Histomorphological Evaluation of Desmoplastic Tumor Stroma in Malignant Ovarian Surface Epithelial Tumors

Ovarian cancer is the 8^th most common cancer in women worldwide. Tumor budding is defined as a type of invasive growth in carcinomas with either a single tumor cell or a cluster of up to four cells at the invasive tumor front and is associated with epithelial-mesenchymal transition. A reactive stroma rich in cancer-associated fibroblasts is associated with higher tumor grade and poorer prognosis in breast, colorectal, and oral cancers.

The present study was conducted to highlight the prognostic significance of tumor budding and fibrotic cancer stroma in malignant ovarian surface epithelial tumors with known prognostic parameters.

This was a retrospective cross-sectional study conducted over a 2-year period, in which all histologically diagnosed cases of malignant ovarian surface epithelial tumors who underwent surgery were included. The fibrotic stroma was classified into three distinct categories - mature, intermediate, and immature. The number of tumor buds was counted at the invasive front of the tumor and graded based on the number of buds - 0-5, 5-9, and ≥10 buds.

Among the 50 cases, 32% (16 cases) had mature stroma, whereas 30% (15 cases) and 38% (19 cases) had intermediate and immature stroma, respectively. Although a significant association could not be established between tumor budding and stroma grade, a fair agreement was established between them. A significant association could be established between histological grade with both tumor budding (P = 0.03) and fibrotic stroma grade (P = 0.02).

The study highlighted the role of stromal response in malignant surface epithelial tumors of the ovary since a higher-grade tumor was associated with an immature stroma, whereas a lower-grade tumor was associated with a mature stroma.