Purpose Men with apparently localized prostate cancer often relapse years after radical prostatectomy (RP). We sought to determine if epithelial-like cells identified from bone marrow (BM) in patients after RP (commonly called disseminated tumor cells, DTC) were associated with biochemical recurrence (BR). Experimental Design We obtained BM aspirates from 569 men prior to RP and from 34 healthy men with PSA<2.5 ng/ml to establish a comparison group. Additionally, an analytic cohort consisting of 98 patients after RP with no evidence of disease (NED) was established to evaluate the relationship between DTC and BR. Epithelial cells in the BM were detected by magnetic bead enrichment with antibodies to CD45 and CD61 (negative selection) followed by antibodies to human epithelial antigen (positive selection) and confirmation with FITC-labeled anti-BerEP4 antibody. Results DTC were present in 72% (408/569) of patients prior to RP. There was no correlation with pathologic stage, Gleason grade, or pre-operative PSA. Three of 34 controls (8.8%) had DTC present. In patients NED post-RP, DTC were present in 56/98 (57%). DTC were detected in 12/14 (86%) NED patients post-RP who subsequently suffered BR. Presence of DTC in NED patients was an independent predictor of recurrence (HR 6.9, CI 1.03–45.9). Conclusions Approximately 70% of men undergoing RP had DTC detected in their BM prior to surgery, suggesting that these cells escape early in the disease. Though pre-operative DTC status does not correlate with pathologic risk factors, persistence of DTC after RP in NED patients was an independent predictor of recurrence.

Disseminated epithelial cells can be isolated from the bone marrow of a far greater fraction of prostate-cancer patients than the fraction of patients who progress to metastatic disease. To provide a better understanding of these cells, we have characterized their genomic alterations. We first present an array comparative genomic hybridization method capable of detecting genomic changes in the small number of disseminated cells (10-20) that can typically be obtained from bone marrow aspirates of prostate-cancer patients. We show multiple regions of copy-number change, including alterations common in prostate cancer, such as 8p loss, 8q gain, and gain encompassing the androgen-receptor gene on Xq, in the disseminated cell pools from 11 metastatic patients.

Purpose Role of adjuvant radiation for Masaoka stage II and III thymoma remains controversial. The aim of this study was to evaluate the clinical benefits of radiation therapy for resected stages II and III thymoma. Methods and Materials We retrospectively reviewed the medical records of 175 thymoma patients treated from July 1996 to January 2013 at University of Washington Medical Center; 88 patients with adequate follow-up and who met histologic criteria were included. We evaluated progression-free survival (PFS) and overall survival (OS), and compared these outcomes in patients treated by surgery (S) alone versus surgery plus radiotherapy (S + RT). Cox regression models and log-rank tests were used to compare PFS and OS for S versus S + RT, and they were further assessed by margin-positive versus margin-negative subgroups using Kaplan-Meier curves. Results Among the 88 thymoma patients, 22 were stage II and 18 were stage III. For all stages II and III patients, adjuvant radiation was not identified as a significant predictor for PFS (P = 0.95) or OS (P = 0.63). A positive surgical margin predicted for a worse OS (hazard ratio = 7.1; P = 0.004). Further investigation revealed for resection margin-positive patients; S + RT had higher OS than S alone (P = 0.006). Conclusions For stages II and III thymoma, postoperative adjuvant radiation was not associated with statistically significant differences in PFS or OS in this study. Our results indicated a potential OS benefit of adjuvant RT in patients with positive resection margins, and therefore may be considered in this patient population.

ObjectivesEvidence has implicated a possible role of tumor mutation status on local control (LC) with radiotherapy. BRAF is a proto-oncogene that is mutated in approximately 50% of patients with melanoma. We sought to analyze the influence of BRAF status on LC of melanoma brain metastases (MBM) following Gamma Knife radiosurgery (GK).MethodsAmong 125 patients treated with GK for MBM at our institution between 2006 and 2015, we identified 19 patients with 69 evaluable metastases whose BRAF mutation status was known and follow-up imaging was available. LC of individual metastases was compared based on BRAF mutation status using statistical techniques to control for measurements of multiple metastases within each patient. CNS progression was defined as either local failure or development of new lesions.ResultsOf the 69 metastases, BRAF was mutated in 30 and wild-type in 39. With a median follow-up of 30 months for all patients and a median follow-up of 5.5 months for treated lesions, 1-year LC was significantly better among metastases with mutated vs. wild-type BRAF (69 vs. 34%, RR = 0.3, 95% CI = 0.1–0.7, p = 0.01). BRAF mutation was found to be a significant predictor of LC after stereotactic radiosurgery (SRS) in both univariate [RR = 0.3 (95% CI 0.1–0.7, p = 0.01)] and multivariate [RR = 0.2 (95% CI 0.1–0.7, p = 0.01)] analyses. There was also a trend toward improved CNS progression free survival (PFS) at 1 year (26 vs. 0%, p = 0.06), favoring BRAF-mutated patients.ConclusionIn this retrospective study, MBM treated with GK had significantly improved LC for patients with BRAF mutation vs. wild-type. Our data suggest that BRAF mutation may sensitize tumors to radiosurgery, and that BRAF wild-type tumors may be more radioresistant.

Supplementary Table 1 from Genomic Alterations Indicate Tumor Origin and Varied Metastatic Potential of Disseminated Cells from Prostate Cancer Patients