987 resultados para Epidemiology. Cancer
Resumo:
Objective: The primary objective of this project was to describe the efficacy of the Levonorgestrel Intrauterine Device (LIUD) for treatment of Complex Endometrial Cancer (CAH) and Grade 1 Endometrial Cancer (G1EEC) in terms of rate of Complete Response (CR) and Partial Response (PR) after 6 months of therapy. Finally, we assessed if any clinical or pathologic features were associated with response to the LIUD. ^ Methods: This study was a retrospective case series designed to report the response rate of patients with CAH or G1EEC treated with LIUD therapy. In addition, this study has a laboratory component to assess molecular predictors of response to LIUD therapy. Retrospective data already collected from patients diagnosed with CAH or EEC grade 1 and treated with LIUD therapy at MD Anderson Cancer Center (MDACC) were used for this study. Patients from all ethnic and race groups were included. A Complete Response (CR) was defined in patients diagnosed with CAH if pathologic report at 6 months demonstrated either no evidence of hyperplasia or no atypia in the setting of simple or complex hyperplasia. Partial Response (PR) was recorded if disease downgraded to only CAH from G1EEC. No Response (NR) was recorded if pathologic report demonstrates no change (Stable Disease, SD) or progression to cancer (Progressive Disease, PD). We calculated the proportion of patients with complete response to LIUD therapy with 95% confidence interval. We compared the response rates (CR/PR vs NR) by obesity status (Obese if BMI > 40 kg/m2 vs non-obese if BMI <= 40 kg/m2) as well as other clinical and pathologic factors, such as age, uterine size (median size), and presence of exogenous progesterone effect. ^ Results: There were 39 patients diagnosed with either CAH or G1EEC treated with the LIUD. Of 39 patients, 12 did not have pathological results of biopsy at 6months time period. Of 27 evaluable patients, 17 were diagnosed with CAH and 10 with G1EEC. Overall response rate (RR) was 78% (95% CI = 62-94%) at 6 months, 18 patients had CR (4 in G1EEC; 14 in CAH), 3 patients had PR (3 in G1EEC), 3 had SD (1 in CAH; 2 in G1EEC), 3 had PD (2 in CAH; 1 in G1EEC). After histology stratification, RR at 6 months was 82.35% (14/17; 95%CI = 67.4-97.3%) in CAH and 70% (7/10; 95% CI = 41-98.4%) in G1EEC. ^ There was no difference in response (R) and no response (NR) based on BMI (p=0.56). He observed a trend showing association between age with response (p=0.1). There was no association between uterine size and response to therapy (p=0.17). We recorded strong association between exogenous progesterone effect and response. ^ Conclusion: LIUD therapy for the treatment of CAH and G1EEC may be effective and safe. Presence of exogenous progesterone effect may predict the response to LIUD therapy at earlier time points. There is need of further studies with larger sample size to explore the relationship of response with other clinical and pathologic factors^
Resumo:
Background: The follow-up care for women with breast cancer requires an understanding of disease recurrence patterns and the follow-up visit schedule should be determined according to the times when the recurrence are most likely to occur, so that preventive measure can be taken to avoid or minimize the recurrence. Objective: To model breast cancer recurrence through stochastic process with an aim to generate a hazard function for determining a follow-up schedule. Methods: We modeled the process of disease progression as the time transformed Weiner process and the first-hitting-time was used as an approximation of the true failure time. The women's "recurrence-free survival time" or a "not having the recurrence event" is modeled by the time it takes Weiner process to cross a threshold value which represents a woman experiences breast cancer recurrence event. We explored threshold regression model which takes account of covariates that contributed to the prognosis of breast cancer following development of the first-hitting time model. Using real data from SEER-Medicare, we proposed models of follow-up visits schedule on the basis of constant probability of disease recurrence between consecutive visits. Results: We demonstrated that the threshold regression based on first-hitting-time modeling approach can provide useful predictive information about breast cancer recurrence. Our results suggest the surveillance and follow-up schedule can be determined for women based on their prognostic factors such as tumor stage and others. Women with early stage of disease may be seen less frequently for follow-up visits than those women with locally advanced stages. Our results from SEER-Medicare data support the idea of risk-controlled follow-up strategies for groups of women. Conclusion: The methodology we proposed in this study allows one to determine individual follow-up scheduling based on a parametric hazard function that incorporates known prognostic factors.^
