Data analyses from the 3 sequential SWOG trials—S0014, S0313, and S1001—were presented at the 2021 American Society of Hematology (ASH) Annual Meeting to highlight extranodal presentation in limited stage (LS) diffuse large B-cell lymphoma (DLBCL).

Recent trials have changed the standard of care for patients with LS DLBCL to lessen the number of chemotherapy cycles and/or eliminate radiotherapy (RT), but an abbreviated treatment approach may not be sufficient for all patients, according to Deborah M. Stephens, DO, Huntsman Cancer Institute, Salt Lake City, Utah, and colleagues.

“With this in mind, Bobillo (2021) retrospectively reviewed patients with LS DLBCL treated with R-CHOP (4-6 cycles) +/- RT and reported an extranodal presentation had shorter progression free survival (PFS) and overall survival (OS) compared with nodal presentation,” continued Dr Stephens and colleagues.

A total of 234 patients with non-bulky LS DLBCL were placed in S0014, S0313, or S1001, and had a median age of 62 (range 18-85) years. Of these patients, 44 percent had extranodal disease. Notably, the most common sites of extranodal disease were head and neck, skin/soft tissue/muscle, gastrointestinal tract, and breast.

“For the whole group, estimated 10-year PFS and OS were 71 percent (95% CI, 64%-77%) and 77 percent (95% CI, 69%-83%), respectively. For patients with extranodal versus nodal disease, there was no difference in the estimated 10-year PFS (74% vs 68%; 2-sided logrank P =.51) or 10-year OS (77% vs 77%; 2-sided logrank P=.65),” explained Dr Stephens and colleagues.

The 10-year PFS and OS among the patients with extranodal disease of the head and neck were 61 percent and 77 percent, respectively. Similar 5-year PFS and 5-year OS rates were determined among the patients with extranodal disease who received involved field radiotherapy (IFRT) versus those who did not receive IFRT. The most common cause of death was lymphoma (n=16, 32%).

“Patients with LS DLBCL treated on 3 SWOG studies had excellent and prolonged PFS and OS regardless of EN versus nodal presentation, or whether they received consolidative IFRT or not. Our dataset does not support extranodal disease as an adverse prognostic factor for patients with LS DLBCL. As such, we do not recommend consolidation with RT in patients with non-bulky LS DLBCL presenting with extranodal disease,” concluded Dr Stephens and colleagues.

Deborah S, Li H, Constine LS, et al. Extranodal Presentation in Limited Stage DLBCL As a Prognostic Marker in Three Sequential SWOG Trials S0014, S0313 and S1001 (NCT00005089, NCT00070018, NCT01359592). Presented at: the 2021 ASH Annual Meeting; Dec. 11-14; 2021; Abstract 1423.