SET antagonist enhances the chemosensitivity of non-small cell lung cancer cells by reactivating protein phosphatase 2A

SET is known as a potent PP2A inhibitor, however, its oncogenic role including its tumorigenic potential and involvement in the development of chemoresistance in non-small cell lung cancer (NSCLC) has not yet been fully discussed. In present study, we investigated the oncogenic role of SET by SET-knockdown and showed that SET silencing impaired cell growth rate, colony formation and tumor sphere formation in A549 cells. Notably, silencing SET enhanced the pro-apoptotic effects of paclitaxel, while ectopic expression of SET diminished the sensitivity of NSCLC cells to paclitaxel. Since the SET protein was shown to affect chemosensitivity, we next examined whether combining a novel SET antagonist, EMQA, sensitized NSCLC cells to paclitaxel. Both the in vitro and in vivo experiments suggested that EMQA and paclitaxel combination treatment was synergistic. Importantly, we found that downregulating p-Akt by inhibiting SET-mediated protein phosphatase 2A (PP2A) inactivation determined the pro-apoptotic effects of EMQA and paclitaxel combination treatment. To dissect the critical site for EMQA functioning, we generated several truncated SET proteins. By analysis of the effects of EMQA on the binding affinities of different truncated SET proteins to PP2A-catalytic subunits, we revealed that the 227-277 amino-acid sequence is critical for EMQA-induced SET inhibition. Our findings demonstrate the critical role of SET in NSCLC, particularly in the development of chemoresistance. The synergistic effects of paclitaxel and the SET antagonist shown in current study encourage further validation of the clinical potential of this combination.

SHP-1 is a target of regorafenib in colorectal cancer

Regorafenib is an inhibitor of multiple protein kinases which exerts antitumor and antimetastatic activities in metastatic colorectal cancer (CRC). SH2 domain-containing phosphatase 1 (SHP-1) is reported to have tumor suppressive potential because it acts as a negative regulator of p-STAT3^Tyr705 signaling. However, little is known about the mechanism regarding regorafenib affects SHP-1 tyrosine phosphatase activity and leads to apoptosis and tumor suppression in CRC. Here, we found that regorafenib triggered apoptotic cell death and significantly enhanced SHP-1 activity, which dramatically decreased the phosphorylated form of STAT3 at Tyr705 (p-STAT3^Tyr705). Importantly, regorafenib augmented SHP-1 activity by direct disruption of the association between N-SH2 and catalytic PTP domain of SHP-1. Deletion of the N-SH2 domain (dN1) or point mutation (D61A) of SHP-1 blocked the effect of regorafenib-induced SHP-1 activity, growth inhibition and a decrease of p-STAT3^Tyr705 expression, suggesting that regorafenib triggers a conformational change in SHP-1 by relieving its autoinhibition. In vivo assay showed that regorafenib significantly inhibited xenograft growth and decreased p-STAT3^Tyr705 expression but induced higher SHP-1 activity. Collectively, regorafenib is a novel SHP-1 agonist exerts superior anti-tumor effects by enhancing SHP-1 activity that directly targets p-STAT3^Tyr705. Small molecule-enhancement of SHP-1 activity may be a promising therapeutic approach for CRC treatment.

A combination of sorafenib and SC-43 is a synergistic SHP-1 agonist duo to advance hepatocellular carcinoma therapy

Sorafenib is the first and currently the only standard treatment for advanced hepatocellular carcinoma (HCC). We previously developed a sorafenib derivative SC-43, which exhibits much more enhanced anti-HCC activity than sorafenib and also promotes apoptosis in sorafenib-resistant HCC cells. Herein, a novel "sorafenib plus" combination therapy was developed by coupling sorafenib treatment with SC-43. Both sorafenib and SC-43 are proven Src homology region 2 domain containing phosphatase 1 (SHP-1) agonists. The combined actions of sorafenib and SC-43 enhanced SHP-1 activity, which was associated with diminished STAT3-related signals and stronger expression of apoptotic genes above that of either drug alone, culminating in increased cell death. Decreased p-STAT3 signaling and tumor size, as well as increased SHP-1 activity were observed in mice receiving the combination therapy in a subcutaneous HCC model. More reduced orthotopic HCC tumor size and prolonged survival were also observed in mice in the combination treatment arm compared to mice in either of the monotherapy arms. These results in the preclinical setting pave the way for further clinical studies to treat unresectable HCC.

