Non Hodgkin’s Lymphoma (NHL) and Deep Vein Thrombosis (DVT): A Dangerous Liaison Still Unexplored.

Introduction DVT incidence ranges from 3 to 15% in cancer patient. Nevertheless there are only few data about DVT in lymphoma. Aim of our study is to define the real DVT risk and incidence in lymphoma patients.

Patients and Methods Our study is a retrospective study including patients of two haematology centers. We considered the age of the patients, sex, histological type of lymphoma (indolent -IL- vs aggressive -AL), localization over or under diaphragm, extranodal localizations, vascular compression, stage of disease, IPI, LDH level, chemotherapy type and timing of administration (weekly vs every 2wks or 3 weeks), the use of chemotherapy regimen containing methotrexate as potential risk factors in DVT onset. Data regarding 567 NHL patients, observed from 2001 to 2006, were collected. 400 patients had indolent NHL (IL) and 167 Aggressive NHL (AL). Median age was 59 years (R 13–94), M/F ratio was 300/267. DVT was diagnosed by ultrasound or CT scan. The statistical analysis was conducted with Yates corrected chi square test, Odds Ratio (OR), Log-rank test (to compare Kaplan-Meier curves).

Results 87 patients (15%) showed DVT. Of these, 37(43%) were localized at legs and 19(22%) involved abdominal veins (especially iliac veins, 10% of total). DVT onset median time was 3 months from NHL diagnosis (Range 0–156 months). Sex, histological type of lymphoma (IL vs AL), localization over or under diaphragm, extranodal localization, stage of disease, IPI, LDH level, and use of chemotherapy regimen containing methotrexate were not related to an increased risk to develop DVT. Vascular compression was the most significant risk factor for DVT development with OR 3.1 (CI95%:1.9–5), Chi Square22.7(p< 0.0001). Patients receiving weekly chemotherapy showed an increased risk to develop DVT (OR 1.8; CI95%:1.1–2.8), Chi Square5.1, p0.024. Patients aged ≥60 presented increased risk of DVT with OR 1.7(CI95%: 1–2.7), Chi Square 4.28 (p 0.04). Patients with DVT within 3 months from NHL diagnosis had an higher risk of disease relapse or non response at first line chemotherapy: OR 3.7 (CI95%: 1.8–7.3), Chi Square 13.4 (p < 0.0001), positive predictive value 0.71(CI95%: 0.57–0.82), specificity 0.95(CI95%: 0.93–0.97). However DVT had no impact on mortality and survival, also in the subgroup of patients with DLBCL. Discussion In our study vascular compression by enlarged lymphonodes, patient age ≥60 y.o., and weekly administration of chemotherapy seem to be the main risk factors to develop DVT in NHL patients. Further studies, concerning genetic conditions and other disease-related parameters, are ongoing to individuate other risk factors for thrombosis in NHL patients. The DVT development within 3 months from NHL diagnosis seems to be a risk factor for non response/relapse. An antithrombotic prophylaxis could be considered in the patients with higher thrombotic risk.