Evaluation of the environmental contamination and exposure risk in medical/non-medical staff after oxaliplatin-based pressurized intraperitoneal aerosol chemotherapy.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a technique to directly deliver chemotherapeutic drugs in the abdomen for the treatment of peritoneal metastases. Pressurization improves the treatment efficacy but increases the risk of exposure for the medical/non-medical staff who can be exposed by dermal or ocular contact, or inhalation of aerosols containing the cytotoxic drugs. The aim of this study was to evaluate the risk of exposure for the medical/non-medical staff (nurses, surgeons, anaesthesiologists and cleaning personnel; n = 13) during PIPAC with oxaliplatin performed according to the protocol recommended in France. Blood samples were collected 1 h before and immediately after PIPAC, and urine samples 1 h before, and then 3 h and the morning after PIPAC. In the control, non-exposed group (n = 7), only one urine and blood sample were collected. Surface contamination in the operating room was assessed in water- and Surfanios-impregnated wipe samples. The total elemental platinum in each sample was quantified by inductively coupled plasma mass spectrometry, using a method adapted to quantify trace amounts (ng.L-1) in very low volumes (100 µl). No surface contamination was detected. Although 25% of urine samples in the exposed group contained platinum, no statistical difference was observed in urine and plasma samples collected before and after PIPAC and with the control group samples. These findings suggest that the French PIPAC protocol does not increase the risk of exposure to platinum in all staff categories involved. This protocol could be considered in future occupational policies and consensus statements. Trial registration: NCT04014426.

MESOTIP: Phase II multicenter randomized trial evaluating the association of PIPAC and systemic chemotherapy vs. systemic chemotherapy alone as 1st-line treatment of malignant peritoneal mesothelioma.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is a rare tumoral disease characterized by the diffuse involvement of the peritoneal serosa. The standard frontline treatment of MPM is cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) unless the peritoneal disease is considered unresectable. For unresectable patients the standard frontline treatment is a combination of cisplatin and pemetrexed but the prognosis remains ominous with only 13 months of overall survival (OS). METHODS: The proposed study is a multicenter randomized non-comparative study evaluating the association of Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) and systemic chemotherapy vs. systemic chemotherapy alone as first-line treatment of MPM. Patients will be randomized with a 2:1 ratio using a minimization technique. Sixty-six patients have to be enrolled. Stratification will be performed according to histology (epithelioid vs. sarcomatoid and biphasic), presence of extraperitoneal disease and center. Primary objective is OS and secondary objectives include progression-free survival (PFS), safety, compliance, feasibility, conversion to resectability, histological response to treatment and quality of life. CONCLUSIONS: We expect to show that intensification of the first line treatment with PIPAC for initially unresectable MPM patients increases OS. TRIAL REGISTRATION: Prospective study. Clinicaltrials.gov: NCT03574493 EudraCT: 2019-001515-23.

Within-host dynamics of the emergence of Tomato yellow leaf curl virus recombinants.

Tomato yellow leaf curl virus (TYLCV) is a highly damaging begomovirus native to the Middle East. TYLCV has recently spread worldwide, recombining with other begomoviruses. Recent analysis of mixed infections between TYLCV and Tomato leaf curl Comoros begomovirus (ToLCKMV) has shown that, although natural selection preserves certain co-evolved intra-genomic interactions, numerous and diverse recombinants are produced at 120 days post-inoculation (dpi), and recombinant populations from different tomato plants are very divergent. Here, we investigate the population dynamics that lead to such patterns in tomato plants co-infected with TYLCV and ToLCKMV either by agro-inoculation or using the natural whitefly vector Bemisia tabaci. We monitored the frequency of parental and recombinant genotypes independently in 35 plants between 18 and 330 dpi and identified 177 recombinants isolated at different times. Recombinants were detected from 18 dpi and their frequency increased over time to reach about 50% at 150 dpi regardless of the inoculation method. The distribution of breakpoints detected on 96 fully sequenced recombinants was consistent with a continuous generation of new recombinants as well as random and deterministic effects in their maintenance. A severe population bottleneck of around 10 genomes was estimated during early systemic infection-a phenomenon that could account partially for the heterogeneity in recombinant patterns observed among plants. The detection of the same recombinant genome in six of the thirteen plants analysed beyond 30 dpi supported the influence of selection on observed recombination patterns. Moreover, a highly virulent recombinant genotype dominating virus populations within one plant has, apparently, the potential to be maintained in the natural population according to its infectivity, within-host accumulation, and transmission efficiency - all of which were similar or intermediate to those of the parent genotypes. Our results anticipate the outcomes of natural encounters between TYLCV and ToLCKMV.