An Advanced Orthotopic Ovarian Cancer Model in Mice for Therapeutic Trials

A nude mouse received subcutaneous injection of human ovarian cancer cells HO-8910PM to form a tumor, and then the tumor fragment was surgically transplanted to the ovary of a recipient mouse to establish an orthotopic cancer model. Tumors occurred in 100% of animals. A mouse displayed an ovarian mass, ascites, intraperitoneal spread, and lung metastasis at natural death. The mean survival time was 34.1 ± 17.2 days, with median survival time of 28.5 days. The findings indicated that the present mouse model can reflect the biological behavior of advanced human ovarian cancers. This in vivo model can be used to explore therapeutic means against chemoresistance and metastasis, and an effective treatment would prolong the survival time.

Metabolomic profiling identifies hair as a robust biological sample for identifying women with cervical cancer

Metabolomics serves as a useful tool for identifying biomarkers of disease and uncovering pathogenic mechanisms. However, most metabolomic studies use biological fluids such as blood and urine as biospecimens, which could be dramatically influenced by daily activities and dietary variation, resulting in measurement fluctuations. In contrast, hair may serve as a robust source of stable longitudinal metabolite information. Here, we conducted a pilot study to investigate the possibility of using hair as a biospecimen for the metabolomic analysis of cervical cancer. Hair, plasma, urine, and cervical tissue samples from cervical cancer and benign tumor patients were collected. Biospecimens were then tested using a gas chromatography-mass spectrometry-based metabolomic platform. The expressions of enzymatic genes related to metabolic changes were validated using qPCR. Statistical analyses were calculated via the R-console platform. Metabolite profiles in both hair and cervical tissue samples were significantly different between cancer and control groups, while no difference was observed in plasma and urine samples. Further analysis showed that most of the altered metabolites in hair were upregulated, and they had a negative correlation with those in the cervical tissue. Eight common metabolites showed an area under the Receiver Operating Characteristic curve greater than 0.95. These metabolites primarily participated in amino acid metabolism, cofactor synthesis, ferroptosis, and glycolysis. The gene expressions (IDH1, OGDH, GLUD1, ENO1, GSS, and GPX4) associated with the shortlisted metabolic pathways were also upregulated. Our study is the first to reveal metabolomic changes of hair in cervical cancer patients and demonstrates the potential for the hair metabolome to be used for biomarker identification in cervical cancer.

Nanosecond electric pulses induce DNA breaks in cisplatin-sensitive and -resistant human ovarian cancer cells

Human ovarian cancer cells COC1 and COC1/DDP (cisplatin-resistant subline) were exposed to 6 kV/cm nanosecond electric pulses (nsEP) with a pulse length of 8, 16 or 24 ns. The potential in a subcellular unit was calculated using a multilayer dielectric spherical model, and area under the voltage-time curves (AUC) integrated with a lower limit of 0.2V. Cell viability was determined, and double-stand and total DNA breaks detected with the neutral and alkaline comet assays. nsEP evoked a higher voltage and AUC in nucleoplasm, and the levels in COC1 cells was just above those in COC1/DDP cells. Comets only appeared in the alkaline assay demonstrating single-stand DNA break. Fewer DNA break (16.51% vs. 35.13% at 24 ns, p=0.0150) and more survival (22.42% vs. 13.19% at 24 ns, p=0.0015) occurred in COC1/DDP cells despite an equal electric energy and almost equal cell sizes. 24-ns EP led to higher rates of cell-death and comet. The comet rate correlated with cell-death fraction in either cell line (r=0.5701, p=0.0135; r=0.5110, p=0.0302). There was no a correlation between the tail length, tail moment or Olive tail moment and cell-death rate. The data showed that response of chemosensitive cells differed from that of chemoresistant cells and DNA damage contributed to percent of cell death.

Ultrasonic therapy for gynecologic tumors

Clinical and potential applications of ultrasonic therapy for gynecologic tumors are overviewed in this minireview. As a noninvasive technique, extracorporeal high-intensity focused ultrasound was clinically used to treat uterine myomas. High-intensity focused ultrasound treats leiomyomas via shrinkage of tumor size, reduction of blood supply, and suppression of cell proliferation, resulting in a relief of symptoms and improvement of quality of life. Preclinical trials have confirmed that ultrasound enhanced a cytotoxic agent against cancers of ovary and cervix; insonation overcomes doxorubicin (adriamycin) and cisplatin resistance in ovarian cancers, suggesting a modality for refractory lesions; ultrasonic hyperthermia induces high temperature increase in deeper cancer tissues thus being a potential modality for treatment of cervical cancers. Transvaginal ultrasonic therapy can be applied for a lesion near the cervix. In summary, ultrasonic therapy is a promising treatment modality for gynecologic tumors, and might change clinical practices.

