Improved outcomes with surgery vs. medical therapy in non-thymomatous myesthenia gravis: a perspective on the results of a randomized trial

Racial Disparity in Surgical Therapy for Thymic Malignancies

BACKGROUND

The primary curative treatment for thymic malignancies is surgery. For lung and esophageal cancer, substantive disparities in outcomes by race exist. Many of these disparities are attributed to the decreased use of surgery in non-White patients. Although thymic malignancies are treated by the same specialists as lung and esophageal cancer, it is unknown if there are racial disparities in the treatment of thymic malignancies.

RESEARCH QUESTION

Do racial disparities exist in the surgical treatment of thymic malignancies?

STUDY DESIGN AND METHODS

A retrospective cohort analysis was performed using the National Cancer Data Base of patients diagnosed with thymoma and thymic carcinoma between 2004 and 2016. Univariate comparisons of demographics were compared using χ ² and rank-sum tests. Multivariable analysis was performed to determine if race was an independent variable associated with receiving surgical resection. Preoperative and postoperative care was compared between races.

RESULTS

Seven thousand four hundred eighty-nine patients met inclusion criteria. Four thousand nine hundred sixty-two (66%) were White, 1,311 (18%) were Black, 487 (7%) were Hispanic, 580 (8%) were Asian or Pacific Islander, and 143 (2%) were other races. Black patients with thymic malignancies were more likely to have a median income < $38,000 and not received surgery. Black and Hispanic patients had the lowest median age (54.3 and 53.6 years, respectively) and were most likely to be uninsured (8.2% and 12.5%, respectively). White patients received surgical therapy 1 week sooner and had a postoperative length of stay 1.5 days shorter than Black patients. Multivariable analysis controlling for age, sex, tumor size, insurance status, comorbidity score, histology, and facility type showed that race remained independently associated with the receipt of surgical resection. White patients had the greatest likelihood of receiving surgery with Black patients being least likely to receive surgery (OR, 0.60).

INTERPRETATION

A racial disparity exists in surgical therapy for thymic malignancies.

Micro-RNA-143 inhibits proliferation and promotes apoptosis of thymocytes by targeting CXCL13 in a myasthenia gravis mouse model

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder, affecting the quality of life of millions of people worldwide. The present study aims to determine the relationship between micro-RNA-143 (miR-143) and C-X-C motif chemokine 13 (CXCL13) and whether it influences the pathogenesis of myasthenia gravis (MG). Thymus specimens were resected from patients with thymic hyperplasia combined with MG and then infused into normal mouse cavities to establish MG mouse models. Immunohistochemistry, reverse transcription-quantitative PCR, in situ hybridization detection, and Western blot analysis were employed to identify the expression of miR-143 and CXCL13 in MG and normal mice. The obtained thymocytes were cultured in vitro and transfected with a series of miR-143 mimic, miR-143 inhibitor, overexpression of CXCL13, or siRNA against CXCL13. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and flow cytometry assays were employed to assess cell viability, cycle entry, and apoptosis of the thymocytes. Dual-luciferase reporter assay provided verification, confirming that CXCL13 was the target gene of miR-143. Low miR-143 expression in the thymus tissues of the MG mice was detected, which presented with a reciprocal relationship with the expression rate of CLCX13. Observations in relation to the interactions between miR-143 mimic or siRNA-CXCL13 exposure showed reduced cell viability, with a greater number of cells arrested at the G0/G1 phase and a greater rate of induced apoptosis. Furthermore, overexpression of CXCL13 rescued miR-143 mimic-induced apoptosis. The findings have identified the potential role of miR-143 as a MG development mediator by targeting CXCL13. The key results obtained provide a promising experimental basis for targeted intervention treatment with miR-143.

Thymectomy is a beneficial therapy for patients with non-thymomatous ocular myasthenia gravis: a systematic review and meta-analysis

Ocular myasthenia gravis, an autoimmune disease, is characterized by extraocular muscle weakness. Myasthenia gravis is closely associated with the functional status of the thymus gland. The efficacy of thymectomy for non-thymomatous ocular myasthenia gravis remains controversial. Here, we present the first systematic review and meta-analysis of studies assessing the outcome of thymectomy in patients with non-thymomatous ocular myasthenia gravis and found that the pooled rate of complete stable remission was 0.5074 with considerable heterogeneity. Furthermore, subgroup analysis showed that the efficacy of thymectomy differed according to geographical location. Furthermore, thymectomy outcomes are better in children than they are in adults. Thymectomy clearly represents an effective treatment for patients with non-thymomatous ocular myasthenia gravis. However, more multicenter, randomized, controlled clinical trials are now required to confirm these conclusions.