Epoetin Beta in Patients Undergoing Chemotherapy for Solid Tumors

Inclusion criteria : * Age \> 18 years * Hemoglobin levels between \[ \> 9g/dl - \< 11 g/dl \] . * Patient requiring erythropoietine beta treatment for a foreseeable duration of at least 8 weeks under the same chemotherapy protocol. * Patient with cancer undergoing chemotherapy * Patient without EPO within 6 months prior to current chemotherapy. * WHO 2 performance status (Appendix 1). * Patient information and signature of informed consent or legal representative Exclusion criteria : * Hemoglobin \< 9 g/dl or \> 11 g/dl * Patient with cancer not treated with chemotherapy (targeted therapy, hormone therapy, etc…) * Patient with cancer treated with concomitant radiation chemotherapy. * Co-treated with Epo beta and scheduled transfusion prior to inclusion. * Hypersensitivity to the active substance or one of the NeoRecormon excipients® * Poorly controlled high blood pressure * Pregnant woman, likely to be pregnant or breastfeeding, * Persons deprived of liberty or under guardianship, * Unable to undergo medical follow-up for geographic, social or psychological reasons.