High expressions of bcl-2 and survivin, and decreased apoptosis in uterine cervical carcinosarcoma compared to cervical squamous cell carcinoma

PURPOSES

Uterine cervical carcinosarcoma (CS) is very rare. To date, only 40 cases have been reported. It seems to have a more aggressive clinical behavior than does cervical squamous cell carcinoma (SCC). The purposes of our study were to characterize the clinicopathologic characteristics and human papillomavirus (HPV) status of the rare tumor and to analyze the molecular features in cervical CS that may account for its aggressive behavior.

METHODS

Three patients were diagnosed with uterine cervical CS at West China Second Hospital of Sichuan University between 1995 and 2009. Data were retrospectively analyzed from available charts and pathological reports. Twelve patients with FIGO stage Ib-IIa cervical SCC were enrolled as the controls, and the expression profiling of p53, Ki-67, bcl-2, survivin and apoptosis index between cervical CS and SCC was compared. Immunohistochemical and apoptosis results were scored separately for the carcinomatous and sarcomatous components.

RESULTS

All three patients were shown to be negative for HPV infection by Hybribio HPV genoarray assay. Expression of p53 was observed in one patient in both carcinomatous and sarcomatous components in a similar proportion; in contrast, the Ki67, bcl-2 and survivin expressions were higher in carcinomatous components than in sarcomatous components in all three cases. Compared to cervical SCC, stronger immunostaining for bcl-2, survivin and lower apoptosis was observed in cervical CS.

CONCLUSIONS

Cervical CS is a peculiar tumor with many different clinicopathologic characteristics from cervical SCC. Dysregulation of apoptosis may confer tumor cells of cervical CS with survival and growth advantages, and thereby facilitate the aggressive behavior of cervical CS.

Biphasically Modulating the Activity of Carboxypeptidase G2 with Ultrasound

BACKGROUND/AIMS

Carboxypeptidase G2 (CPG2) has been used for cancer prodrug therapy to realize the targeted release of active drugs, but there yet lacks a means to modulate the CPG2 activity. Here ultrasound was used to modulate the CPG2 activity.

METHODS

The activity of insonated CPG2 was determined, and then underlying biochemical (i.e., monomer, dimer and conformation) and ultrasonic (i.e., heat and cavitation) mechanisms were explored.

RESULTS

Ultrasound (1.0 MHz) increased or decreased the enzymatic activity; the activity decreased as zero- or first-order kinetics, depending on the intensity. L1 (10 W/cm2 for 200 s) improved the activity via increasing the specific activity. L2 or L3 (20 W/cm2 for 1200 or 3000 s) decreased the activity via disassembling the dimer, degrading the monomer, inducing glycosylation, transforming conformation and decreasing the specific activity. An increase or a slight decrease of activity attributable to 10 W/cm2 was reversible, but the activity decrease due to 20 W/cm2 was irreversible. The enzymatic modulation was realized via cavitation.

CONCLUSION

Ultrasound can biphasically modulate the CPG2 activity, and can be employed in the CPG2-prodrug therapy to adjust the release and moles of active drugs.

Ultrasonically Enhanced ZD2767P-Carboxypeptidase G2 Deactivates Cisplatin-Resistant Human Lung Cancer Cells

