Time to PSA doubling is defined as the number of days between the baseline date and the study day of the first post-baseline PSA evaluation date (within treatment period, typically up to 24-month evaluations) on which the PSA value was at least twice as much as the baseline PSA value, and the immediate subsequent value, if available, was at least 85% of two times the baseline value. Participants who never achieved PSA doubling were censored at the last post-baseline, non-missing PSA evaluation.

ITT Population: all participants randomized to study treatment. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm; 1 in dutasteride arm). Only participants who experienced PSA doubling (82 in placebo, 41 in dutasteride) contributed to summary statistics.

Time to disease progression is defined as the number of days between baseline and the first occurrence of any of the following: PSA doubling time (PSADT)<=91 days, PSA value is at least 50% more than baseline value (>20 nanogram/milliliter [ng/ml] for primary radiotherapy group or >10 ng/ml for radical prostatectomy group), rescue treatment, cancer-positive biopsy, cancer-positive bone scan. (Confirmation of PSA criteria is required in an immediate subsequent PSA, if available, and PSA values for consideration are restricted to treatment period, typically up to 24-month evaluations.)

ITT Population. Only those participants with disease progression have been summarized.

Disease progression is defined as the first occurrence of any of the following: PSADT<=91 days, PSA value is at least 50% more than baseline value (>20 ng/ml for primary radiotherapy group or >10 ng/ml for radical prostatectomy group), rescue treatment, cancer-positive biopsy, cancer-positive bone scan. If one of the PSA criteria is qualifying (within treatment period, typically up to 24-month evaluations), an immediate subsequent PSA, if available, must confirm either criterion (or at least 85% of the qualifying value).

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

Treatment responders at Month X were defined as participants (par.) with either a PSA decrease or an increase <=15% from baseline to Month X confirmed in all PSA measurements between baseline (BL) and Month X.

ITT Population. Par. not having a post-BL measurement could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm). Different par. may contribute data at different time points (TP); the number of par. analyzed at each TP are those with BL as well as post-baseline data at the particular TP.

A participant was designated as having a PSA rise if there existed a post-baseline PSA value (within treatment period, typically up to 24-month evaluations) that was >1.15 times the baseline PSA value, and all subsequent PSA values were >1.15 times the baseline PSA value. The study day for the first PSA evaluation that qualified for analysis of PSA rise was used for time to PSA rise. If none of the post-baseline PSA values qualified for analysis of PSA rise during the study, time to PSA rise was censored at the last post-baseline PSA evaluation.

ITT Population. Only those participants with PSA rise have been summarized.

A participant was designated as having a PSA rise if there existed a post-baseline PSA value (within treatment period, typically up to 24-month evluations) that was >1.15 times the baseline PSA value, and all subsequent PSA values were >1.15 times the baseline PSA value.

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

A participant was designated as having PSA progression if there existed a post-baseline PSA value (within treatment period, typically up to 24-month evaluations) that was >10 ng/ml if radical prostatectomy or >20 ng/ml if primary radiotherapy and PSA >=1.5 times the baseline PSA value, or 0\

ITT Population. Only those participants with PSA progression have been summarized.

A participant was designated as having a PSA progression if there existed a post-baseline PSA value (within treatment period, typically up to 24-month evaluations) that was (>10 ng/ml if radical prostatectomy or >20 ng/ml if primary radiotherapy) and PSA >=1.5 times the baseline PSA value), or 0\

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

Change in PSA from baseline at Month X = Month X PSA - Baseline PSA. The missing PSA value for scheduled visits could have been replaced by non-missing PSA values within 30 days after the clinic visit date. If such replacement was not possible, the latest non-missing post-baseline PSA before the scheduled visit was used for the scheduled visit PSA (Last Observation Carried Forward).

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

Percent change in PSA from baseline at Month X = 100*(Month X PSA - Baseline PSA)/Baseline PSA. The missing PSA value for scheduled visits could have been replaced by non-missing PSA values within 30 days after the clinic visit date. If such replacement was not possible, the latest non-missing post-baseline PSA before the scheduled visit was used for the scheduled visit PSA (Last Observation Carried Forward).

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

PSA doubling is defined as the first post-baseline PSA value (within treatment period, typically up to 24-month evaluations) that was at least twice as much as the baseline PSA value and was confirmed as such (at least 85% of two times the baseline PSA value) in the immediate subsequent PSA value if one is available.

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

Time to PSA doubling is defined as the number of days between the baseline date and the study day of the first post-baseline PSA evaluation date within Year 1 (Y1; within treatment period, typically up to 12-month evaluations) on which the PSA value was at least twice as much as the baseline PSA value, and the immediate subsequent value, if available, was at least 85% of two times the baseline value.

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm). Only participants with PSA doubling within Year 1 (50 in placebo, 15 in dutasteride) contributed to summary statistics.