Resumo:
Background: No studies have attempted to determine whether nodal surgery utilization, time to initiation and completion of chemotherapy or surveillance mammography impact breast cancer survival. ^ Objectives and Methods: To determine whether receipt of nodal surgery, initiation and completion of chemotherapy, and surveillance mammography impact of racial disparities in survival among breast cancer patients in SEER areas, 1992-2005. ^ Results: Adjusting for nodal surgery did not reduce racial disparities in survival. Patients who initiated chemotherapy more than three months after surgery were 1.8 times more likely to die of breast cancer (95% CI 1.3-2.5) compared to those who initiated chemotherapy less than a month after surgery, even after controlling for known confounders or controlling for race. Despite correcting for chemotherapy initiation and completion and known predictors of outcome, African American women still had worse disease specific survival than their Caucasian counterparts. We found that non-whites underwent surveillance mammography less frequently compared with whites and mammography use during a one- or two-year time interval was associated with a small reduced risk of breast-cancer-specific and all-cause mortality. Women who received a mammogram during a two-year interval could expect the same disease-specific survival benefit or overall survival benefit as women who received a mammogram during a one-year interval. We found that while adjustment for surveillance mammography receipt and physician visits reduced differences in mortality between blacks and whites, these survival disparities were eliminated after adjusting for the number of surveillance mammograms received. ^ Conclusions: The disparities in survival among African American and Hispanic women with breast cancer are not explained by nodal surgery utilization or chemotherapy initiation and chemotherapy completion. Surveillance mammograms, physician visits and number of mammograms received may play a major role in achieving equal outcomes for breast cancer-specific mortality for women diagnosed with primary breast cancer. Racial disparities in all-cause mortality were explained by racial differences in surveillance mammograms to certain degree, but were no longer significant after controlling for differences in comorbidity. Focusing on access to quality care and post treatment surveillance might help achieve national goals to eliminate racial disparities in healthcare and outcomes. ^
Resumo:
Background: Inflammatory breast cancer (IBC) is rare and accounts for 2.5% of all invasive breast cancers. The 5-year survival rates are significantly lower than for other types of breast cancer, highlighting the significance of cancer prevention in IBC. The comprehensive multi-disciplinary team Morgan Welch Inflammatory Breast Cancer Research Program and Clinic at University of Texas MD Anderson Cancer Center treats the largest number of Inflammatory Breast patients in a single center. Because of this unique center, large patient resources, and good medical and epidemiological records, we were able to conduct the largest single center case-control and case-case study on IBC. Methods: We identified 246 patients diagnosed with IBC and 397 cancer free patients seen at the Dan L Duncan Cancer Prevention Clinic. Breast cancer reproductive risk factors and lifestyle risk factors were compared between tumor subtypes of IBC patients (Estrogen Receptor positive (ER+) and/or Progesterone Receptor positive (PR+), Human Epidermal Growth Factor 2 positive (HER2+)), and (ER -/PR-/HER2-)) and cancer free controls. Results: Breastfeeding was the only significant risk factor (p<0.01) between tumor subtypes in IBC patients. In the case-control study that included all IBC patients and cancer free patients the descriptive statistics indicate significant difference in BMI, history of smoking, number of children, age of first pregnancy, any breastfeeding and total time breastfeeding (p<0.05). No differences were found in the frequency of other breast cancer risk factors. Conclusion: The associations determined between cancer free controls and IBC patients have identified previously unknown risk factors for IBC. The risk factors identified by the case control study suggest BMI, history of smoking, and the protective effect of breastfeeding as potential modifiable risk factors that can be used to decrease the incidence of IBC. Impact: These results highlight the importance of evaluating epidemiologic risk factors of IBC, which could lead to the identification of distinct etiologic pathways that could be targeted for prevention.^
