Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Stephen S. Cha is active.

Publication


Featured researches published by Stephen S. Cha.


Circulation | 2006

Secular Trends in Incidence of Atrial Fibrillation in Olmsted County, Minnesota, 1980 to 2000, and Implications on the Projections for Future Prevalence

Yoko Miyasaka; Marion E. Barnes; Bernard J. Gersh; Stephen S. Cha; Kent R. Bailey; Walter P. Abhayaratna; James B. Seward; Teresa S.M. Tsang

Background— Limited data exist on trends in incidence of atrial fibrillation (AF). We assessed the community-based trends in AF incidence for 1980 to 2000 and provided prevalence projections to 2050. Methods and Results— The adult residents of Olmsted County, Minnesota, who had ECG-confirmed first AF in the period 1980 to 2000 (n=4618) were identified. Trends in age-adjusted incidence were determined and used to construct model-based prevalence estimates. The age- and sex-adjusted incidence of AF per 1000 person-years was 3.04 (95% CI, 2.78 to 3.31) in 1980 and 3.68 (95% CI, 3.42 to 3.95) in 2000. According to Poisson regression with adjustment for age and sex, incidence of AF increased significantly (P=0.014), with a relative increase of 12.6% (95% CI, 2.1 to 23.1) over 21 years. The increase in age-adjusted AF incidence did not differ between men and women (P=0.84). According to the US population projections by the US Census Bureau, the number of persons with AF is projected to be 12.1 million by 2050, assuming no further increase in age-adjusted incidence of AF, but 15.9 million if the increase in incidence continues. Conclusions— The age-adjusted incidence of AF increased significantly in Olmsted County during 1980 to 2000. Whether or not this rate of increase continues, the projected number of persons with AF for the United States will exceed 10 million by 2050, underscoring the urgent need for primary prevention strategies against AF development.


The New England Journal of Medicine | 1991

Effective Surgical Adjuvant Therapy for High-Risk Rectal Carcinoma

James E. Krook; Charles G. Moertel; Leonard L. Gunderson; Harry S. Wieand; Roger T. Collins; Robert W. Beart; Theodore P. Kubista; Michael A. Poon; William C. Meyers; James A. Mailliard; Donald I. Twito; Roscoe F. Morton; Michael H. Veeder; Thomas E. Witzig; Stephen S. Cha; Subhash C. Vidyarthi

BACKGROUND Radiation therapy as an adjunct to surgery for rectal cancer has been shown to reduce local recurrence but has not improved survival. In a previous study, combined radiation and chemotherapy improved survival significantly as compared with surgery alone, but not as compared with adjuvant radiation, which many regard as standard therapy. We designed a combination regimen to optimize the contribution of chemotherapy, decrease recurrence, and improve survival as compared with adjuvant radiation alone. METHODS Two hundred four patients with rectal carcinoma that was either deeply invasive or metastatic to regional lymph nodes were randomly assigned to postoperative radiation alone (4500 to 5040 cGy) or to radiation plus fluorouracil, which was both preceded and followed by a cycle of systemic therapy with fluorouracil plus semustine (methyl-CCNU). RESULTS After a median follow-up of more than seven years, the combined therapy had reduced the recurrence of rectal cancer by 34 percent (P = 0.0016; 95 percent confidence interval, 12 to 50 percent). Initial local recurrence was reduced by 46 percent (P = 0.036; 95 percent confidence interval, 2 to 70 percent), and distant metastasis by 37 percent (P = 0.011; 95 percent confidence interval, 9 to 57 percent). In addition, combined therapy reduced the rate of cancer-related deaths by 36 percent (P = 0.0071; 95 percent confidence interval, 14 to 53 percent) and the overall death rate by 29 percent (P = 0.025; 95 percent confidence interval, 7 to 45 percent). Its acute toxic effects included nausea, vomiting, diarrhea, leukopenia, and thrombocytopenia. These effects were seldom severe. Severe, delayed treatment-related reactions, usually small-bowel obstruction requiring surgery, occurred in 6.7 percent of all patients receiving radiation, and the frequencies of these complications were comparable in both treatment groups. CONCLUSIONS The combination of postoperative local therapy with radiation plus fluorouracil and systemic therapy with a fluorouracil-based regimen significantly and substantively improves the results of therapy for rectal carcinoma with a poor prognosis, as compared with postoperative radiation alone.


