Safety and Efficacy of Smoked Cannabis for Improving Quality of Life in Advanced Cancer Patients

Inclusion Criteria: 1. Written informed consent 2. Adult male and female patients at least 18 years of age 3. Subject agreed to follow the protocol 4. Advanced cancer for which there is no known curative therapy 5. Patients experiencing pain ≥4 on NRS due to cancer related pain 6. Life expectancy six weeks or longer 7. PPI score less than or equal to 4 (survival more than 6 weeks) 8. PPS greater than or equal 70% 9. PaP Score Group A (30-day survival probability \>70%) 10. An Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2 11. The patient has a clinical diagnosis of cancer related pain, which is not alleviated with their current optimized opioid treatment 12. The patient is using no more than one type of breakthrough opioid analgesia 13. Normal cognitive status according to MDAS and MiniCog 14. Normal liver function (defined as aspartate aminotransferase 10-40 U/L and alanine aminotransferase 7-56 U/L) 15. Normal renal function (defined as serum creatinine level \<133 µmol/L and Estimated Glomerular Filtration Rate (eGFR) greater than or equal to 60) 16. The patient is able to perform deep inhalations and hold breath for at least 5 to 10 seconds. If there is any pulmonary disease diagnosed previously (obstructive and/or restrictive pathology), the patient must be able to perform a maximal inhalation of at least 12-15 ml/kg measured with an incentive spirometer, followed by a normal exhalation 17. Ability to read and respond to questions in French or English. 18. Previous or current use of opioid analgesics (at least 1 week) 19. A female volunteer must meet one of the following criteria: If of childbearing potential - agrees to use one of the accepted contraceptive regimens from at least 28 days prior to the first drug administration, during the study and for at least 60 days after the last dose. An acceptable method of contraception includes one of the following: * Abstinence from heterosexual intercourse * Systemic contraceptives (birth control pills, injectable/implant/insertable hormonal birth control products, transdermal patch) * Intrauterine device (with or without hormones) * Condom with spermicide or condom with intravaginally applied spermicide If of non-childbearing potential - should be surgically sterile (i.e. has undergone complete hysterectomy, bilateral oophorectomy, or tubal ligation) or in a menopausal state (at least one year without menses) 20. A male volunteer with sexual partners who are pregnant, possibly pre…