Resumo:
This thesis project is motivated by the potential problem of using observational data to draw inferences about a causal relationship in observational epidemiology research when controlled randomization is not applicable. Instrumental variable (IV) method is one of the statistical tools to overcome this problem. Mendelian randomization study uses genetic variants as IVs in genetic association study. In this thesis, the IV method, as well as standard logistic and linear regression models, is used to investigate the causal association between risk of pancreatic cancer and the circulating levels of soluble receptor for advanced glycation end-products (sRAGE). Higher levels of serum sRAGE were found to be associated with a lower risk of pancreatic cancer in a previous observational study (255 cases and 485 controls). However, such a novel association may be biased by unknown confounding factors. In a case-control study, we aimed to use the IV approach to confirm or refute this observation in a subset of study subjects for whom the genotyping data were available (178 cases and 177 controls). Two-stage IV method using generalized method of moments-structural mean models (GMM-SMM) was conducted and the relative risk (RR) was calculated. In the first stage analysis, we found that the single nucleotide polymorphism (SNP) rs2070600 of the receptor for advanced glycation end-products (AGER) gene meets all three general assumptions for a genetic IV in examining the causal association between sRAGE and risk of pancreatic cancer. The variant allele of SNP rs2070600 of the AGER gene was associated with lower levels of sRAGE, and it was neither associated with risk of pancreatic cancer, nor with the confounding factors. It was a potential strong IV (F statistic = 29.2). However, in the second stage analysis, the GMM-SMM model failed to converge due to non- concaveness probably because of the small sample size. Therefore, the IV analysis could not support the causality of the association between serum sRAGE levels and risk of pancreatic cancer. Nevertheless, these analyses suggest that rs2070600 was a potentially good genetic IV for testing the causality between the risk of pancreatic cancer and sRAGE levels. A larger sample size is required to conduct a credible IV analysis.^
Resumo:
Colorectal cancer (CRC) is the third leading cancer in both incidence and mortality in Texas. This study investigated the adherence of CRC treatment to standard treatment guidelines and the association between standard treatment and CRC survival in Texas. The author used Texas Cancer Registry (TCR) and Medicare linked data to study the CRC treatment patterns and factors associated with standard treatment in patients who were more than 65 years old and were diagnosed in 2001 through 2007. We also determined whether adherence to standard treatment affect patients' survival. Multiple logistic regression and Cox regression analysis were used to analyze our data. Both regression models are adjusted for demographic characteristics and tumor characteristics. We found that for the 3977 regional colon cancer patients 80 years old or younger, 60.2% of them received chemotherapy, in adherence to the recommended treatment guidelines. People with younger age, female gender, higher education and lower comorbidity score are more likely adherent to this surgery guideline. Patients' adherence to chemotherapy in this cohort have better survival compared to those who are not (HR: 0.76, 95% CI: 0.68-0.84). For the 12709 colon cancer patients treated with surgery, 49.3% have more than 12 lymph nodes removed, in adherence to the treatment guidelines. People with younger age, female gender, higher education, regional stage, lager tumor size and lower comorbidity score are more likely to adherent to this surgery guideline. Patients with more than 12 lymph nodes removed in this cohort have better survival (HR: 0.86, 95% CI: 0.82-0.91). For the 1211 regional rectal cancer patients 80 years old or younger, 63.2% of them were adherent to radiation treatment. People with smaller tumor size and lower comorbidity score are more likely to adherent to this radiation guideline. There is no significant survival difference between radiation adherent patients and non-adherent patients (HR: 1.03, 95% CI: 0.82-1.29). For the 1122 regional rectal cancer patients 80 years old or younger who were treated with surgery, 76.0% of them received postoperative chemotherapy, in adherence to the treatment guidelines. People with younger age and smaller comorbidity score are related with higher adherence rate. Patients adherent with adjuvant chemotherapy in this cohort have better survival than those were not adherent (HR: 0.60, 95% CI: 0.45-0.79).^