The New England Journal of Medicine | 2014

Medication-Assisted Therapies — Tackling the Opioid-Overdose Epidemic

Nora D. Volkow; Thomas R. Frieden; Pamela S. Hyde; Stephen S. Cha

Deeming prescription-opioid overdoses an epidemic, the Department of Health and Human Services is working to reduce opioid abuse while ensuring appropriate access to opioids. One key element of the solution is greater use of medication-assisted therapies for addiction.


Gynecologic Oncology | 2003

Retrospective review of 208 patients with leiomyosarcoma of the uterus: prognostic indicators, surgical management, and adjuvant therapy☆

Robert L. Giuntoli; Daniel S. Metzinger; Connie S DiMarco; Stephen S. Cha; Jeff A. Sloan; Gary L. Keeney; Bobbie S. Gostout

Abstract Objective We evaluated the predictive value of several proposed prognostic indicators and the effect of surgical management and adjuvant therapy on clinical outcome associated with leiomyosarcoma (LMS) of the uterus. Methods A medical record search of patients treated at Mayo Clinic from 1976 through 1999 was performed using the International Classification of Diseases, Ninth Revision codes for LMS and malignant neoplasm of the uterus. Study inclusion criteria included confirmation of the diagnosis of LMS of the uterus by a pathologist at our institution. Survival curves were generated using the Kaplan–Meier method. Multivariate analysis was performed using the Cox proportional hazards model. A case-control investigation was also performed. Results A total of 208 patients met study requirements. The median follow-up for survivors was 7.7 years. Multivariate analysis showed that high grade, advanced stage, and oophorectomy were associated with significantly worse disease-specific survival. Case-control investigations suggested that ovarian preservation does not adversely affect survival and that adjuvant pelvic radiation therapy does not significantly improve survival. An LMS risk-assessment index that was generated is highly predictive of survival. Conclusions Tumor grade and stage (using modified criteria for endometrial cancer) appear to be valid prognostic indicators for LMS of the uterus. Ovarian preservation may be considered in premenopausal patients with early-stage leiomyosarcoma of the uterus. Additionally, adjuvant therapy does not appear to significantly affect survival. Finally, our highly predictive LMS risk-assessment index may be useful for counseling patients.


Annals of Surgery | 2003

Curative Potential of Multimodality Therapy for Locally Recurrent Rectal Cancer

Dieter Hahnloser; Heidi D. Nelson; Leonard L. Gunderson; Imran Hassan; Michael G. Haddock; Michael J. O’Connell; Stephen S. Cha; Daniel J. Sargent; Alan Horgan

ObjectiveTo assess the results of multimodality therapy for patients with recurrent rectal cancer and to analyze factors predictive of curative resection and prognostic for overall survival. Summary Background DataLocally recurrent rectal cancer is a difficult clinical problem, and radical treatment options with curative intent are not generally accepted. MethodsA total of 394 patients underwent surgical exploration for recurrent rectal cancer. Ninety were found to have unresectable local or extrapelvic disease and 304 underwent resection of the recurrence. The latter patients were prospectively followed to determine long-term survival and factors influencing survival. ResultsOverall 5-year survival was 25%. Curative, negative resection margins were obtained in 45% of patients; in these patients a 5-year survival of 37% was achieved, compared to 16% (P < .001) in patients with either microscopic or gross residual disease. In a logistic regression analysis, initial surgery with end-colostomy and symptomatic pain (both univariate) and increasing number of sites of the recurrent tumor fixation in the pelvis (multivariate) were associated with palliative surgery. Overall survival was significantly decreased for symptomatic pain (P < .001) and more than one fixation (P = .029). Survival following extended resection of adjacent organs was not different from limited resection (28% vs. 21%, P = .11). Patient demographics and factors related to the initial rectal cancer did not affect outcome. Perioperative mortality was only 0.3%, but significant morbidity occurred in 26% of patients, with pelvic abscess being the most common complication. ConclusionsThis study demonstrates that many patients with locally recurrent rectal cancer can be resected with negative margins. Long-term survival can be achieved, especially for patients with no symptoms and minimal fixation of the recurrence in the pelvis, provided no gross residual disease remains.


