Contemporary Patterns and Survival Outcome of Adjuvant Systemic Therapy for Localized Gastrointestinal Stromal Tumors.

OBJECTIVES: To describe contemporary patterns of and factors associated with adjuvant therapy use and survival outcome after resection of localized gastrointestinal stromal tumors (GISTs) using a large contemporary clinical database. METHODS: We queried the National Cancer Data Base to identify localized GIST cases diagnosed from 2004 to 2011, and used descriptive and logistic regression analyses to determine patterns of and factors associated with adjuvant therapy. Kaplan-Meier and Cox proportional-hazard model were utilized to generate survival probabilities and hazard ratios (HRs). RESULTS: Of 4694 patients, 73.5% received surgery alone, and 26.5% received adjuvant therapy during 2004 to 2011. Receipt of adjuvant therapy more than doubled between 2006 (13.2%) and 2007 (30.5%), peaked to 37.9% in 2009, and then decreased to 25.6% in 2011 (P for trend<0.0001). Receipt of adjuvant therapy monotonically decreased with older age (P for trend<0.0001), and was higher in patients with larger tumor size (>10 cm) than those with smaller tumor size (≤5 cm) (44.1% vs. 15.8%; P<0.0001). Patients who received adjuvant therapy had 46% lower risk of death than those who received surgery alone (HR=0.55; 95% confidence interval, 0.37-0.79; P<0.001); survival benefit was statistically significant for GISTs with >10 cm tumor size (HR=0.42; 95% confidence interval, 0.20-0.89; P=0.02). CONCLUSIONS: In a large nationwide dataset, we showed that the use of adjuvant therapy for localized GISTs has significantly increased over time and patients treated with adjuvant therapy have better survival than patients treated with surgery alone.

Combination external beam radiation and brachytherapy boost with androgen deprivation for treatment of intermediate-risk prostate cancer: long-term results of CALGB 99809.

BACKGROUND: Combined transperineal prostate brachytherapy and external beam radiation therapy (EBRT) is widely used for treatment of prostate cancer. Long-term efficacy and toxicity results of a multicenter phase 2 trial assessing combination of EBRT and transperineal prostate brachytherapy boost with androgen deprivation therapy (ADT) for intermediate-risk prostate cancer are presented. METHODS: Intermediate-risk patients per Memorial Sloan-Kettering Cancer Center/National Comprehensive Cancer Network criteria received 6 months of ADT, and 45 grays (Gy) EBRT to the prostate and seminal vesicles, followed by transperineal prostate brachytherapy with I125 (100 Gy) or Pd103 (90 Gy). Toxicity was graded using the National Cancer Institute Common Toxicity Criteria version 2 and Radiation Therapy Oncology Group late radiation morbidity scoring systems. Disease-free survival (DFS) was defined as time from enrollment to progression (biochemical, local, distant, or prostate cancer death). In addition to the protocol definition of biochemical failure (3 consecutive prostate-specific antigen rises>1.0 ng/mL after 18 months from treatment start), the 1997 American Society for Therapeutic Radiology and Oncology (ASTRO) consensus and Phoenix definitions were also assessed in defining DFS. The Kaplan-Meier method was used to estimate DFS and overall survival. RESULTS: Sixty-one of 63 enrolled patients were eligible. Median follow-up was 73 months. Late grade 2 and 3 toxicity, excluding sexual dysfunction, occurred in 20% and 3% of patients. Six-year DFS applying the protocol definition, 1997 ASTRO consensus, and Phoenix definitions was 87.1%, 75.1%, and 84.9%. Six deaths occurred; only 1 was attributed to prostate cancer. Six-year overall survival was 96.1%. CONCLUSIONS: In a cooperative setting, combination of EBRT and transperineal prostate brachytherapy boost plus ADT resulted in excellent DFS with acceptable late toxicity for patients with intermediate-risk prostate cancer.

Combination external beam radiation and brachytherapy boost with androgen suppression for treatment of intermediate-risk prostate cancer: an initial report of CALGB 99809.

PURPOSE: Transperineal prostate brachytherapy (TPPB) can be used with external beam radiation therapy (EBRT) to provide a high-dose conformal boost to the prostate. The results of a multicenter Phase II trial assessing safety of combination of EBRT and TPPB boost with androgen suppression (AST) in treatment of intermediate-risk prostate cancer are present here. MATERIALS AND METHODS: Patients had intermediate-risk prostate cancer. Six months of AST was administered. EBRT to the prostate and seminal vesicles was administered to 45Gy followed by TPPB using either (125)I or (103)Pd to deliver an additional 100Gy or 90Gy. Toxicity was graded using the National Cancer Institute CTC version 2 and the Radiation Therapy Oncology Group late radiation morbidity scoring systems. RESULTS: Sixty-three patients were enrolled. Median follow-up was 38 months. Side effects of AST including sexual dysfunction and vasomotor symptoms were commonly observed. Apart from erectile dysfunction, short-term Grade 2 and 3 toxicity was noted in 21% and 7%, primarily genitourinary related. Long-term Grade 2 and 3 toxicities were noted in 13% and 3%. Two patients had Grade 3 dysuria that resolved with longer follow-up. The most common Grade 2 long-term toxicity was urinary frequency (5%). No biochemical or clinical evidence of progression was noted for the entire cohort. CONCLUSIONS: In a cooperative group setting, combination EBRT and TPPB boost with 6 months of AST was generally well tolerated with expected genitourinary and gastrointestinal toxicities. Further follow-up will be required to fully assess long-term toxicity and cancer control.