Introduction
Around worldwide Breast cancer has been considered the most common cancer and it has caused higher rates of mortality and morbidity among women.1 Several studies have been performed to demonstrate genetic changes and oncogene protein products which affect the mechanism of progression and differentiation of tumor growth. Angiogenesis is critical for the survival and progression for the tumor development and metastases to distant sites.2, 3
Vascular endothelial growth factor (VEGF) is a potent angiogenic factor and is crucial factor for tumor development, progression and metastasis.4, 5 VEGF signaling helps in evading apoptotic stimuli in tumor cells and also beneficial in tumor migration and invasion.6, 7, 8 VEGF is an upregulated biomarker in various solid cancers including breast cancer. In comparison with normal or benign breast tissues, malignant breast lesions showed higher levels of VEGF.9
Several studies have showed results that VEGF expression in tumour tissue has significant correlation with microvessel density and associated with poor prognosis.10, 11 Our main objective was to study expression of VEGF mainly in breast cancer so that it can be useful for therapeutic purpose. And also its expression was studied in the normal breast and in benign breast lesions.
Materials and Methods
Study design
A retrospective study was conducted in the department of Pathology at Mysore Medical College and Research Institute during period of January 2019 to March 2020.
Source of data
A total of 100 cases were included out of which 20 cases were of normal breast tissue, 40 cases of benign breast lesions and 40 cases of malignant lesions. The study group included women aged between 15 and 70 years irrespective of any other morbidity.
20 cases of normal breast tissue obtained from benign breast lesions are taken are as control group. 40 cases of benign breast lesions including fibroadenoma and fibrocystic disease were compared with 40 cases of malignant lesions of study group which were between the age group of 15 and 70 years.
Specimen collection and examination
Tumour and breast tissue samples that have been obtained during surgery were sent to the Department of pathology, Mysore medical college and research institute, for histopathological diagnosis. Tumour tissue samples with invasive breast cancer were used, as well as normal breast tissue samples from patients with benign breast diseases.
The diagnosis was performed with hematoxylin-eosin stained sections. Tumours were classified according to the World Health Organization criteria. Modified Scarff-Bloom-Richardson grading system was used to assign grade to tumors. Tumour size was graded in three categories: I (tumour size was 0,1–2 cm), II (tumour size was 2–5 cm), and III (tumour size was >5 cm).
Appropriate formalin fixed paraffin embedded tissue sections were subjected to immunohistochemistry using VEGF antibody, VEGF immunoreactivity was considered as any positive staining in the cytoplasm of cells. The intensity of stained was graded as shown in Table 1.
Statistical analysis was performed using Chi square chart. If the p value was < 0.05, it was considered statistically significant.
Results
The study included normal breast tissue of 20 cases, benign breast lesions of 40 cases and invasive carcinoma breast of 40 cases.
The cases shown in Table 3 were in the age group between 15 and 70 years. The study showed that maximum were in age group of 31 to 45 years of age and accounted to 38% of total number of cases.
The Table 4 showed that out of 20 benign breast lesions 7 cases showed VEGF overexpression. 3 cases had moderate VEGF intensity and 4 cases with strong intensity.
According to Table 5, among malignant breast lesions 22 cases showed VEGF overexpression, maximum number of cases had moderate expression, around 30% had strong intensity and 24% with mild intensity.
Table 6 showed majority of the malignant cases belonged to higher grade and stage II followed by grade II and Stage III. Least number of cases were in grade I and stage I.
Table 7 showed VEGF expression in 10 out of 14 cases in stage II, 13 out of 15 cases in stage III and 9 out of 10 cases in stage IV.
Representative photographs of fibroadenoma breast in hematoxylin, positive staining of VEGF in fibroadenoma, invasive ductal carcinoma breast in hematoxylin 20x, 40x, positive VEGF staining in invasive ductal carcinoma breast 20x and 40x are shown in Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6 respectively.
Table 1
VEGF overexpression scoring
Table 2
Distribution of cases
|
Nature of breast tissue |
No of cases |
|
Normal |
20 |
|
Benign |
40 |
|
Malignant |
40 |
|
Total |
100 |
Table 3
Age wise distribution of cases
|
Age group |
No of cases |
|
15-30 |
35 |
|
31-45 |
38 |
|
45-60 |
17 |
|
61-75 |
10 |
|
Total |
100 |
Table 4
Pattern of VEGF expression in benign breastlesions
|
Intensity of staining VEGF |
No of cases |
Percentage |
|
1 |
0 |
0 |
|
2 |
3 |
43 |
|
3 |
4 |
57 |
|
4 |
0 |
0 |
Table 5
Pattern of VEGF expression in malignant breast lesions
|
Intensity of staining of VEGF |
No of cases |
Percentage |
|
1 |
8 |
24 |
|
2 |
15 |
46 |
|
3 |
10 |
30 |
|
4 |
0 |
0 |
Discussion
The results showed no significant correlation between VEGF overexpression and age. This is due to natural course of disease frequently occurring in older women. The results are consistent with studies done by Obermair A et al and Li J et al.12, 13
The conducted study showed that VEGF expression was absent in the normal breast tissue comparable to studies conducted by Esraa A et al. and Yasushi Nakamura et al., showed negative expression of VEGF in the normal breast tissues.14, 15
The study showed that out of 40 cases of benign lesions of breast, 7 cases showed positive staining in benign breast lesions accounting to 17.5% which was almost nearing to the results of ES Al Harris et al.16 who had got around 19% positive staining in benign breast lesions. 33 cases showed positive staining in malignant breast lesions accounting to 82.5% which is similar to the study conducted by Yasushi Nakumura et al. who reported 83.7%.17 It was higher than the study conducted by Melanie Schmidt et al. who reported 60% VEGF overexpression in breast cancer.18
In relation to grading of tumors, the immunohistochemical expression of VEGF showed that 4 cases were grade 1 positive, 16 cases were grade 2 positive and 20 cases were grade 3 positive. There was statistically significant correlation of VEGF overexpression with grading of tumors. This was similar to studies conducted by Konecny GE et al. and Shankar R et al.19, 20
In stage, I tumors, a case showed overexpression of VEGF, out of 14 cases belonging to stage II maximum cases expressed VEGF overexpression and in stage IV all cases were positive for staining except for a single case. The number of cases were more in higher stage and there was statistically significant correlation of VEGF overexpression with staging of tumors. These findings were comparable to studies performed by AL-Harris et al.16 who found that staging of breast and VEGF overexpression had significant correlation.
Conclusion
VEGF overexpression can be used as a prognostic tool and for therapeutic purpose. It’s overexpression in benign breast lesions may be associated with increased risk for development of breast cancer. Henceforth, advanced research is essential to study the risk of progression of benign lesions into cancer.
Since the VEGF overexpression showed statistical significance with grade and stage of tumor, it can be considered that positive tumors have poorer prognosis and aggressive behavior. The breast cancer genesis is a complex process, multifactorial and has very less understanding about the genetic changes. Much more research in this progress is needed to know the etiopathogenesis to integrate better therapeutic strategies.
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