Ketamine Promoted Breast Cancer Invasion and Metastasis Through Up-regulating Wnt, BMP, and EGFR Signaling.

BACKGROUND/AIM: In this study, we used an orthotropic breast cancer model combined with ketamine addiction and next-generation sequencing (NGS) to comprehensively investigate molecular alterations in ketamine-mediated metastasis. Ketamine is widely used in anesthesia and drug abuse. Our previous study revealed that ketamine promotes the growth of breast cancer cells; however, the detailed molecular mechanism remains unknown. MATERIALS AND METHODS: An orthotropic breast cancer model was established by injecting EO771 breast cancer cells into the mammary fat pad of mice intraperitoneally administered ketamine (30 mg/kg, daily) for 68 days. Tumors collected at day 38 were frozen for future analysis, and their metastasis state was checked at day 68. RESULTS: Tumors were grouped and subjected to NGS analysis, followed by differential gene expression analysis (DEseq) and pathway identification. DEseq analysis showed that ketamine up-regulated metastasis-related signaling, and the key genes were BMP5, FZD6, MMP1B, EGFR, WNT5A, BMP7, and DCN. CONCLUSION: Ketamine addiction up-regulates the expression of genes involved in the Wnt, EGFR, and BMP signaling cascades, which may be associated with breast cancer progression and metastasis.

Asiatic acid exhibits antimetastatic activity in human prostate cancer cells by modulating the MZF-1/Elk-1/Snail signaling axis.

Prostate cancer metastasis is associated with poor prognosis and is difficult to treat clinically. Numerous studies have shown that Asiatic Acid (AA) has antibacterial, anti-inflammatory, and antioxidant effects. However, the effect of AA on prostate cancer metastasis is still unclear. This purpose of this study is to investigate the effect of AA on prostate cancer metastasis and to better understand its molecular mechanisms of action. Our results indicate that AA ≤ 30 µM did not influence cell viability and cell cycle distribution in PC3, 22Rv1 and DU145 cells. AA inhibited the migratory and invasive capabilities of three prostate cancer cells to be due to its effects on Snail, but did not have activity on Slug. We observed that AA inhibited the Myeloid zinc finger 1 (MZF-1) and ETS Like-1 (Elk-1) protein interaction and affected the complex's binding capacity to the Snail promoter region, ultimately blocking Snail transcription activity. Kinase cascade analysis revealed that phosphorylation of MEK3/6 and p38MAPK was inhibited by AA treatment. Moreover, knockdown of p38MAPK enhanced AA-suppressed protein levels of MZF-1, Elk-1, and Snail, suggesting that p38MAPK influences prostate cancer cell metastasis. These results provide promise for AA as a future candidate in the development of drug therapies to prevent or treat prostate cancer metastasis.

Ten-years outcome analysis in patients with clinically localized prostate cancer treated by radical prostatectomy or external beam radiation therapy.

Purpose: Since there was no consensus on treatment options for localized prostate cancer, we performed a retrospective study to compare the long-term survival benefit of radiotherapy (RT) versus laparoscopic radical prostatectomy (LRP) in Taiwan. Methods: 218 patients with clinically localized prostate cancer treated between 2008 and 2017 (64 with LRP and 154 with RT) were enrolled in this study. The outcomes of RT and LRP were assessed after patients were stratified according to Gleason score, stage, and risk group. Crude survival, prostate cancer-specific survival, and metastasis-free survival were evaluated using the log-rank test. Results: The 5-year crude survival rate was 93.3% in the LRP group and 59.3% in the RT group. A significant survival benefit was found in the LRP group compared with the RT group (p = 0.004). Furthermore, significant differences were found in disease-specific survival (93.3% vs. 64.7%, p = 0.022) and metastasis-free survival (48% vs. 40.2%, p = 0.045) between the LRP and RT groups. Conclusions: Men with localized prostate cancer treated initially with LRP had a lower risk of prostate cancer-specific death and metastases compared with those treated with RT.

Ketamine promotes breast tumor growth in a mouse breast tumor model involving with high expression of miR-27b-3p and EGFR.

