A Study of Serum Folate Levels in Patients Treated With Olaparib

Inclusion Criteria: * Willing and able to provide signed informed consent * Female, post-menopausal, ≥18 years of age inclusive, at the time of signing the consent form * Individuals who have ovarian cancer or breast cancer who are recommended to start olaparib * Patients must have normal organ and bone marrow function measured within 28 days prior to administration of study treatment as defined below: * Haemoglobin ≥ 9 g/dL with no blood transfusion in the past 28 days * Absolute neutrophil count (ANC) ≥ 1.5 x 109/L * Platelet count ≥ 100 x 109/L * Total bilirubin ≤ 1.5 x institutional upper limit of normal (ULN) * Aspartate aminotransferase (AST) (Serum Glutamic Oxaloacetic Transaminase (SGOT)) / Alanine aminotransferase (ALT) (Serum Glutamic Pyruvate Transaminase (SGPT)) ≤ 2.5 x institutional upper limit of normal unless liver metastases are present in which case they must be ≤ 5x ULN * Patients must have creatinine clearance estimated of ≥51 mL/min * Eastern Cooperative Oncology Group (ECOG) performance status 0-1). * Patients must have a life expectancy ≥ 16 weeks. * At least one lesion (measurable and/or non-measurable) that can be accurately assessed at baseline by CT and is suitable for repeated assessment. Exclusion Criteria: * Patients with folic acid deficiency, defined as folate \<7 ng/mL, or those taking folic acid supplementation within 30 days of olaparib initiation. * Other malignancy unless curatively treated with no evidence of disease for ≥5 years except…