Gynecologic Oncology | 1992

HER-2/neu expression: A major prognostic factor in endometrial cancer☆

David J. Hetzel; Timothy O. Wilson; Gary L. Keeney; Patrick C. Roche; Stephen S. Cha; Karl C. Podratz

The HER-2/neu oncogene encodes for a specific cell-surface glycoprotein similar to the human growth factor receptor. An analysis of 247 patients with endometrial cancer treated between 1979 and 1983 was performed using an immunoperoxidase technique on paraffin-embedded tissue samples to detect HER-2/neu overexpression. Specimens were graded blindly with regard to HER-2/neu staining intensity. Overexpression of HER-2/neu was identified as strong in 37 patients (15%), mild in 144 (58%), and none in 66 (27%). The 5-year progression-free survival was 56% for the strong, 83% for the mild, and 95% for the nonstaining groups. The strong (P < 0.0001) and the mild (P = 0.028) staining groups were distinct from the nonstaining group in predicting progression-free survival. Likewise, strong overexpression was associated with a poor (51%) overall survival (P < 0.0001). Multivariate analysis revealed that intense overexpression had independent significance in predicting progression-free (P = 0.0003) and overall survival (P < 0.0001). In stage I patients (203), the 5-year progression-free survival was 62% for the strong and 97% for the nonstaining groups (P = 0.0007). This retained independent significance when subjected to multivariate analysis (P = 0.0017). Other significant stage I prognostic factors in multivariate analysis included DNA ploidy, histologic subtype, and histologic grade but not depth of invasion.


Journal of Gastrointestinal Surgery | 2005

Hepatic Resection of Hepatocellular Carcinoma in Patients With Cirrhosis: Model of End-Stage Liver Disease (MELD) Score Predicts Perioperative Mortality

Swee H. Teh; John D. Christein; John H. Donohue; Florencia G. Que; Michael L. Kendrick; Michael B. Farnell; Stephen S. Cha; Patrick S. Kamath; Raymond Kim; David M. Nagorney

Hepatic resection for hepatocellular carcinoma (HCC) in patients with cirrhosis is generally recommended for patients with Child-Turcotte-Pugh (CTP) Class A liver disease and early tumor stage. The Model for End-Stage Liver Disease (MELD) has been shown to accurately predict survival in patients with cirrhosis, but whether MELD is useful for selection of patients with cirrhosis for hepatic resection is unknown. We examined whether MELD was predictive of perioperative mortality and correlated MELD with other potential clinicopathologic factors to overall survival in patients with cirrhosis undergoing hepatic resection for HCC. A retrospective chart review was undertaken of patients with HCC and cirrhosis undergoing hepatic resection between 1993 and 2003. Eighty-two patients (62 men, 20 women; mean age, 62 years) were identified. Forty-five patients had MELD score ≥9 (range, 9–15) and CTP score ranged from 5 to 9 points. Fifty-nine patients underwent minor (<3 segments) hepatic resections (MELD ≤8, n = 29; MELD ≥9, n = 30) and 23 underwent major (≥3 segments) hepatic resections (MELD ≤8, n = 8; MELD ≥9, n = 15). Perioperative mortality rate was 16%. MELD score ≤8 was associated with no perioperative mortality versus 29% for patients with an MELD score ≥9 (P < 0.01). Multivariate analysis demonstrated that MELD score ≥9 (P < 0.01), clinical tumor symptoms (P < 0.01), and ASA score (P = 0.046) are independent predictors of perioperative mortality. Multivariate analysis showed MELD ≥9 (P < 0.01), tumor size >5 cm(P < 0.01), high tumor grade (P = 0.03), and absence of tumor capsule (P < 0.01) as independent predictors of decreased long-term survival. MELD score was a strong predictor of both perioperative mortality and long-term survival in patients with cirrhosis undergoing hepatic resection for HCC. In patients with cirrhosis, hepatic resection (minor or major) for HCC is recommended if the MELD score is ≤8. In patients with MELD score ≥9, other treatment modalities should be considered.


