Favorable outcome of abbreviated R-CHOP in patients with primary testicular lymphoma
Patients with limited stage primary testicular lymphoma (PTL) receive a multimodality treatment approach including 6 cycles of R-CHOP to prevent relapses. In low-risk limited stage DLBCL, the number of cycles of R-CHOP is nowadays reduced to 4. However, it is unknown whether the reduction of cycles of R-CHOP in patients with PTL is feasible. Therefore, we aimed to investigate whether reduced R-CHOP impacted the outcome in a real-world cohort of PTL patients.
PTL patients ≥18 years, Ann Arbor stage I-II, diagnosed in 2014-2021, who received ≥3 cycles of R-CHOP were identified in the Netherlands Cancer Registry, with survival follow-up through 2023. Patients with CNS involvement at diagnosis were excluded. Treatment modalities were categorized as 3 or 6 cycles R-CHOP. The endpoints were progression-free survival (PFS), overall survival (OS) and cumulative incidence function (CIF) of CNS relapse. Uni-and multivariable analyses were conducted, using Cox regression analyses, to establish independent predictors of risk of relapse and mortality among patients who received 3 cycles of R-CHOP versus 6 cycles of R-CHOP.
A total of 140 patients were identified: median age, 70 years (range, 37-86 years); stage I, 69%; IPI 0, 87%. Of these patients, 44 received 3 cycles R-CHOP and 96 received 6 cycles R-CHOP. Patients with stage I disease more commonly received 3 cycles of R-CHOP compared to patients with stage II (p<0.01; Table 1). Of the patients who received 3 cycles R-CHOP, 32% received <4 MTX IT cycles, compared to 14% in patients who received 6 cycles R-CHOP (p=0.01). The median follow-up from end of treatment was 36 months (inter quartile range [IQR], 12-56 months). Overall response rate (ORR; partial remission or greater) for patients who received 3 cycles R-CHOP and 6 cycles R-CHOP were similar (77% versus 86%, respectively, p=0.17).
The 5-year PFS and OS were 59% and 64%, respectively. Regarding 3 versus 6 R-CHOP, the 5-year PFS and OS were similar, i.e. 61% versus 57% (p=0.80) and 70% versus 58% (p=0.44), respectively (Figure 1). In uni- and multivariable analysis, in addition to the number of cycles, patients older than 60 years negatively impacted the risk of relapse or mortality. The 5-year CIF of CNS was 14%, with a median time from end of treatment to CNS relapse of 25 months. No difference in 5-year CIF of CNS was observed between patients receiving 3 cycles of R-CHOP versus those receiving 6 cycles (17% versus 10% respectively, p=0.39).
In this nationwide PTL population, nearly one-third of patients received 3 instead of 6 R-CHOP cycles, with no difference in survival. These data challenge the use of 6 cycles of R-CHOP in limited stage PTL.