Pemetrexed is used in the treatment of non-small cell lung cancer (NSCLC). Its elimination is mainly renal and its nephrotoxicity requires an interruption of treatment when the CrCLCG falls below 45 mL / min. Patients with NSCLC frequently have impaired renal function by other cytotoxic drugs.

The dose adjustment of pemetrexed is performed as a function of body surface area (SC) without any pharmacokinetic rational. The challenge is to treat patients with renal insufficiency (RR) with a safe dose, based on CRCL, providing equivalent biological exposure to patients with preserved renal function.

• Primary objective: Evaluate the impact of calculating the dose of pemetrexed to be administered versus creatine clearance according to Cockcroft-Gault (CrCLCG) versus body surface area (SC) on median time before discontinuation of treatment for renal function ≤ 45mL / min in patients treated for non-small cell lung cancer predominantly non-squamous in maintenance.
• Secondary objective: To evaluate the impact of calculating the dose of pemetrexed to be administered versus CRCLCG versus SC over time to treatment discontinuation, progression-free survival (PFS), and patient overall survival.

Inclusion Criteria:

• Patient over 18 years of age
• Patient with non-small cell lung cancer predominantly non-epidermoid histologically documented
• Patient who is scheduled to initiate treatment or undergoing maintenance therapy by pemetrexed
• Neutrophils> 1500 / mm3; Chips> 100,000 / mm3
• Informed, dated and signed consent For patients of childbearing age, effective contraceptive method
• Creatinine clearance according to the Cockcroft-Gault formula between 70 and 45 mL / min
• PS = 0 or 1

Exclusion Criteria:

• Patient with a contraindication to pemetrexed therapy
• Patient with symptomatic brain metastases
• Pregnant or nursing women
• Patient under guardianship or curatorship or subject to a system of protection for persons of full age
• Patient not affiliated to a social security scheme (beneficiary or beneficiary)