A consecutive series on patients with breast cancer (3010 patients) were extracted from the database at Cancer Research Center of the shahid beheshti University of Medical Sciences, the average age at diagnosis was 49.1 years ± 11.6.
The proportion of breast cancer patients’ levels of education were 4.2 % illiterate (126/3010), 7.8% primary school (233/3010), 7.5% middle school (227/3010), 21.8% high school and diploma (656/3010), 18.6% university and above (560/3010), and 40.1% unspecified (1208/3010).
2750 patients (91.4%) had pathologic report of invasive ductal carcinoma, 220 patients (7.3%) had invasive lobular carcinoma and 40 patients (1.3%) had other pathology types except invasive ductal carcinoma and invasive lobular carcinoma respectively.
256 cases (8%) had low differentiated grade, 1181 patients (39.2%) had intermediate grade, 726 patients (24.1%) had high grade and 847 cases (28.2%) were with unknown grade respectively.
There was, 1133 patients (37.6%) with zero involved lymph nodes, 498 patients (16.5%) with 1-2 pathologic positive lymph nodes, 760 patients (25.3%) with≥3 pathologic positive lymph nodes and 619 patients (20.6%) with unspecified pathologic lymph nodes.
We had, 878 cases (29.2%) with tumor ≤2centimeters (cm), 1425 cases (47.3%) with tumor size 2-5 cm, 253 cases (8.4 %) with tumor size >5, and 454cases (15.1%) with unknown tumor size.
Based on tumor stage, 491 cases (16.3%) had stage I, 1352 cases (44.9%) had stage II, 568 cases (18.7%) had stage III, 83 cases (2.7%) had stage IV and 516 patients (17.1%) were with unspecified stage.
There were in 3010 for patients for ER status: 1496 (49.7%) patients had ER positive, 629 cases (20.9%) were ER negative and 885 (29.4%) cases were with unspecified ER receptor status.
For PR status, there was, 1413 (46.9%) patients, 712 (23.7%) patients and 885 (29.4%) patients with PR positive, PR negative and unknown PR receptor status respectively.
There were in all patients, 701 patients (23.3%), 1808 patients (60.1%) and 501 patients (16.6%) with HER 2 positive, HER 2 negative and unspecified HER 2 status respectively.
Table 1 summarizes baseline characteristics, clinical-pathological features and educational level of 3010 adult patients with breast cancer
As of December 2019, a median follow-up time was 71 months (range 48-192 months), 1092 cases (36.3%) underwent MRM, 1580 patients (52.5%) underwent BCS and 338 patients (11.2%) were with unspecified surgery.
In all patients, 161 cases (5.4%) received NAC, 1625 patients (54%) received AC, 40 cases (1.3 %) did not receive any chemotherapy and 1184 patients (39.3%) were with unspecified chemotherapy.
In 3010 cases, 1927 cases (64%) received radiotherapy, 61 cases (2%) did not receive any radiotherapy and 1022 patients (34%) were with unspecified radiotherapy.
There were in 3010 patients, 1596 cases (53%) received endocrine therapy, 1143 cases (38%) did not receive any endocrine therapy and 271 patients (9%) were with unspecified endocrine therapy.
Table 2 summarizes treatment modalities of 3010 adult patients with breast cancer.
Based on univariate logistic regression analysis, the illiterate group had 65.1% of early stage breast cancer (stage I and stage II), and the university and above group had 73.4% of early stage breast cancer (p-value<.001). Conversely the highest rate of pathological advanced breast cancer (stage III and stage IV), was found within the illiterate group (31.7 %) and the lowest was university and above group (17.6 %) (p-value<.001). Thus different education backgrounds had a significant impact on final pathological staging distribution.
There were no significant differences in tumor size for the illiterate group who had 34.2% of tumor size≤2cm and the university and above group who had 29.5% of tumor size≤2cm and the rate of tumor size>5cm, was found within the illiterate group (6.3%) and was lower than the university and above group (8.2%)(p-value=0.145). Thus different education backgrounds did not have a significant impact on final tumor size distribution.
The rate of MRM in the illiterate group, the primary school, the middle school, the high school and diploma and the university and above group was 73.8%, 70.8%, 72.7%, 46.4%, and 15.9% respectively. The rate of BCS in the illiterate group, the primary school, the middle school, the high school and diploma, and the university and above group was 15.1%, 18%, 16.3%, 42.5%, and 73.2% respectively. Based on univariate logistic regression analysis, these differences were significant (p-value<.001). Thus patients with higher education took BCS and patients with lower education took MRM.
According to univariate logistic regression analysis, 35.7%, 69.1%, 75.4%, 80%, and 93.7% of the illiterate group, the primary school, the middle school, the high school and diploma, and the university and above group received chemotherapy in their treatment modalities respectively (p-value<.001). These differences were significant. Thus patients with higher education received more chemotherapy than patients with lower education, in in their treatment modalities.
There was shown: 42.1%, 54.5%, 60.3%, 70.7%, and 64.3% in the illiterate group, the primary school, the middle school, the high school and diploma, and the university and above group receiving radiotherapy in their treatment modalities respectively(p-value<.001). Thus patients in the university and above group received more radiotherapy than patients within the illiterate and the primary school group in in their treatment modalities.
We also found: 50%, 64%, 69.2%, 70%, and 71.1% in the illiterate group, the primary school, the middle school, the high school and diploma, and the university and above group receiving endocrine therapy in their treatment modalities respectively(p-value<.001). Thus patients with higher education received more endocrine therapy than patients with lower education, in in their treatment modalities. These differences were significant, based on univariate logistic regression analysis.
Table 3 summarizes univariate logistic regression analysis for association between education level and pathological breast cancer stage, tumor size and treatment modalities in 3010 adult patients with breast cancer.
Based on univariate logistic regression analysis education backgrounds had a significant impact on final pathological staging distribution. To prove whether education background of breast cancer patients was an independent factor, that affecting final pathological tumor stage, we rounded a multivariate analysis with a total of 2494 cases this time ((1843 early stages (stage I and stage II) versus 651 advanced stages (stages III and IV)).
Based on multivariable logistic regression analysis, there was not a significant correlation between middle and high school vs. primary school and below and final pathological tumor stage with odds ratio=0.83 and 95% confidence interval (0.62 -1.11) (p-value=0.2). The results suggested that education level with middle and high school vs. primary school and below was not an independent protective factor
According to multivariable logistic regression analysis, there was a significant correlation between university and above group versus primary school and below group and final pathological tumor stage with odds ratio= 0.57 and 95% confidence interval (0.35-0.93) (p-value=0.02). The results suggested that education level was an independent factor that affecting final pathological tumor stage. Compared with primary education and below, University and above education was an independent protective factor.
Table 4 summarizes multivariable logistic regression for association between education level and breast cancer stage (stage I and stage II versus stages III and IV).