The prodrug-enzyme regimen ZD2767P+CPG2 is limited by low efficacy. Here, ultrasound was used to modulate ZD2767P+CPG2 (i.e., ZD2767P+CPG2+US) against cisplatin-resistant human lung cancer cells. A549 and A549/DDP (resistant subline) cells received ZD2767P+CPG2 or ZD2767P+CPG2+US. Either ZD2767P+CPG2 or ZD2767P+CPG2+US led to cell death and apoptosis, and ZD2767P+CPG2+US produced stronger effects; comet assays revealed that these two means directly caused DNA double-strand break. Z-VAD-fmk and/or ferrostatin-1 increased the cell survival percentage, and Z-VAD-fmk decreased the apoptosis percentage. The level of transferrin was increased in treated cells, but those of ferroportin and glutathione peroxidase 4 (GPX4) were reduced, with higher intracellular levels of reactive oxygen species and of iron. Intracellular pharmacokinetics of ZD2767D (activated drug) indicated that the peak level, area under the drug level vs. time curve, and mean residence time in ZD2767P+CPG2+US were higher than those in ZD2767P+CPG2. Both ZD2767P+CPG2 and ZD2767P+CPG2+US were effective on xenograft tumors in nude mice; inhibitory rates were 39.7% and 63.5% in A549 tumors and 50.0% and 70.1% in A549/DDP tumors, respectively. A higher apoptosis level and a lower GPX4 level were noted in tumors receiving treatments. No severe adverse events were observed. These data demonstrated that ZD2767P+CPG2+US deactivated cancer cells via apoptosis and ferroptosis pathways, being a candidate therapy for cisplatin-resistant lung cancer.

Extracorporeal ultrasound-guided high intensity focused ultrasound: implications from the present clinical trials

Extracorporeal ultrasound-guided high intensity focused ultrasound (HIFU) has been clinically used for 15 years, and over 36000 cases have been reported. However, there yet lacked a consensus in the clinical values, suggesting the necessity of checking clinical findings. Clinical trials were searched and data reevaluated. HIFU was hardly performed alone; almost all present anticancer means have been applied during an HIFU treatment, and a specific regimen varied between trials; there were heterogeneity and disagreement between trials. The complexity made it difficult to distinguish the effect of HIFU. Based upon evaluable data, the efficacy of HIFU was similar to that of radio frequency, chemoembolization, chemotherapy, radiotherapy, or hormone therapy; a combined therapy did not improve the efficacy. The survival rate of HIFU plus radiotherapy was lower than that of radical surgery in liver cancers. Adverse events had no downtrend in the past years. HIFU was not a standardized procedure where the intensity and insonation mode were modified constantly throughout a treatment, limiting an evaluation from the perspective of ultrasonics. These implied that HIFU should be applied as an alternative at most occasions. The present clinical trials had defects making against the understating of HIFU.

Nanosecond Electric Pulses Induce Early and Late Phases of DNA Damage and Cell Death in Cisplatin-Resistant Human Ovarian Cancer Cells

Chemoresistance is a challenge for management of ovarian cancer, and therefore the response of resistant cells to nanosecond electric pulses (nsEP) was explored. Human ovarian cancer cell line COC1 and the cisplatin-resistant subline COC1/DDP were subjected to nsEP (32 ns, 10 kV/cm, 10 Hz pulse repletion frequency, and 10 min exposure duration), and then the cellular responses were followed. The percentages of dead cells and of comet-formed cells in the alkaline assay displayed two peak levels (i.e., 2 and 8 h after nsEP exposure), with the highest value noted at 8 h; the percentage of comet-formed cells in the neutral assay was increased at 8 h; the apoptotic percentage was increased at 8 h, with collapse of the mitochondrial membrane potential and the activation of caspase-3 and caspase-9. The comet assay demonstrated DNA single-strand break at 2 h and double-strand break at 8 h. nsEP resulted in lower cytotoxicity in COC1/DDP cells compared with COC1 cells. These findings indicated that nsEP induced early and late phases of DNA damage and cell death, and these two types of cell death may have distinct applications to treatments of chemoresistant ovarian cancers.

Effects of high intensity focused ultrasound on vascular endothelial growth factor in melanoma bearing mice

This study was to investigate the effects of high intensity focused ultrasound on vascular endothelial growth factor. A B16 melanoma model was adopted in our study. Melanoma bearing mice were randomly divided into two groups: HIFU group and surgery group. While the control group was only injected with isovolumetric normal saline solution and treated as the surgery group. We detected VEGF both in tissues and sera through immunohistochemical method and ELISA respectively. Tissues were sampled pre- and at the 3rd day post-operation in HIFU group and blood samples were taken pre- and at the 1st, 3rd, and 7th day post-operation in all the groups. As a result, in the tissues, VEGF was expressed in 80% melanomas, but none was detected in the targeted area after HIFU treatment. In the sera, there was a decreasing tendency of serum-VEGF concentrations in group HIFU and surgery after operation, while that in the control group increased after operation. The levels in the HIFU group on day 1, 3, and 7 postoperatively were all lower than that in the surgery group respectively (79.16 pg/ml vs 91.59 pg/ml; 33.64 pg/ml vs 49.39 pg/ml; 30.37 pg/ml vs 46.68 pg/ml), but there wasn't any significant difference (P > 0.05). So HIFU can destroy VEGF in the targeted area and maybe have less of an effect on serum-VEGF than surgery.

