SAN FRANCISCO—Isolated testicular relapse in children with acute lymphoblastic leukemia (ALL) is associated with improved outcomes compared with patients who experience combined bone marrow and testicular relapse, the ALL-REZ BFM 83-2002 study (Abstract 66) presented at the 56th American Society of Hematology (ASH) Annual Meeting and Exposition has shown.
However, bilateral testicular involvement, rather than unilateral involvement, was an independent risk factor for relapse, and patients identified as having very early/early isolated bilateral testicular relapse were likely to have a poor prognosis.
For the retrospective study, researchers analyzed outcomes of children with ALL who experienced testicular relapse in the ALL-REZ BFM studies that were conducted between March 1983 and December 2013. Patients were only included if it was their first relapse.
Of the 1,603 boys in the ALL-REZ BFM studies, 302 had testicular involvement. Patients treated with local therapy received orchiectomy or irradiation at 24 Gy of clinically involved testes.
Results showed that there was no significant difference in extent and time point of relapse between isolated testicular relapse and combined bone marrow and testicular relapse.
Patients with isolated testicular relapse were found to have improved 5 year-event free survival (pEFS) compared with those who experienced combined relapse (0.70±0.04 vs. 0.54±0.04, P=0.005). Particularly, those with bilateral testicular involvement had worse pEFS compared with unilateral involvement (0.48±0.05 vs. 0.71±0.04, P<0.0001).
Patients with very early or early isolated bilateral testicular involvement had poor outcomes (0.40±0.09 vs. 0.68±0.08, P = 0.015), while those with late relapse had no significant difference in outcomes (0.79±0.11 vs. 0.86±0.05, P=0.11).
In addition, subsequent local relapse was uncommon, but 32.5% of patients who suffered a relapse experienced a subsequent, typically bone marrow relapse.
“With our data, in patients with early isolated unilateral testicular relapse, we wouldn’t recommend any kind of stem cell transplantation, but for patients with bilateral involvement, we would recommend stem cell transplantation,” Christiane Chen-Santel MD, of the Department of Pediatric Oncology/Hematology, Charité University Medicine Berlin in Berlin, Germany, said while presenting at the meeting.