Hepatocellular carcinoma - prognostic criteria of individualized treatment

BACKGROUND

Though the sixth most frequent malignancy, hepatocellular carcinoma (HCC) is the third most common cause of death amongst solid tumours. Only surgery in the early stages may provide the cure; however, HCC still has a high recurrence rate. Non-surgical treatment lacks comparable efficacy. It was not sooner than in 2017 that the therapy galore started to extend. Thus prognostic factors driving the therapy have been gaining importance.

MATERIAL AND METHODS

All relevant literature was checked for aetiology, epidemiology, dia-gnostic means, and individualised treatment of HCC. Cytochrome P-450 expression data from 22 patients operated in the University Hospital Brno in the period 2017-2020 were included.

RESULTS

Screening the population at risk (presence of cirrhosis) with the transabdominal ultrasound lies at the centre of the dia-gnostic algorithm. Making the dia-gnosis does not require a bio-psy in most cases. Only a few parameters are thus known before the treatment - a size and number of lesions, and AFP level. These drive the indication to surgery. Relapses after surgery and response to palliative treatment depend on the expression of MET and AXL that directly affect anti-VEGF therapy. High AFP predicts a good response to regorafenib but early relapse after surgery. The pattern of P450 expression was found linked with tumour differentiation. The differentiation correlates with the size and number of lesions. We also found a link between the P450 expression and some mi-RNAs possibly detectable using liquid bio-psy techniques.

CONCLUSION

The share of deaths from HCC overweighs its incidence. The risk population to screen is well-defined (cirrhosis). The BCLC staging system probably gives the best complication/efficacy results. This system does not require any bio-psy and does not comprise all predictive factors important in the expanding targeted molecular therapy. According to our results, small molecules to treat HCC should work better in poorly differentiated tumours. Surgery is more effective in those well-differentiated. It isnt easy to get all relevant information before therapy. Some factors need macrobio-psy (surgical). The pretreatment workup will probably require a mandatory bio-psy in BCLC B and C stages to get the information. This opens up a way for the liquid bio-psy that could use some specific mi RNAs.

New trends in neoadjuvant therapy of locally advanced rectal cancer from a surgeons perspective - a commentary

BACKGROUND

Rectal cancer treatment advanced rapidly during last decades. The most important factors of this progress are new neoadjuvant therapy options, improvement in imaging (allowing for quality staging and restaging) and routine implementation of the total mesorectal excision technique. For the best outcomes, it is crucial to combine the treatment methods in the best way possible with ideal timing. It is necessary to keep in mind both advantages and complications of the individual kinds of approach. Therefore, interdisciplinary agreement is essential in the treatment of rectal cancer. Considering these new therapeutic possibilities, the debate about timing, indication and radicality of the surgical procedures is reopened. Surgical approaches are currently focused on mini-invasive methods and robotic surgery. New trend with promising potential seems to be clinical complete response achievement with watch and wait follow-up strategy. This approach, in the spirit of the organ sparing philosophy, however asks new questions about indication, timing and conception of this method. Proper answers are essential for sparing, yet radical oncotherapy of this disease.

Synchronous liver metastases of rectal cancer and the possibility of simultaneous resection

Treatment of metastatic rectal cancer and liver metastases continues to pose a major challenge. Synchronous liver metastases are present in up to one fifth of patients diagnosed with rectal carcinoma. Multidisciplinary cooperation is essential for determination of the consequent diagnostic and therapeutic plan. Only tight collaboration of experts from different medical fields allows for optimal timing of various medical procedures leading to a maximal benefit for the patient. Given the complexity of the problem, different specific methods and combinations thereof are applied in the course of the therapy, making the design of straightforward guidelines impossible. Since open surgery is complicated by the vastly distant locations of the rectum and liver, minimally invasive approach brings more perspectives in simultaneous surgery. A novel possibility of robotic and/or laparoscopic surgery performed by two teams is currently being developed. Despite the progress in surgical technology, optimal strategy has not yet been established.

Evaluation of Thermally Induced Degradation of Branched Polypropylene by Using Rheology and Different Constitutive Equations

In this work, virgin as well as thermally degraded branched polypropylenes were investigated by using rotational and Sentmanat extensional rheometers, gel permeation chromatography and different constitutive equations. Based on the obtained experimental data and theoretical analysis, it has been found that even if both chain scission and branching takes place during thermal degradation of the tested polypropylene, the melt strength (quantified via the level of extensional strain hardening) can increase at short degradation times. It was found that constitutive equations such as Generalized Newtonian law, modified White-Metzner model, Yao and Extended Yao models have the capability to describe and interpret the measured steady-state rheological data of the virgin as well as thermally degraded branched polypropylenes. Specific attention has been paid to understanding molecular changes during thermal degradation of branched polypropylene by using physical parameters of utilized constitutive equations.

