The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Plant odors as fruit fly attractants

Plant odors consist of a mixture of volatile compounds that are conveyed by diffusion through air and may disperse over a long distance. They play a major role in mediating insect-plant relationships, particularly food location and selection of suitable sites for mating or oviposition. This chapter presents state-of-the-art research on the response of fruit flies (Diptera, Tephritidae) to plant odors and their potential for the development of trapping systems. Main research results from Tephritids of economic importance (i.e., Rhagoletis, Ceratitis, Bactrocera/Dacus, and Anastrepha) show evidence of response to (i) general plant volatiles from host or non-host plants, the so-called 'green leaf volatiles', (ii) essential oils from host or non-host plants, and (iii) fruit odors (whole fruit, wounded or crushed fruit, extracts, etc.). Synergies between plant odors and food odors or sex pheromones are also addressed. Factors including insect physiology (age, mating status, egg load, etc.), experience (learning), and genetic background can substantially modify the response pattern to plant odors. One of the main challenges of using plant odors as fruit fly attractant is to improve the technology for identification (analysis), synthesis and emission (dispensers) of key compounds that may compete with natural volatile blends in the field. Further research should include the role of microorganisms in host location and recognition by fruit flies. Synthetic plant odors could be used either as kairomones for trapping systems, as allomones to push flies away from the crop or to disrupt host location, or as synomones to attract natural enemies to the crop. (Résumé d'auteur