C David Fuller

Publications of C David Fuller

• Nomogram for predicting the benefit of adjuvant chemoradiotherapy for resected gallbladder cancer.

  Authors: Samuel J Wang, Andrew Lemieux, Jayashree Kalpathy-Cramer, Celine B Ord, Gary V Walker, C David Fuller, Jong-Sung Kim, Charles R Thomas

  Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 11/2011; 29(35):4627-32.

  Although adjuvant chemoradiotherapy for resected gallbladder cancer may improve survival for some patients, identifying which patients will benefit remains challenging because of the rarity of thisAlthough adjuvant chemoradiotherapy for resected gallbladder cancer may improve survival for some patients, identifying which patients will benefit remains challenging because of the rarity of this disease. The specific aim of this study was to create a decision aid to help make individualized estimates of the potential survival benefit of adjuvant chemoradiotherapy for patients with resected gallbladder cancer. Patients with resected gallbladder cancer were selected from the Surveillance, Epidemiology, and End Results (SEER) -Medicare database who were diagnosed between 1995 and 2005. Covariates included age, race, sex, stage, and receipt of adjuvant chemotherapy or chemoradiotherapy (CRT). Propensity score weighting was used to balance covariates between treated and untreated groups. Several types of multivariate survival regression models were constructed and compared, including Cox proportional hazards, Weibull, exponential, log-logistic, and lognormal models. Model performance was compared using the Akaike information criterion. The primary end point was overall survival with or without adjuvant chemotherapy or CRT. A total of 1,137 patients met the inclusion criteria for the study. The lognormal survival model showed the best performance. A Web browser-based nomogram was built from this model to make individualized estimates of survival. The model predicts that certain subsets of patients with at least T2 or N1 disease will gain a survival benefit from adjuvant CRT, and the magnitude of benefit for an individual patient can vary. A nomogram built from a parametric survival model from the SEER-Medicare database can be used as a decision aid to predict which gallbladder patients may benefit from adjuvant CRT.

• Individualized estimation of conditional survival for patients with head and neck cancer.

  Authors: Samuel J Wang, Amanda R Wissel, Celine B Ord, Jayashree Kalpathy-Cramer, C David Fuller, John M Holland, Neil D Gross

  Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery. 03/2011; 145(1):71-3.

  Survival for cancer patients is usually only reported as survival from time of diagnosis. For patients who survive 1 or more years after diagnosis, however, survival probability changes over time andSurvival for cancer patients is usually only reported as survival from time of diagnosis. For patients who survive 1 or more years after diagnosis, however, survival probability changes over time and is more accurately depicted by conditional survival. The specific aim of this project was to build a survival regression model and Web-based tool to make individualized estimates of conditional survival for patients with head and neck cancer based on tumor and patient characteristics. Using data from the Surveillance, Epidemiology, and End Results (SEER) database, a prediction modeling tool was built that can estimate prognosis for patients with head and neck cancer who have already survived a period of time after diagnosis. Having more accurate prognostic information may empower both patients and clinicians to make more appropriate decisions regarding follow-up, surveillance testing, and future treatment.

• An interactive tool for individualized estimation of conditional survival in rectal cancer.

  Authors: Samuel J Wang, Amanda R Wissel, Join Y Luh, C David Fuller, Jayashree Kalpathy-Cramer, Charles R Thomas

  Annals of surgical oncology. 01/2011; 18(6):1547-52.

  For rectal cancer patients who have already survived a period of time after diagnosis, survival probability changes and is more accurately depicted by conditional survival. The specific aim of thisFor rectal cancer patients who have already survived a period of time after diagnosis, survival probability changes and is more accurately depicted by conditional survival. The specific aim of this study was to develop an interactive tool for individualized estimation of changing prognosis for rectal cancer patients. A multivariate Cox proportional hazards (CPH) survival model was constructed using data from rectal cancer patients diagnosed from 1994 to 2003 from the Surveillance, Epidemiology, and End Results (SEER) database. Age, race, sex, and stage were used as covariates in the survival prediction model. The primary outcome variable was overall survival conditional on having survived up to 5 years from diagnosis. Data from 42,830 rectal cancer patients met the inclusion criteria. The multivariate CPH model showed age, race, sex, and stage as significant independent predictors of survival. The survival prediction model demonstrated good calibration and discrimination, with a bootstrap-corrected concordance index of 0.75. A web-based prediction tool was built from this regression model that can compute individualized estimates of changing prognosis over time. An interactive prediction modeling tool can estimate prognosis for rectal cancer patients who have already survived a period of time after diagnosis and treatment. Having more accurate prognostic information can empower both patients and clinicians to be able to make more appropriate decisions regarding follow-up, surveillance testing, and future treatment.

• Parametric survival models for predicting the benefit of adjuvant chemoradiotherapy in gallbladder cancer.

  Authors: Samuel J Wang, Jayashree Kalpathy-Cramer, Jong Sung Kim, C David Fuller, Charles R Thomas

  AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium. 01/2010; 2010:847-51.

  The Cox proportional hazards model is the most commonly used survival model in oncology; however, this semi-parametric model may not be the most appropriate survival model when the proportionalityThe Cox proportional hazards model is the most commonly used survival model in oncology; however, this semi-parametric model may not be the most appropriate survival model when the proportionality assumption does not hold. In this study, we consider the use of several types of accelerated failure time parametric survival techniques for modeling the benefit of adjuvant chemoradiotherapy for gallbladder cancer. In comparing the Weibull, exponential, log-logistic, and log-normal models, we found that the log-normal had the most favorable Akaike Information Criterion, and additional analyses of this model indicated that our gallbladder cancer dataset exhibited a good fit with the log-normal cumulative hazard function. This log-normal survival model can be used to help predict which patients will benefit from adjuvant chemoradiotherapy.

