Outcome of Breast Cancer Clinical Trial
Official title:
Longitudinal Observational Study About the Influence of Ductal Carcinoma in Situ on the Outcome of Invasive Breast Cancer
A prospective observational longitudinal study of 464 patients was performed between 2010 and 2015. Patients with invasive ductal carcinoma (IDC) and ductal carcinoma in situ associated to invasive ductal carcinoma (DCIS +IDC) were included and analyzed.
Type of study:
A prospective observational longitudinal study was performed on patients who had undergone
curative surgery for primary invasive breast cancer between 2010 and 2015. The study was
performed in a single breast pathology unit [Alt Penedés hospital and Sant Camil
hospital(GAP)]. Only patients with a definitive histopathology-based diagnostic of ductal
carcinoma were included. Patients diagnosed with metastasis were excluded. Patients with
bilateral breast cancer were included as two independent study cases.
Patients:
Sample size calculation: 191. A total of 464 patients were included in the study. IDC was
present in 221 patients (47.6%) and IDC + DCIS was present in 243 patients (52.4%).
Data collected included clinical characteristics (age, laterality and clinical symptoms at
the time of diagnostic), histopathological information (tumor size, tumor grade, hormone
receptors, nodal status, HER-2 mutation (erb-b2 receptor tyrosine kinase 2), number of ki67,
presence and percentage of DCIS, grade of DCIS, and surrogate subtype) and surgical procedure
performed.
Tumor histopathology and the number of lymph nodes involved were evaluated by routine
hematoxylin-eosin (H&E) staining. The histological response to chemotherapy was assessed
according to Miller-Payne criteria of grading (MPG) and Residual Disease in Breast and Nodes
(RDBN).
The percentage of DCIS and its grade (classified as low, intermediate or high) was measured
by two independent pathologists.
Statistical analysis:
Quantitative data are shown as the median or mean of values and their variability is
expressed as the range or standard deviation (SD), as specified for each analysis.
Qualitative data are shown as absolute values or percentages. The incidence was used as a
measure of frequency and the relative risk as a measure of association between independent
groups.
The study of the normality of quantitative variables was done applying the Kolmogorov-Smirnov
or the Shapiro-Wilk tests, as indicated for each analysis. For significance assessment of
quantitative data, unpaired Student's T-test or two-tailed Mann-Whitney U test was applied,
as specified for each analysis. For significance assessment of qualitative data, Fisher's
exact test or Chi-squared test was applied. For the analysis of more than two groups, one-way
ANOVA and Tukey's range test for post hoc pairwise comparison of groups, or Kruskal-Wallis
were used. Survival was analyzed with the Kaplan-Meier estimate and survival distributions
compared with the Log-Rank test. Multivariate Cox proportional hazards regression model was
used to simultaneously evaluate the effect of several factors on survival and mortality.
Statistical analysis was performed using the software SPSS® (Statistical Package for the
Social Sciences) version 21.
The aim of the investigator's study is to compare the clinical and histopathological factors
between patients with IDC or DCIS-associated IDC (IDC + DCIS) and find the prognostic factors
associated to recurrence and mortality in each group.
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