Impact of stress and levels of corticosterone on the development of breast cancer in rats

Figures & data

Table 1 Number, diameter, and volume of tumors in both rat groups

Parameter	Cancer (control) group (mean ± SD)	Cancer + stress group (mean ± SD)
Number of tumors	1.1±0.31	1.6±0.84
Number of tumors with larger than average diameter	2.62±2.27	2.56±1.96
Number of tumors with larger than average diameter without outliers	1.99±0.88	2.19±1.30
Approximate average total volume of tumors	7.06±7.07	24.65±67.85
Approximate average total volume of tumors without outliers	5.56±5.30	7.93±11.72

Abbreviation: SD, standard deviation.

Table 2 Comparison between both groups with the Mann–Whitney U-test, significant difference P<0.05

Parameter	U-value	P-value*
Number of tumors	34	0.226477
Larger diameter	87	0.960643
Approximate total volume	43	0.596702

Notes:

* Mann–Whitney U-test; significant difference P<0.05.

Figure 1 Comparison between the level of corticosterone in the group with CIC and CIIC.

Abbreviations: CIC, cancer induction condition; CIIC, cancer induction and isolation condition; SE, standard error; vs, versus.

Figure 2 Histopathologic characteristics.

Notes: In the tumor of CIC group, the neoplastic cells have smaller nucleus and increased tubule formation. Mast cells infiltrating the tumor are observed (×40). Tumor of CIIC group shows abundant cellularity (40×), lower degree of histological differentiation, areas more solid without inflammation, cells with larger nucleus and less cytoplasm; indicating a process of division more active.
Abbreviations: CIC, cancer induction condition; CIIC, cancer induction and isolation condition.