Incorporating PHI in decision making: external validation of the Rotterdam risk calculators for detection of prostate cancer.

PURPOSE: External validation of existing risk calculators (RC) to assess the individualized risk of detecting prostate cancer (PCa) in prostate biopsies is needed to determine their clinical usefulness. The objective was to externally validate the Rotterdam Prostate Cancer RCs 3 and 4 (RPCRC-3/4) and that incorporating PHI (RPCRC-PHI) in a contemporary Spanish cohort. METHODS: Multicenter prospective study that included patients suspicious of harboring PCa. Men who attended the urology consultation were tested for PHI before prostate biopsy. To evaluate the performance of the prediction models: discrimination (receiver operating characteristic (ROC) curves), calibration and net benefit [decision curve analysis (DCA)] were calculated. These analyses were carried out for detection of any PCa and clinically significant (cs)PCa, defined as ISUP grade ≥ 2. RESULTS: Among the 559 men included, 337 (60.28%) and 194 (34.7%) were diagnosed of PCa and csPCa, respectively. RPCRC-PHI had the best discrimination ability for detection of PCa and csPCa with AUCs of 0.85 (95%CI 0.82-0.88) and 0.82 (95%CI 0.78-0.85), respectively. Calibration plots showed that RPCRC-3/4 underestimates the risk of detecting PCa showing the need for recalibration. In DCA, RPCRC-PHI shows the highest net benefit compared to biopsy all men. CONCLUSIONS: The RPCRC-PHI performed properly in a contemporary clinical setting, especially for prediction of csPCa.

Do PHI and PHI density improve detection of clinically significant prostate cancer only in the PSA gray zone?

OBJECTIVES: Prostate health index (PHI) is a predictive biomarker of positive prostate biopsy. The majority of evidence refers to its use in the PSA gray zone (4-10 ng/mL) and negative digital rectal exam (DRE). We aim to evaluate and compare the predictive accuracy of PHI and PHI density (PHId) with PSA, percentage of free PSA and PSA density, in a wider range of patients for the detection of clinically significant prostate cancer (csPCa). METHODS: Multicenter prospective study that included patients suspicious of harboring prostate cancer. Non-probabilistic convenience sampling, where men who attended the urology consultation were tested for PHI before prostate biopsy. To evaluate and compare diagnostic accuracy AUC and decision curve analysis (DCA) were calculated. All these procedures were performed for the overall sample and the following subsamples: PSA < 4 ng/ml; PSA 4-10 ng/ml; PSA 4-10 ng/ml plus negative DRE and PSA > 10 ng/ml. RESULTS: Among the 559 men included, 194 (34.7%) were diagnosed of csPCa. PHI and PHId outperfomed PSA in all subgroups. PHI best diagnostic performance was found in PSA 4-10 ng/ml with negative DRE (sensitivity 93.33, NPV 96.04). Regarding AUC, significant differences were found between PHId and PSA in the subgroup of PSA 4-10 ng/ml, whatever DRE status. In DCA, PHI density shows the highest net benefit. CONCLUSIONS: PHI and PHId outperfom PSA in csPCa detection, not only in the PSA grey zone with negative DRE, but also in a wider range of PSA values. There is an urgent need of prospective studies to established a validated threshold and its incorporation in risk calculators.

The Prevention of Ischemia-Reperfusion Injury in Elderly Rats after Lower Limb Tourniquet Use.

Background: Lower limb ischemia-reperfusion injury (IRI-LL) is a common major complication of orthopedic surgery, especially in elderly patients. It has previously been demonstrated that folinic acid (FA) reduced IRI-LL damage in 3−4-month-old rats. This current work analyses the effect of FA in the prevention of IRI-LL in elderly animals. Methods: Forty-two 18-month-old male WAG/RijHsd rats were subjected to 3 h of ischemia. Eighteen animals received FA (2.5 mg/kg, ip) 20 min before the end of the ischemia period, while the other half received the same volume of saline solution. The animals were sacrificed after 3 h, 24 h, and 14 days of reperfusion for biochemical (tissue damage markers and electrolytes), histopathological studies of the gastrocnemius muscle and the daily assessment of the limb function by the Rota Rod test, respectively. Results: The administration of FA prior to the end of the ischemia period reduced the increase in LDH and CK observed in non-treated animals by 30−40% (p < 0.0001). When the histological sections were analyzed, FA was found to have reduced the number of damaged muscle fibers per field by 20% (60 ± 17.1 vs. 80.7 ± 16.4, p < 0.0001). The functional test revealed that FA also led to an improvement in the muscle function, assessed by the length of time that the animals kept running on the rod, compared to untreated animals. Conclusions: The administration of FA, prior to the end of the ischemic period, decreases the damage induced by IRI-LL, also achieving a faster recovery of mobility.