Risk of Ischemic Stroke in Patients With Gastric Cancer: A Nationwide Population-Based Cohort Study

Improvements in therapeutic modalities have prolonged the survival of gastric cancer patients. Comorbidities such as thromboembolic events that emerge as a result of disease complexities and/or treatments received have not been considered. The objectives of this study are to examine the relationship between gastric cancer and ischemic stroke, and to determine predictive risk factors. A nationwide population-based cohort study was conducted using data from the Taiwan National Health Insurance database. A total of 45,060 gastric cancer patients and non-cancer counterparts without antecedent stroke were recruited. Hazard ratios (HRs) and the cumulative incidence of ischemic stroke were calculated, and risk factors for ischemic stroke were assessed. Gastric cancer patients were associated with higher risk of ischemic stroke (HR 1.11, 95% confidence interval [CI] 1.03-1.19, P = 0.007), especially in participants younger than 65 years (HR 1.61, 95% CI 1.39-1.86, P < 0.001) and in female participants (HR 1.30, 95% CI 1.14-1.49; P < 0.001) when compared with the matched cohort. Independent risk factors of ischemic stroke in gastric cancer patients included age, hypertension, atrial fibrillation, dyslipidemia, and having received major surgery for gastric cancer. Our findings suggest the importance of stroke surveillance and prevention strategies in high-risk patients. Having received major surgery for gastric cancer is a significant risk factor in these patients.

Abstract 2924: Suppressing SET reactivates PP2A function in EGFR wide-type NSCLC and synergizes with taxol to exert anti-cancer effects

Background:

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-associated death in the world. Conventional chemotherapy is the standard-of-care for majority of patients with advance NSCLC and tyrosine kinase inhibitors of epithelial growth factor receptor (EGFR) only benefit patients with tumor containing specific mutation forms of EGFR. However, high disease recurrence rate after currently available therapeutics limited patient's survival. Therefore, there is a timely need to improve current treatment for patients with NSCLC, especially those with EGFR wide type tumors.

Protein phosphatase 2A (PP2A) is an important tumor suppression whose function is inhibited in tumor tissue by the appearance of SET. In current study, we showed that inhibiting SET binding to PP2A by a novel small molecular compound significantly improved the chemosensitivity of EGFR wide-type NSCLC cells.

Method:

EGFR wide-type NSCLC cell lines, including A549, H358 and H460, were treated with taxol and a novel quinzoline derivative, PA, which was designed and developed to interrupt the binding of SET to PP2A. Apoptosis of cancer cell, signal transduction and phosphatase activity were analyzed after treatments. Combination index (CI) was applied to determine the synergistic effects of PA and taxol. Co-immunoprecipitation (co-IP) and proximity ligation assay (PLA) were used to identify in vivo binding between SET and PP2A. In vivo anti-tumor effects of treatment containing PA and taxol were also determined in A549 xenografted mice.

Results:

After treating the cancer cells with PA and taxol, apoptosis of cancer cells, in concordance with enhancing PP2A-dependent p-Akt downregulation, were observed in a dose-dependent manner in all EGFR wide-type NSCLC cell lines. CI determined by the results of sub-G1 analysis confirmed the synergy between PA and taxol. Overexpression of Akt and inhibition of PP2A diminished the therapeutic effects of this combination. By two different strategies, co-IP and PLA, we found that this combination treatment inhibited the association of SET and PP2A within lung cancer cells. When overexpression SET in treated cancer cells, the therapeutic effects of this combination were abolished. The anti-tumor effects of treatment combining PA and taxol were also validated in A549 xenografted mice. Our data suggested that PP2A inactivation determines the drug sensitivity of taxol in lung cancer cells, and by interfering the binding of SET and PP2A, PA significantly promote PP2A activity and increase the cytotoxic effects of taxol in EGFR wide-type NSCLC.

Conclusion:

By interfering the binding of SET to PP2A, the novel PP2A enhancer, PA, is shown to reactivate PP2A and work synergistically with taxol for the treatment of EGFR wide-type NSCLC.

