Incidence of Second Primary Malignancies in Patients with Castration-Resistant Prostate Cancer: An Observational Retrospective Cohort Study in the United States

Table 3

Clinical characteristics of study cohort (N = 2,234).

Variable	No. of patients^† ()
Characteristics at initial prostate cancer diagnosis
Stage (derived group)^‡
Stage I or II^§	543 (24.3)
Stage III	107 (4.8)
Stage IV	583 (26.1)
Unknown	1,001 (44.8)
Characteristics on or before cohort entry date
Comorbidities
Chronic pulmonary disease	947 (42.4)
Diabetes without chronic complications	920 (41.2)
Peripheral vascular disease	830 (37.2)
Cerebrovascular disease	681 (30.5)
Congestive heart failure	636 (28.5)
Mild liver disease	512 (22.9)
Renal disease	487 (21.8)
Myocardial infarction	359 (16.1)
Diabetes with chronic complications	273 (12.2)
Rheumatic disease	183 (8.2)
Peptic ulcer disease	171 (7.7)
Paraplegia and hemiplegia	87 (3.9)
Dementia	83 (3.7)
Moderate or severe liver disease	18 (0.8)
AIDS/HIV	< 11
Metastases^††
Lymph node	296 (13.2)
Bone	1,797 (80.4)
Bone-directed therapy^††	1,326 (59.4)
Either bone metastases or bone-directed therapy	1,887 (84.5)
Castration method
Surgical	52 (2.3)
Medical	2,106 (94.3)
Surgical and medical	76 (3.4)
Time from initial diagnosis to development of CRPC
Mean (SD), months	42.1 (32.6)
Distribution
< 6 months	89 (4.0)
6 months to 1 year	251 (11.2)
> 1 to 1.5 years	279 (12.5)
> 1.5 to 2 years	223 (10.0)
> 2 years	1,392 (62.3)

AIDS, acquired immune deficiency syndrome; HIV, human immunodeficiency virus; CRPC, castration-resistant prostate cancer; SD, standard deviation.
^† Unless stated otherwise.
^‡ Stage according to the AJCC Staging Manual, Sixth Edition [14].
^§ Categories were combined to avoid reporting a count of < 11.
Individual patients can have multiple comorbidities; thus, the sum of all comorbidities adds up to more than 100%.
^†† Recorded anytime between initial date of prostate cancer diagnosis and 30 days after the cohort entry date.