Rheological Indicators for Environmental Stress Cracking Resistance of Polyethylene

Most studies on environmental stress cracking resistance (ESCR) of polymers have focused on performing mechanical tests in the solid state. In this work, investigations in the melt state were carried out, to identify potential melt indicators for a relative measure of ESCR. A normalized characteristic relaxation time (λN), obtained from dynamic shear experiments, was established as a valid measure of ESCR of linear low density polyethylene, where a large content of short chain branches is present. In addition, the melt strain hardening coefficient (MSHC), obtained from extensional rheological methodologies, was found to be another potential and reliable indicator of ESCR. An inverse correlation between MSHC and ESCR was observed, indicating an inverse relationship between ESCR and chain extensibility in the melt. Furthermore, a new factor called “melt hardening stiffness (mHS)” was developed from the slope of a stress vs. Hencky strain obtained from a Sentmanat extensional rheometer. mHS was found to be another promising indicator of ESCR obtained from rheological studies conducted in this work.

Numerical Simulation of Polymer Coextrusion Flows

Non-isothermal calculation of flow history dependent visco-elastic stresses in a coextrusion die is performed using the 8-mode modified Leonov constitutive equation and the deformation rate field from finite element simulations. It is shown that a heuristic criterion based on the difference of normal stress differences across the layer interfaces in the merging area may be used to potentially detect the onset of interfacial instabilities. The developed technique can be a useful tool for coextrusion die design as well as for proper selection of materials and process conditions for coextrusion.

Tensile Strength Characteristics of Polymer Melts

Two different methodologies were employed to determine tensile strength properties of two LDPEs and two metallocene LLDPE resins through capillary and Haul-off (Rheotens-like) measurements. It has been shown that the tensile strength properties obtained by both methods yield almost the same values. Moreover, these values can be correlated to the drawability in tubular film blowing for corresponding materials.

On PVT and Rheological Measurements of Polymer Melts

The relation between PVT and rheological measurements of several polymer melts including polyethylenes, polypropylene, polystyrene, poly(methyl methacrylate), and polycarbonate has been taken into investigation. Pressure-temperature dependent viscosities, determined on rotational and backpressure-modified capillary rheometers, were fitted through the Carreau-Yasuda model. PVT data was analyzed by the help of the Simha-Somcynsky equation of state (SS EOS). The thermodynamical parameters of the SS EOS were connected to constant-stress viscosity (experimental) and zero-shear viscosity (extrapolated). The Doolittle relationship was modified into the form of η   =   exp ( C 1   ln ( h ′ h ) ) . The relation was employed and tested for the data evaluation. It proved to be a good tool for linearization of PVT and rheological data.

Pressure and Temperature Dependence of LDPE Viscosity and Free Volume: The Effect of Molecular Structure

Temperature and pressure dependencies of shear and elongational viscosities were examined using rotational and capillary rheometers. Two different batches of the same polymer grade have shown that the molecular structure diversion significantly influences the magnitudes of pressure coefficients, which vary more than the temperature coefficients. The pressure effect on viscosity notably depends on the amount of long-chain branching in polymer. Further, the paper shows that pVT data analysis via the Simha-Somcynsky equation of state can be employed to reveal differences in temperature and pressure viscosity dependencies through the free volume fraction.

The process of embryonic mortality in seven initial laying strains during incubation

Abstract. In five segments of incubation (within the 4th day, on the 7th, 14th, 20th days and in the stage of breaking through the shell) we studied the fertility of hatching eggs, the hatchability and embryonic mortality of seven initial laying strains (RIR – 1, RIR – 2, RIR – 3, RIW – 1, SU – 1, BPR – 1 and BPR – 2) in the course of three egg sets of individual pedigree hatching. The average hatchability of all the seven strains was 71.5%, the proportion of unfertilised eggs was 11.3% and embryonic mortality reached 17.2%. The embryonic mortality of all the seven strains culminated in two periods, i.e. within the 4th day of incubation (36.9% of the total embryonic mortality) and at the end of incubation (from the 15th to 20th day of incubation – 23.4% and during breaking through the shell – 18.1%). In terms of the inter-line differences, the embryonic mortality was the highest in three lines, which had a higher coefficient of inbreeding (Fx < 12.5%), i.e. RIR – 1 (20.9%), BPR – 2 (20.3%) and RIW – 1 (23.7%). All the three lines bear the recessive gene (k+) on locus K, which is responsible for the rapid type of feathering using feathersexing. Within the 7th day of incubation the embryonic mortality was higher in both BPR lines (BPR – 1–58.1%, BPR – 2–53.6% of the total embryonic mortality), while in the last trimester of incubation and in the period of breaking through the shell it was the lowest (BPR – 1–30.8%, BPR – 2–36.2% of the total embryonic mortality).