesity, is associated with raised risk of breast cancer in men, probably because of the conversion of testosterone to estrogen by aromatase in adipose tissue. The association is particularly strong for HER2-expressing tumors.

Estradiol-Testosterone Imbalance Is Associated with Erectile Dysfunction in Patients with Klinefelter Syndrome

Erectile dysfunction (ED) is a frequent sexual disorder in adult men. Klinefelter syndrome (KS) is the most common sex chromosomal disorder and a frequent cause of male hypogonadism. Psychological and cognitive aspects are quite typical in KS and have been linked to ED, while the role of testosterone (T) levels in sexual function of KS subjects has not been fully elucidated. The purpose of the present study is to investigate the role of hormonal disturbances in erectile function of subjects with KS. We conducted a retrospective study involving 52 Klinefelter patients newly diagnosed who never received androgen replacing therapy. All the subjects underwent medical history, accurate physical examination, and blood tests. The International Index of Erectile Function questionnaire (IIEF-EF) score correlated negatively with estradiol/testosterone ratio (E2/T); this correlation remained statistically significant after correction for age (ρ −0.320 p = 0.018). A multiple linear regression analysis identified age and E2/T as the main predictors of IIEF-EF score (R2 0.169 F = 3.848 p = 0.008). Our findings corroborate previous KS data obtained in the general population showing an association between higher E2/T ratio and impaired erectile function. Larger studies are required to better elucidate the pathophysiology of ED in patients with KS.

Morbidity in Klinefelter syndrome and the effect of testosterone treatment

Klinefelter syndrome (KS; 47,XXY) is the most common sex chromosome abnormality in males (150 per 100,000 males). The condition leads to hypergonadotropic hypogonadism and ever since the condition was described approximately 80 years ago, testosterone treatment has been the cornerstone in care for individuals with KS. However, KS is associated with an array of health-related and socioeconomic challenges and it is becoming progressively clear that proper care for boys and men with KS reaches far beyond simply supplementing with testosterone. There are no widely implemented guidelines for KS care, and studies investigating crucial aspects of testosterone treatment in individuals with KS, including both beneficial and potentially adverse effects, have only begun to emerge during the last decades. For this descriptive review, we present an overview of literature describing health-related outcomes of testosterone treatment in KS and outline the clinical applications of testosterone treatment in KS. Collectively, beneficial effects of testosterone treatment on overall health in KS are described with few apparent adverse effects. However, larger randomized studies in adult and pediatric patients are warranted to elucidate key aspects of treatment. We stress the implementation of centralized multidisciplinary clinics and the need for a dedicated international guideline to ensure optimal care of boys and men with KS.