Results
224 patients with HL were screened for inclusion. Of the total charts examined 93 patients were found to be eligible; 46 patients had received ABVD and 47 patients had received ABVE-PC chemotherapy as initial chemotherapy. 129 patients were not included due to either receiving either a different therapy or a variation of the two therapies in question, and 2 patients were excluded due to having received initial therapy at a different institution. There were no significant differences in the two groups regarding gender, ethnicity, and race (Table 1). Of note, the ABVE-PC group contained statistically significantly older patients on average compared to the ABVD group (14.5 vs 12.7 years, p =0.03).
Known prognostic factors are summarized in Table 2. As risk classification has changed multiple times during the time period examined, patients were stratified retrospectively and uniformly into comparable risk groups utilizing the criteria employed by the COG AHOD0031 study.9 There were no statistically significant differences found in risk stratification (Table 2,p =0.56). There were also no differences in splenic involvement, extra-nodal extension, erythrocyte sedimentation rate, leukocyte count, or hemoglobin concentration.
Patients were followed for a median of 3.9 years from diagnosis (range 0.3-18.1 years, interquartile range 1.5-5.8 years). There was no difference found in EFS and OS between patients who received ABVE-PC and those who received ABVD (Figures 1A and 1B, p =0.46 andp =0.37, respectively). There was no difference in the proportion of patients requiring more than four cycles of chemotherapy or requiring a chemotherapy regimen change (Table 3). Notably, more patients in the ABVE-PC group received external beam radiation when compared to the ABVD group in intention-to-treat analysis (59.6% vs 32.6%, Table 3,p =0.01), although 6 patients achieved complete response but were randomized to receive radiation on the AHOD0031 study. When the 6 patients were analyzed as not having radiation, the difference was not statistically significant (46.8% vs 32.6%, Table 3, p =0.21). Response by PET-CT was only available for a subset of the cohort (n =34). 90% of patients receiving ABVD (n =9 of 10 total) and 58.3% of patients receiving ABVE-PC (n =14 of 24 total) had rapidly-responsive lesions on PET-CT following 2 cycles of therapy (i.e., Deauville score of 1, 2, or 3) (p =0.11).
Late effects are summarized in Table 4; statistics are not available due to extremely low event rates. There were no apparent differences seen in reduced cardiac shortening fractions (SF, reduced SF defined as <29%), reduced diffusing capacity of the lung for carbon monoxide (DLCO), second malignancies or evidence of early gonadal dysfunction (as measured by follicle stimulating hormone above gender-defined norms).