Breast cancer remains the most common malignancy among women worldwide, and environmental exposures may contribute to breast carcinogenesis through inflammatory pathways such as NLR, PLR, and interferon-γ. This study aimed to examine the association between agricultural environmental exposure, represented by rice field area, and inflammatory biomarkers including the Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Interferon-γ in breast cancer. A case–control method was applied to 128 histopathologically confirmed samples consisting of 100 malignant (Invasive Carcinoma NST) and 28 benign (Fibroadenoma Mammae) breast tumors; hematologic indices were derived from preoperative blood tests, IFN-γ expression was analyzed immunohistochemically, and rice field proportions near participants’ residences were obtained from national statistics, with data analyzed using Chi-square and multivariate logistic regression. The results showed that agricultural exposure (rice field ≥60%) was not significantly associated with breast cancer (p = 0.703), whereas elevated NLR (OR = 4.89, p = 0.014), PLR (OR = 12.13, p = 0.017), and IFN-γ expression ≥20% (aOR = 23.94, p = 0.049) were significantly associated with malignancy. In conclusion, although agricultural land area was not a direct risk factor, inflammatory and immune biomarkers—particularly IFN-γ—served as strong predictors of breast cancer, indicating their potential utility in risk stratification for agrarian populations.