Citation Format: Man-Hsin Hung, Chung-Wai Shiau, Yung-Jen Hsiao, Hui-Chuan Yu, Wei-Tien Tai, Chun-Yu Liu, Cheng-Yi Wang, Kuen-Feng Chen. Suppressing SET reactivates PP2A function in EGFR wide-type NSCLC and synergizes with taxol to exert anti-cancer effects. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2924. doi:10.1158/1538-7445.AM2015-2924

Abstract 1737: Carfilzomib transcriptionally regulates CIP2A/PP2A/p-Akt signaling and induces apoptosis in leukemia cells

Background: Protein phosphatase 2A (PP2A) has been shown to be an important tumor suppressor protein and loss of PP2A function has been identified in several solid cancers and in leukemias. Recent studies have suggested strategies for enhancing PP2A activity as an anti-leukemic approach. Among the potential key players regulating PP2A, a new oncoprotein, called cancerous inhibitor of protein phosphatase 2A (CIP2A), is recently identified as a key factor in the development of malignancies in various human cells. Previously we studied novel drug mechanisms of bortezomib, a proteasome inhibitor, on acute leukemia cells. We discovered that CIP2A plays an indispensable role in mediating bortezomib-induced apoptosis in acute leukemia cells (Hematologica 2013), hepatocellular carcinoma cells (Oncogene 2010) and in breast cancer cells (Breast Cancer Research 2012). Importantly, this mechanism by bortezomib is independent to its proteasome inhibition. Carfilzomib, a more selective proteasome inhibitor than bortezomib, has shown efficacy in multiple myeloma and is being investigated in phase III clinical trials. In this study, we examined the effect of carfilzomib on CIP2A in leukemia cells.

Methods: Leukemia cell lines (HL-60, KG-1, THP-1, and K562) were used for in vitro studies. Apoptosis was examined by both flow cytometry and Western blot. Signal transduction pathways in cells were assessed by Western Blot. Quantitative RT-PCR was used for assessing gene transcription. In vivo efficacy of carfilzomib was tested in nude mice with subcutaneous leukemia xenografts.

Results: We found carfilzomib induced differential antiproliferative effects and apoptosis. HL-60, KG-1 and THP-1, but not K562 cells, were sensitive to carfilzomib-induced apoptosis. Similarly, carfilzomib-induced apoptosis may be dissociated with its proteasome inhibition. We found CIP2A mediated this apoptotic effect of carfilzomib in leukemia cells. Carfilzomib down-regulated CIP2A in association with p-Akt downregulation. Furthermore, carfilzomib increased PP2A activity and over-expression of CIP2A up-regulated p-Akt and suppressed carfilzomib-induced apoptosis. In addition, carfilzomib downregulated CIP2A mRNA but did not affect the degradation of CIP2A protein. Further dissecting the regulatory mechanism showed that carfilzomib may affect CIP2A transcription though transcriptional factors. Importantly, carfilzomib demonstrated anti-tumor activity in xenografted mice models.

Conclusions: CIP2A is a major determinant mediating carfilzomib-induced apoptosis in leukemia cells and may be a therapeutic target in leukemia. This study disclosed a novel drug mechanism of carfilzomib in leukemia cells. (Supported by Taiwan Clinical Oncology Research Foundation, MOST 103-2325-B-075-002, V103C-141; and TVGH-NTUH Joint Research Program VN103-08)

Citation Format: Chun-Yu Liu, Wen-Chun Tsai, Man-Hsin Hung, Yuan-Bin Yu, Po-Shen Ko, Cheng-Hwai Tzeng, Chung-Wai Shiau, Kuen-Feng Chen. Carfilzomib transcriptionally regulates CIP2A/PP2A/p-Akt signaling and induces apoptosis in leukemia cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1737. doi:10.1158/1538-7445.AM2015-1737

Abstract 4447: Targeting SET oncoprotein reactivates the tumor-suppressor PP2A and shows synergy with sorafenib in hepatocellular carcinoma

Background:

Hepatocellular carcinoma (HCC) is the fifth major cancer in the world. Sorafenib is the first and only approved targeted therapy for patients with advanced HCC that brought only a 3-month additive survival benefit to patient. Thus, there is an unmet need for developing effective treatment against HCC. Protein phosphatase 2A (PP2A) is an important tumor suppressor whose functions are suppressed by the presence of its cancerous inhibitor, such as SET/I2PP2A and cancerous inhibitor of PP2A (CIP2A). Previously, we’ve shown that enhancing PP2A activity by inhibiting CIP2A promotes apoptosis of HCC (Oncogene 2010, MCT 2011). Here, we report the anti-HCC potential of a new approach to reactivate PP2A by interrupting the binding between SET and PP2A.

Method:

Using the quinzoline backbone, we designed and developed a novel PP2A activator, PA. HCC cell lines were treated with PA alone or in combination with sorafenib, and apoptosis, signal transduction and phosphatse activity were analyzed. Combination index (CI) was used to evaluate the synergy of combining PA and sorafenib. Small interference RNA was applied to silence gene; co-immunoprecipitation (co-IP) and proximity ligation assay (PLA) were used to determine the association of SET and PP2A within tumor cells. In vivo anti-HCC effects of PA and combination therapy of PA and sorafenib were tested in xenografted nude mice.