Non-medical use of ketamine as an adulterant to ecstasy is more prevalent than amphetamine in Taiwan. Ketamine's effect on immunosuppression might play some functional role in tumor growth, while it is still controversial whether ketamine abuse could increase tumor growth or not. This study aimed to investigate the influence of ketamine addiction in breast tumors and related gene expressions. The effect of ketamine treatment on proliferation, colony formation, migration, and invasion of triple-negative breast cancer cell line EO771 was examined. In addition, a ketamine addiction mice model was established by intraperitoneal injection (IP) of ketamine in mice and used to investigate the effects of ketamine addiction on tumor growth and the possible mechanisms. In the in vitro studies, ketamine treatment at different concentrations did not affect EO771 cell proliferation and colony formation. But ketamine did enhance migration and invasion of EO771 cells. The in vivo experiments showed significantly increased breast tumor volume and weight in ketamine-addicted mice than in normal saline groups. miR-27b-3p level, human epidermal growth factor receptor 2 (HER2), and epidermal growth factor receptor (EGFR) significantly increased in tumors of ketamine addiction mice compared to control mice. In vivo evidence showed that Ketamine might increase tumor growth on the tumor microenvironment, and miR-27b-3p, HER2, and EGFR might play a role in the process.

Effect of phenylurea hydroxamic acids on histone deacetylase and VEGFR-2.

A series of phenylurea hydroxamic acids incorporating pharmacophores of inhibitors of HDAC inhibitors and VEGFR-2 has been designed. Most of the compounds show antiproliferative activity comparable to that of Vorinostat and Sorafenib, and better EPC inhibitory activity. Enzymatic assays and Western blotting results indicated that compound 14 not only inhibits HDAC but also has slight VEGFR-2 inhibitory activity. A docking study revealed that the polar hydroxamic acid retains the interaction with HDAC through a zinc ion and also interacts with some residues of the active site of VEGFR-2. Despite 14 displaying a weaker VEGFR-2 activity, a possible route to develop potent HDAC/VEGFR-2 inhibitors is suggested.

Melatonin impedes prostate cancer metastasis by suppressing MMP-13 expression.

Prostate cancer has high metastatic potential. Men with higher urinary levels of the sleep hormone melatonin are much less likely to develop advanced prostate cancer compared with men with lower levels of melatonin. Melatonin has shown anticancer activity in experimental investigations. Nevertheless, the therapeutic effect of melatonin in metastatic prostate cancer has largely remained a mystery. Analyses of Gene Expression Omnibus data and human tissue samples indicated that levels of matrix metallopeptidase 13 (MMP-13) expression are higher in prostate cancer patients than in healthy cancer-free individuals. Mechanistic investigations revealed that melatonin inhibits MMP-13 expression and the migratory and invasive capacities of prostate cancer cells via the MT1 receptor and the phospholipase C, p38, and c-Jun signaling cascades. Importantly, tumor growth rate and metastasis to distant organs were suppressed by melatonin in an orthotopic prostate cancer model. This is the first demonstration showing that melatonin impedes metastasis of prostate cancer by suppressing MMP-13 expression in both in vitro and in vivo models. Thus, melatonin is promising in the management of prostate cancer metastasis and deserves to undergo clinical investigations.

Modified paramedian versus conventional paramedian technique in the residency training: an observational study.

BACKGROUND: Residency training includes positive and negative aspects. Well-trained doctors must be educated, but the process may bring additional risks to patients. Anesthesiologists' performance when conducting neuraxial anesthesia is related to their experience. We hypothesized that a modified neuraxial anesthesia method would improve both residency training and patient safety. METHODS: We recruited 518 patients who were scheduled for a cesarean section and used spinal anesthesia (n = 256), epidural anesthesia (n = 154), and combined spinal-epidural anesthesia (SEA; n = 108). We observed and evaluated the anesthesia performance of five second-year resident anesthesiologists in elective cesarean sections using the conventional and modified methods. The number of attempts, implant error rate, and the incidence of complications were recorded and analyzed. RESULTS: Better success puncture attempts occurred in all three groups when the modified method was applied. For the groups with an implant assessment, the complication rate and implant error rate were lower when using the modified method. We employed generalized estimating equation (GEE) analysis to correct for possible confounding factors. When using the conventional method, the resident anesthesiologists required more attempts, made more implant errors, and caused more complications in patients. CONCLUSIONS: We found that a modified method for neuraxial anesthesia could improve residency performance and patient safety. The modified method may be a suitable training process for resident anesthesiologists when practicing neuraxial anesthesia. TRIAL REGISTRATION: The study was approved by the Research Ethics Committee of National Taiwan University (IRB:200812040R) Clinicaltrials register: NCT03389672 .

Synthesis and biological evaluation of 2-quinolineacrylamides.

