Challenges in Facing the Lung Cancer Epidemic and Treating Advanced Disease in Latin America

Lung cancer, the deadliest cancer worldwide, is of particular concern in Latin America. The rising incidence poses a myriad of challenges for the region, which struggles with limited resources to meet the health care needs of its low- and middle-income populations. In this environment, we are concerned that governments are relatively unaware of the pressing need to implement effective strategies for screening, diagnosis, and treatment of lung cancer. The region has also been slow in adopting molecularly-based therapies in the treatment of advanced disease: testing for epidermal growth factor receptor mutations and anaplastic lymphoma kinase rearrangements are not routine, and access to targeted agents such as monoclonal antibodies and tyrosine kinase inhibitors is problematic. In this paper, we review the current situation in the management of lung cancer in Latin America, hoping that this initiative will help physicians, patient associations, industry, governments, and other stakeholders better face this epidemic in the near future.     

Thymus hyperplasia after resolution of hypercortisolism in ACTH-dependent Cushing's syndrome: the importance of thymic vein catheterization

Thymic hyperplasia has been described after the resolution of hypercortisolism from several etiologies, causing great diagnostic dilemmas. We describe a case where the catheterization of the thymic vein was essential for the differential diagnosis of a thymic enlargement in an adrenalectomized patient with ACTH-dependent Cushing's syndrome. The patient was a 48-year-old female with clinical and laboratorial data suggesting Cushing's disease. She underwent a transsphenoidal surgery with no tumor visualization and no remission of the syndrome. Histopathological studies disclosed a normal pituitary. She underwent a bilateral adrenalectomy and 8 months later a chest CT showed an increase of left thymic lobe, which was previously non-existent. After a negative (111)In-pentetreotide scintigraphy, the patient underwent simultaneous and bilateral catheterism of the petrosus sinuses and catheterization of the thymic and inominate veins and no ACTH gradient was shown among the sites of collection. She did not undergo thoracotomy and a follow-up was established. During the evolution, there was a spontaneous regression of the thymic lesion 38 months after the diagnosis. The ACTH gradient during the catheterization of thymic vein was essential for the differential diagnosis of the thymic enlargement tumor after hypercortisolism resolution in ACTH-dependent Cushing's syndrome, especially in this case, where the ACTH source was occult, thus avoiding an invasive surgical procedure for a benign entity with spontaneous resolution.     

Influence of alleles and haplotypes of the main histocompatibility complex on the susceptibility to systemic lupus erythematosus in the Mexican population

HLA alelles with susceptibility to systemic lupus erythematosus (SLE) have been found in many ethnic groups. In addition, some neighboring genes such as TNF-alpha and HSP70, that may contribute to this disease have also been described. Interestingly some of the genetic associations differ among several ethnic groups, which might suggest that ethnicity plays an important role in the predisposition to SLE. In this study, we analyze gene frequencies of HLA-DRB1, DQA1, DQB1, HSP70-2 alelles and the polymorphism of TNF-alpha promoter region among 81 Mexican mestizo SLE patients. A control group of 99 healthy Mexican mestizos was included. We found that the HLA-DRB1*0301-DQA1*0501-DQB1*0201 haplotype was significantly increased in SLE patients compared to healthy controls (p=0.01, OR=2.97, IC 95%=1.18-7.68). The DRB1*1501 allele was more frequent among patients than among controls. A significantly decreased frequency of the HLA-DRB1*0802 alelle in SLE patients was also observed. Since the HLA alelles associated with SLE are uncommon in Mexican ethnic groups, we performed admixture estimates analysis and found that the incorporation of SLE susceptibility markers in Mexican mestizo groups might have come from genetic admixture with Caucasian populations.