Results:

PA induced apoptosis, in association with reactivation of PP2A and downregulation of p-AKT, in a dose-dependent manner in HCC cell lines (PLC5, Hep3B, SK-Hep1, Huh7). Overexpression of Akt and knockdown of PP2A abolished the anti-HCC effects of PA. Using co-IP and PLA, we found that PA interrupts the binding of SET and PP2A within HCC cells in a dose-dependent and time-dependent manner. These data indicated that inhibition of SET-associated PP2A inactivation mediated the downregulation of p-Akt and the cytotoxic effects of PA against HCC. In addition, adding PA to sorafenib significantly induced more potent cell death than sorafenib alone in all HCC cell lines tested. CI suggested good synergy between PA and sorafenib under the combination ratio of 1:5. Importantly, the anti-tumor effects of PA and PA combining with sorafenib were validated in PLC5 xenografted tumors.

Conclusion:

In the current study, we showed that interfering the binding of SET to PP2A induce potent cellular death through PP2A-dependent p-Akt downregulation. This novel approach demonstrates great potency of PP2A enhancer and its synergy with sorafenib for the treatment of HCC.

Citation Format: Man-Hsin Hung, Chung-Wai Shiau, Chih-Ting Shin, Hui-Chuan Yu, Wei-Tien Tai, Chun-Yu Liu, Cheng-Yi Wang, Kuen-Feng Chen. Targeting SET oncoprotein reactivates the tumor-suppressor PP2A and shows synergy with sorafenib in hepatocellular carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4447. doi:10.1158/1538-7445.AM2015-4447

Secondary primary malignancy risk among patients with esophageal cancer in Taiwan: a nationwide population-based study

BACKGROUND

To evaluate the risk and sites of metachronous secondary primary malignancies (SPMs) among patients with esophageal cancer.

METHODS

Newly diagnosed esophageal cancer patients between 1997 and 2011 were recruited. To avoid surveillance bias, SPMs that developed within one year were excluded. Standardized incidence ratios (SIRs) of metachronous SPMs in these patients were calculated by comparing to the cancer incidence in the general population. Risk factors for SPM development, included age, sex, comorbidities and cancer-related treatments, were estimated by Cox proportional hazards models.

RESULTS

During the 15-year study period, 870 SPMs developed among 18,026 esophageal cancer patients, with a follow-up of 27,056 person-years. The SIR for all cancers was 3.53. The SIR of follow-up period ≥ 10 years was 3.56; 5-10 years, 3.14; and 1-5 years, 3.06. The cancer SIRs of head and neck (15.83), stomach (3.30), lung and mediastinum (2.10), kidney (2.24) and leukemia (2.72), were significantly increased. Multivariate analysis showed that age ≥ 60 years (hazard ratio [HR] 0.74), being male (HR 1.46) and liver cirrhosis (HR 1.46) were independent factors. According to the treatments, major surgery (HR 1.24) increased the risk, but chemotherapy was nearly significant.

CONCLUSIONS

Patients with esophageal cancer were at increased risk of developing metachronous SPMs. The SIR remained high in follow-up > 10 years, so that close monitoring may be needed for early detection of SPM among these esophageal cancer patients.

Lymphocyte/monocyte ratio and cycles of rituximab-containing therapy are risk factors for hepatitis B virus reactivation in patients with diffuse large B-cell lymphoma and resolved hepatitis B

Reactivation of hepatitis B virus (HBV) following rituximab (R)-containing chemotherapy for lymphoma is a major concern, and risk factors remain to be defined. We enrolled 190 patients diagnosed with diffuse large B-cell lymphoma (DLBCL) and resolved hepatitis B, receiving first-line R-CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone)-based regimens. Twenty-seven patients (14.2%) developed HBV reactivation during a median follow-up of 23.6 months. Two independent risk factors were identified: cycles of rituximab>8 (hazard ratio [HR], 2.797; 95% confidence interval [CI], 1.184-6.612) and lymphocyte/monocyte ratio (LMR)<2.50 (HR, 2.733; 95% CI, 1.122-6.657). Two-year overall survival in patients with or without HBV reactivation was 53.8% vs. 77.6% (p=0.025). Regarding the negative impact on clinical outcome, patients at "super high risk" of HBV reactivation, including those receiving more than eight cycles of R and having low LMR at diagnosis, may warrant first priority for antiviral prophylaxis.

