Outcome of patients with HER2-positive breast cancer treated with or without adjuvant trastuzumab in the Finland Capecitabine Trial (FinXX).

"Declaration of interest: The authors alone are responsible for the content and writing of the paper. Declaration of interest:"

"The FinXX study was sponsored by the Finnish Breast Cancer Group, and supported financially by Roche, Sanofi-Aventis, AstraZeneca, Cancer Society of Finland, Academy of Finland, Helsinki University Research Funds, Sigrid Juselius Foundation. We are indebted to the study monitor Ms. Raija Husa, and many medical, nursing, and clerical staff members for the support at the participating centers; and to all women participating in the FinXX trial for their contribution to this research. The clinical research institute of HJ has received research funding from Sanofi and Novartis; P-LK-L has received honoraria, research funding and other remuneration from Sanofi, Roche and Pfizer; MT honoraria or remuneration from AstraZeneca, GlaxoSmithKline, Roche, MSD and Novartis; LH a fee from Roche; GN honoraria from Roche, Sanofi and AstraZeneca; and VK honoraria from Roche and Sanofi. RH, AJ-V, RK, JA, PA, OS, KV, PN, ML, PB and HL declare no conflict of interest. Although the standard duration of adjuvant trastuzumab administration is currently 12 months, the optimal duration remains unknown. The recent findings from the HERA trial suggest that two years of trastuzumab administration may be regarded as inferior to one year of administration, since two years of trastuzumab does not improve survival but results in more cardiac toxicity [] and requires more healthcare resources [,]. Results from the PHARE trial that compares six versus 12 months of adjuvant trastuzumab remained inconclusive after a relatively short median follow-up time of 3.5 years []. The present results on nine-week administration of trastuzumab concomitantly with docetaxel provide support for continuation of the ongoing randomized adjuvant trials that evaluate short durations of trastuzumab, since we found no difference in RFS or survival between the subsets of patients who received trastuzumab for nine weeks or for 12 months. The characteristics of the patients and tumors were similar in the groups except for presence of more hormone receptor-negative cancers in the 9-week group. This difference, which likely occurred by chance, is unlikely to favor the 9-week group []. This observation should, however, be interpreted with caution due to the small number of patients who were treated with 9-week duration of trastuzumab (n = 45), the retrospective and exploratory nature of the analysis, and administration of single-agent trastuzumab after completion of chemotherapy to most patients in the 12-month group, which is probably less effective as compared with concomitant administration []."

"Women who had histologically confirmed invasive breast cancer with regional lymph nodes containing cancer, or node-negative cancer with primary tumor diameter > 20 mm and negative progesterone receptor (PR) expression in immunohistochemistry (usually defined as staining of < 10% of cancer cells) were eligible []. Other key inclusion criteria were age 18 to 65 years; the World Health Organization (WHO) performance status < 2; the time interval between surgery and randomization ≤ 12 weeks; and normal hepatic, renal and cardiac function. Patients who had distant metastases at the time of study entry were excluded, as were patients who had node-negative mucinous, papillary, medullary or tubular cancer, and those who had clinically significant cardiac disease or who had received neoadjuvant chemotherapy. The study was conducted in accordance with the Helsinki Declaration, registered (www.ClinicalTrials.gov identifier NCT00114816), and the institutional review boards approved the study protocol. The patients provided written informed consent prior to study entry."