Elsevier

Steroids

Volume 118, February 2017, Pages 47-54
Steroids

Hormone therapy and lung cancer mortality in women: Systematic review and meta-analysis

https://doi.org/10.1016/j.steroids.2016.12.005Get rights and content

Highlights

  • Lung cancer is estrogen related, thus, hormone therapy may affect female patients.

  • We summarized the associations between hormone therapy and lung cancer mortality.

  • A protective role of hormone therapy in pooled prospective cohorts.

Abstract

The mortality of lung cancer presents a significant difference between the sexes. A role of hormone therapy (HT) in lung cancer mortality has been suggested, but the evidence is inconclusive. We sought to elucidate this issue with a meta-analysis. We conducted a systematic literature search in both Pubmed and Embase. Studies that reported the association of HT and mortality of lung cancer cases were included. Pooled hazard ratio (HR) was computed as the effect size to reflect the association between HT and lung cancer mortality. In total, 11 studies were included in the meta-analysis. The pooled HR of HT in relation to lung cancer mortality was 0.97 (95% CI 0.83–1.12, I2 = 59.2%, p = 0.006) in all studies disregarding study design, and it was 0.80 (95% CI: 0.69–0.92, I2 = 21.4%, p = 0.278) in prospective cohort studies. Results of this meta-analysis were robust, and there was no indication of significant differences in association in small and large studies. We observed a protective role of HT use in lung cancer mortality in pooled prospective cohorts, but not in pooled retrospective cohorts and post hoc analyses of randomized controlled trials. Future studies that address smoking, type and time of HT, menopausal status, and histology are warranted.

Introduction

Lung cancer presents some distinctive differences in both etiology and prognosis between the sexes. Women are more likely to develop adenocarcinoma than men [1]. The incidence of lung cancer in never smokers is significantly higher in women, and women are more susceptible to cigarette exposure in terms of lung cancer incidence [2]. This kind of gender-related difference also exists in lung cancer mortality, which is reflected by the observation that women with lung cancer present significantly better clinical outcomes than their male counterparts. This prognosis advantage retains after a full consideration of stages and histological subtypes [3]. The incidence and prognosis of lung cancer are thus suspected to be sex hormone related. More relevant studies emerged after the verification of the expression of estrogen and progesterone receptors in lung cancer tissue [4], [5].

Hormone therapy (HT) is the primary source of long-term exogenous estrogen and/or progestogen exposure in postmenopausal women. Although many studies have explored the association between HT and lung cancer incidence [6], limited studies explored the possible association between HT use and lung cancer mortality, while existing findings were highly inconsistent [7], [8]. The potential prognostic role of HT in lung cancer mortality remains elusive, given a small number of lung cancer cases in most studies that employed different designs and had some unique features in their study populations. We summarized present evidence to elucidate the association between HT use and mortality in female lung cancer patients by conducting a systematic review and meta-analysis.

Section snippets

Literature search strategy

We conducted a literature search in Pubmed and Embase. We completed all electronic search of the literature on February 22, 2016. The time range of publication search was set between 1985 and 2016. We only included publications written in English. We developed a search strategy which consists of: (1) hormone therapy, hormone replacement therapy, hormone use, menopausal hormone therapy, estrogen or progestogen; (2) lung cancer, lung carcinoma, lung tumor or lung neoplasm; (3) survival, mortality

Results

The literature screening process is shown in Fig. 1. After screening according to the preset inclusion criteria, 11 studies were eligible and included in the final meta-analysis [7], [8], [16], [17], [18], [19], [20], [21], [22], [23], [24]. We did not encounter significant discrepancies in judging eligibility and extracting data.

Discussion

In this systematic review and meta-analysis, we found that the pooled HRs of all included studies, post hoc analyses of RCTs, and cohorts with retrospective survival data were statistically insignificant. We only found a protective role of HT use in lung cancer mortality in prospective cohorts.

Lung cancer presents marked differences in prognosis between the sexes. In addition to established factors (e.g. smoking, occupational exposure, consumption of meat and vegetable/fruits), factors that may

Conflicts of interest and source of funding

This study was not supported by any fund. The authors declare no actual or potential competing financial interests.

Funding source

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

References (34)

  • H.A. Wakelee et al.

    Lung cancer incidence in never smokers

    J. Clin. Oncol.

    (2007)
  • L.P. Stabile et al.

    Estrogen receptor pathways in lung cancer

    Cur. Oncol. Rep.

    (2004)
  • J.M. Bae et al.

    Hormonal replacement therapy and the risk of lung cancer in women: an adaptive meta-analysis of cohort studies

    J. Prev. Med. Public Health

    (2015)
  • A.K. Ganti et al.

    Hormone replacement therapy is associated with decreased survival in women with lung cancer

    J. Clin. Oncol.

    (2006)
  • G. Wells, B. Shea, D. O’connell, J. Peterson, V. Welch, M. Losos, P. Tugwell, The Newcastle-Ottawa Scale (NOS) for...
  • ...
  • I. Shrier et al.

    Should meta-analyses of interventions include observational studies in addition to randomized controlled trials? A critical examination of underlying principles

    Am. J. Epidemiol.

    (2007)
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