and Risk Factors Study 2019 (GBD 2019) provided systematic estimates of incidence, morbidity, and mortality to inform local and international efforts toward reducing cancer burden. OBJECTIVE To estimate cancer burden and trends globally for 204 countries and territories and by Sociodemographic Index (SDI) quintiles from 2010 to 2019. EVIDENCE REVIEWThe GBD 2019 estimation methods were used to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-adjusted life years (DALYs) in 2019 and over the past decade. Estimates are also provided by quintiles of the SDI, a composite measure of educational attainment, income per capita, and total fertility rate for those younger than 25 years. Estimates include 95% uncertainty intervals (UIs).FINDINGS In 2019, there were an estimated 23.6 million (95% UI, 22.2-24.9 million) new cancer cases (17.2 million when excluding nonmelanoma skin cancer) and 10.0 million (95% UI, 9.36-10.6 million) cancer deaths globally, with an estimated 250 million (235-264 million) DALYs due to cancer. Since 2010, these represented a 26.3% (95% UI, 20.3%-32.3%) increase in new cases, a 20.9% (95% UI, 14.2%-27.6%) increase in deaths, and a 16.0% (95% UI, 9.3%-22.8%) increase in DALYs. Among 22 groups of diseases and injuries in the GBD 2019 study, cancer was second only to cardiovascular diseases for the number of deaths, years of life lost, and DALYs globally in 2019. Cancer burden differed across SDI quintiles. The proportion of years lived with disability that contributed to DALYs increased with SDI, ranging from 1.4% (1.1%-1.8%) in the low SDI quintile to 5.7% (4.2%-7.1%) in the high SDI quintile. While the high SDI quintile had the highest number of new cases in 2019, the middle SDI quintile had the highest number of cancer deaths and DALYs. From 2010 to 2019, the largest percentage increase in the numbers of cases and deaths occurred in the low and low-middle SDI quintiles. CONCLUSIONS AND RELEVANCEThe results of this systematic analysis suggest that the global burden of cancer is substantial and growing, with burden differing by SDI. These results provide comprehensive and comparable estimates that can potentially inform efforts toward equitable cancer control around the world.

The cornea is the clear tissue at the front of the eye which enables the transmission of light to the retina for normal vision. The surface of the cornea is composed of an epithelium which is renewed by stem cells located at the periphery of the cornea, a region known as the limbus. These limbal stem cells can become deficient as a result of various diseases of the eye's surface, resulting in the blinding disease of limbal stem cell deficiency. The treatment of this disease is often difficult and complex. In 1997, it was proposed that a small amount of limbal tissue containing limbal stem cells could be culture expanded and then transplanted. Since then various case reports and case series have been reported showing promising results. Here, we review the outcomes of this procedure over the past 13 years with the aim of highlighting the best culture and surgical techniques to date.

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The corneal epithelium is maintained by a population of stem cells known as limbal stem cells (LSCs) due to their location in the basal layer of the outer border of the cornea known as the limbus. Treatment of limbal stem cell deficiency (LSCD) has been achieved with transplantation of ex vivo expanded LSCs taken from a small biopsy of limbus. This is a relatively new technique, and as such, specific national or international guidance has yet to be established. Because of the lack of such specific guidance, our group has sought to minimize any risk to the patient by adopting certain modifications to the research methodologies in use at present. These include the replacement of all non‐human animal products from the culture system and the production of all reagents and cultures under Good Manufacturing Practice conditions. In addition, for the first time, a strictly defined uniform group of patients with total unilateral LSCD and no other significant ocular conditions has been used to allow the success or failure of treating LSCD to be attributable directly to the proposed stem cell therapy. A prospectively designed study with strict inclusion and exclusion criteria was used to enroll patients from our database of patients with unilateral LSCD. Eight eyes of eight consecutive patients with unilateral total LSCD treated with ex vivo expanded autologous LSC transplant on human amniotic membrane (HAM) with a mean follow‐up of 19 (RANGE) months were included in the study. Postoperatively, satisfactory ocular surface reconstruction with a stable corneal epithelium was obtained in all eyes (100%). At last examination, best corrected visual acuity improved in five eyes and remained unchanged in three eyes. Vision impairment and pain scores improved in all patients (p < .05). This study demonstrates that transplantation of autologous limbal epithelial stem cells cultured on HAM without the use of non‐human animal cells or products is a safe and effective method of reconstructing the corneal surface and restoring useful vision in patients with unilateral total LSCD. STEM CELLS 2010;28:597–610