Downregulation of signal transducer and activator of transcription 3 by sorafenib: A novel mechanism for hepatocellular carcinoma therapy

Hepatocellular carcinoma is one of the most common cancers worldwide, and a leading cause of cancer-related death. Owing to unsatisfactory clinical outcomes under the current standard of care, there is a need to search for and identify novel and potent therapeutic targets to improve patient outcomes. Sorafenib is the first and only approved targeted therapy for the treatment of hepatocellular carcinoma. Besides functioning as a multiple tyrosine kinase, sorafenib also acts via a kinase-independent mechanism to target signal transducer and activator of transcription 3 (STAT3) signaling in hepatocellular carcinoma cells. STAT3 is a key regulator of inflammation, cell survival, and tumorigenesis of liver cells, and the high percentage of hepatocellular carcinoma cells with constitutively active STAT3 justifies targeting it for the development of novel therapeutics. Sorafenib inactivates STAT3 and STAT3-related signaling by inducing a conformational change in and releasing the autoinhibition of Src homology region 2 domain-containing phosphatase-1. This phosphatase negatively regulates STAT3 activity, which leads to the subsequent apoptosis of cancer cells. The novel anti-cancer property of sorafenib will be discussed in this review, not only adding information regarding its mechanism of action but also providing an innovative approach for the development of cancer therapeutics in the future.

STAT3 mediates regorafenib-induced apoptosis in hepatocellular carcinoma

PURPOSE

Here, we aim to investigate the molecular mechanism of regorafenib and verify the potential druggable target for the treatment of hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

HCC cell lines (PLC5, HepG2, Hep3B, SK-Hep1, and HA59T) were used to investigate the in vitro effect of regorafenib. Phosphatase activity was analyzed in HCC cells and purified SHP-1 proteins. PLC5-bearing mice were used to test the therapeutic efficiency of 20 and 40 mg/kg/d treatment with regorafenib ([Formula: see text] mice). The clinical relevance of STAT3 signaling was investigated with 142 tumor samples from different patients with HCC. Descriptive statistical analysis was used to compare the baseline characteristics of patients and the expression of p-STAT3.

RESULTS

Regorafenib inhibited STAT3-related signaling in a dose-dependent manner and was a more potent inhibitor of STAT3 than sorafenib. Regorafenib increased SHP-1 phosphatase activity in purified SHP-1 protein directly. N-SH2 domain deletion and D61A mutants mimicking open-form SHP-1 partially abolished regorafenib-induced STAT3 inhibition and apoptosis. Importantly, a higher level of expression of STAT3 was found in patients with advanced clinical stages (P = 0.009) and poorly differentiated tumors (P = 0.035).

CONCLUSIONS

Regorafenib induced significant tumor inhibition by relieving the autoinhibited N-SH2 domain of SHP-1 directly and inhibiting p-STAT3 signals. STAT3 may be suitable as a prognostic marker of HCC development, and may be a druggable target for HCC-targeted therapy using regorafenib.

Systemic sclerosis and the risk of tuberculosis

OBJECTIVE

Pulmonary involvement is common in patients with systemic sclerosis (SSc), and this condition causes substantial morbidity and mortality. Disrupted immunity from the disease or associated medication may render such patients subject to tuberculosis (TB) infection. However, the relationship between SSc and TB has not yet been investigated.

METHODS

Using the Taiwan National Health Insurance Research Database, 838 patients with SSc diagnosed in Taiwan during 2000-2006 were identified and followed for emergence of TB infection. Incidence rate ratios (IRR) of TB compared to 8380 randomly selected age-, sex-, and comorbidity-matched controls without SSc were calculated. The Cox proportional hazards model was used for multivariate adjustment to identify independent risk factors for TB infection.

RESULTS

The risk of TB infection was higher in the SSc cohort than in controls (IRR 2.81, 95% CI 1.36-5.37; p = 0.004), particularly for pulmonary TB (IRR 2.53, 95% CI 1.08-5.30; p = 0.022). Other independent risk factors for TB infection in patients with SSc were age ≥ 60 years [hazard ratio (HR) 3.52, 95% CI 1.10-11.33; p = 0.035] and pulmonary hypertension (PH; HR 6.06, 95% CI 1.59-23.17; p = 0.008). Mortality did not differ for SSc patients with or without TB.

CONCLUSION

In this nationwide study, the incidence of TB infection was significantly higher among patients with SSc than in controls without SSc. Special care should be taken in managing patients with SSc who are at high risk for TB, especially those aged ≥ 60 years or who also have PH.

