Surgical care of thoracic malignancies during the COVID-19 pandemic in México: An expert consensus guideline from the Sociedad Mexicana de Oncología (SMeO) and the Sociedad Mexicana de Cirujanos Torácicos Generales (SMCTG)

To date, the impact, timeline and duration of COVID‐19 pandemic remains unknown and more than ever it is necessary to provide safe pathways for cancer patients. Multiple triage systems for nonemergent surgical procedures have been published, but potentially curative cancer procedures are essential surgery rather than elective surgery. In the present and future scenario of our country, thoracic oncology teams may have the difficult decision of weighing the utility of surgical intervention against the risk for inadvertent COVID‐19 exposure for patients and medical staff. In consequence, traditional pathways of surgical care must be adjusted to reduce the risk of infection and the use of resources. It is recommended that all thoracic cancer patients should be offered treatment according to the accepted standard of care until shortage of services require a progressive reduction in surgical cases. Here, we present a consensus of recommendations discussed by a multidisciplinary panel of experts on thoracic oncology and based on the best available evidence, and hope it will provide a modifiable framework of guidance for local strategy planners in thoracic cancer care services in Mexico.

Key points

Significant findings of the study

This article provides recommendations to guarantee the continuity of surgical care for thoracic oncology cases during COVID‐19 pandemic, whilst maintaining the safety of patients and medical staff.

What this study adds

This guideline is the result of an expert consensus on thoracic surgical oncology with recommendations adapted to medical, economic and social realities of Mexico.

Consensus statement to guide the practice of thoracic surgical oncology during COVID‐19 pandemic in México.

Characterization of DNA methylation of the promoters CTCF and BORIS (CTCFL) in breast and ovarian cancer

e22151

Background: Genetic and epigenetic alterations may promote the initiation or development of cancer. Global DNA hypomethylation and local hypermethylation have been observed, particularly in cell cycle control-associated genes, such as tumor suppressor genes like CTCF. The dissociation of CTCF is associated with hypermethylation of several promoters; its paralogue gene (BORIS) is normally expressed in testicular tissue during spermatogenesis. BORIS over-expression has been identified in multiple neoplasms such as melanoma, gynecological cancer, glioblastoma and – recently – breast cancer. The aim of this study was to characterize the methylation status of the promoter regions of CTCF and BORIS in samples from breast and ovarian cancer compared to non-neoplastic tissue, and correlate it to its expression. Methods: Tissue samples from breast and ovarian cancer, as well as healthy controls were analyzed by MS-PCR for CTCF and BORIS. BorismRNA expression was also analyzed by RT-PCR. Results: A total of 8 ovarian and 16 breast tumors, as well as 10 tumor-adjacent breast tissue samples were prospectively obtained. In non-neoplastic tissue, BORIS was found to be hypermethylated, while in ovarian tumors a loss of methylation was identified in 75% of the samples. The same phenomenon was observed in 68% of breast cancer samples when compared to non-neoplastic tissue. A correlation between loss of DNA methylation of the promoter and gene over-expression was found by RT-PCR, thus suggesting that methylation is an epigenetic phenomenon associated to the over-expression of the oncogene BORIS. The methylation analysis of CTCF did not show any differences between neoplastic and non-neoplastic tissue, suggesting that epigenetic changes mainly affect BORIS. Conclusions: Loss of methylation of the promoter region of BORIS is associated with the over-expression of the gene. No differences were found in the methylation status between healthy and neoplastic tissue for CTCF.