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Joel E Tepper

Publications and source records attributed to Joel E Tepper.

5 recordsLinked to original sources
PubMed2004

Impact of hospital procedure volume on surgical operation and long-term outcomes in high-risk curatively resected rectal cancer: findings from the Intergroup 0114 Study.

PURPOSE: Prior studies have demonstrated superior outcomes after a curative surgical resection of rectal cancer at hospitals where the volume of such surgeries is high. However, because these studies often lack detailed information on tumor and treatment characteristics as well as cancer recurrence, the true nature of this relation remains uncertain. PATIENTS AND METHODS: We studied a nested cohort of 1,330 patients with stage II and stage III rectal cancer participating in a multicenter, adjuvant chemoradiotherapy trial. We analyzed differences in rates of sphincter-preserving operations, overall survival, and cancer recurrence by hospital surgical volume. RESULTS: We observed a significant difference in the rates of abdominoperineal resections across tertiles of hospital procedure volume (46.3% for patients resected at low-volume, 41.3% at medium-volume, and 31.8% at high-volume hospitals; P <.0001), even after adjustment for tumor distance from the anal verge. However, this higher rate of sphincter-sparing operations at high-volume centers was not accompanied by any increase in recurrence rates. Hospital surgical volume did not predict overall, disease-free, recurrence-free, or local recurrence-free survival. However, among patients who did not complete the planned adjuvant chemoradiotherapy (270 patients), those who underwent surgery at low-volume hospitals had a significant increase in cancer recurrence (adjusted hazard ratio, 1.94; 95% CI, 1.01 to 3.72; P =.04 for the trend) and a nonsignificant trend toward increased overall mortality (P =.08) and local recurrence (P =.10). In contrast, no significant volume-outcome relation was noted among patients who did complete postoperative therapy. CONCLUSION: Using prospectively recorded data, we found that hospital surgical volume had no significant effect on rectal cancer recurrence or survival when patients completed standard adjuvant therapy. Sphincter-preserving surgery was more commonly performed at high-volume centers.

Adult↗
PubMed2002

Impact of T and N substage on survival and disease relapse in adjuvant rectal cancer: a pooled analysis.

PURPOSE: To determine the rates of survival and disease control by TNM and MAC stage in three randomized North American rectal adjuvant studies. MATERIALS AND METHODS: Data were merged from 2551 eligible patients on NCCTG 79-47-51 (n = 200), NCCTG 86-47-51 (n = 656), and INT 114 (n = 1695). All patients received postoperative radiation, and 96% were randomized to receive concomitant and maintenance chemotherapy. Five-year follow-up was available in 94% of patients and 7-yr follow-up in 84%. Kaplan-Meier curves were used to estimate the distribution of overall survival (OS) and disease-free survival (DFS), and p values were derived using the log-rank test. Time to local and distant relapse was estimated using cumulative incidence methodology. Analyses were adjusted for treatment effect using Cox proportional hazards models. RESULTS: OS and DFS were dependent on both TN stage and NT stage (N substage within T stage and T substage within N stage). Even among N2 patients (4 or more LN+), T stage influenced 5-yr OS (T1-2, 69%; T3, 48%; T4, 38%). Three risk groups of patients were defined: (1) intermediate: T3N0, T1-2N1; (2) moderately high: T4N0, T1-2N2, T3N1; and (3) high: T3N2, T4N1, T4N2. For Group 1, 5-yr OS was 74% and 81%, and 5-yr DFS was 66% and 74%. For Group 2, 5-yr OS ranged from 61% to 69%, and for Group 3, OS ranged from 33% to 48%. Cumulative incidence rates of local relapse and distant metastases revealed similar differences by TN and NT stage, as seen in the survival analyses. CONCLUSION: Patients with a single high-risk factor of either extension beyond the rectal wall (T3N0) or nodal involvement (T1-2N1) have improved OS, DFS, and disease control when compared to those with both high risk factors. Different treatment strategies may be indicated for intermediate- (T3N0, T1-2N1) vs. moderately high or high-risk patients in view of differential survival and rates of relapse. For future trial design, it may be preferable to perform separate studies, or a planned statistical analysis, for the "intermediate-risk" vs. the "moderately high" or "high-risk" subsets of patients.

Chemotherapy, Adjuvant↗
PubMed2002

Radiation treatment parameters in the adjuvant postoperative therapy of gastric cancer.

Radiation therapy will be used much more commonly in the treatment of adenocarcinoma of the stomach because of the results of the Intergroup Trial demonstrating an advantage to adjuvant postoperative chemoradiation therapy. Previous descriptions of radiation fields have not emphasized the variation in local spread patterns between tumors located in different portions of the stomach and the varying extent of the primary tumor and lymph node spread. Based on data obtained from surgical and pathologic series, we have recommended a variation in the radiation fields from those routinely applied at the present time. Tumors located primarily in the region of the gastric cardia have the highest risk of nodal involvement in the pericardial region and along the lesser and greater curvature, as well as risk of spread into the periesophageal tissue. However, there is a lower risk of involvement in the distally located nodes, especially in the gastric antrum, periduodenal, and porta hepatis regions. For a patient who has been well evaluated both surgically and pathologically, and found to be node negative, it may not be necessary to treat the nodes in these lower risk sites. Similarly, tumors that originate in the distal stomach, in the region of the gastric antrum, have a high likelihood of spread to the periduodenal, peripancreatic, and porta hepatis nodes, and a lower likelihood of spread to the nodes near the cardia of the stomach, the periesophageal and mediastinal nodes, or to the splenic hilar nodes. Any tumor originating in the stomach has a high propensity of spread to nodes along the greater and lesser curvature, although they are most likely to spread to those sites in close anatomic proximity to the primary tumor mass. Based on such information, we have described the nodal and primary sites that should be treated for different T- and N-stage tumors located in the cardia, body, or antrum of the stomach. These should be used as guides for defining appropriate field arrangements for the adjuvant postoperative therapy of gastric cancer.

Chemotherapy, Adjuvant↗
PubMed2002

Dose optimization via index-dose gradient minimization.

This paper presents an iterative optimization algorithm based on gradient minimization of index dose, defined as the product of physical dose and a numerical index. Acting as a template the index distribution is designed to represent the dosimetry that meets the dose volume histogram-based optimization objectives. The treatment dosimetry is optimized when the uniformity of the index-dose distribution is maximized. Prior to optimization the user can select all or only some of the beams to be intensity modulated. The remaining unmodulated beams can be either open or wedged photon beams, electron beams, or beams of previous treatments. The optimization result and treatment delivery efficiency can often be enhanced by including not only the IM photon beams but also all suitable fixed-beams available on the linac in the treatment plan. In addition, the doses from previous treatments can also be considered in the optimization of current treatment. Five clinical examples with different complexities in optimization objective are presented. The effects of two nonoptimization variables, beam setup and initial beam weights, on the quality of the dose optimization are also presented. The results are analyzed in terms of isodose distribution, dose volume histograms, and a dose optimization quality factor. The optimization algorithm, implemented in our in-house TPS PLanUNC, has been used in clinical application since 1996. The primary advantages of our optimization algorithm include computational efficiency, intensity modulation selection choice, and performance reliability for a wide range of clinical beam setups and optimization objectives.

Algorithms↗