FOcal Radiation for Oligometastatic Castration-rEsistant Prostate Cancer (FORCE)

Duration of overall response is measured from the time measurement criteria are met for CR or PR (whichever is first recorded) until the first date that recurrent or progressive disease is objectively documented. A patient's designated response at any one time is a combination of the assessment of target lesions, non-target lesions, bone lesions and disease symptoms. Progression in this measure is defined as worsened pain or new sites of disease on imaging. Progression by pain due to prostate cancer requires evidence of disease at the site of pain and one or more palliative intervention (opioid therapy for 10 out of 14 consecutive days, radionuclide therapy or radiation therapy). Response and progression definitions used will be a combination of the criteria proposed by the Response Evaluation Criteria in Solid Tumors (RECIST) Committee v1.1 and the Prostate Cancer Working Group 3.

PFS is defined as the duration of time from start of treatment to date of progression or death (whichever is first). Initiation of other prostate directed therapies (excluding bisphosphonates or RANKL inhibitors) is considered to be progression. Reported as Kaplan-Meier estimates, including median at 12 months and 24 month.

The Median PSA PFS is defined as the median duration of time from start of treatment to date that PSA progression is documented or death occurs (whichever is first). PSA progression is defined as a 25% increase over baseline or nadir whichever is lower and an increase in the absolute value of PSA level by 2 ng/ml. Reported as Kaplan-Meier estimates, including median at 12 months and 24 month.

Radiographic PFS is defined as the duration of time from start of treatment to date that progression is radio-graphically documented or death occurs (whichever is first). Reported as Kaplan-Meier estimates, including median at 12 months and 24 month.

Overall survival (OS) is defined as the duration of time from start of treatment to death. Reported as Kaplan-Meier estimates, including median at 12 months and 24 month.

Prostate Cancer Specific Survival (PCSS) is defined as the duration of time from start of treatment to death from prostate cancer. Reported as Kaplan-Meier estimates, including median at 12 months and 24 month.

Non-irradiated metastases free survival is defined as the duration of time from start of treatment to the date of progressive disease of a new target lesion, a new non-measurable/non-target lesion or emergence of 2 or more new skeletal lesions on a bone scan. Reported as Kaplan-Meier estimates, including median at 12 months and 24 month.

The number of patients whose PSA becomes undetectable (≤0.2 ng/ml) will be counted in each treatment arm and divided by the number of patients who received any protocol treatment to provide the proportion of patients with complete PSA response. Complete PSA response is defined as an undetectable PSA (≤0.2 ng/ml).

The number of patients whose PSA declines by 50% decline (PSA partial response 50 (PR50)) will be counted in each treatment arm and divided by the number of patients who received any protocol treatment to provide the proportion of patients with PR50. PR50 response is defined as a decrease in PSA value by ≥ 50%.

The number of patients whose PSA declines by 90% decline (PSA partial response 90 (PR90)) will be counted in each treatment arm and divided by the number of patients who received any protocol treatment to provide the proportion of patients with PR90. PR90 response is defined as a decrease in PSA value by ≥ 90%.

The measurable disease response rate (CR + PR) will be calculated for patients evaluable for measurable disease response. Complete response (CR) is defined as a disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduced in short axis to <10 mm. There can be no appearance of new lesions. Partial Response (PR) is defined as at least a 30% decrease in the sum of the longest diameter (LD) of target lesions, taking as reference the baseline sum LD. There can be no appearance of new lesions.

The National Comprehensive Cancer Network Functional Assessment of Cancer Therapy - Prostate Symptom Index (NFPSI-17), version 2 is used to assess high priority symptoms/QOL concerns in patients with advanced prostate cancer (PC). It is a 17-item survey with a recall period of the past 7 days; scored using a 5 point Likert-type scale. Items are scored from 1-4 with some items reverse scored. Described using means or medians. score range is 0-68 with higher scores indicating better health