Human embryonic stem cells (hESCs) are pluripotent cells capable of differentiating into any cell type of the body. It has long been known that the adult stem cell niche is vital for the maintenance of adult stem cells. The cornea at the front of the eye is covered by a stratified epithelium that is renewed by stem cells located at its periphery in a region known as the limbus. These so-called limbal stem cells are maintained by factors within the limbal microenvironment, including collagen IV in basement membrane and limbal fibroblasts in the stroma. Because this niche is very specific to the stem cells (rather than to the more differentiated cells) of the corneal epithelium, it was hypothesized that replication of these factors in vitro would result in hESC differentiation into corneal epithelial-like cells. Indeed, here we show that culturing of hESC on collagen IV using medium conditioned by the limbal fibroblasts results in the loss of pluripotency and differentiation into epithelial-like cells. Further differentiation results in the formation of terminally differentiated epithelial-like cells not only of the cornea but also of skin. Scanning electron microscopy shows that some differences exist between hESC-derived and adult limbal epithelial-like cells, necessitating further investigation using in vivo animal models of limbal stem cell deficiency. Such a model of hESC differentiation is useful for understanding the early events of epithelial lineage specification and to the eventual potential application of epithelium differentiated from hESC for clinical conditions of epithelial stem cell loss.

There are several different technical approaches to the isolation of hematopoietic stem cells (HSCs) with longterm repopulating ability, but these have problems in terms of yield, complexity, or cell viability. Simpler strategies for HSC isolation are needed. We have enriched primitive hematopoietic progenitors from murine bone marrow of mice from different genetic backgrounds by lineage depletion followed by selection of cells with high aldehyde dehydrogenase activity using the Aldefluor reagent (BD Biosciences, Oxford, U.K.

Ocular surface reconstruction with ex vivo expanded limbal stem cells (LSCs) is a widely used clinical treatment for patients with limbal stem cell deficiency (LSCD). This is not applicable to patients with bilateral LSCD where there are no remaining LSCs. Cultivated oral mucosa epithelium (OME) has been used as an alternative source of autologous epithelial stem cells for ocular reconstruction in few clinical trials. However, successful generation of stratified OME epithelium has only been achieved in the presence of animal feeder cells and/or animal-derived products in the culture media, likely to contribute to increased risk of pathogen transmission and graft rejection. In this study, we report generation of multilayered OME epithelium that shares many of the characteristics of corneal epithelium using a fully compliant good manufacturing practice, feeder- and animal product-free method. Proof of concept was achieved by transplantation of autologous ex vivo expanded OME in two patients with histologically confirmed bilateral total LSCD that resulted in successful reversal of LSCD in the treated eye up to 24 months.

Human embryonic stem cells (hESCs) have been derived from the inner cell mass (ICM) of day 5-7 blastocysts and hold great promise for research into human developmental biology and the development of cell therapies for the treatment of human diseases. We report here that our novel three-step culture conditions successfully support the development of day-8 human blastocysts, which possess significantly (p <.01) more ICM cells than day-6 blastocysts. Plating of ICMs isolated from day-8 blastocysts resulted in the formation of a colony with hESC morphology from which a new hESC line (hES-NCL1) was derived. Our stem cell line is characterized by the expression of specific cell surface and gene markers: GTCM-2, TG343, TRA1-60, SSEA-4, alkaline phosphatase, OCT-4, NANOG, and REX-1. Cytogenetic analysis of the hESCs revealed that hES-NCL1 line has a normal female (46, XX) karyotype. The pluripotency of the cell line was confirmed by the formation of teratomas after injection into severely combined immunodeficient mice and spontaneous differentiation under in vitro conditions.