Proposal of New Safety Limits for In Vivo Experiments of Magnetic Hyperthermia Antitumor Therapy.

BACKGROUND: Lately, major advances in crucial aspects of magnetic hyperthermia (MH) therapy have been made (nanoparticle synthesis, biosafety, etc.). However, there is one key point still lacking improvement: the magnetic field-frequency product (H × f = 4.85 × 108 Am-1s-1) proposed by Atkinson-Brezovich as a limit for MH therapies. Herein, we analyze both local and systemic physiological effects of overpassing this limit. METHODS: Different combinations of field frequency and intensity exceeding the Atkinson-Brezovich limit (591-920 kHz, and 10.3-18 kA/m) have been applied for 21 min to WAG/RijHsd male rats, randomly distributed to groups of 12 animals; half of them were sacrificed after 12 h, and the others 10 days later. Biochemical serum analyses were performed to assess the general, hepatic, renal and/or pancreatic function. RESULTS: MH raised liver temperature to 42.8 ± 0.4 °C. Although in five of the groups the exposure was relatively well tolerated, in the two of highest frequency (928 kHz) and intensity (18 kA/m), more than 50% of the animals died. A striking elevation in liver and systemic markers was observed after 12 h in the surviving animals, independently of the frequency and intensity used. Ten days later, liver markers were almost recovered in all of the animals. However, in those groups exposed to 591 kHz and 16 kA/m, and 700 kHz and 13.7 kA/m systemic markers remained altered. CONCLUSIONS: Exceeding the Atkinson-Brezovich limit up to 9.59 × 109 Am-1s-1 seems to be safe, though further research is needed to understand the impact of intensity and/or frequency on physiological conditions following MH.

Folinic Acid Potentiates the Liver Regeneration Process after Selective Portal Vein Ligation in Rats.

Liver resection remains the gold standard for hepatic metastases. The future liver remnant (FLR) and its functional status are two key points to consider before performing major liver resections, since patients with less than 25% FLR or a Child-Pugh B or C grade are not eligible for this procedure. Folinic acid (FA) is an essential agent in cell replication processes. Herein, we analyze the effect of FA as an enhancer of liver regeneration after selective portal vein ligation (PVL). Sixty-four male WAG/RijHsd rats were randomly distributed into eight groups: a control group and seven subjected to 50% PVL, by ligation of left portal branch. The treated animals received FA (2.5 m/kg), while the rest were given saline. After 36 h, 3 days or 7 days, liver tissue and blood samples were obtained. FA slightly but significantly increased FLR percentage (FLR%) on the 7th day (91.88 ± 0.61%) compared to control or saline-treated groups (86.72 ± 2.5 vs. 87 ± 3.33%; p < 0.01). The hepatocyte nuclear area was also increased both at 36 h and 7days with FA (61.55 ± 16.09 µm2, and 49.91 ± 15.38 µm2; p < 0.001). Finally, FA also improved liver function. In conclusion, FA has boosted liver regeneration assessed by FLR%, nuclear area size and restoration of liver function after PVL.

Curcumin Reduces Colorectal Cancer Cell Proliferation and Migration and Slows In Vivo Growth of Liver Metastases in Rats.

