PET-Guided Chemotherapy May Boost Hodgkin Lymphoma PFS

Response-adapted protocol findings support its use for patients with advanced-stage Hodgkin lymphoma

medwireNews: US research suggests that progression-free survival (PFS) may be improved when chemotherapy for stage III and IV classic Hodgkin lymphoma is guided by fluorodeoxyglucose (FDG)-positron emission tomography (PET).

The Southwest Oncology Group S0816 response-adapted therapy protocol assessed HIV-negative patients after two cycles of doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD), explain Oliver Press, from the Fred Hutchinson Cancer Research Center in Seattle, Washington, and co-workers.

In all, 271 patients with a negative PET scan, defined as a Deauville score of 3 or less, continued with a further four cycles of ABVD. The vast majority (96%) of these patients achieved complete remission, with 4% recorded as partial responders due to the absence of bone marrow biopsy evidence.

The 60 patients with a positive PET scan, defined as a Deauville score of 4 or 5, were offered six cycles of escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine and prednisone (eBEACOPP), 49 of whom accepted the aggressive treatment. A complete response was achieved by 55% of eBEACOPP-treated patients, while 38% had a partial response, 5% stable disease and 2% an unknown result.

After a median of 39.7 months, 2-year rates of overall survival and PFS in the whole treatment group were estimated to be 98% and 79%, respectively.

This included an estimated 2-year PFS of 64% for patients with a positive PET scan after initial ABVD therapy, which exceeded the prespecified target of 48% and “is much higher than the expected 2-year PFS of 15 to 30%”, the researchers report inthe Journal of Clinical Oncology.

And for patients with a negative PET scan, the 2-year PFS was 82%, they add.

The researchers note that adherence to treatment was poorer in patients assigned to receive eBEACOPP than those continuing on ABVD; the intensified regimen was, as expected, significantly more toxic, with 85.7% of patients experiencing grade 4 to 5 toxicity compared with 36.7% of patients who continued ABVD.

Commenting in a press release, author Jonathan Friedberg, from the University of Rochester Medical Center in New York, USA, noted that the response-adapted protocol exposed just 20% of patients, who had a median age of 32 years, to eBEACOPP treatment.

“This response-adapted therapy would ensure that the people who need the more toxic drugs receive them - and would spare others from infertility and serious toxicities”, he said.

The team cautions, however: “Although the results of SWOG S0816 argue strongly for a response-adapted approach for advanced-stage [Hodgkin lymphoma] using early interim FDG-PET/[computed tomography], it must be acknowledged that the outcomes are being compared with historical figures with their inherent limitations.”

They highlight the need for longer follow-up, as well as further clinical trials to test both the hypothesis of response-adapted treatment and identify more accurate methods of determining which patients should be selected for intensified chemotherapy.

“Until that time, our results suggest that the response-adapted strategy of increasing treatment to eBEACOPP in [PET]-positive patients is a reasonable option for advanced-stage [Hodgkin lymphoma] therapy”, they conclude.

Reference

Press OW, Li H, Schoder H, et al. US Intergroup trial of response-adapted therapy for stage III to IV Hodgkin lymphoma using early interim fluorodeoxyglucose-positron emission tomography imaging: Southwest Oncology Group S0816. J Clin Oncol 2016; Advance online publication 11 April. doi: 10.1200/JCO.2015.63.1119

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