Demographics, pattern of practice and clinical outcomes in rectal squamous cell carcinoma.

AIM: The aim of this study was to describe the baseline clinical features, treatment patterns and outcomes in rectal squamous cell carcinoma (SCC). METHOD: This is a retrospective study of patients with rectal SCC treated at the Princess Margaret Cancer Centre (Toronto, Canada) between 1 January 1995 and 31 December 2020. Clinical factors associated with locoregional failure (LRF), distant metastases (DM), disease-free survival (DFS) and overall survival (OS), such as age, sex, HIV status, T-category, nodal status, grade and primary treatment, were investigated with univariate analysis (UVA). RESULTS: Twenty nine patients with rectal SCC were analysed with a median follow-up of 7.4 years (range 0.3-20.4 years). The median age at diagnosis was 52 years, with the majority presenting with clinical T3 disease or higher (n = 21, 72%) and positive regional lymph nodes (n = 16, 55%), while more than quarter of patients (28%) had metastatic disease. Definitive chemoradiation was the treatment modality of choice in more than half of all cases (n = 17, 59%) with a response rate of 100%. The 10-year cumulative incidence of LRF and DM was, respectively, 12% (95% CI 1.8%-32.9%) and 31% (95% CI: 12.0%-52.6%). The 5- and 10-year OS was 82% (95% CI 66.1%-100%). UVA revealed a trend towards an association of male gender (hazard ratio = 4.65, 95% CI 0.9%-24.1; p = 0.067) and primary surgical treatment (hazard ratio = 0.76, 95% CI 0.09-6.34; p = 0.061) with DFS. CONCLUSION: Definitive chemoradiation is an effective and preferred treatment for rectal SCC allowing for sphincter preservation with complete clinical response observed in all patients.

Nematodes enhance plant growth and nutrient uptake under C and N-rich conditions.

The role of soil fauna in crucial ecosystem services such as nutrient cycling remains poorly quantified, mainly because of the overly reductionistic approach adopted in most experimental studies. Given that increasing nitrogen inputs in various ecosystems influence the structure and functioning of soil microbes and the activity of fauna, we aimed to quantify the role of the entire soil nematode community in nutrient mineralization in an experimental set-up emulating nutrient-rich field conditions and accounting for crucial interactions amongst the soil microbial communities and plants. To this end, we reconstructed a complex soil foodweb in mesocosms that comprised largely undisturbed native microflora and the entire nematode community added into defaunated soil, planted with Lolium perenne as a model plant, and amended with fresh grass-clover residues. We determined N and P availability and plant uptake, plant biomass and abundance and structure of the microbial and nematode communities during a three-month incubation. The presence of nematodes significantly increased plant biomass production (+9%), net N (+25%) and net P (+23%) availability compared to their absence, demonstrating that nematodes link below- and above-ground processes, primarily through increasing nutrient availability. The experimental set-up presented allows to realistically quantify the crucial ecosystem services provided by the soil biota.