About 30% of pts with UM develop metastatic disease (MUM) despite PTx. Liver is by far the commonest site of metastases. MUM has poor prognosis and no systemic treatment (STx) has been proven to improve overall survival (OS). However, the role of active surveillance for metastatic disease is still controversial.
We performed an outcome analysis of all UM pts prospectively registered onto our active surveillance programme after PTx. All pts had systemic staging at initial diagnosis of UM and then 6-monthly liver imaging (CT triple-phase or ultrasound) and clinical review for the first 5 years and 12-monthly afterwards. Progression-free survival (PFS) was calculated from time of first systemic relapse to first disease progression, OS from time of first systemic relapse to death or latest FU.
Out of 166 pts registered between April 2009 and April 2017, 36 (22%) developed MUM: 14 pts relapsed 5 yrs from PTx. MUM pts characteristics: males 19 (53%); median age 58 (range 34-85); median tumour thickness at diagnosis 9mm (2-22); sites of metastases: liver only 13 (36%), liver + other sites 21 (58%), extra-hepatic only 2 (6%). Relapses were asymptomatic and detected on surveillance imaging in 29 (80%) pts. Nine pts (7 detected from surveillance) underwent primary hepatic metastasectomy (HM), 27 (75%) pts were non-resectable (NR) and underwent STx (n = 18), locoregional Tx (n = 4), best supportive care (n = 5). Overall, 29/36 MUM pts received immunotherapy with either ipilimumab or nivolumab/pembrolizumab. At a median FU of 36.5 mos (1-103), 27 pts have died and the median OS is 16.6 mos (95%CI: 7.8-25.3). Both PFS and OS were statistically significantly longer for HM pts compared to NR pts (PFS: 10.8 vs 4.4mos, p = 0.01/OS: 24.9 vs 13.4mos, p = 0.04). Eight out of 9 pts developed further disease relapse after HM.
Our data indicate that active surveillance after PTx of UM can allow detection of asymptomatic potentially resectable liver metastases, especially in pts with high risk UM (i.e. tumour thickness >5mm). Although durable remission after HM is rare PFS and OS may be significantly prolonged.
Clinical trial identification
Legal entity responsible for the study
St Vincent's Healthcare Group
All authors have declared no conflicts of interest.