Evaluation of Absolute Lymphocytes: Absolute Monocytes (ALC:AMC) Ratio As Prognostic Marker in Classical Hodgkin Lymphoma Patients Treated with ABVD Chemotherapy at a Single Center in Saudi Arabia

In our clinical practice, international prognostic score (IPS) comprising of seven parameters has been in use for prognostication of advance stage Hodgkin's lymphoma (HL). Simple scoring system, that can stratify patients and or predict outcome both in early stage and advance stage HL, would be both helpful and practical to apply in daily practice. This is a retrospective study to find out whether recently reported absolute monocyte count (AMC) and absolute lymphocyte : monocyte ratio (LMR) at diagnosis are valid parameters for predicting prognosis of classical Hodgkin lymphoma (cHL) patients treated with ABVD at our center. Among many cut-off values for ALC/AMC ratio reported in literature (1.1, 1.5, 2.1, 2.8, 3.5) we chose the cut off of ≥2.1 as reported in the largest series by Tadmore et al.

Data from patients' records were collected after approval by local institutional review board. All studies were performed in accordance with the principles of the Declaration of Helsinki. Patients were included into this study if they had histopathological diagnosis of cHL, no human immunodeficiency virus infection, availability of data on all clinical and laboratory features and treatments given, as well as outcome, and follow-up. Only patients treated with ABVD as initial chemotherapy with or without subsequent radiation therapy were included as this chemotherapy regimen is currently considered the standard of care in North America and at our institution.

Response criteria were based on the guidelines from the International Harmonization Project on Lymphoma revised by Cheson et al.

We excluded 4 patients with Nodular Lymphocyte Predominant HL(NLPHL), as NLPHL is considered to be a different disease entity. Hence we found 164 patients with cHL treated at King Fahad Medical City, Riyadh from 2006, through July 2015 with ABVD. Out of 164 patients we identified nodular sclerosis 116/164 (70%) and mixed cellularity 31/164 (19%) were the most common. The median age of the patients was 26 years (range, 14-86 years); 70 (41.6%) patients had bulky disease, 84 (52.1%) had extranodal disease; Median IPS was 3; Pre-Treatment ALC median was 1635/ul (range 192-825), AMC median was 841/ul (range 60-9600), and Pre-Treatment ALC/AMC Ratio (LMR) median was 2.168 (range 0.28-19.81). Overall survival was for ALC/AMC Ratio of >=2.1 was 97.5% and 92.8% for ALC/AMC Ratio of <2.1 (p=0.172) indicating some trend for better outcome.

This study confirms that L/M ratio has prognostic value in cHL. However we plan to define our own best cut off value by ROC and AUC analysis as ALC/AMC Ratio of ≥2.1 did not discriminate survival advantage clearly in our patients. In addition to geographical and genetic differences, variations in hematology cell counters may be a plausible contributing factor.