Laparoscopic or open abdominal surgery with thoracotomy for patients with oesophageal cancer: ROMIO randomized clinical trial

OBJECTIVE

This study investigated if hybrid oesophagectomy with minimally invasive gastric mobilization and thoracotomy enabled faster recovery than open surgery.

METHODS

In eight UK centres, this pragmatic RCT recruited patients for oesophagectomy to treat localized cancer. Participants were randomly allocated to hybrid or open surgery, stratified by centre and receipt of neoadjuvant treatment. Large dressings aimed to mask patients to their allocation for six days post-surgery. The authors present the intention-to-treat analysis of outcome measures from the first 3 months post-randomization, including the primary outcome, the patient-reported physical function scale of the EORTC QLQ-C30, and cost-effectiveness. Current Controlled Trials registration: ISRCTN 59036820 (feasibility study), 10386621 (definitive study).

FINDINGS

There was no evidence of a difference between hybrid (n = 267) and open (n = 266) surgery in average physical function over 3 months post-randomization: difference in means 2.1, 95% c.i. -2.0 to 6.2, P = 0.3. Complication rates were similar; for example, 88 (34%) participants in the open and 82 (32%) participants in the hybrid surgery groups experienced a pulmonary infection within 30 days. There was no evidence that hybrid surgery was more cost-effective than open surgery at 3 months.

CONCLUSIONS

Patient-reported physical function in the 3 months post-randomization provided no evidence of a difference in recovery time between hybrid and open surgery, or a difference in cost-effectiveness. Both approaches to surgery were completed safely, with a similar risk of key complications, suggesting that surgeons who have a preference for one of the two approaches need not change their practice.

The effect of TRV027 on coagulation in COVID-19: A pilot randomized, placebo-controlled trial

COVID-19 causes significant thrombosis and coagulopathy, with elevated D-dimer a predictor of adverse outcome. The precise mechanism of this coagulopathy remains unclear; one hypothesis is that loss of angiotensin-converting enzyme 2 activity during viral endocytosis leads to pro-inflammatory angiotensin-II accumulation, loss of angiotensin-1-7 and subsequent vascular endothelial activation. We undertook a double-blind randomized, placebo-controlled experimental medicine study to assess the effect of TRV027, a synthetic angiotensin-1-7 analogue on D-dimer in 30 patients admitted to hospital with COVID-19. The study showed a similar rate of adverse events in TRV027 and control groups. There was a numerical decrease in D-dimer in the TRV027 group and increase in D-dimer in the placebo group; however, this did not reach statistical significance (P = .15). A Bayesian analysis demonstrated that there was a 92% probability that this change represented a true drug effect.

The roles of WRN and BLM RecQ helicases in the Alternative Lengthening of Telomeres

Approximately 10% of all cancers, but a higher proportion of sarcomas, use the recombination-based alternative lengthening of telomeres (ALT) to maintain telomeres. Two RecQ helicase genes, BLM and WRN, play important roles in homologous recombination repair and they have been implicated in telomeric recombination activity, but their precise roles in ALT are unclear. Using analysis of sequence variation present in human telomeres, we found that a WRN– ALT+ cell line lacks the class of complex telomere mutations attributed to inter-telomeric recombination in other ALT+ cell lines. This suggests that WRN facilitates inter-telomeric recombination when there are sequence differences between the donor and recipient molecules or that sister-telomere interactions are suppressed in the presence of WRN and this promotes inter-telomeric recombination. Depleting BLM in the WRN– ALT+ cell line increased the mutation frequency at telomeres and at the MS32 minisatellite, which is a marker of ALT. The absence of complex telomere mutations persisted in BLM-depleted clones, and there was a clear increase in sequence homogenization across the telomere and MS32 repeat arrays. These data indicate that BLM suppresses unequal sister chromatid interactions that result in excessive homogenization at MS32 and at telomeres in ALT+ cells.

The role of recombination in telomere length maintenance

Human telomeres shorten during each cell division, predominantly because of incomplete DNA replication. This eventually results in short uncapped telomeres that elicit a DNA-damage response, leading to cellular senescence. However, evasion of senescence results in continued cell division and telomere erosion ultimately results in genome instability. In the long term, this genome instability is not sustainable, and cancer cells activate a TMM (telomere maintenance mechanism), either expression of telomerase or activation of the ALT (alternative lengthening of telomeres) pathway. Activation of the ALT mechanism results in deregulation of recombination-based activities at telomeres. Thus ALT+ cells show elevated T-SCE (telomere sister-chromatid exchange), misprocessing of t-loops that cap chromosomes and recombination-based processes between telomeres or between telomeres and ECTRs (extrachromosomal telomeric repeats). Some or all of these processes underlie the chaotic telomere length maintenance that allows cells in ALT+ tumours unlimited replicative capacity. ALT activation is also associated with destabilization of a minisatellite, MS32. The connection between the minisatellite instability and the deregulation of recombination-based activity at telomeres is not understood, but analysis of the minisatellite can be used as a marker for ALT. It is known that telomere length maintenance in ALT+ cells is dependent on the MRN [MRE11 (meiotic recombination 11)-Rad50-NBS1 (Nijmegen breakage syndrome 1)] complex, but knowledge of the role of other genes, including the Werner's (WRN) and Bloom's (BLM) syndrome DNA helicase genes, is still limited.