Adherence and persistence with oral adjuvant chemotherapy in older women with early-stage breast cancer in CALGB 49907: adherence companion study 60104.
OBJECTIVE
Patient adherence is critical in evaluating the effectiveness of an oral therapy. We sought to measure adherence among women randomly assigned to capecitabine in a preplanned substudy of a multicenter clinical trial.


METHODS
Cancer and Leukemia Group B study CALGB 49907 was a randomly assigned trial comparing standard chemotherapy versus oral chemotherapy with capecitabine in patients age 65 years or older with early-stage breast cancer. We used microelectronic monitoring system (MEMS) caps on participants' capecitabine bottles to record pill bottle openings. Capecitabine was given in two divided daily doses for 14 consecutive days of a 21-day cycle for six cycles. Adherence was calculated as the number of doses taken divided by doses expected, taking into account toxicity-related dosing changes. A participant was defined as adherent if 80% or more of expected doses were recorded by MEMS.


RESULTS
Overall, 161 patients were enrolled. Median age was 71 years (range, 65 to 89 years); 124 patients (83%) persisted with capecitabine to completion of planned protocol therapy. Adherence was 78% across all cycles, and adherence did not vary by cycle (P = .32). Twenty-five percent of participants took fewer than 80% of expected doses and were nonadherent. In a logistic regression model, participants with node-negative disease (P = .01) and mastectomy (P = .01) were more likely to be nonadherent. Adherence was not related to age, tumor stage, or hormone receptor status. Adherence was not significantly associated with relapse-free survival or grade 3 or 4 toxicity.


CONCLUSIONS
Most older women with early-stage breast cancer were adherent to short-term oral chemotherapy in a randomized clinical trial. Age was not associated with adherence.
Partridge
Ann H
AH
Dana-Farber Cancer Institute, 44 Binney St, Boston, MA 02115, USA. ahpartridge@partners.org
Archer
Laura
L
Kornblith
Alice B
AB
Gralow
Julie
J
Grenier
Debjani
D
Perez
Edith
E
Wolff
Antonio C
AC
Wang
Xiaofei
X
Kastrissios
Helen
H
Berry
Donald
D
Hudis
Clifford
C
Winer
Eric
E
Muss
Hyman
H
D000284:Administration, Oral; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage* / Q000009:adverse effects; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D002170:Canada; D000069287:Capecitabine; D017024:Chemotherapy, Adjuvant; D003841:Deoxycytidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000295:instrumentation; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D006801:Humans; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D016015:Logistic Models; D008408:Mastectomy; D055118:Medication Adherence; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation; D009367:Neoplasm Staging; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil