Cannabis in Recurrent Epithelial Ovarian Cancer: A Case Report

Introduction: There has been only one reported case of low-grade serous ovarian cancer successfully treated with cannabis oil. This case is the second, but of the high-grade serous type. Case Presentation: A female patient in her 40s was referred to our clinic with a 1-month history of a palpable abdominal mass. The patient had previously undergone complete surgery in December 2018. Pathological examination revealed high-grade serous carcinoma of the right ovary, stage 2A. Adjuvant chemotherapy (carboplatin + paclitaxel: PT) was administered for six cycles. Two years after surgery, the patient experienced her first recurrence (2×3 cm) on the left side of the rectal serosa, as detected by computerized tomography of the whole abdomen (CTWA). Second-line PT was given, and a complete response (CR) was achieved. Three years after surgery, the patient had a second recurrence (2.6 cm) at the exact same location. She refused further chemotherapy but was aware of a reported case of low-grade serous ovarian cancer treated with cannabis oil. As an alternative to chemotherapy, treatment with cannabis oil was initiated. We started tetrahydrocannabinol (THC)/cannabidiol (CBD) 1:1 cannabis oil therapy with 1 drop sublingually (SL) at bedtime (hs). This resulted in a decrease in CA125 levels without any concurrent chemotherapy. Four years after surgery, the patient again showed rising CA125 levels. However, stable disease (SD) was confirmed (2.7 cm at that time), and the cannabis oil dosage was increased to 2 drops SL at bedtime. Conclusion: This case demonstrates that cannabis oil shows inhibitory effects on recurrent highgrade serous epithelial ovarian cancer.