Resumo:
Introduction: The average age of onset of breast cancer among Hispanic women is 50 years, more than a decade earlier than non-Hispanic white women. Age at diagnosis is an important prognostic factor for breast cancer; younger age at onset is more likely to be associated with advanced disease, poorer prognosis, hormone receptor negative breast tumors, and a greater likelihood of hereditary breast cancer. Studies of breast cancer risk factors including reproductive risk factors, family history of breast cancer, and breast cancer subtype have been conducted predominately in non-Hispanic whites. Breast cancer is a heterogeneous disease with the presence of clinically, biologically, and epidemiologically distinct subtypes that also differ with respect to their risk factors. The associations between reproductive risk factors and family history of breast cancer have been well documented in the literature. However, only a few studies have assessed these associations with breast cancer subtype in Hispanic populations. Methods: To assess the associations between reproductive risk factors and family history of breast cancer we conducted three separate studies. First, we conducted a case-control study of 172 Mexican-American breast cancer cases and 344 age matched controls residing in Harris County, TX to assess reproductive and other risk factors. We conducted logistic regression analysis to assess differences in cases and controls adjusted for age at diagnosis and birthplace and then we conducted a multinomial logistic regression analysis to compare reproductive risk factors among the breast tumor subtypes. In a second study, we identified 139 breast cancer patients with a first- or second-degree family history of breast cancer and 298 without a family history from the ELLA Bi-National Breast Cancer Study. In this analysis, we also computed a multinomial logistic regression to evaluate associations between family history of breast cancer and breast cancer subtypes, and logistic regression to estimate associations between breast cancer screening practices with family history of breast cancer. In the final study, we employed a cross-sectional study design in 7279 Mexican-American women in the Mano a Mano Cohort Study. We evaluated associations with family history of breast cancer and breast cancer risk factors including body mass index (BMI), lifestyle factors, migration history, and adherence to American Cancer Society (ACS) guidelines. Results: In the results of our first analyses, reproductive risk factors differed in the magnitude and direction of associations when stratified by age and birthplace among cases and controls. In our second study, family history of breast cancer, and having at least one relative diagnosed at an early age (<50 years) was associated with triple negative breast cancer (TNBC). Mammography prior to receiving a breast cancer diagnosis was associated with family history of breast cancer. In our third study that assessed lifestyle factors, migration history and family history of breast cancer; we found that women with a first-degree family history of breast cancer were more overweight or obese compared with their counterparts without a family history. There was no indication that having a family history contributed to women practicing healthier lifestyle behaviors and/or adhering to the ACS guidelines for cancer prevention. Conclusions: We observed that among Mexican-American women, reproductive risk factors were associated with breast cancer where the woman was born (US or Mexico). Having a family history of breast cancer, especially having either a first- or second-degree relative diagnosed at a younger age, was strongly associated with TNBC subtype. These results are consistent with other published studies in this area. Further, our results indicate that women with strong family histories of breast cancer are more likely to undertake mammography but not to engage in healthier lifestyle behaviors.^
Resumo:
Peer reviewed
Resumo:
"June 1979."
Resumo:
NIH publication no. 92-3330.
Resumo:
Shipping list no: 94-0140-P.
Resumo:
Item 507-L
Resumo:
"09/00"--Colophon.
Resumo:
"Prepared by Therese A. Dolecek, Tiefu Shen, Janice L. Snodgrass"--P. [leaf 2 ].
Resumo:
Data derived from the Surveillance, Epidemiology, and End Results (SEER) Program and the National Center for Health Statistics.