Uterine leiomyomas (fibroids or myomas), benign tumours of the human uterus, are the single most common indication for hysterectomy. They are clinically apparent in up to 25% of women and cause significant morbidity, including prolonged or heavy menstrual bleeding, pelvic pressure or pain, and, in rare cases, reproductive dysfunction. Thus, both the economic cost and the effect on quality of life are substantial. Surgery has been the mainstay of fibroid treatment, and various minimally invasive procedures have been developed in addition to hysterectomy and abdominal myomectomy. Formation of new leiomyomas after these conservative therapies remains a substantial problem. Although medications that manipulate concentrations of steroid hormones are effective, side-effects limit long-term use. A better approach may be manipulation of the steroid-hormone environment with specific hormone antagonists. There has been little evidence-based evaluation of therapy. New research into the basic biology of these neoplasms may add new treatment options for the future as the role of growth factors and genetic mutations in these tumours are better understood.

Background Uterine fibroids (UFs) are the most common neoplasm affecting women that can cause significant morbidity and may adversely impact fertility.Objectives To examine UF epidemiology and to evaluate the relative strengths of putative risk factors.Search strategy MEDLINE and Embase were searched for studies published in English between January 1995 and April 2015.Selection criteria Publications reporting relevant data from registries and other observational studies with over 1000 patients and single-centre studies with over 100 patients were selected.Data collection and analysis Data on UF incidence, prevalence and associated risk factors were extracted from 60 publications.Main results Wide ranges were reported in both UF incidence (217-3745 cases per 100 000 women-years) and prevalence (4.5-68.6%), depending on study populations and diagnostic methods. Black race was the only factor that was recurrently reported to increase UF risk, by two-threefold compared with white race. Eleven other factors affected UF risk to a magnitude similar to or greater than race. Age, premenopausal state, hypertension, family history, time since last birth, and food additive and soybean milk consumption increased UF risk; use of oral contraceptives or the injectable contraceptive depot medroxyprogesterone acetate, smoking in women with low body mass index and parity reduced UF risk.Conclusions We identified 12 risk factors that play an important role in UF epidemiology. The UF risk factor with the strongest evidence is black race. High-quality prospective observational data are needed to improve our understanding of UF epidemiology, and thus its aetiology and optimal management.Keywords Epidemiology, incidence, leiomyoma, prevalence, race, risk factors, uterine fibroids.Tweetable abstract Uterine fibroids occur in about 70% of women. Black race and 11 other factors affect uterine fibroid risk.

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

A map of 30,181 human gene-based markers was assembled and integrated with the current genetic map by radiation hybrid mapping. The new gene map contains nearly twice as many genes as the previous release, includes most genes that encode proteins of known function, and is twofold to threefold more accurate than the previous version. A redesigned, more informative and functional World Wide Web site (www.ncbi.nlm.nih.gov/genemap) provides the mapping information and associated data and annotations. This resource constitutes an important infrastructure and tool for the study of complex genetic traits, the positional cloning of disease genes, the cross-referencing of mammalian genomes, and validated human transcribed sequences for large-scale studies of gene expression.