A series of C6-substituted N-hydroxy-2-quinolineacrylamides (3-15), with four types of bridging groups have been synthesized. Most of these compounds exhibit antiproliferative activity against A549 and HCT116 cells and Western blot analysis revealed that they are able to inhibit HDAC. Measurement of the HDAC isoform activity of ether-containing compounds showed that compound 9 has distinct HDAC6 selectivity, more than 300-fold over other isoforms. This paper describes the development of 6-aryloxy-N-hydroxy-2-quinolineacrylamides as potential HDAC6 inhibitors.

Effects of systemic and neuraxial morphine on the immune system.

In the study, we tried to evaluate the effects of morphine injected through the systemic or neuraxial route on immune cell function and cytokine production in healthy women.In total, 29 paired samples of fresh peripheral blood were collected from healthy women who had been administered morphine for anesthetic analgesia through intravenous (IV), epidural, or spinal route postpartum. Their isolated peripheral blood mononuclear cells were mitogen-activated and stained with fluorochrome-conjugated anti-CD4, anti-CD8, anti-interleukin (IL)-2, and anti-interferon (IFN)-γ antibodies for flow cytometry, and the plasma levels of cytokines, including IL-6, IFN-α2, IL-10, IL-8, GM-CSF, and monocyte chemoattractant protein (MCP)-1, were measured through enzyme-linked immunosorbent assay.The results demonstrated that regardless of the administration route, morphine delivery slightly reduced IL-2 expression in CD4 cells after activation, and the same effect was not noted for CD8 cells. Intravenous or epidural morphine tended to reduce IFN-γ expression in CD8 cells. Spinal and IV morphine substantially increased IL-6 production, whereas epidural morphine hindered IL-10 and GM-CSF production. IV morphine injection reduced MCP-1 production in plasma. Compared with spinal morphine, IV or epidural morphine may more effectively inhibit the expression of various cytokines and thus affect immune response.All 3 routes of morphine injection tended to decrease IL-2 production by CD4 cells, whereas IV or epidural morphine injection showed lower IFN-γ production by CD8 cells. However, additional large-scale studies with longer follow-up durations are warranted.

Phomaketide A Inhibits Lymphangiogenesis in Human Lymphatic Endothelial Cells.

Lymphangiogenesis is an important biological process associated with cancer metastasis. The development of new drugs that block lymphangiogenesis represents a promising therapeutic strategy. Marine fungus-derived compound phomaketide A, isolated from the fermented broth of Phoma sp. NTOU4195, has been reported to exhibit anti-angiogenic and anti-inflammatory effects. However, its anti-lymphangiogenic activity has not been clarified to date. In this study, we showed that phomaketide A inhibited cell growth, migration, and tube formation of lymphatic endothelial cells (LECs) without an evidence of cytotoxicity. Mechanistic investigations revealed that phomaketide A reduced LECs-induced lymphangiogenesis via vascular endothelial growth factor receptor-3 (VEGFR-3), protein kinase Cδ (PKCδ), and endothelial nitric oxide synthase (eNOS) signalings. Furthermore, human proteome array analysis indicated that phomaketide A significantly enhanced the protein levels of various protease inhibitors, including cystatin A, serpin B6, tissue factor pathway inhibitor (TFPI), and tissue inhibitor matrix metalloproteinase 1 (TIMP-1). Importantly, phomaketide A impeded tumor growth and lymphangiogenesis by decreasing the expression of LYVE-1, a specific marker for lymphatic vessels, in tumor xenograft animal model. These results suggest that phomaketide A may impair lymphangiogenesis by suppressing VEGFR-3, PKCδ, and eNOS signaling cascades, while simultaneously activating protease inhibitors in human LECs. We document for the first time that phomaketide A inhibits lymphangiogenesis both in vitro and in vivo, which suggests that this natural product could potentially treat cancer metastasis.

Resistin facilitates VEGF-A-dependent angiogenesis by inhibiting miR-16-5p in human chondrosarcoma cells.

