Peri-operative SARS-CoV-2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS-CoV-2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre-operative SARS-CoV-2 infection were compared with those without previous SARS-CoV-2 infection. The primary outcome measure was 30-day postoperative mortality. Logistic regression models were used to calculate adjusted 30-day mortality rates stratified by time from diagnosis of SARS-CoV-2 infection to surgery. Among 140,231 patients (116 countries), 3127 patients (2.2%) had a pre-operative SARS-CoV-2 diagnosis. Adjusted 30-day mortality in patients without SARS-CoV-2 infection was 1.5% (95%CI 1.4-1.5). In patients with a pre-operative SARS-CoV-2 diagnosis, mortality was increased in patients having surgery within 0-2 weeks, 3-4 weeks and 5-6 weeks of the diagnosis (odds ratio (95%CI) 4.1 (3.3-4.8), 3.9 (2.6-5.1) and 3.6 (2.0-5.2), respectively). Surgery performed ≥ 7 weeks after SARS-CoV-2 diagnosis was associated with a similar mortality risk to baseline (odds ratio (95%CI) 1.5 (0.9-2.1)). After a ≥ 7 week delay in undertaking surgery following SARS-CoV-2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2-8.7) vs. 2.4% (95%CI 1.4-3.4) vs. 1.3% (95%CI 0.6-2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS-CoV-2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay.

SARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk of venous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS-CoV-2 diagnosis was defined as peri-operative (7 days before to 30 days after surgery); recent (1-6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre-operative anti-coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism rate was 0.5% (666/123,591) in patients without SARS-CoV-2; 2.2% (50/2317) in patients with peri-operative SARS-CoV-2; 1.6% (15/953) in patients with recent SARS-CoV-2; and 1.0% (11/1148) in patients with previous SARS-CoV-2. After adjustment for confounding factors, patients with peri-operative (adjusted odds ratio 1.5 (95%CI 1.1-2.0)) and recent SARS-CoV-2 (1.9 (95%CI 1.2-3.3)) remained at higher risk of venous thromboembolism, with a borderline finding in previous SARS-CoV-2 (1.7 (95%CI 0.9-3.0)). Overall, venous thromboembolism was independently associated with 30-day mortality ). In patients with SARS-CoV-2, mortality without venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76). Patients undergoing surgery with peri-operative or recent SARS-CoV-2 appear to be at increased risk of postoperative venous thromboembolism compared with patients with no history of SARS-CoV-2 infection. Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and these data should be interpreted accordingly.

Tumor heterogeneity can be traced back to a small subset of cancer stem cells (CSCs), which can be derived from a single stem cell and show chemoresistance. Recent studies showed that CSCs are sensitive to mitochondrial targeting antibiotics such as doxycycline. However, little is known about how cancer cells undergo sphere formation and how antibiotics inhibit CSC proliferation. Here we show that under sphere-forming assay conditions, prostate cancer cells acquired CSC-like properties: promoted mitochondrial respiratory chain activity, expression of characteristic CSC markers and resistance to anticancer agents. Furthermore, those CSC-like properties could reversibly change depending on the culture conditions, suggesting some kinds of CSCs have plasticity in tumor microenvironments. The sphere-forming cells (i.e. cancer stem-like cells) showed increased contact between mitochondria and mitochondrial associated-endoplasmic reticulum (ER) membranes (MAM). Mitochondrial targeting doxycycline induced activating transcription factor 4 (ATF4) mediated expression of ER stress response and led to p53-upregulated modulator of apoptosis (PUMA)-dependent apoptosis only in the cancer stem-like cells. We also found that doxycycline effectively suppressed the sphere formation in vitro and blocked CD44v9-expressing tumor growth in vivo. In summary, these data provide new molecular findings that monolayer cancer cells acquire CSC-like properties in a reversible manner. These findings provide important insights into CSC biology and a potential new treatment of targeting mitochondria dependency.

There are multiple reports on the value of complete blood count (CBC)-related parameters on prognosis in docetaxel-treated castration-resistant prostate cancer (CRPC) patients before the emergence of androgen receptor pathway inhibitors (ARPIs). We investigated the prognostic significance of CBC-related parameters in docetaxel-treated CRPC patients. Patients treated with docetaxel chemotherapy for CRPC between 2008 and 2018 were included. We analyzed the relevance of CBCrelated parameters to oncological prognosis in docetaxel chemotherapy, associated with prior use of novel ARPIs. Among 144 Japanese men treated with docetaxel, 49 men (34.0%) had already received ARPI therapy. A high neutrophil-lymphocyte ratio (NLR) was a prognostic factor for poor progression-free survival and overall survival (OS) in both univariate and multivariate analyses. In addition, a low hemoglobin (Hb) level and a high systemic immuneinflammation index (SII) were prognostic factors of poor OS in univariate analysis. Hb level was a prognostic factor of OS in both ARPI-naive and ARPI-treated patients.However, a high NLR and SII were only associated with a poor prognosis in ARPI-naive but not in ARPI-treated patients. Hb, NLR, and SII have been suggested to be prognosticators in docetaxel-treated CRPC patients. The differential prognostic value of NLR and SII between ARPInaive and ARPI-treated patients may require caution when using these markers in docetaxel-treated CRPC patients.

Background: Mitochondria play crucial roles in cell signaling events, interorganellar communication, aging, cell proliferation and apoptosis, and mitochondrial impairment has been shown to accelerate or modulate cancer progression. Ubiquitous mitochondrial creatine kinase (uMtCK) is predominantly localized in the intermembrane space of mitochondria and catalyzes the reversible exchange of high-energy phosphate between adenosine tri-phosphate (ATP) and phosphocreatine. However, little is known about its expression and function in human prostate cancer progression.Method: We investigated the expression of uMtCK in 148 prostate carcinoma tissues and matched normal tissue by immunohistochemistry. The expression and localization of uMtCK and hexokinase II, a marker of glycolysis, were examined in prostate carcinoma cell lines using western blot and immunofluorescence.Results: MtCK expression was significantly lower in high Gleason grade carcinoma compared with normal prostate or low grade carcinoma. Western blot further revealed that uMtCK was highly expressed in LNCaP and 22Rv1 cell lines, as well as in the normal prostate cell line RWPE-1. However, uMtCK expression was almost absent in PC3 and DU145 cell lines, in correlation with absent or mutant p53 expression, respectively. In contrast, hexokinase II was overexpressed in PC3 cells. Moreover, in the low uMtCK expressing cell lines, glycolytic ATP production was increased, whereas mitochondrial ATP production was decreased.Conclusions: These data suggest that uMtCK is downregulated as prostate cancer progresses in correlation with a metabolic switch in ATP usage.