Atopic dermatitis and risk of ischemic stroke: a nationwide population-based study

BACKGROUND

Epidemiological studies have shown a strong association between systemic inflammatory diseases, particularly allergic diseases, and cardiovascular diseases. However, the relationship between atopic dermatitis (AD) and ischemic stroke remains unclear.

METHOD

The study identified 20,323 AD patients and 20,323 comorbidity-matched subjects between 2005 and 2008. The two cohorts were followed until 31 December 2009. Ischemic stroke and other cardiovascular events were determined.

RESULTS

During the follow-up period, 301 (1.48%) patients in the AD cohort and 228 (1.12%) matched subjects experienced ischemic stroke. After multivariate adjustment, patients with AD had a 1.33-fold (95% confidence interval (CI), 1.12-1.59; P = 0.001) increased incidence of ischemic stroke. Adjusted hazard ratios for the risk of ischemic stroke in patients with mild, moderate, and severe AD were 1.20 (95% CI, 1.00-1.45; P = 0.052), 1.64 (95% CI, 1.23-2.19; P = 0.001), and 1.71 (95% CI, 1.15-2.56; P = 0.008), respectively. The log-rank test showed a higher cumulative incidence of ischemic stroke in the severe AD group than in the moderate and mild AD groups during the follow-up period (P < 0.001).

CONCLUSIONS

AD may be an independent risk factor for ischemic stroke, and risk of ischemic stroke increases with AD severity.

Cancer risk among patients with coal workers' pneumoconiosis in Taiwan: a nationwide population-based study

This study is aimed to evaluate the cancer risk among patients with coal workers' pneumoconiosis (CWP) using a nationwide population-based dataset. Patients without previous cancer who had been diagnosed with CWP and followed-up for more than 1 year between 1997 and 2006 were recruited from the Taiwan National Health Insurance database. Standardized incidence ratios (SIRs) of cancers in CWP patients were calculated and compared to the cancer incidence in the general population. Risk factors for cancer development were also analyzed. After a median follow-up of 9.68 years, 954 cancers developed among 8,051 recruited CWP patients, with a follow-up of 69,398 person-years. The SIR for all cancers was 1.12 [95% confidence interval (CI) 1.04-1.18]. Males older than 80 years had a SIR of 1.27 (95% CI: 1.06-1.51). The SIRs of esophageal (1.76, 95% CI: 1.24-2.44), gastric (1.42, 95% CI: 1.13-1.76), liver and biliary tract (1.18, 95% CI: 1.01-1.37) and lung and mediastinal (1.45, 95% CI: 1.26-1.66) cancers were significantly higher in the CWP group than in the general population. Multivariate analysis showed that age ≥ 60 years [hazard ratio (HR) 1.70, 95% CI: 1.41-2.05), male gender (HR = 1.79, 95% CI: 1.44-2.23) and liver cirrhosis (HR = 3.99, 95% CI: 2.89-5.51) were significant predictors of cancer development in patients with CWP. We concluded that patients with CWP, especially elderly males, were at increased risk of cancer. Age, male gender and liver cirrhosis were independent risk factors for cancer development.

Effect of age and biological subtype on the risk and timing of brain metastasis in breast cancer patients

BACKGROUND

Brain metastasis is a major complication of breast cancer. This study aimed to analyze the effect of age and biological subtype on the risk and timing of brain metastasis in breast cancer patients.

PATIENTS AND METHODS

We identified subtypes of invasive ductal carcinoma of the breast by determining estrogen receptor, progesterone receptor and HER2 status. Time to brain metastasis according to age and cancer subtype was analyzed by Cox proportional hazard analysis.

RESULTS

Of the 2248 eligible patients, 164 (7.3%) developed brain metastasis over a median follow-up of 54.2 months. Age 35 or younger, HER2-enriched subtype, and triple-negative breast cancer were significant risk factors of brain metastasis. Among patients aged 35 or younger, the risk of brain metastasis was independent of biological subtype (P = 0.507). Among patients aged 36-59 or >60 years, those with triple-negative or HER2-enriched subtypes had consistently increased risk of brain metastasis, as compared with those with luminal A tumors. Patients with luminal B tumors had higher risk of brain metastasis than luminal A only in patients >60 years.

CONCLUSIONS

Breast cancer subtypes are associated with differing risks of brain metastasis among different age groups. Patients age 35 or younger are particularly at risk of brain metastasis independent of biological subtype.