PSA doubling is defined as the first post-baseline PSA value (within treatment period, typically up to 12-month evaluations) that was at least twice as much as the baseline PSA value and was confirmed as such (at least 85% of two times the baseline PSA value) in the immediate subsequent PSA value if one is available.

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

Change from nadir PSA at Month X = Month X PSA - nadir PSA. Nadir PSA was reported by the site as the lowest historical PSA value after the radical therapy. A nadir value below the detection level was captured as 0.0. The missing PSA value for scheduled visits could have been replaced by non-missing PSA values within 30 days after the clinic visit date. If such replacement was not possible, the latest non-missing post-baseline PSA before the scheduled visit was used for the scheduled visit PSA (Last Observation Carried Forward).

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

Percent change from nadir PSA at Month X = 100*(Month X PSA - nadir PSA)/Nadir PSA. Nadir PSA was reported by the site as the lowest historical PSA value after the radical therapy. A nadir value below the detection level was captured as 0.0. The missing PSA value for scheduled visits could have been replaced by non-missing PSA values within 30 days after the clinic visit date. If such replacement was not possible, the latest non-missing post-baseline PSA before the scheduled visit was used for the scheduled visit PSA (Last Observation Carried Forward).

ITT Population. Participants not having any post-baseline PSA measurements could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 1 in dutasteride arm).

Participants with improvement included those whose PSADT at a specified visit was positive but more than the baseline PSADT, whose PSA at the visit was the same as the baseline PSA, or whose PSA at the visit was less than the baseline PSA. Participants with worsening included those whose PSADT at the visit was positive but less than the baseline PSADT.

ITT Population. Participants having no baseline (BL) PSADT (due to incomplete PSA data or no rise in PSA at BL) or no post-BL measurement could not be evaluated and were hence excluded from this analysis (3 in placebo arm, 3 in dutasteride arm). Participants with missing PSA data at a specific visit were excluded from that visit's analysis .

MAX-PC is an 18-item, self-reported measure that evaluates prostate cancer-related anxiety. The score ranges from 0 to 54, and an increase in the score indicates a worsened anxiety level. Change from Baseline at Month X = Month X MAX-PC score - Baseline MAX-PC score. A missing post-baseline value is replaced by the last available post-baseline value (Last Observation Carried Forward(LOCF)). A general linear model controls for previous therapy, site cluster, and baseline MAX-PC score.

ITT Population. Participants not having a baseline value or not having any post-baseline value could not be evaluated for this endpoint and were hence excluded from this analysis (3 in placebo arm, 4 in dutasteride arm). Participants were excluded from a specific visit analysis if the value for the visit (after LOCF application) was missing.

A participant has a normal value for a laboratory parameter if the value is within the low and high range of normal provided by the laboratory. Each laboratory parameter is evaluated for shift from normal at baseline to abnormal any time post-baseline. A participant with any laboratory parameter showing this shift is counted. A participant is counted only once even if he had such a shift in more than one laboratory parameter or more than once among all post-baseline evaluations.

ITT Population. Participants not having any baseline measurements, or having a baseline but no post-baseline measurements of at least one of the same parameter could not be evaluated and were hence excluded from this analysis (7 in placebo arm, 9 in dutasteride arm).

Threshold laboratory values are defined in terms of a multiplicative factor of the testing laboratory's normal range, pre-specified in the analysis plan. A laboratory value that is above the upper limit factor multiplied by the upper limit of the normal range is considered a high threshold value. A laboratory value that is below the lower limit factor multiplied by the lower limit of the normal range is considered a low threshold value.

ITT Population. Participants not having a baseline as well as a post-baseline measurement of at least one laboratory parameter could not be evaluated and were hence excluded from this analysis (7 in placebo arm, 9 in dutasteride arm).

Participants underwent clinical examination of the breasts, to evaluate for palpable breast tissue. Clinical significance of the results was determined by subjective judgment of the clinical personnel performing the examination.

ITT Population. Only those participants with PBT at baseline or PBT at any time post-baseline were measured for clinical significance.

Participants underwent clinical examination of the breasts, to evaluate for nipple tenderness. Clinical significance of the results was determined by subjective judgment of the clinical personnel performing the examination.

ITT Population. Only those participants with NT at baseline or NT at any time post-baseline were measured for clinical significance.

Participants underwent a digital rectal examination to evaluate for focal abnormality of the prostate.

ITT Population

Threshold vital signs are defined as follows: < 80 mmHg or > 165 mmHg for systolic blood pressure; < 40 mmHg or > 105 mm Hg for diastolic blood pressure, < 40 beats per minute (bpm) or > 100 bpm for heart rate.

ITT Population. Participants not having a baseline as well as a post-baseline measurement of at least one vital sign parameter were excluded from this analysis (6 in placebo arm, 4 in dutasteride arm).