INVESTIGATOR: Suzanne Dibble, DNSc, RN
STUDY LOCATION: University of California, San Francisco
PROJECT TITLE: Treating Chemotherapy-Induced Delayed Nausea with Cannabinoids
PROJECT TYPE: Clinical Study
The primary purpose of this pilot study was to determine whether or not marijuana was a safe and acceptable treatment for nausea resulting from cancer chemotherapy. Secondary goals were to estimate our recruitment ability and number of subjects needed for a larger study. Patients who enrolled participated in a six-day outpatient trial among three groups undergoing chemotherapy. Those groups received a) placebo Marinol® (an inert pill that looks like Marinol®) and active marijuana, b) active Marinol® and placebo marijuana (a cigarette that smells and tastes like marijuana but has no active ingredient), and c) placebo Marinol® and placebo marijuana. Differences in quality of life, anxiety, and the ability of participants to function "normally" were assessed.
Unfortunately, recruitment proved more difficult than anticipated and the study was discontinued. In total, 172 people were screened, but only 6 completed the study. Most people who could not participate in the study lacked a "moderate amount of nausea." This may be in large part due to recent advances in anti-nausea drug treatments. As the target for enrollment was 81 patients, the 6 who completed were not sufficient to produce analyzable results.
In 2002, an estimated 203,500 women in the United States are expected to be diagnosed with breast cancer (American Cancer Society, 2002). To treat their disease, many of these women will receive doxorubicin hydrochloride (Adriamycin®) and cyclophosphamide with or without fluorouracil chemotherapy [CA/CAF]. These regimens containing Adriamycin® tend to cause more nausea and vomiting than other regimens. Although the latest serotonin receptor antagonists have controlled a notable portion of the vomiting associated with chemotherapy administration, particularly in the acute phase, delayed nausea, occurring after day 1 of chemotherapy, continues to be a significant problem (Hickok, et al., 1999, Yarker & McTavish, 1994). Although anecdotal reports reveal that cannabinoids are effective antiemetics, there has been no credible study comparing inhaled versus oral administration of cannabinoids in women with chemotherapy-induced nausea. Perhaps cannabinoid therapy will improve the treatment experience for these women and thus improve their quality of life while undergoing treatment for breast cancer.
The specific aims of this pilot randomized clinical trial (n=80) are to ascertain the acceptability of the intervention to the participants including adherence to protocol; estimate our accrual potential; and estimate the effect size of this intervention in order to estimate sample size and statistical power for a larger trial. In the larger trial to be funded (hopefully) by the NCI, we plan to compare differences in the nausea experience and intensity among four groups of women undergoing chemotherapy for breast cancer. The groups are those receiving a) usual nausea care plus active smoked marijuana, b) usual nausea care plus placebo smoked marijuana, and c) usual nausea care plus Marinol® and d) usual nausea care plus placebo Marinol®. Secondarily, the differences in quality of life, anxiety, and functional status among group participants will be explored. Women, who experience a moderate amount of nausea with a previous chemotherapy, will be accrued from three sites in California. They will receive the intervention on Days 2 though 4 of their second or third chemotherapy cycle. Data will be analyzed using Repeated Measures Analysis of Variance to determine the appropriate effect size for a future study.