Sonochemotherapy inhibits the adhesion, migration and invasion of human ovarian cancer cells with highly metastatic potential

PURPOSE

Preclinical trials have shown that sonochemotherapy is effective for human ovarian cancers. Therefore, the effects of sonochemotherapy on cell adhesion and motility were investigated in this study, considering their roles in cancer metastasis.

MATERIALS AND METHODS

Cell lines, HO-8910 and its highly metastatic potential subline HO-8910PM, were subjected to cisplatin, paclitaxel and sonochemotherapy (anticancer drugs followed by insonation). Cytotoxicity was determined, and then cell adhesion, migration and invasion assays were performed.

RESULTS

Neither cisplatin (0.5 μg/ml) nor paclitaxel (6.0 μg/ml) alone led to cell death. The addition of ultrasound did not potentiate an anticancer drug, suggesting that there was a threshold dose for a cytotoxic agent employed in sonochemotherapy. The survival rate was decreased when combining cisplatin and paclitaxel followed by insonation. 6.0 μg/ml of paclitaxel completely suppressed cell adhesion and motility, thus the concentration was decreased to 1.2 μg/ml. Migration and invasion assays were only successfully performed in HO-8910PM cells. Cisplatin and paclitaxel inhibited adhesion, migration and invasion, resulting in lower rates, which were additionally decreased by insonation. No cell traveled through the membrane when cisplatin, paclitaxel and ultrasound were combined. Quantitative evaluations indicated that ultrasound enhanced anticancer agents via synergistic and/or additive effects.

CONCLUSION

Ultrasound synergized a combined regime and sonochemotherapy was a measure to suppress cancer spread.

Nanosecond electric pulses deprive zinc ions of carboxypeptidase G2

Nanosecond electric pulses (nsEP, 10kV/cm with a pulse duration of 8, 16 or 24ns) inhibited the activity of carboxypeptidase G2 (CPG2), a zinc-dependent homodimer; the relative activity was <20% when the total exposure time was >120s. No alterations were detected in electrophoresis, chromatography, mass spectroscopy and circular dichroism, thus demonstrating intactness of the apoenzyme. Inductively coupled plasma-mass spectrometry indicated that zinc levels were 3.30μg/mg protein in control CPG2, and decreased to 0.40, 0.12 or 0.38μg/mg protein after 240s of 8-, 16- or 24-ns pulses, respectively. In CPG2 exposed to 240s of 8-, 16- and 24-ns pulses, the reloading of zinc with redialysis recovered the activity to 94.7±3.4%, 84.0±5.2% and 81.7±7.0%, respectively (p=0.0853, 0.0741, 0.0668). These data demonstrated that nsEP inhibited CPG2 via removal of zinc, and that nsEP can be used to modulate CPG2.

Use of intraoperative ultrasonography to monitor surgery for large acoustic neuromas: a pilot study

PURPOSE

Operations for large acoustic neuromas were difficult. The aim of this pilot study was to determine whether intraoperative ultrasonography (IOUS) was a useful adjunct to the microsurgery.

METHODS

Fifteen patients with large acoustic neuromas underwent surgical interventions. IOUS was applied in seven cases, and the other eight cases served as controls. IOUS was performed to monitor the surgery, and the intraoperative data were compared with postoperative CT/MRI scans.

RESULTS

All tumors could be identified in ultrasonic images. Lesions appeared as solid (2/7) or mixed patterns (5/7) with clear boundaries. A larger tumor volume was seen in the IOUS group but without statistical significance (29.05 ± 15.47 vs. 21.82 ± 14.78 cm(3), P = 0.3718). The use of IOUS did not prolong the operation time (404.29 ± 111.18 vs. 420.00 ± 114.24 min, P = 0.7921) and did not increase the rate of intracranial infections (28.57 vs. 25.00%, P = 1.000). The residual tumor detected with IOUS immediately after the operation was consistent with the data from postoperative CT/MRI scans in all cases.

CONCLUSION

IOUS can be used to monitor surgery in real time as a technique to assist microsurgical procedures for large acoustic neuromas with trouble.

