原発性後腹膜軟部肉腫の現代的治療法の改善：単一施設における経時的な転帰の向上

This study aimed to investigate outcome for patients affected by primary retroperitoneal sarcomas (RPS) treated over time at a single large referral institution.

The study included all consecutive patients with primary, localized, adult-type soft tissue sarcoma of the retroperitoneum observed and treated at the authors' institution from January 2002 to December 2021. The primary endpoint was overall survival (OS). The secondary endpoints were crude cumulative incidence (CCI) of local recurrence (LR) and distant metastases (DM), and post-recurrence OS. Based on the date of primary surgery, the patients were divided in two groups (2002-2011 and 2012-2021).

The study identified 872 patients: 244 treated between 2002 and 2011 (early cohort) and 628 treated between 2012 and 2021 (recent cohort). The median follow-up period was 77.1 months (interquartile range [IQR], 41.7-115.4): 136.7 months (IQR, 118.1-166.4 months) for the early cohort and 59.5 months (IQR, 34.1-88.9 months) for the recent cohort. At the multivariable analysis, the patients in the recent cohort had significantly better OS. The early cohort had a 5 year OS of 61.7% (95% CI, 55.9-68.2%) and a 10 year OS of 47.7% (95% CI, 41.7-54.6%), whereas the recent cohort had a 5 year OS of 78.8% (95% CI, 75.1-82.6%) and a 10 year OS of 64.0% (95% CI, 57.8-70.8%). The recent cohort had fewer distant metastases (hazard ratio [HR], 1.50; 95% CI, 1.06-2.11; p = 0.022) and a similar rate of local recurrences (HR, 1.31; 95% CI, 0.97-1.76; p = 0.080). The 30 month post-recurrence OS was 41.9% (95% CI, 34.5-50.9%) in the early cohort and 65.9% (95% CI, 59.5-72.9%) in the recent cohort (p < 0.001).

Management of RPS in the recent years has resulted in prolonged OS. These findings establish new standards for historical comparisons of emerging strategies.