For patients with testicular diffuse large B-cell lymphoma (T-DLBCL), intravenous central nervous system (CNS)–directed chemotherapy and prophylactic treatment of the contralateral testis offer the best survival outcomes, according to findings from a recent retrospective analysis.
In contrast, intrathecal chemotherapy offered no benefit, reported lead author Susanna Mannisto, MD, of Helsinki University Hospital in Finland, and her colleagues. Survival advantages gained by CNS-directed chemotherapy were generally due to control of systemic disease rather than prevention of CNS progression, they noted.
There have not been randomized trials conducted specifically in T-DLBCL and treatment guidelines are currently based on phase 2 trials. Treatment for T-DLBCL typically involves cyclophosphamide, doxorubicin, vincristine, prednisolone plus rituximab (R–CHOP), with the addition of CNS prophylaxis with either intravenous or intrathecal methotrexate or cytarabine (AraC) in eligible patients. “Thus far, however, no prospective randomised studies on the benefit of this approach have been published,” the investigators wrote. The study is in the European Journal of Cancer.
They drew data from the Danish Lymphoma Registry and three Southern Finland University Hospitals. Out of 235 patients diagnosed with T-DLBCL between 1987 and 2013, 192 (82%) were treated with curative anthracycline-based chemotherapy. As some cases dated back to 1987, about one-third (36%) were treated before rituximab was available. A slightly higher proportion received intravenous CNS-directed chemotherapy (40%). Due to data availability, 189 patients were included in the survival analysis.
Results of multivariate analyses showed that CNS-directed chemotherapy (intravenous methotrexate, high-dose AraC, or both), was associated with an approximately 58% decreased risk of death across the entire population (hazard ratio [HR] for overall survival, 0.419; 95% confidence interval, 0.256-0.686; P = .001), with elderly patients realizing the greatest benefit.
“[I]t is important to note that we did not observe reduction in the CNS recurrence rate, but rather a better control of the systemic disease, suggesting that R–CHOP alone may not be a sufficient therapy for the patients with testicular DLBCL involvement,” the investigators wrote.
Intrathecal CNS-targeted therapy did not correlate with improved survival in the study. Likewise, for the entire population, rituximab did not boost survival; however, for high risk patients (International Prognostic Index, 3-5), immunochemotherapy did provide a better rate of 5-year disease-specific survival than that of conventional chemotherapy (44% vs 14%; P = .019).
Treatment of the contralateral testis was worthwhile for the entire population, with a 46% decreased risk of death (HR for overall survival, 0.514, 95% CI, 0.338-0.782; P = .002).
Shortest overall survival times, regardless of treatment type, were reported among patients with poor performance status, elevated lactate dehydrogenase (LDH), primary T-DLBCL, more extranodal sites, higher International Prognostic Index, and patients older than 70 years.
“[O]ur results recommend aggressive chemotherapy with [intravenous high-dose methotrexate and/or high-dose AraC] for better control of systemic disease for eligible patients,” the investigators concluded. “In addition, treatment of the contralateral testis with either radiotherapy or orchiectomy should be included in the management strategy of patients with T-DLBCL.”
The study was funded by the Academy of Finland, the Finnish Cancer Foundation, the Sigrid Juselius Foundation, and others. The investigators reported additional relationships with Pfizer, Takeda, Roche, Sanofi, and others.
SOURCE: Mannisto S et al. Eur J Cancer. 2019 May 10. doi: 10.1016/j.ejca.2019.04.004.