Insulin Treatment Cannot Promote Lipogenesis in Rat Fetal Lung in Gestational Diabetes Mellitus Because of Failure to Redress the Imbalance Among SREBP-1, SCAP, and INSIG-1

Gestational diabetes mellitus (GDM) has a higher incidence of neonatal respiratory distress syndrome, and lipogenesis is required for the synthesis of pulmonary surfactants. The aim of this study was to determine the effect of insulin treatment in GDM on the production of lipids in the lungs of fetal rats. GDM was induced by streptozotocin, and insulin was used to manage diabetes. Type II alveolar epithelial cells (AEC II), bronchoalveolar lavage fluid (BALF), and lung tissues of the neonatal rats were sampled for analyses. Insulin treatment could not decrease plasma glucose to normal level at a later gestational stage. Lipids/phospholipids in AEC II, BALF, and lung tissues decreased in GDM, and insulin treatment could not increase the levels; quantitative PCR and western blotting demonstrated a lower level of sterol regulator element-binding protein 1 (SREBP-1), SREBP cleavage-activating protein (SCAP), and insulin-induced gene 1 (INSIG-1) in GDM, but insulin treatment upregulated only SREBP-1. Nuclear translocation of the SREBP-1 protein in AEC II was impaired in GDM, which could not be ameliorated by insulin treatment. These findings indicated that insulin treatment in GDM cannot promote lipogenesis in the fetal lung because of failure to redress the imbalance among SREBP-1, SCAP, and INSIG-1.

Thioridazine Enhances Cisplatin-Induced DNA Damage in Cisplatin-Resistant Human Lung Cancer Cells

Thioridazine was used to sensitize cisplatin against cisplatin-resistant human lung cancer cells. Cells received thioridazine, cisplatin, or both drugs (the combination). Thioridazine synergized cisplatin to increase percentages of dead and apoptotic cells. DNA damage was detected using the comet assays; the combination led to the highest alkaline- and neutral-comet percentages, demonstrating exacerbation of both single- and double-strand breaks. After thioridazine treatment, levels of glutathione, and BRCA2, RAD51, and ERCC1 proteins were decreased. These data manifested that thioridazine decreased the capacities of detoxification and DNA repair, thereby enhancing cisplatin-induced DNA damage in resistant cells.

LPCAT3 regulates the proliferation and metastasis of serous ovarian cancer by modulating arachidonic acid

BACKGROUND

Lysophosphatidylcholine acyltransferase 3 (LPCAT3) promotes ferroptosis through the incorporating polyunsaturated fatty acids into membrane phospholipids, however, its role in serous ovarian cancer remains unclear. Here explored cancer proliferation and metastasis after modulating LPCAP3.

METHODS

LPCAT3 protein in ovarian cancer tissues was detected using bioinformatic and immunohistoche mical assays. Cell behaviors were observed after up- or down-regulating LPCAT3. Lipid metabolites were determined, and then the pathway enrichment analysis was performed.

RESULTS

The expression level of LPCAT3 in serous ovarian cancer tissues was lower than that in other types of ovarian cancer, and high expression was associated with a longer survival time. Overexpressing LPCAT3 reduced cell proliferation, migration and invasion via enhancing ferroptosis and decreasing the survival signaling; these behaviors were enhanced in LPCAT3-downknocked cells, where a higher abundance of arachidonic acid was observed followed by up-regulation of the downstream survival signaling. In vivo, up-regulation of LPCAT3 decreased tumor growth, but down-regulation enhanced tumor growth and metastasis.

CONCLUSIONS

LPCAT3 modulated metabolism of arachidonic acid, thereby regulating ferroptosis and the survival signaling to determine cancer growth and metastasis.

[Temporal Pattern of DNA Breaks in Human Ovarian Cancer Cells after Exposure to Nanosecond Electric Pulses]

This study aims to explore the temporal pattern of DNA breaks induced by nanosecond electric pulses (nsEP) in cisplatin-sensitive and cisplatin-resistant human ovarian cancer cells. Human ovarian cancer cells A2780 (cisplatin-sensitive subline) and C30 (cisplatin-resistant subline) were exposed to nsEP. Sham exposed groups were shame exposed to nsEP. Cell viability was determined using CCK-8 assay after 0 h, 4 h, 8 h, 12 h and 24 h, respectively, and the percentage of dead cells was calculated. The DNA break was detected with the alkaline single cell gel electrophoresis (comet assay), and the 75th percentiles of TL (tail length), TM (tail moment) and OTM (Olive tail moment) were measured. Cell viability displayed an early decrease and late increase, with the valley value seen at 8 h. Percentages of cell death and comet-formed in A2780 cells were higher than those in C30 cells (P < 0.05) at 8 h, respectively. TL, TM and OTM in C30 cells were less than those in A2780 cells (P < 0.05). The percentage of comet-formed correlated with that of cell death in either A2780 (r = 0.997, P < 0.05) or C30 (r = 0.998, P < 0.05) cells. DNA breaks induced by nsEP in cisplatin-sensitive cells differred from that in resistant cells, and DNA break resulted in fraction of cell death.

