Self-Reported Adherence to Trifluridine and Tipiracil Hydrochloride for Metastatic Colorectal Cancer: A Retrospective Cohort Study.

BACKGROUND: A novel oral agent that consists of trifluridine and tipiracil hydrochloride (TFTD) has been established as salvage-line treatment for metastatic colorectal cancer (mCRC). Adherence to TFTD is crucial to maintaining appropriate curative effects. This study sought to clarify adherence to TFTD and identify candidate factors deteriorating adherence at our institution.

METHODS: A total of 50 consecutive mCRC patients who received TFTD monotherapy between June 1, 2014 and July 31, 2015 were analyzed in this study. Adherence to TFTD was checked by pharmacists using a self-reported treatment diary and interviewing nonadherents at a pharmaceutical outpatient clinic. The adherence rate was defined as the number of patient intakes per 20 scheduled intakes in one cycle. We retrospectively surveyed the factors from the electronic patient record associated with reduced adherence. We measured relative dose intensity, defined as the dose intensity divided by the initial dose (each in milligrams per square meter per week).

RESULTS: Patient characteristics were as follows: males/females, 20/30; median age, 61 years (range, 34-83 years); performance status 0/1, 37/13. Median relative dose intensity of TFTD was 91.0%. Adherence rates were 95.0% for the first cycle of TFTD, 97.3% for the second cycle, 98.0% for the third cycle, and 98.2% for the fourth cycle. Factors associated with deteriorated adherence to TFTD were nausea/vomiting/decreased appetite (27.1%, 23 instances), pain (25.9%, 22 instances), neutropenia (11.8%, 10 instances), and missed dose (4.7%, 4 instances). Increased nonadherence to TFTD was associated with Eastern Cooperative Oncology Group performance status 1, while increased TFTD adherence in the first cycle was associated with prior regimens ≥4.

CONCLUSIONS: The high frequency of treatment-related gastrointestinal disorder is the main factor affecting adherence to TFTD. Intensive supportive care in the management of these symptoms could assist adequate adherence to TFTD in mCRC patients.