The risk of cancer in patients with benign anal lesions: a nationwide population-based study

OBJECTIVE

To evaluate the risk of cancer among patients diagnosed with hemorrhoids and benign anal inflammatory lesions.

METHODS

A population-based, retrospective cohort study was conducted that included patients diagnosed with hemorrhoids or benign inflammatory anal lesions (eg, anal fissure, fistula, and perianal abscesses) that were registered in the National Health Insurance Research Database in Taiwan between January 1, 2000 and December 31, 2010. Standardized incidence ratios (SIRs) were calculated to compare the cancer incidence of these patients to the general population.

RESULTS

During a median observation period of 6.23 years, 3080 cancers developed among 70,513 hemorrhoid patients, with a follow-up period of 438,425.6 person-years, entailing the SIR of 1.52 (95% confidence interval [CI], 1.47-1.58). Increased cancer risk (SIR 1.16; 95% CI, 1.11-1.21) was still noted even after excluding the first year of observation. Significant long-term risk for colorectal cancer (SIR 1.50; 95% CI, 1.35-1.66) and prostate cancer (SIR 1.40; 95% CI, 1.17-1.66) was observed after corrections were made for multiple comparisons. In contrast, there was no remarkable increase in cancer risk for patients with inflammatory anal lesions when cancers detected within the first year of diagnosis were excluded.

CONCLUSION

The presence of hemorrhoids is associated significantly with a long-term risk of developing colorectal cancer or prostate cancer. In contrast, benign inflammatory anal lesions do not appear to increase the risk of malignancy.

Absolute lymphocyte count predicts response to rituximab-containing salvage treatment for relapsed/refractory B-cell non-Hodgkin's lymphoma with prior rituximab exposure

BACKGROUND

Rituximab-containing salvage chemotherapy has shown promising efficacy in patients with relapsed/refractory B-cell non-Hodgkin's lymphoma (NHL). The aim of this study was to examine the efficacy of rituximab-containing treatment in patients with B-cell NHL who developed relapsed or refractory disease after prior rituximab use and to explore the predictive factors of response using this approach.

METHODS

Patients with relapsed/refractory B-cell NHL who received rituximab-containing salvage treatment after failing first-line rituximab-combining chemotherapy were enrolled in this retrospective study. The characteristics of the patients were collected and analyzed. Logistic regression analysis was used for determining predictive factors of response to rituximab-containing salvage treatment.

RESULTS

A total of 68 patients were enrolled in this study and the overall response rate to rituximab-containing salvage treatment was 61.7%. The median event-free survival and overall survival with rituximab-containing salvage treatment was 11.3 and 21.73 months, respectively. Results of a multivariate analysis showed high absolute lymphocyte count at the time of rituximab-containing salvage treatment [(ALC-R), ALC-R ≥ 1000/UL, p = 0.003)], which was the only independent factor predicting response to rituximab-containing salvage treatment.

CONCLUSION

Our study results show that for patients with relapsed/refractory B-cell NHL, rituximab-containing salvage treatment is feasible and generally tolerable. A high ALC-R value was significantly associated with a better response to this treatment.

Incidence and risk of mood disorders in patients with breast cancers in Taiwan: a nationwide population-based study

OBJECTIVE

The objective of this study is to assess the incidence and risk of mood disorders, including major depression, anxiety, and bipolar disorders, in Taiwanese patients after the diagnosis of breast cancer compared with a matched cohort.

METHODS

From January 2000 to December 2005, 26,629 newly diagnosed breast cancer patients were enrolled by the Taiwan National Health Insurance program database. The control cohort was selected randomly from 1,000,000 National Health Insurance beneficiaries from a population of 21,400,826 enrolled throughout Taiwan. Each patient was matched with one subject without breast cancer by age, sex, and presence of comorbidities with the same diagnosis index date. The diagnosis of mood disorders was defined by compatible International Classification of Diseases, 9th revision, clinical modification codes plus the prescription of antidepressants for at least 30 days.

RESULTS

The overall incidence rate ratio of mood disorders was 1.33 (95% CI 1.28-1.39, p < 0.001) in the breast cancer cohort compared with the matched cohort. The incidence rate ratios for specific mood disorders were 2.06 for bipolar disorder (95% CI 1.37-3.15 p = 0.0003), 1.94 for major depressive disorder (95% CI 1.76-2.13 p < 0.001), and 1.22 for anxiety (95% CI 1.16-1.27 p < 0.001). Independent risk factors for developing mood disorders included breast cancer, as well as age, hypertension, chronic obstructive pulmonary disease, autoimmune disease, ischemic heart disease, and cerebrovascular disease.

