Table 1.
Demographic and Clinical Characteristics of Patients with Metastatic CRPC Who Initiated Abiraterone Acetate or Enzalutamide Therapy
| Characteristic | Abiraterone acetate cohort (N = 2591) | Enzalutamide cohort (N = 807) | P valuea |
|---|---|---|---|
| Age, mean ± SD [median] | 73.8 ± 10.5 [75.0] | 72.8 ± 10.8 [73.0] | .0216b |
| Age category, yrs, N (%) | |||
| 35–44 | 3 (0.1) | 2 (0.2) | .3408 |
| 45–54 | 69 (2.7) | 36 (4.5) | .0100b |
| 55–64 | 546 (21.1) | 171 (21.2) | .9435 |
| 65–74 | 669 (25.8) | 222 (27.5) | .3408 |
| ≥75 | 1304 (50.3) | 376 (46.6) | .0638 |
| Region, N (%) | |||
| Northeast | 617 (23.8) | 165 (20.4) | .0472b |
| North Central | 706 (27.2) | 217 (26.9) | .8416 |
| South | 789 (30.5) | 276 (34.2) | .0450b |
| West | 464 (17.9) | 136 (16.9) | .4923 |
| Unknown | 15 (0.6) | 13 (1.6) | .0046b |
| Year of index date, N (%) | |||
| 2012 | 418 (16.1) | 127 (15.7) | .7892 |
| 2013 | 1400 (54.0) | 280 (34.7) | <.0001b |
| 2014 | 773 (29.8) | 400 (49.6) | <.0001b |
| Payment type, N (%) | |||
| Medicare | 1994 (77.0) | 607 (75.2) | .3078 |
| Commercial | 597 (23.0) | 200 (24.8) | .3078 |
| Plan type, N (%) | |||
| Preferred provider organization | 1135 (43.8) | 354 (43.9) | .9758 |
| Comprehensive | 896 (34.6) | 280 (34.7) | .9521 |
| Health maintenance organization | 315 (12.2) | 68 (8.4) | .0034b |
| Point of service | 101 (3.9) | 42 (5.2) | .1065 |
| Consumer-driven health plan | 53 (2.0) | 18 (2.2) | .7484 |
| High-deductible health plan | 33 (1.3) | 12 (1.5) | .6434 |
| Exclusive provider organization | 5 (0.2) | 1 (0.1) | 1.0000 |
| Capitated or partially capitated point of service | 4 (0.2) | 2 (0.2) | .6325 |
| Unknown | 49 (1.9) | 30 (3.7) | .0026b |
| Physician specialty, N (%) | |||
| Oncology/hematology | 1239 (47.8) | 388 (48.1) | .8973 |
| Urology | 315 (12.2) | 97 (12.0) | .9167 |
| Internist/family practitioner/PCP | 784 (30.3) | 250 (31.0) | .6977 |
| Other specialty/unknown | 253 (9.8) | 72 (8.9) | .4773 |
| Quan-Charlson comorbidity index, mean ± SD [median] | 6.0 ± 2.3 [6.0] | 6.1 ± 2.3 [6.0] | .3794 |
| Baseline comorbidities, N (%) | |||
| Diabetes | 587 (22.7) | 211 (26.1) | .0411b |
| Depression | 135 (5.2) | 59 (7.3) | .0247b |
| Hypertension | 1316 (50.8) | 396 (49.1) | .3933 |
| Cardiovascular disease | 1004 (38.7) | 317 (39.3) | .7867 |
| Any CNS conditionsc | 848 (32.7) | 280 (34.7) | .3000 |
| Malignant neoplasms, N (%) | |||
| Lip, oral cavity, and pharynx | 3 (0.1) | 3 (0.4) | .1500 |
| Digestive organs and peritoneum | 89 (3.4) | 29 (3.6) | .8299 |
| Respiratory and intrathoracic organs | 59 (2.3) | 18 (2.2) | .9380 |
| Bone, connective tissue, skin, and breast | 214 (8.3) | 55 (6.8) | .1846 |
| Genitourinary organs (excluding 185.xx) | 151 (5.8) | 42 (5.2) | .5041 |
| Other and unspecified sites | 1932 (74.6) | 613 (76.0) | .4250 |
| Eye | 3 (0.1) | 0 (0.0) | 1.0000 |
| Brain | 9 (0.3) | 2 (0.2) | 1.0000 |
| Nervous system | 9 (0.3) | 3 (0.4) | 1.0000 |
| Thyroid glands and related structures | 5 (0.2) | 3 (0.4) | .4044 |
| Endocrine glands and related structures | 1 (0.0) | 0 (0.0) | .4186 |
| Other ill-defined sites | 17 (0.7) | 6 (0.7) | .7915 |
| Secondary malignant neoplasm and unspecified lymph nodes | 264 (10.2) | 101 (12.5) | .0624 |
| Secondary malignant neoplasm of respiratory and digestive sites | 197 (7.6) | 65 (8.1) | .6747 |
| Secondary malignant neoplasm of other specified sites | 1781 (68.7) | 559 (69.3) | .7761 |
| Malignant neoplasm without specification of site | 316 (12.2) | 116 (14.4) | .1048 |
| Lymphatic and hematopoietic tissues | 68 (2.6) | 22 (2.7) | .8752 |
| Prostate cancer treatments, N (%) | |||
| Chemotherapy | |||
| Docetaxel | 299 (11.5) | 161 (20.0) | <.0001b |
| Cabazitaxel | 42 (1.6) | 33 (4.1) | <.0001b |
| Other chemotherapy | 372 (14.4) | 203 (25.2) | <.0001b |
| Hormonal treatmentsd | 2236 (86.3) | 658 (81.5) | .0009b |
| Sipuleucel-T | 150 (5.8) | 62 (7.7) | .0521 |
| Radium 223 | 0 (0.0) | 0 (0.0) | — |
| Corticosteroids | 1419 (54.8) | 344 (42.6) | <.0001b |
| Prednisone | 1145 (44.2) | 221 (27.4) | <.0001b |
| Dexamethasone | 446 (17.2) | 219 (27.1) | <.0001b |
| Other corticosteroids | 416 (16.1) | 126 (15.6) | .7645 |
NOTE: Characteristics were evaluated during the 6-month baseline period.
P value was calculated using chi-square tests for categorical variables and t-tests for continuous variables.
Indicates P <.05.
CNS conditions include amnesia/memory impairment, anxiety, ataxia, cognitive disorders, confusion, convulsions, disturbance in attention, dizziness, falls, fatigue/asthenia, hallucinations, headaches, insomnia, pain, paresthesia, and seizures.
Hormone therapy includes LhRH/GnRH, estrogens, antiandrogens, and adrenal androgen blockers.
CNS indicates central nervous system; CRPC, castration-resistant prostate cancer; GnRH, gonadotropin-releasing hormone; LhRH, luteinizing hormone-releasing hormone; PCP, primary care provider; SD, standard deviation.