Resistin is an adipokine that is associated with obesity, inflammation, and various cancers. Chondrosarcomas are primary malignant bone tumors that have a poor prognosis. VEGF-A is a critical angiogenic factor that is known to promote angiogenesis and metastasis in chondrosarcoma. It is unknown as to whether resistin affects human chondrosarcoma angiogenesis. In this study, we show how resistin promotes VEGF-A expression and subsequently induces angiogenesis of endothelial progenitor cells (EPCs). Resistin treatment activated the phosphatidylinositol-3-kinase (PI3K) and Akt signaling pathways, while PI3K and Akt inhibitors or siRNA diminished resistin-induced VEGF-A expression. In vitro and in vivo studies revealed the downregulation of micro RNA (miR)-16-5p in resistin-induced VEGF-A expression and EPCs angiogenesis. We also found a positive correlation between resistin and VEGF-A expression, and a negative correlation between resistin and VEGF-A with miR-16-5p in chondrosarcoma patients. These findings reveal that resistin facilitates VEGF-A expression and angiogenesis through the inhibition of miR-16-5p expression via PI3K/Akt signaling cascades. Resistin may be a promising target in chondrosarcoma angiogenesis.

Pharmacogenetic study of pruritus induced by epidural morphine for post cesarean section analgesia.

OBJECTIVE: The mechanism through which neuroaxial morphine causes pruritus has not been elucidated clearly and thoroughly. MATERIALS AND METHODS: a study in 129 female parturients was conducted to investigate the effect of 14 single nucleotide polymorphisms (SNPs) on phenotype (pruritus) induced by neuroaxial (including intrathecal or epidural) morphine for cesarean section. Clinical phenotype, subjective complaints and objective observations were recorded. DNA from blood samples was used to record the SNPs. Eleven SNPs were then analyzed further. RESULTS: no significant association with the presence of phenotype (pruritus) versus genotype was observed (all p-values > 0.05). No significant association with severity of phenotype versus genotype of the 11 SNPs was observed except for unadjusted data for rs2737703. There was no significant difference between severity or incidence of IVPCA morphine-induced nausea and vomiting and genotype (11 SNPs). CONCLUSION: our results showed no association between SNPs of any of the genes studied with neuroaxial morphine inducing pruritus.

The use of tenoxicam to prevent symptoms of discomfort induced by vagotonia during uterus manipulation in cesarean sections.

PURPOSE: Symptoms such as nausea, vomiting, tightness of the chest, bradycardia, and shoulder or abdominal discomfort, caused by vagotonia occurring during uterus manipulation, have concerned healthcare professionals for some time. Patients sometimes report these symptoms when undergoing spinal anesthesia for cesarean sections (CSs). We designed a prospective, double-blind study to investigate the effectiveness of tenoxicam in preventing these symptoms of discomfort. METHODS: A total of 105 American Society of Anesthesiologists (ASA) class I-II nulliparous pregnant women, who were scheduled for a CS, were enrolled into this prospective, double-blind study. Spinal anesthesia was conducted to reach a peak dermatome level of no more than T3. The 100 patients were randomly divided into 2 groups having completed study course: Group T (N = 50) received a 20 mg dose of tenoxicam in 5 mL of normal saline (NS) immediately after skin incision and Group N (N = 50) only received 5 mL NS. The incidence and severity of the symptoms experienced by the patients were recorded by a nurse anesthetist who was blinded to the injection regimen the patients were receiving. A chi-square test was used for statistical analysis t test and P < .05 was defined as significant. RESULTS: The incidence and degree of severity of nausea and vomiting were same in both the groups. The incidence and degree of severity of bradycardia, nausea, vomiting, tightness of the chest, shoulder discomfort, and abdominal discomfort were lower in Group T than in Group N. CONCLUSION: Tenoxicam might theoretically block the parasympathetic vagus pathway and decrease the visceral pain or visceral-specific symptoms, alleviating the symptoms caused by vagotonia. However, the prophylactic effect of tenoxicam in reducing the incidence and severity of nausea and vomiting was not statistically significant. This could be because nausea and vomiting are not solely caused by vagotonia, but also by other mechanisms.

Prospective observational pharmacogenetic study of side effects induced by intravenous morphine for postoperative analgesia.

