Relationship between neutrophil counts following ABVD chemotherapy and survival in Hodgkin's Lymphoma cases

HL is a rare hematological malignancy among all lymphomas with a high cure rate. ABVD chemotherapy is the most commonly used chemotherapy combination for many years. Chemotherapy-associated hematotoxicity can cause adverse side effects such as dose-limiting or delaying treatment in chemotherapy. Our aim in this study is to investigate the effects of treatment-related neutropenia on progression free survival, overall survival and treatment responses. For this purpose, 123 patients whose records could be accessed retrospectively were included in the study and their demographic data, diagnosis dates, stages, neutrophil values before chemotherapy and on days 5-11 and 20-26 after chemotherapy, treatment responses, progression and/or death dates, B symptoms, extranodal involvements, bulky involvements, febrile neutropenia history, radiotherapy status, G-CSF requirement data were recorded. The median follow-up period was 35.5 (36-46) months. The patient population was divided into two groups according to the neutrophil cutoff value of 1000/mm3. Those who had absolute neutrophil count lower than 1000/mm3 on days 5-11 and/or 20-26 were included in the neutropenia group. The others who did not have an absolute neutrophil count lower than 1000/mm3 were set in the non-neutropenia group. In the general population, the 5-year PFS was 68.2% (95%CI 64%-79%) while the 5-year OS was 88.7% (95%CI 84.5%-96.5%). The OS was found to be significantly shorter in the group whose neutrophil counts were below 1000/mm3 on days 5-11 than those whose neutrophil value was above or equal to 1000/mm3 on the same days regardless of days 20-26. However, no significant difference was observed in terms of PFS between these two groups. There were no significant differences in PFS and OS durations between the group who had neutrophil counts below 1000/mm3 on days 20-26 and the group who had neutrophil counts above or equal to 1000/mm3 on days 20-26. When the treatment responses were examined, no statistically significant differences were found between the neutrophil value and the interim PET-CT responses and end-of-treatment PET-CT responses. When demographic and clinical data were examined, only age was found to be a factor affecting overall survival. There was no significant effect of gender, stage, B symptoms, extranodal involvement, bulky involvement, febrile neutropenia, use of G-CSF and radiotherapy history on OS. Similar studies examining the relationship between neutropenia and survival in HL patients found that treatment-related neutropenia had a positive contribution to overall survival. In our study, the reasons for not providing an overall survival advantage in the neutropenia arm; neutropenic complications are more common in patients who died, the median age is higher than the population in the other studies, the advanced stage at the time of diagnosis is more common in our study and the higher incidence of febrile neutropenia comparing to other studies could be the reasons. We believe that it is important to investigate the effect of neutropenia on survival with further studies on this subject. Key Words: Hodgkin lymphoma, ABVD, Neutropenia, Prognostic indicator