Breast cancer patients with hormone neoadjuvant bridging therapy due to asymptomatic Corona virus infection. Case report, clinical and histopathologic findings

Estrogen receptor inhibition mediates radiosensitization of ER-positive breast cancer models

Endocrine therapy (ET) is an effective first-line therapy for women with estrogen receptor-positive (ER + ) breast cancers. While both ionizing radiation (RT) and ET are used for the treatment of women with ER+ breast cancer, the most effective sequencing of therapy and the effect of ET on tumor radiosensitization remains unclear. Here we sought to understand the effects of inhibiting estrogen receptor (ER) signaling in combination with RT in multiple preclinical ER+ breast cancer models. Clonogenic survival assays were performed using variable pre- and post-treatment conditions to assess radiosensitization with estradiol, estrogen deprivation, tamoxifen, fulvestrant, or AZD9496 in ER+ breast cancer cell lines. Estrogen stimulation was radioprotective (radiation enhancement ratios [rER]: 0.51–0.82). Conversely, when given one hour prior to RT, ER inhibition or estrogen depletion radiosensitized ER+ MCF-7 and T47D cells (tamoxifen rER: 1.50–1.60, fulvestrant rER: 1.76–2.81, AZD9496 rER: 1.33–1.48, estrogen depletion rER: 1.47–1.51). Combination treatment resulted in an increase in double-strand DNA (dsDNA) breaks as a result of inhibition of non-homologous end joining-mediated dsDNA break repair with no effect on homologous recombination. Treatment with tamoxifen or fulvestrant in combination with RT also increased the number of senescent cells but did not affect apoptosis or cell cycle distribution. Using an MCF-7 xenograft model, concurrent treatment with tamoxifen and RT was synergistic and resulted in a significant decrease in tumor volume and a delay in time to tumor doubling without significant toxicity. These findings provide preclinical evidence that concurrent treatment with ET and RT may be an effective radiosensitization strategy.

Practical Recommendations for the Preoperative Screening and Protective Protocols in Cancer Surgeries During COVID-19: A Systematic Review

Introduction: The new coronavirus (COVID-19) has posed many new challenges to the health care and the timing of surgical care. At the beginning of the pandemic many guidelines recommended postponing elective surgical procedures to reallocate resources. As regards, delay in cancer treatment could be effective on cancer progression. The aim of this systematic review was to outline a guideline for preoperative screening before cancer surgeries and protecting health care workers during the pandemic.

Materials and Methods: This study was conducted through a search in electronic databases up to August 2020. PubMed, EMBASE, Web of Science, Scopus, Science Direct, and Google Scholar databases were searched without time limitation. The keywords were a combination of preoperative, cancer surgery, COVID-19, and their synonyms.

Results: The most commonly used ways to triage preoperatively were telephone pre-assessment for suspicious symptoms and history of contact or travel, 14-day self-isolation, in- hospital queries at admission, temperature monitoring, and isolation in a single room COVID-free ward or physical distancing. Reverse transcription-polymerase chain reaction (RT-PCR) test 24–72 h before operation was recommended commonly, except in inaccessible centers, but non-contrast chest-CT scan is not routinely advised for elective surgeries to salvage medical resources. Recommended personal protective equipment (PPE) for staffs were wearing N95 mask in addition to gown, gloves, eye protection in aerosol-generating procedures (AGPs), and wearing gloves, hats, and disposable surgical masks, practice distancing, and hand hygiene for all staffs. Meanwhile team separation of hospital staffs caring for COVID-19 patients, segregated areas for COVID-19 clean and contact, restriction of visitors and family members, and personal distancing are mostly recommended.

Conclusion: We hope this review would be a guidance for triage, preoperative testing, and summarizing safety principles during COVID-19 pandemic alongside with surgical reintegration.

COVID-19 and Malignancy: Exploration of the possible genetic and epigenetic interlinks and overview of the vaccination scenario

BACKGROUND

Malignancy is one of the prime global causes of mortality. Cancer Patients suffering from SARS-CoV-2 have demonstrated higher rates of severe complications exacerbating towards death. Possible genetic and epigenetic alterations may exist in cancer patients which have the potential to contribute towards their increased vulnerability towards COVID-19.

METHOD

An exhaustive literature search using 'COVID-19', 'SARS-CoV-2', 'Cancer', 'Malignancy', 'Relationships', Interlinks', 'Genetic', 'Epigenetic', 'Epidemiological studies', 'Clinical Studies', 'Vaccination', 'Vaccine scenario' were conducted in PubMed and EMBASE till 2nd June 2021.

RESULT

In this narrative review, 17 epidemiological studies were listed which focused on clinical parameters of several malignancy patient cohorts who contracted COVID-19. Besides, genetic and epigenetic alterations seen among cancer patients are also discussed which may plausibly increase the vulnerability of cancer patients to SARS-CoV-2 infection. Also, global vaccination scenario among malignant patients along with the necessity to prioritize them in the vaccination campaigns are also elaborated.

CONCLUSION

Genetic and epigenetic modifications present in ACE2, TMPRSS2, IL-6 and several cytokines require more in-depth research to elucidate the shared mechanisms of malignancy and SARS-CoV-2.