Browsing by Author "Zhao, Hui"
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Item Adherence to treatment guidelines and survival for older patients with stage II or III colon cancer in Texas from 2001 through 2011(Wiley, 2018) Zhao, Hui; Zhang, Ning; Ho, Vivian; Ding, Minming; He, Weiguo; Niu, Jiangong; Yang, Ming; Du, Xianglin; Zorzi, Daria; Chavez-MacGregor, Mariana; Giordano, Sharon H.BACKGROUND: Treatment guidelines for colon cancer recommend colectomy with lymphadenectomy of at least 12 lymph nodes for patients with stage I to stage III disease as surgery adherence (SA) and adjuvant chemotherapy for individuals with stage III disease. Herein, the authors evaluated adherence to these guidelines among older patients in Texas with colon cancer and the associated survival outcomes. METHODS: Using Texas Cancer Registry data linked with Medicare data, the authors included patients with AJCC stage II and III colon cancer who were aged ?66 years and diagnosed between 2001 and 2011. SA and adjuvant chemotherapy adherence rates to treatment guidelines were estimated. The chi-square test, general linear regression, survival probability, and Cox regression were used to identify factors associated with adherence and survival. RESULTS: The rate of SA increased from 47.2% to 84% among 6029 patients with stage II or stage III disease from 2001 to 2011, and the rate of adjuvant chemotherapy increased from 48.9% to 53.1% for patients with stage III disease during the same time period. SA was associated with marital status, tumor size, surgeon specialty, and year of diagnosis. Patient age, sex, marital status, Medicare state buy-in status, comorbidity status, and year of diagnosis were found to be associated with adjuvant chemotherapy. The 5-year survival probability for patients receiving guideline-concordant treatment was the highest at 87% for patients with stage II disease and was 73% for those with stage III disease. After adjusting for demographic and tumor characteristics, improved cancer cause-specific survival was associated with the receipt of stage-specific, guideline-concordant treatment for patients with stage II or stage III disease. CONCLUSIONS: The adherence to guideline-concordant treatment among older patients with colon cancer residing in Texas improved over time, and was associated with better survival outcomes. Future studies should be focused on identifying interventions to improve guideline-concordant treatment adherence.Item Regional differences in recommended cancer treatment for the elderlyHo, Vivian; Ku-Goto, Meei-Hsiang; Zhao, Hui; Hoffman, Karen E.; Smith, Benjamin D.; Giordano, Sharon H.; James A. Baker III Institute for Public PolicyAbstract Background Little is known about regional variation in cancer treatment and its determinants. We compare rates of adherence to treatment guidelines for elderly patients across Texas and whether local specialist supply is an important determinant of treatment variation. Methods Previous literature reviewed indicated 7 recommended courses of treatment for colorectal, pancreatic, and prostate cancer. We analyzed Texas Cancer Registry data linked with Medicare claims for the years 2004 to 2007 to study patients with these cancers. We tested for unadjusted and adjusted differences in treatment rates across 22 hospital referral regions (HRR). We tested whether variation in the local supply of specialists treating each cancer was an important determinant of treatment. Results We found significant differences in adjusted treatment rates across regions. For removal and examination of 12+ lymph nodes with colon cancer resection, 13 of 22 HRRs had rates significantly different from the median region. For adjuvant chemotherapy for regional colon cancer, five HRRs significantly differed from the median. For prostate cancer treatment with a favorable diagnosis, nine HRRs differed from the median HRR. Of the 7 treatments, only the local availability of surgeons was an important determinant for excision of lymph nodes for colon cancer patients. Conclusions There are significant variations across Texas for seven recommended cancer treatments. No one region has consistently higher or lower treatments than other regions, and local specialist supply is not an important predictor of treatment. Different factors may be determining regional variation in treatment rates across cancer types and treatment options.Item Second harmonic microscopy of monolayer MoS2(American Physical Society, 2013) Kumar, Nardeep; Najmaei, Sina; Cui, Qiannan; Ceballos, Frank; Ajayan, Pulickel M.; Lou, Jun; Zhao, HuiWe show that the lack of inversion symmetry in monolayer MoS2 allows strong optical second harmonic generation. The second harmonic of an 810-nm pulse is generated in a mechanically exfoliated monolayer, with a nonlinear susceptibility on the order of 10−7 m/V. The susceptibility reduces by a factor of seven in trilayers, and by about two orders ofmagnitude in even layers. A proof-of-principle second harmonicmicroscopymeasurement is performed on samples grown by chemical vapor deposition, which illustrates potential applications of this effect in the fast and noninvasive detection of crystalline orientation, thickness uniformity, layer stacking, and single-crystal domain size of atomically thin films of MoS2 and similar materials.