International Journal of Radiation Oncology Biology Physics | 1993

Patterns of failure in grossly resected pancreatic ductal adenocarcinoma treated with adjuvant irradiation ± 5 fluorouracil

May L. Foo; Leonard L. Gunderson; David M. Nagorney; Donald C. Mcllrath; Jonathon A. van Heerden; Jay S. Robinow; Larry K. Kvols; Graciela R. Garton; James A. Martenson; Stephen S. Cha

PURPOSE Analyze patterns of failure, survival, and tolerance in patients with totally resected ductal adenocarcinoma of the pancreas treated with adjuvant irradiation alone or combined with chemotherapy. METHODS AND MATERIALS The records of 29 patients treated with radiotherapy following curative resection of pancreas cancer at the Mayo Clinic were retrospectively reviewed. Twenty-two (76%) patients underwent a subtotal pancreatectomy (Whipple procedure), six (21%) a total pancreatectomy, and one (3.5%) a distal pancreatectomy. Twenty-six (90%) had lesions located in the head of the pancreas and three (10%) were located either in the body or tail. Twelve (41%) of the tumors were histologic Grade 3, 15 (52%) Grade 2, and two Grade 1. Contiguous invasion of adjacent tissues or organs was found in fifteen patients (52%) and seventeen (59%) had lymph node involvement. Greater than 75% of patients received more than 45 Gy, with a median dose of 54 Gy, and twenty-seven (93%) patients received concomitant 5-fluorouracil chemotherapy. RESULTS The median survival was 22.8 months and the 2-year survival 48%. When survival was compared with that achieved with surgery alone in our institution, data suggested a doubling in both median and long-term survival with the addition of adjuvant treatment. Eighty-three percent of patients experienced tumor relapse with seventeen of 29 (59%) developing either liver metastases or peritoneal spread. In three patients, tumors recurred locally; one of one with microscopic residual disease after resection and two of 28 (7%) with negative margins (one of the two was treated with inadequate radiation portals). Patients tolerated adjuvant treatment with minimal acute toxicity consisting mostly of vomiting or nausea which, were controlled with medication in all patients. Chronic toxicity was acceptable; while 5 of 29 (17%) developed some form of possible treatment related complication, only one patient (3.5%) developed a small bowel obstruction. CONCLUSION These results corroborate data in previous studies which have shown a survival benefit when adjuvant irradiation plus 5-fluorouracil is used in patients with completely resected ductal adenocarcinoma of the pancreas. The patterns of failure indicate that post-operative adjuvant treatment can effectively control disease locally but that future survival improvements will be achieved only by reducing the incidence of liver and peritoneal metastases.


European Heart Journal | 2008

Obesity as a risk factor for the progression of paroxysmal to permanent atrial fibrillation: a longitudinal cohort study of 21 years

Teresa S.M. Tsang; Marion E. Barnes; Yoko Miyasaka; Stephen S. Cha; Kent R. Bailey; Grace C Verzosa; James B. Seward; Bernard J. Gersh

