Thoracic Radiotherapy for Renal Cell Carcinoma Metastases: Local Control for the Management of Lung and Mediastinal Disease in the Modern Era.

INTRODUCTION/BACKGROUND: Radiotherapy (RT) is an alternative local therapy to metastasectomy in the treatment of thoracic metastases from renal cell carcinoma (RCC), including the management of life-threatening disease. PATIENTS AND METHODS: We reviewed patients with lung and mediastinal RCC metastases treated with RT at our institution. Overall survival (OS) and metastasis control (MC) was measured from the start of RT using the Kaplan-Meier (KM) method. RESULTS: Seventy-one patients were treated with RT for 89 lung (n = 58) or mediastinal (n = 31) metastases. Of 89 treated lesions, 11 (12%) had local tumor recurrence, at a median of 1.6 years (range 0.4-2.9). MC at 1, 3, and 5-years was 96.6%, 83.5%, and 67.9%, respectively. For the 58-lung metastasis-directed RT courses, MC rates at 1, 3, and 5-years were 95.0%, 84.5%, and 84.5%, respectively (median MC not reached). For the 31-mediastinum metastasis-directed RT courses, MC rates at 1, 3, and 5-years were 100%, 43.4%, and 43.4%, respectively (median MC 2.9 years). MC was significantly improved for lung lesions compared to mediastinal lesions (P = .046). OS for the entire cohort at 1, 3, and 5 years was 65.2%, 48.5%, and 38.0%. There was no difference in OS based on metastatic sites in the 71 patients. Nineteen patients received RT to 19 lesions with the intention of preventing an event such as airway compromise or vascular invasion. One and two-year MC for these 19 lesions were 88.9% and 71.1%, respectively (median local control 2.4 years). OS in these 19 patients at 1, 2, and 5 years were 62.1%, 48.3%, and 32.2% respectively, with median survival 1.2 years. No patients developed grade 4 or 5 acute or late toxicities. CONCLUSION: Radiation therapy can safely achieve high metastasis control rates for lung and mediastinal metastases from RCC, including lesions at high risk for causing a life-threatening event.

Differential impact of tumor suppressor gene (TP53, PTEN, RB1) alterations and treatment outcomes in metastatic, hormone-sensitive prostate cancer.

BACKGROUND: Altered tumor suppressor genes (TSG-alt) in prostate cancer are associated with worse outcomes. The prognostic value of TSG-alt in metastatic, hormone-sensitive prostate cancer (M1-HSPC) is unknown. We evaluated the effects of TSG-alt on outcomes in M1-HSPC and their prognostic impact by first-line treatment. METHODS: We retrospectively identified patients with M1-HSPC at our institution treated with first-line androgen deprivation therapy plus docetaxel (ADT + D) or abiraterone acetate (ADT + A). TSG-alt was defined as any alteration in one or more TSG. The main outcomes were Kaplan-Meier-estimated progression-free survival (PFS) and overall survival, analyzed with the log-rank test. Clinical characteristics were compared with the χ2 test and Kruskal-Wallis rank sum test. Cox regression was used for univariate and multivariable analyses. RESULTS: We identified 97 patients with M1-HSPC: 48 (49%) with ADT + A and 49 (51%) with ADT + D. Of 96 patients with data available, 33 (34%) had 1 TSG-alt, 16 (17%) had 2 TSG-alt, and 2 (2%) had 3 TSG-alt. The most common alterations were in TP53 (36%) and PTEN (31%); 6% had RB1 alterations. Median PFS was 13.1 (95% CI, 10.3-26.0) months for patients with normal TSGs (TSG-normal) vs. 7.8 (95% CI, 5.8-10.5) months for TSG-alt (P = 0.005). Median PFS was lower for patients with TSG-alt vs TSG-normal for those with ADT + A (TSG-alt: 8.0 [95% CI, 5.8-13.8] months vs. TSG-normal: 23.2 [95% CI, 13.1-not estimated] months), but not with ADT + D (TSG-alt: 7.8 [95% CI, 5.7-12.9] months vs. TSG-normal: 9.5 [95% CI, 4.8-24.7] months). On multivariable analysis, only TSG-alt predicted worse PFS (hazard ratio, 2.37; 95% CI, 1.42-3.96; P < 0.001). CONCLUSIONS: The presence of TSG-alt outperforms clinical criteria for predicting early progression during first-line treatment of M1-HSPC. ADT + A was less effective in patients with than without TSG-alt. Confirmation of these findings may establish the need for inclusion of molecular stratification in treatment algorithms.