HOLLYWOOD, FLA. – Compliance with tamoxifen treatment regimens among hormone receptor–positive breast cancer patients is suboptimal, but use of an oral liquid formulation could help change that, findings from a large CAPTURE (Compliance and Preference for Tamoxifen Registry) Internet-based survey suggest.
Of 626 women with breast cancer who were using tamoxifen and who participated in the health care provider–administered survey, 88 (14%) reported missing between 2 and 10 doses each month, and 75 (12%) said they had stopped taking tamoxifen for periods of more than 2 weeks; 13% said they would prefer an oral liquid formulation over the tablet formulation, 22% said they would be willing to try an oral liquid formulation, and 7% said they believed an oral liquid formulation would help them improve long-term adherence, Dr. Stefan Gluck reported in a poster at the annual conference of the National Comprehensive Cancer Network.
Of those who reported missing two or more doses per month, 22% said they would prefer an oral liquid formulation, 30% said they would try a liquid formulation, and 16% said they thought an oral liquid formulation would help improve their compliance, said Dr. Gluck of the University of Miami Health System’s Sylvester Comprehensive Cancer Center, Miami.
Responses on the validated Eating Assessment Tool (EAT-10), which was administered along with the 36-item survey, suggested that swallowing difficulties contributed to the lack of compliance in 48 (8%) of respondents, Dr. Gluck said.
Those with swallowing difficulties did not differ significantly from the overall study population with respect to age, race, or education, although a higher percentage of those with swallowing difficulties had undergone a mastectomy (65% vs. 46%), and had experienced or been diagnosed with persistent or frequent symptoms of heartburn, acid reflux, or gastroesophageal reflux disease (44% vs. 26%). Of those with swallowing difficulties, 35% said they would prefer an oral liquid form, 50% said they were willing to try a liquid formulation, and 25% said a liquid formulation would help improve their compliance with long-term tamoxifen therapy.
Reasons given for stopping tamoxifen for more than 2 weeks included side effects in 27% of cases, physician recommendation in 17% of cases, "felt better" in 4% of cases, expense in 3% of cases, and "other" reasons in 49% of cases.
Respondents were women with a mean age of 55 years at a mean of 3 years since breast cancer diagnosis. Most (66%) had invasive disease, 29% had noninvasive disease, and 5% had metastatic disease. The vast majority (97%) had undergone surgery, 58% received radiation therapy, and 47% received chemotherapy. The women had been taking tamoxifen for a median of 2 years, with the vast majority (98%) taking a 20-mg dose.
The importance of adherence to 5 full years of tamoxifen for long-term positive outcomes in women with hormone receptor–positive breast cancer has been well documented, and breast cancer treatment guidelines updated by the National Comprehensive Cancer Network in March 2013 recommend consideration of up to 10 years of tamoxifen therapy, Dr. Gluck noted.
Though limited by factors inherent in survey methodology, including self-reported data, the findings of this study "provide an avenue for improving the adherence of patients to long-term tamoxifen treatment by providing them a choice between a tablet and an oral liquid," he concluded.
CAPTURE is a project of DARA BioSciences, which markets the only Food and Drug Administration–approved liquid tamoxifen formulation (Soltamox).