BACKGROUND: New therapeutic approaches are an essential need for patients suffering from colorectal cancer liver metastases. Curcumin, a well-known plant-derived polyphenol, has been shown to play a role in the modulation of multiple signaling pathways involved in the development and progression of certain cancer cells in vitro. This study aims to assess the anti-tumor effect of curcumin on CC531 colorectal cancer cells, both in vitro and in vivo. METHODS: On CC531 cultures, the cell viability and cell migration capacity were analyzed (wound healing test) 24, 48, and 72 h after treatment with curcumin (15, 20, 25, or 30 µM). Additionally, in WAG/RijHsd tumor-bearing rats, the total and individual liver lobe tumor volume was quantified in untreated and curcumin-treated animals (200 mg/kg/day, oral). Furthermore, serum enzyme measurements (GOT, GPT, glucose, bilirubin, etc.) were carried out to assess the possible effects on the liver function. RESULTS: In vitro studies showed curcumin's greatest effects 48h after application, when all of the tested doses reduced cell proliferation by more than 30%. At 72 h, the highest doses of curcumin (25 and 30 µM) reduced cell viability to less than 50%. The wound healing test also showed that curcumin inhibits migration capacity. In vivo, curcumin slowed down the tumor volume of liver implants by 5.6-fold (7.98 ± 1.45 vs. 1.41 ± 1.33; p > 0.0001). CONCLUSIONS: Curcumin has shown an anti-tumor effect against liver implants from colorectal cancer, both in vitro and in vivo, in this experimental model.

Biochemical and Metabolomic Changes after Electromagnetic Hyperthermia Exposure to Treat Colorectal Cancer Liver Implants in Rats.

BACKGROUND: Hyperthermia (HT) therapy still remains relatively unknown, in terms of both its biological and therapeutic effects. This work aims to analyze the effects of exposure to HT, such as that required in anti-tumor magnetic hyperthermia therapies, using metabolomic and serum parameters routinely analyzed in clinical practice. METHODS: WAG/RigHsd rats were assigned to the different experimental groups needed to emulate all of the procedures involved in the treatment of liver metastases by HT. Twelve hours or ten days after the electromagnetic HT (606 kHz and 14 kA/m during 21 min), blood samples were retrieved and liver samples were obtained. 1H-nuclear-magnetic-resonance spectroscopy (1H-NMR) was used to search for possible diagnostic biomarkers of HT effects on the rat liver tissue. All of the data obtained from the hydrophilic fraction of the tissues were analyzed and modeled using chemometric tools. RESULTS: Hepatic enzyme levels were significantly increased in animals that underwent hyperthermia after 12 h, but 10 d later they could not be detected anymore. The metabolomic profile (main metabolic differences were found in phosphatidylcholine, taurine, glucose, lactate and pyruvate, among others) also showed that the therapy significantly altered metabolism in the liver within 12 h (with two different patterns); however, those changes reverted to a control-profile pattern after 10 days. CONCLUSIONS: Magnetic hyperthermia could be considered as a safe therapy to treat liver metastases, since it does not induce irreversible physiological changes after application.

Ultrasound Tumor Size Assessment, Histology and Serum Enzyme Analysis in a Rat Model of Colorectal Liver Cancer.

During tumor development, tissue necrosis appears as a natural phenomenon directly associated with an increase in tumor size. The aim of this study was to assess the use of ultrasound (US) for predicting natural tumor necrosis in a rat liver implant model of colorectal cancer. To achieve this goal, we sought to establish a correlation between US-measured tumor volume, serum enzyme levels and histopathological findings, particularly those regarding necrosis phenomena in liver implants. Under US guidance, CC531 colorectal cancer cells were injected into the left liver lobe of WAG/RijHsd rats. Twenty-eight days after cell inoculation, tumor volume was measured by US, and rats were sacrificed to obtain samples of tumor tissue as well as blood serum. In hematoxylin and eosin-stained tumor samples, the percentage of tumor that was necrotic was estimated. The association between percentage tumor necrosis and US-measured tumor volume was assessed by univariate logistic regression analysis, and a linear regression equation was obtained. Serum enzyme levels did not differ significantly between tumor-bearing and tumor-free rats. Tumor implants appeared as well-defined hyper-echoic regions with a mean volume of 0.61 ± 0.39 mL and tumor necrosis percentage of 8.6 ± 7.7%. Linear regression analysis revealed a very strong relationship (Pearson correlation coefficient r = 0.911) between US-measured tumor volume and tumor necrosis percentage; the regression equation was tumor necrosis percentage = 21 × US-measured tumor volume (in mL) - 3.1. The study found US to be a useful tool in animal-based trials. Tumors inside the liver (ranging in volume from 0.24-1.37 mL) can be observed by US, and moreover, US-measured tumor volume on day 28 can be used to estimate tumor necrosis occurring as the natural evolution of tumor implants.