Lung Cancer in Women Treated With Anti-oestrogens anD Inhibitors of EGFR

Lung Cancer is to become the first cause of death related to cancer in France as it's already the case in United States. At Present, Lung Cancer in women and in men is treated similarly. Nevertheless, numerous studies shows that lung cancer in women has specificities : at the time of the diagnosis female patients are younger, there are less clinical signs, clinical stages are earlier, histology is often adenocarcinoma. The link with tabagism is weaker . Sensitivity to tabagism is higher (more cancer in women with the same tabagism). Response rate to chemotherapy is better. Prognosis is better Numerous hypotheses have been put forward to account for the specific characteristics of female lung cancer described above.

• One hypothesis is that there are different genetic anomalies in women. Some studies show an increase of EGFR mutation and HER2 expression and a decrease of expression of repair enzymes (ERCC1, RRM1, BRCA) which can explain the increase sensitivity to tabagism and to chemotherapy.
• Another hypothesis is that hormones play a role in oncogenesis. Indeed, lung cancer presents hormonal risk factors : pre-menopause, less than 3 kids, short menstrual cycle, hormone replacement therapy. Estrogens would have a deleterious effect on cancer incidence and on survival of lung cancer in women. Cellular and animal models show that ER pathway is activated in lung cancer and participates in oncogenesis.
• Moreover an interaction between RE and EGFR pathway has been demonstrated on lung cancer cell lines and mouse models. EGFR-TKI have shown benefit in women with wild type EGFR or unknown status (with erlotinib) and in women with EGFR mutations (with gefitinib). In this study, the use of these two treatment will be in accordance with their market authorisations. The objective of this study is to test the addition of an anti-estrogen (fulvestrant) to EGFR-TKI. Fulvestrant is a pure anti-oestrogen that binds to ER, blocks it and accelerates its breakdown. It has a market authorisation in breast cancer. Furthermore the association between EGFR-TKI and anti-estrogen could have a synergetic effect due to interaction between RE and EGFR pathways .