CT‐based assessment of body composition following neoadjuvant chemohormonal therapy in patients with castration‐naïve oligometastatic prostate cancer

BACKGROUND: The purpose of this study is to assess the body composition changes in men with recently diagnosed oligometastatic prostate cancer following neoadjuvant chemohormonal therapy. Further, we evaluated whether CT‐based body composition parameters are associated with biochemical recurrence or imaging progression. MATERIAL AND METHODS: Recently diagnosed castration‐naïve oligometastatic prostate cancer patients who received neoadjuvant docetaxel chemotherapy and androgen deprivation treatment (ADT) before prostatectomy and consolidation of local and oligometastatic disease (total eradication therapy), as part of a phase‐II prospective clinical trial were included. Body composition parameters including cross‐sectional areas of the psoas muscle, total, visceral, and subcutaneous adipose tissue were measured on serial CT scans obtained before and following completion of neoadjuvant treatment. RESULTS: A total of 22 prostate cancer patients were included (median age 58 years, median Gleason score 8). The median time intervals between commencement of neoadjuvant chemohormonal therapy and first and second follow‐up CTs were 3 and 12 months, respectively. Compared to the baseline scan, there were significant declines in psoas muscle cross‐sectional areas with estimated percentage declines of −13.9% (IQR: 7.6%–16.5%, p < .001) and −13.2% (IQR: 6%–11.2%, p < .001) on first and second follow‐up CTs. There were significant increases in subcutaneous adipose tissue following neoadjuvant chemohormonal therapy with percentage increases of +8.9% (IQR: 5.1%–21.5%, p = .002) and +18.9% (IQR: 6.1%–33.8%, p < .001), respectively. The median follow‐up was 34.5 months. The estimated 2‐year prostate‐specific antigen progression‐free and radiologic progression‐free survival were 95.5%. No significant association between baseline or percentage change in body composition parameters and disease progression were identified. CONCLUSIONS: Our findings showed a significant reduction in muscle mass and an increase in subcutaneous adiposity in men treated with neoadjuvant docetaxel and ADT, more pronounced on the first follow‐up scan after completion of neoadjuvant treatment. Body composition parameters were not found to be significant predictors of disease progression in our cohort.