CONCLUSIONS

Breast cancer is a prominent risk factor for mood disorders, including major depressive disorder, anxiety, and bipolar disorder. The impact is most potent in the first year after diagnosis. Psychological support is a critical issue in these patients.

The risk of cancer in patients with generalized anxiety disorder: a nationwide population-based study

OBJECTIVE

To evaluate the risk of cancer among patients with generalized anxiety disorder (GAD) in a nationwide population-based dataset.

METHODS

We recruited newly-diagnosed GAD patients aged 20 years or older without antecedent cancer from the Taiwan National Health Insurance Research database between 2000-2010. Standardized incidence ratios (SIRs) of cancers were calculated in GAD patients, and the subgroup of GAD patients diagnosed by psychiatric specialists.

RESULTS

A total of 559 cancers developed among 19,793 GAD patients with a follow-up of 89,485 person-years (median follow-up of 4.34 years), leading to a significantly increased SIR of 1.14 [95% confidence interval (CI) 1.05-1.24]. Male GAD patients had a significantly increased SIR overall (1.30, 95% CI 1.15-1.46) and for lung and prostate cancer (1.77, 95% CI 1.33-2.30 and 2.17, 95% CI 1.56-2.93, respectively). Patients over 80 years of age also had a significantly increased SIR (1.56, 95% CI 1.25-1.92), especially in males. However, psychiatrist-diagnosed GAD patients did not show increased cancer risk relative to the general population, perhaps due to having fewer physical comorbidities than non-psychiatrist-diagnosed GAD patients.

CONCLUSION

This study found that overall cancer risk is elevated among patients with GAD. The risk of lung and prostate cancer also increased in male patients with GAD. This increased cancer risk may be due to physical comorbidities and surveillance bias. Further prospective study is necessary to confirm these findings.

Efficient formulation of the force distribution equations for general tree-structured robotic mechanisms with a mobile base

In this paper, an efficient and systematic formulation of the force distribution equations for general tree-structured robotic mechanisms is presented. The applicable platforms include not only systems with star topologies, such as walking machines that have multiple legs with a single body but also general tree-structured mechanisms, such as variably configured wheeled vehicles having multiple modules. The force balance equations that govern the relationship between the contact forces and the resultant inertial forces/moments of the vehicle will be derived through a recursive and computationally efficient algorithm. Also, the joint torque constraints that specify the joint actuator limits, and contact friction constraints that may be used to avoid slippage and maintain contact, are efficiently incorporated in the formulation. Based on this formulation, several standard optimization techniques, such as linear programming or quadratic programming, can be applied to obtain the solution. An algorithm summarizing the results developed, and suitable for computer implementation, is included. The algorithm has been applied to an n-module actively articulated wheeled vehicle, and the computational cost evaluated. The efficiency of the algorithm is demonstrated with results showing real-time execution on a Pentium PC.

The conditional probabilities of survival in patients with anaplastic astrocytoma or glioblastoma multiforme

BACKGROUND

By the use of conditional probabilities of survival, we studied the yearly survival rates for individual tumor survivors.

METHODS

Conditional survival rate was estimated in 114 consecutive patients with anaplastic astrocytoma or glioblastoma multiforme. Conditional probabilities of surviving some years given survival to a specific period of time after craniotomy and 95% confidence intervals were calculated in the individual tumor survivors.

RESULTS

The estimated median survival was 30 months for 45 patients with anaplastic astrocytoma and 12 months for 69 patients with glioblastoma multiforme. The conditional probabilities of surviving next one year given survival to 1 year, 2 years, 3 years, 4 years, or 5 years after craniotomy for anaplastic astrocytoma were 86.2%, 75.0%, 85.9%, 77.8%, or 85.7%, respectively; for glioblastoma multiforme 64.8%, 58.7%, 85.7%, 80.0%, or 75.0%, respectively. The conditional probability of surviving to 5 years given survival to 2 years after craniotomy for anaplastic astrocytoma, i.e., surviving an additional 3 years, was 50.1%, which was better than observed 5-year survival rate (28.6%); for glioblastoma multiforme it was 40.2%, which also was better than observed 5-year survival rate (12.4%).

CONCLUSIONS

The conditional probability of survival was a good method to clinically predict yearly survival rate for individual tumor survivors. In addition, the method can estimate the probabilities of surviving next some years given survival to a specific period of time after craniotomy. It also showed a more encouraging result than observed survival rate in patients with supratentorial malignant astrocytomas.