Effects of quality of treatment on prognosis in primary breast cancer patients treated in daily practice.
Information on treatment outcome outside clinical trials is sparse. This is the first study that relates surgical and medical quality of care in daily practice with outcome.


BACKGROUND
In a previous study we showed, that the quality of chemotherapy as described by a guideline and given in daily practice to premenopausal primary breast cancer patients was suboptimal with only 68% and 53% of the patients receiving chemotherapy with a dose intensity (DI) and relative dose intensity (RDI) of > or = 85%, respectively. Many invalid reasons for delay and dose reductions were identified.


METHODS
Premenopausal node-positive primary breast cancer patients treated from 1988 to 1992 were traced using two national registries. Relevant data were collected from their records. The following treatment-related variables were correlated with prognosis: type of surgery, number of investigated lymph nodes, radiotherapy, chemotherapy, interval between surgery and start of chemotherapy, DI, duration, delays and dose adjustments of chemotherapy and hospital size.


RESULTS
Twenty-four of the 254 traced patients did not receive any chemotherapy, 230 received the recommended schedule of cyclophosphamide (C), methotrexate (M) and 5-fluorouracil (F). The median time of follow-up was 6.7 (range 0.9-10.2) years. The 5-year disease-free survival (DFS) and overall survival (OS) was 61% and 77%, respectively. In an univariate analysis DI < 65% correlated with a worse DFS and OS (p=0.05 and p=0.03, respectively). The use of chemotherapy correlated with a better DFS (p=0.03) than no use. In a multivariate analysis DI between 65 and 85% resulted in a better DFS (p=0.02) than DI > or = 85% and DI < 65%.


CONCLUSIONS
The prognosis of the breast cancer patients in this population was comparable with the results of randomised trials using adjuvant CMF. The only treatment related variable of value for prognosis was DI. Unexpectedly DI between 65% and 85% resulted in the best prognosis in this population. The relevance of this observation remains unclear and warrants further investigation.
Ottevanger
P B
PB
Department of Medicine, University Medical Centre St. Radboud, Nijmegen, The Netherlands. P.Ottevanger@onco.azn.nl
De Mulder
P H M
PH
Grol
R P T M
RP
Van Lier
H
H
Beex
L V A M
LV
D001943:Breast Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery / Q000628:therapy*; D002173:Cancer Care Facilities / Q000592:standards; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D009426:Netherlands; D011379:Prognosis; D011787:Quality of Health Care; D016032:Randomized Controlled Trials as Topic / Q000592:standards; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome