This project represents a first systematic, prospective, single-arm cohort study of a safe and effective dosing regimen of an orally administered cannabis oil formulation in a cancer subject population with poorly controlled pain.

Over a 1-2 year period, 40 cancer patients experiencing poorly controlled pain will be enrolled in to a prospective single-arm cohort study, in which they will receive an orally administered cannabis oil formulation as an add-on therapy to current treatment regimens. Subjects entering the acute study phase will be titrated to a tolerated dose at which a sustained pain response is reached, and may subsequently enter a 12 week chronic phase during which safety and durability of pain response will be assessed at their stable dose.

Inclusion Criteria:

1. Men and women with breast, prostate, lung, gastrointestinal or genitourinary cancer who have poorly controlled pain defined by the use of three or more PRN, or as needed, doses of opioids in a 24-hour period for a minimum of three days per week in the week prior to study registration.
2. Age 25-70 years.
3. An ESAS score of 2 or more recorded as their worst pain at the time of study registration.

Exclusion Criteria:

1. Current use of cannabis within the last 30 days from date of study consent (urine screen test positive).
2. Brain metastases.
3. ECOG performance > 2.
4. Life expectancy < 6 months.
5. Daily morphine milligram equivalent (MME) dose < 15 or > 120.
6. Current major psychiatric illness, such as bipolar disorder, major depression, active suicidal intent or psychosis that could be exacerbated by the administration of cannabis.
7. Chemotherapy induced neuropathy.
8. Poorly controlled hypertension, unstable angina, or myocardial infarction within the previous 6 months.
9. Known history or presence of any clinically significant hepatic, renal/genitourinary, gastrointestinal, cardiovascular (e.g. arrhythmias, ischemic heart disease, tachycardia), cerebrovascular, pulmonary, endocrine, immunological, musculoskeletal, neurological, psychiatric (e.g. depression, disorientation, euphoric mood and dissociation), dermatological or hematological disease or condition unless determined as not clinically significant.
10. Women who are not practicing an effective form of birth control (condoms, diaphragm, birth control pill, IUD) or are currently pregnant or lactating.
11. Anticipated change in chemotherapy or radiotherapy treatment plan during the 43-day course of the acute study.
12. Known history of substance abuse.
13. Inability to speak or read English.
14. Inability to provide informed consent.