Nausea and vomiting are probably the most unpleasant side effects that occur when morphine used. A number of studies have investigated the effect on pain relief of single nucleotide polymorphisms (SNPs) in genes involved in morphine's metabolism, distribution, binding, and cellular action. The mechanism through which morphine causes nausea and vomiting has not been elucidated clearly. We examined all the reported SNPs which are associated with the complications of morphine, including SNPs in genes for phase I and phase II metabolic enzymes, ABC binding cassette drug transporters, κ and δ opioid receptors, and ion channels implicated in the postreceptor action of morphine.A prospective, observational study in 129 female patients was conducted to investigate the effect of 14 SNPs on nausea or vomiting induced by intravenous patient-controlled analgesia (IVPCA) with morphine after gynecology surgery. Clinical phenotype, subjective complaints, and objective observations were recorded. DNA from blood samples was used to record the SNPs. Eleven SNPs were then analyzed further.No significant association with the presence of phenotype (nausea or vomiting) versus genotype was observed (all P > .05). No significant association with severity of phenotype versus genotype of the 11 SNPs was observed except for unadjusted data for rs2737703.There was no significant difference between severity or incidence of IVPCA morphine-induced nausea and vomiting and genotype (11 SNPs). Further study should perhaps be focused on mRNA and proteinomics rather than SNPs.

CCL5 promotes VEGF-C production and induces lymphangiogenesis by suppressing miR-507 in human chondrosarcoma cells.

Chondrosarcoma is the second most frequently occurring type of bone malignancy that is characterized by the distant metastasis propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumor lymphangiogenesis and lymphatic metastasis. Chemokine CCL5 has been reported to facilitate angiogenesis and metastasis in chondrosarcoma. However, the effect of chemokine CCL5 on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has largely remained a mystery. In this study, we showed a clinical correlation between CCL5 and VEGF-C as well as tumor stage in human chondrosarcoma tissues. We further demonstrated that CCL5 promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium (CM) from CCL5-overexpressed cells significantly induced tube formation of human lymphatic endothelial cells (LECs). Mechanistic investigations showed that CCL5 activated VEGF-C-dependent lymphangiogenesis by down-regulating miR-507. Moreover, inhibiting CCL5 dramatically reduced VEGF-C and lymphangiogenesis in the chondrosarcoma xenograft animal model. Collectively, we document for the first time that CCL5 induces tumor lymphangiogenesis by the induction of VEGF-C in human cancer cells. Our present study reveals miR-507/VEGF-C signaling as a novel mechanism in CCL5-mediated tumor lymphangiogenesis. Targeting both CCL5 and VEGF-C pathways might serve as the potential therapeutic strategy to block cancer progression and metastasis in chondrosarcoma.

Butein inhibits metastatic behavior in mouse melanoma cells through VEGF expression and translation-dependent signaling pathway regulation.

BACKGROUND: Melanoma is an aggressive skin cancer and a predominant cause of skin cancer-related deaths. A previous study has demonstrated the ability of butein to inhibit tumor proliferation and invasion. However, the anti-metastatic mechanisms and in vivo effects of butein have not been fully elucidated. METHODS: MTT cell viability assays were used to evaluate the antitumor effects of butein in vitro. Cytotoxic effects of butein were measured by lactate dehydrogenase assay. Anti-migratory effects of butein were evaluated by two-dimensional scratch and transwell migration assays. Signaling transduction and VEGF-releasing assays were measured by Western blotting and ELISA. We also conducted an experimental analysis of the metastatic potential of tumor cells injected into the tail vein of C57BL/6 mice. RESULTS: We first demonstrated the effect of butein on cell viability at non-cytotoxic concentrations (1, 3, and 10 µM). In vitro, butein was found to inhibit the migration of B16F10 cells in a concentration-dependent manner using transwell and scratch assays. Butein had a dose-dependent effect on focal adhesion kinase, Akt, and ERK phosphorylation in B16F10 cells. Butein efficiently inhibited the mTOR/p70S6K translational inhibition machinery and decreased the production of VEGF in B16F10 cells. Furthermore, the in vivo antitumor effects of butein were demonstrated using a pulmonary metastasis model. CONCLUSION: The results of the present study indicate the potential utility of butein in the treatment of melanoma.

Comparison of extracorporeal shock wave lithotripsy running models between outsourcing cooperation and rental cooperation conducted in Taiwan.

