Abstract 2918: Menopausal hormone therapy and B-cell non-Hodgkin lymphoma (NHL) risk in the Los Angeles County NHL Case-Control Study
Authors: Wang Sophia S. , Luo Jianning , Sullivan-Halley Jane , Lu Yani , James V. Lacey , Cozen Wendy , Bernstein Leslie 
Published: May 2015

Introduction: Immune modulation has long been established as a risk factor for non-Hodgkin lymphoma (NHL). Menopausal hormone therapy (MHT) has been shown to affect immune function in both animal and human studies. However, the evidence for an association between MHT and NHL remains unclear. Cohort studies have suggested either no association or increased risk between MHT use and NHL, particularly for the follicular lymphoma subtype. A recent pooled analysis of case-control studies from the United States, Europe, and Australia reported a decreased risk for NHL among women who used MHT, but this analysis was limited by the lack of information on MHT formulation, dose, and duration.

Methods: The Los Angeles County NHL Case-Control Study comprises 1010 B-cell NHL patients diagnosed 2004-2008 from the Los Angeles Cancer Surveillance Program, matched 1:1 by age and race to female neighborhood controls. Extensive information on MHT use was ascertained, along with information on demographic and known NHL risk factors. Among 685 post-menopausal women diagnosed with NHL and 685 matched controls, we conducted conditional logistic regression, adjusting for age, race and socioeconomic status, to evaluate the association between MHT use, formulation, dose and duration, and risk for B-cell NHL.

Results: B-cell NHL risk was reduced among women who reported having ever used MHT (HR = 0.66, 95% CI = 0.52-0.85) compared to never users. This risk reduction was similar for women who reported using unopposed estrogen only (HR = 0.75, 95% CI =0.56-1.01), estrogen plus progestin only (HR=0.62, 95% CI =0.45-0.85), sequential use of unopposed estrogen followed by estrogen plus progestin (HR=0.36, 95% CI=0.18-0.70), and sequential use of unopposed estrogen plus progestin followed by unopposed estrogen (HR=0.57, 95% CI=0.32-1.00). Among women who reported using unopposed estrogen or estrogen plus progestin by pill or patch (prescription only), reduced B-cell NHL risk was most pronounced among those who started MHT use early, at age 45 years or younger (HR=0.60, 95% CI=0.42-0.85) and generally among women with longer duration of use. The protective associations associated with MHT use were consistent among major B-cell NHL subtypes, including diffuse large B-cell lymphoma and follicular lymphoma.

Conclusions: These data provide evidence for an association between MHT use - either unopposed estrogen or estrogen plus progestin use - and decreased risk of B-cell NHL, supporting a role for postmenopausal hormones in B-cell NHL etiology.

Citation Format: Sophia S. Wang, Jianning Luo, Jane Sullivan-Halley, Yani Lu, James V. Lacey, Jr., Wendy Cozen, Leslie Bernstein. Menopausal hormone therapy and B-cell non-Hodgkin lymphoma (NHL) risk in the Los Angeles County NHL Case-Control Study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2918. doi:10.1158/1538-7445.AM2014-2918