Laparoscopic technique for identifying the main trunk of the uterine artery by tracing its superior branch

AIM

To determine the feasibility of identifying the main trunk of the uterine artery by tracing its superior branch with a laparoscopic technique.

MATERIAL AND METHODS

Ten patients with symptomatic myomas who had indication for surgical intervention were enrolled in this prospective nonrandomized study between November 2009 and February 2010.The uterine artery was identified by tracing its superior branch with a laparoscopic technique, and then performing occlusion of the uterine artery. Estimated uterus weight, operating time, blood loss, and intraoperative complications were recorded.

RESULTS

Bilateral uterine arteries were successfully isolated in all cases (n = 10) without intraoperative complications. The estimated uterine weight was 290 g (220-370 g). The operation time from the opening of anterior peritoneum of the broad ligament to the occlusion of unilateral uterine artery was 3 min (2.3-6 min). The volume of estimated blood loss was less than 10 mL.

CONCLUSION

This pilot trial demonstrated that it was feasible to locate the main trunk of the uterine artery by tracing its superior branch. This technique provided a fast modality for laparoscopic surgery.

Erratum: DR2 blocker thioridazine: A promising drug for ovarian cancer therapy

[This corrects the article DOI: 10.3892/ol.2017.7184.].

[Induction of Apoptosis of Human Cisplatin-resistance Lung Cancer Cells with MPPa-photodynamic Therapy]

Lung cancer is the leading cause of cancer-related deaths worldwide.Despite the development and use of several targeting drugs for lung cancer therapy,the five-year survival rate has remained as low as 15%for the past three decades.Cisplatin-based chemotherapy is considered the first-line therapeutic strategy for lung cancer.However,developments of chemoresistance is a major obstacle for the successful treatment.Therefore,the development of novel therapy against cisplatin-resistance lung cancer is imperative.Photodynamic therapy(PDT),which is a non-invasive combinatorial therapeutic modality using light,photosensitizer(PS)and oxygen,may provide an unprecedented tool to develop more effective treatments.To provide experimental basis for its application in cisplatin-resistance lung cancer,we will discuss the biological effects of MPPa-photodynamic therapy in human cisplatin-resistance lung cancer cells in this article.Human cisplatin-resistance lung cancer cells A549/DDP were co-cultured with MPPa(0,1,2,4,8,16μmol/L)and exposed to light(0,0.6,1.2,2.4,3.6,4.8J/cm2),and cell viability was determined with CCK-8assay.Flow cytometry was used to detect apoptosis,DCFH-DA staining was employed to observe reactive oxygen species(ROS),and Western blot was used to detect the expressions of B-cell lymphoma-2(Bcl-2)protein and Bcl-2associated X protein(Bax).The proliferation of A549/DDP cells was suppressed by PDT.The apoptotic rate in the PDT group was significantly higher than that in the control,MPPa or light group(P<0.05).The level of ROS was increased.The expression of Bax was increased,and that of Bcl-2was decreased.MPPa-photodynamic therapy can significantly suppress cell viability,and induce apoptosis in human cisplatin-resistance lung cancer cells.

Clinical Trials of High-intensity Focused Ultrasound for Cancer: Concerns Arising from Low Post-Hoc Power

Prospective controlled trials of high-intensity focused ultrasound (HIFU) for cancers were evaluated. Post-hoc power was <0.80 in 30/46 trials and in 22/38 trials with positive results, indicating low quality in most trials. Unscientific endpoints, small sample sizes, and high dropout rates led to low post-hoc power that caused inter-trial heterogeneity and overestimated the therapeutic effect. The objective response rate was not a substitute for survival time for estimating the sample size and assessing the efficacy. The present data can interpret a paradox: HIFU is considered to have slighter cytotoxicity to noncancer tissues and no radiation but is frequently combined with chemotherapy and/or radiotherapy in practice.