BACKGROUND/PURPOSE: We conducted a retrospective study to compare the cost and effectiveness between two different running models for extracorporeal shock wave lithotripsy (SWL), including the outsourcing cooperation model (OC) and the rental cooperation model (RC). METHODS: Between January 1999 and December 2005, we implemented OC for the SWL, and from January 2006 to October 2011, RC was utilized. With OC, the cooperative company provided a machine and shared a variable payment with the hospital, according to treatment sessions. With RC, the cooperative company provided a machine and received a fixed rent from the hospital. We calculated the cost of each treatment session, and evaluated the break-even point to estimate the lowest number of treatment sessions to make the balance between revenue and cost every month. Effectiveness parameters, including the stone-free rate, the retreatment rate, the rate of additional procedures and complications, were evaluated. RESULTS: Compared with OC there were significantly less treatment sessions for RC every month (42.6±7.8 vs. 36.8±6.5, p=0.01). The cost of each treatment session was significantly higher for OC than for RC (751.6±20.0 USD vs. 684.7±16.7 USD, p=0.01). The break-even point for the hospital was 27.5 treatment sessions/month for OC, when the hospital obtained 40% of the payment, and it could be reduced if the hospital got a greater percentage. The break-even point for the hospital was 27.3 treatment sessions/month for RC. No significant differences were noticed for the stone-free rate, the retreatment rate, the rate of additional procedures and complications. CONCLUSION: Our study revealed that RC had a lower cost for every treatment session, and fewer treatment sessions of SWL/month than OC. The study might provide a managerial implication for healthcare organization managers, when they face a situation of high price equipment investment.

Associations of VEGF-C genetic polymorphisms with urothelial cell carcinoma susceptibility differ between smokers and non-smokers in Taiwan.

BACKGROUND: Vascular endothelial growth factor (VEGF)-C is associated with lymphangiogenesis, pelvic regional lymph node metastasis, and an antiapoptotic phenotype in urothelial cell carcinoma (UCC). Knowledge of potential roles of VEGF-C genetic polymorphisms in susceptibility to UCC is lacking. This study was designed to examine associations between VEGF-C gene variants and UCC susceptibility and evaluate whether they are modified by smoking. METHODOLOGY/PRINCIPAL FINDINGS: Five single-nucleotide polymorphisms (SNPs) of VEGF-C were analyzed by a TaqMan-based real-time polymerase chain reaction (PCR) in 233 patients with UCC and 520 cancer-free controls. A multivariate logistic regression was applied to model associations between genetic polymorphisms and UCC susceptibility, and to determine if the effect was modified by smoking. We found that after adjusting for other covariates, individuals within the entire population and the 476 non-smokers carrying at least one A allele at VEGF-C rs1485766 respectively had 1.742- and 1.834-fold risks of developing UCC than did wild-type (CC) carriers. Among the 277 smokers, we found that VEGF-C rs7664413 T (CT+TT) and rs2046463 G (AG+GG) allelic carriers were more prevalent in UCC patients than in non-cancer participants. Moreover, UCC patients with the smoking habit who had at least one T allele of VEGF-C rs7664413 were at higher risk of developing larger tumor sizes (p = 0.021), compared to those patients with CC homozygotes. CONCLUSIONS: Our results suggest that the involvement of VEGF-C genotypes in UCC risk differs among smokers compared to non-smokers among Taiwanese. The genetic polymorphism of VEGF-C rs7664413 might be a predictive factor for the tumor size of UCC patients who have a smoking habit.

Nationwide survey to evaluate medical utilization by patients with inguinal hernia and the risk of developing varicocele in Taiwan.

BACKGROUND: The purpose of this study was to analyze age, geographical and seasonal variations in medical service utilization by patients with inguinal hernia in Taiwan, and the influence of herniorrhaphy on development of ipsilateral varicocele in male patients. METHODS: Between 2001 and 2008, comprehensive data on the characteristics of medical service utilization by patients with inguinal hernia was evaluated via a retrospective nationwide population-based study. Data were obtained from the National Health Insurance Research Database in Taiwan. Parameters for comparison included newly diagnosed inguinal hernia cases, number of herniorrhaphies, and incidence rates every year, number of outpatient visits for inguinal hernia, and herniorrhaphy by age, season, and area of Taiwan. RESULTS: There was an average of 1,466 newly diagnosed inguinal hernia cases and 871.9 herniorrhaphies performed per year per million population during the study period. The male ratio for both newly diagnosed inguinal hernia cases and number of herniorrhaphies increased significantly by age. The number of newly diagnosed inguinal hernia cases and outpatient visits for inguinal hernia was highest during summer, followed by spring, autumn, and winter, and in the north of Taiwan, followed by the center, south, and east. Additionally, the incidence of developing ipsilateral varicocele after herniorrhaphy was low in male patients. CONCLUSION: The number of newly diagnosed inguinal hernia cases and outpatient visits for inguinal hernia is highest during summer and lowest in eastern Taiwan. In addition, the incidence of developing ipsilateral varicocele after herniorrhaphy is higher in patients aged 10-19 years.