AIMS Obesity has been shown to be a risk factor for first atrial fibrillation (AF), but whether it is associated with progression from paroxysmal to permanent AF is unknown. METHODS AND RESULTS In this longitudinal cohort study, Olmsted County, MN residents confirmed to have developed paroxysmal AF during 1980-2000 were identified and followed passively to 2006. The interrelationships of body mass index (BMI), left atrial (LA) size, and progression to permanent AF were analysed. Of a total of 3248 patients (mean age 71 +/- 15 years; 54% men) diagnosed with paroxysmal AF, 557 (17%) progressed to permanent AF (unadjusted incidence, 36/1000 person-years) over a median follow-up period of 5.1 years (interquartile range 1.2-9.4). Adjusting for age and sex, BMI independently predicted the progression to permanent AF (hazard ratio, HR 1.04, CI 1.03-1.06; P < 0.0001). Compared with normal BMI (18.5-24.9 kg/m(2)), obesity (30-34.9 kg/m(2)) and severe obesity (>or=35 kg/m(2)) were associated with increased risk for progression [HR 1.54 (CI 1.2-2.0; P = 0.0004) and 1.87 (CI 1.4-2.5; P < 0.0001, respectively)]. BMI remained highly significant even after multiple adjustments. In the subgroup with echocardiographic assessment (n = 744), LA volume was incremental to BMI for independent prediction of progression after multiple adjustments, and did not weaken the association between BMI and progression to permanent AF (HR 1.04; CI 1.02-1.05; P < 0.0001). CONCLUSION There was a graded risk relationship between BMI and progression from paroxysmal to permanent AF. This relationship was not weakened by LA volume, which was independent of and incremental to BMI for the prediction of progression to permanent AF.


International Journal of Radiation Oncology Biology Physics | 1997

Locally advanced primary colorectal cancer: intraoperative electron and external beam irradiation +/- 5-FU.

Leonard L. Gunderson; Heidi Nelson; James A. Martenson; Stephen S. Cha; Michael G. Haddock; Richard M. Devine; Jennifer M. Fieck; Bruce G. Wolff; Roger R. Dozois; Michael J. O'Connell

PURPOSE For locally advanced primary colorectal cancer, our institution has combined intraoperative electron irradiation (IOERT) with external beam irradiation (EBRT) +/- 5-fluorouracil (5-FU) and surgical resection. Disease control and survival were compared with the current IOERT and prior non-IOERT regimens. METHODS AND MATERIALS From April 1981 through August 1995, 61 patients received an IOERT dose of 10-20 Gy, usually combined with 45-55 Gy of fractionated EBRT; 56 had minimum follow-up of 18 months. The amount of residual disease remaining at IOERT after exploration and maximal resection in the 56 patients was gross in 16, < or = microscopic in 39, and unresected in 1. RESULTS Survival (SR) and disease control were analyzed as a function of potential prognostic factors. Factors that achieved statistical significance for improved overall survival included treatment sequence of preop EBRT + 5-FU (vs. postoperative EBRT + 5-FU, p = 0.003) and < or = microscopic residual disease after maximal resection (vs. gross residual, p = 0.005). Those that appeared to favorably impact disease-free survival included EBRT + 5-FU (vs. EBRT alone, p = 0.01), < or = microscopic residual (vs. gross, p = 0.0014), and colon site of primary (vs. rectum, p = 0.009). Failures within an irradiation field have occurred in 4 of 16 patients (25%) who presented with gross residual after partial resection vs. 2 of 39 (5%) with < or = microscopic residual after gross total resection (p = 0.01). The significant prognostic factors for a decrease in distant metastases were the same as for disease-free SR with respective p-values of 0.013 (EBRT + 5-FU), 0.008 (microscopic residual), and 0.03 (colon primary). The current data suggests a relationship between IOERT dose and incidence of Grade 2 or 3 neuropathy (< or = 12.5 Gy--1 of 29 or 3%, > or = 15 Gy--6 of 26 or 23%, p = 0.03). CONCLUSIONS Both overall survival and disease control appear to be improved with the addition of IOERT to standard treatment. More routine use of systemic therapy is indicated as a component of IOERT containing treatment regimens because the incidence of distant metastases was 50% of patients at risk.

Collaboration


Dive into the Stephen S. Cha's collaboration.

Researchain Logo
Decentralizing Knowledge