• Relative lack of conditional survival improvement in young adults with cancer.

  Authors: Archie Bleyer, Mehee Choi, C David Fuller, Charles R Thomas, Samuel J Wang

  Seminars in oncology. 10/2009; 36(5):460-7.

  Cancer prognosis is usually reported in terms of survival from time of diagnosis. For patients surviving a period of time after diagnosis, conditional survival (CS) accounts for changing risk overCancer prognosis is usually reported in terms of survival from time of diagnosis. For patients surviving a period of time after diagnosis, conditional survival (CS) accounts for changing risk over time. This report provides information on how CS in cancer patients changes as a function of age at diagnosis. Using data from the US Surveillance, Epidemiology and End Results database, we examined survival for patients diagnosed between 1973 and 2002. The average annual percent change (AAPC) in CS during the first 5 years after diagnosis was evaluated for the 14 most common cancers occurring in young adults, defined as 15- to 39-year-olds, and how they compared with cancers that are more common in older and younger patients. For all cancers, young adult patients had less CS improvement over time than younger or older patients, and this difference was most pronounced in those aged 20 to 29 years (45% below the mean). Eleven of the 14 most common cancers in 15- to 39-year-olds either had a lower CS improvement after diagnosis than either younger or older patients, or than just the older patients. Young adults with leukemia had the greatest improvement in CS over time. In conclusion, young adults with cancer have not enjoyed the same improvement in CS over time compared with other age groups. Explanations for this deficit include the biologic nature of the type of cancers in young adults and less effective therapies for patients in the age group. Regardless of the reasons, the deficit is yet another challenge faced by young adult patients that merits further study.

• Prediction model for estimating the survival benefit of adjuvant radiotherapy for gallbladder cancer.

  Authors: Samuel J Wang, C David Fuller, Jong Sung Kim, Dean F Sittig, Charles R Thomas, Peter M Ravdin

  Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 06/2008; 26(13):2112-7.

  PURPOSE: The benefit of adjuvant radiotherapy (RT) for gallbladder cancer remains controversial because most published data are from small, single-institution studies. The purpose of this study wasPURPOSE: The benefit of adjuvant radiotherapy (RT) for gallbladder cancer remains controversial because most published data are from small, single-institution studies. The purpose of this study was to construct a survival prediction model to enable individualized predictions of the net survival benefit of adjuvant RT for gallbladder cancer patients based on specific tumor and patient characteristics. METHODS: A multivariate Cox proportional hazards model was constructed using data from 4,180 patients with resected gallbladder cancer diagnosed from 1988 to 2003 from the Surveillance, Epidemiology, and End Results database. Patient and tumor characteristics were included as covariates and assessed for association with overall survival (OS) with and without adjuvant RT. The model was internally validated for discrimination and calibration using bootstrap resampling. RESULTS: On multivariate regression analysis, the model showed that age, sex, papillary histology, stage, and adjuvant RT were significant predictors of OS. The survival prediction model demonstrated good calibration and discrimination, with a bootstrap-corrected concordance index of 0.71. The model predicts that adjuvant RT provides a survival benefit in node-positive or >or= T2 disease. A nomogram and a browser-based software tool were built from the model that can calculate individualized estimates of predicted net survival gain attributable to adjuvant RT, given specific input parameters. CONCLUSION: In the absence of large, prospective, randomized, clinical trial data, a regression model can be used to make individualized predictions of the expected survival improvement from the addition of adjuvant RT after gallbladder cancer resection.

• Ethnic disparities in conditional survival of patients with non-small cell lung cancer.

  Authors: Samuel J Wang, C David Fuller, Charles R Thomas

  Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer. 04/2007; 2(3):180-90.

  PURPOSE: Conditional survival (CS) is an accurate estimate of survival probability for patients who have already survived at least 1 year after diagnosis. The purpose of this study was to determinePURPOSE: Conditional survival (CS) is an accurate estimate of survival probability for patients who have already survived at least 1 year after diagnosis. The purpose of this study was to determine whether ethnicity plays a role in 5-year CS rates for patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Using the Surveillance, Epidemiology, and End Results database, we analyzed 96,480 patients with NSCLC diagnosed between 1988 and 1995. Patients were divided into five ethnic groups: White (non-Hispanic), Hispanic, African American, Asian/Pacific Islander, and Native American/Alaskan. Using the life table method, we computed observed 5-year CS rates for patients who had already survived up to 5 years after diagnosis. Results were analyzed by stage, age, sex, and histology. RESULTS: In general, 5-year CS rates increase for all ethnicities as time from diagnosis increases, but African Americans continued to have lower CS rates compared with other ethnic groups, even up to 5 years from diagnosis. When analyzed by stage, Hispanics with stage IV disease showed the greatest improvement in CS rate, increasing to 73% at 5 years from diagnosis. Among patients older than 70 years, African Americans had the lowest CS at 5 years--only 28%, compared with 40% to 47% for other groups. When analyzed by histology, Hispanics with large cell carcinoma had the worst CS rate (35% at 5 years). CONCLUSION: For patients with NSCLC surviving a period of time after diagnosis, 5-year CS rates vary by ethnicity. CS can provide accurate prognostic information for patients with NSCLC who have already survived several years after diagnosis.

• Multidisciplinary approach to superior sulcus tumors.

  Authors: Juan A Garcia, Samir Bhakta, C David Fuller, Charles R Thomas

  Cancer journal (Sudbury, Mass.). 11(3):189-97.