Clinical perspectives and outcomes of the giant breast phyllodes tumor and sarcoma: a real-world retrospective study

Abstract

Background: Giant breast malignant phyllodes tumor or sarcoma (GBPS) are rare entities with diameter larger than 10 cm and variously histological pleomorphisms. This disease poses a significant threat to the quality of life of individuals, and its prognosis remains unclear. This study aimed to explore the differential diagnosis, treatment, and prognosis of GBPS in a real-world retrospective cohort.

Methods: We collected GBPS (diameter > 10 cm, n = 10) and BPS (diameter ≤ 10 cm, n = 126) from patients diagnosed with sarcoma or malignant phyllodes tumor between 2008 and 2022. We analyzed clinical characteristics, histological status, treatment, and local recurrence using the Fisher's exact test between GBPS (diameter > 10 cm) and BPS (diameter ≤ 10 cm) cohort. We described overall survival (OS) and disease-free survival (DFS) using Kaplan-Meier curves and identified risk factors for local recurrence using logistic regression. The tumor size, age at diagnosis, and differential immunohistochemistry markers of breast sarcoma or phyllodes tumor to determine the prognosis of GBPS.

Results: In our retrospective analysis of breast malignancies, we identified 10 cases of GBPS and 126 cases of BPS, corresponding to a GBPS prevalence of 0.17% (10/6000). The median age was 38.5 years (inter-quartile range, IQR: 28.25-48.5 years). During the follow-up of period (median: 80.5 months, IQR: 36.75-122 months), the local recurrence (LR) rate was 40% and 20.6%, respectively. Clinical characteristics of young age (HR:2.799, 95%CI -00.09276-0.017, p < 0.05) and cytological characteristics of marked stromal atypia (HR:0.88, 95% CI 0.39-1.40, p < 0.05) were risk factors for the poor prognosis of GBPS by COX regression model analysis. The Kaplan-Meier curves of GBPS 5-year disease-free survival (DFS) and overall survival (OS) were 31.5 months and 40 months, respectively, and were not associated with adjuvant radiation or chemotherapy.

Conclusion: We recommend mastectomy with a clear surgical margin as the preferred treatment for GBPS. Age and stromal atypia are significantly associated with recurrence. Adjuvant radiation therapy is advised; however, there was no improvement in overall survival. There is no consensus on the effectiveness of adjuvant chemotherapy and genetic methods, highlighting the need for further research into this aggressive tumor. We recommend a multidisciplinary approach involving a dedicated team for the management of GBPS.

Keywords: Giant breast tumor; Malignant phyllodes tumor; Phyllodes tumor; Sarcoma; Spindle cell.

Fig. 1

Screening flow chart

Fig. 2

Kaplan–Meier survival curves for of the GBPS. A Disease free survival (DFS) is analyzed in Kaplan–Meier curves for a 5-year follow-up. B Overall survival (OS) is analyzed in Kaplan–Meier curves for a 5-year follow-up

Fig. 3

Kaplan–Meier survival curves of DFS between GBPS and BPS. There is significantly survival difference between GBPS and BPS (p < 0.05)

Fig. 4

Forest plot of the association between risk factors and local recurrence rate of GBPS. Hazard ratios for local recurrence with 95% confidence interval (CI) and p-values analyzed by a Cox proportional model. Squares represent study-specific relative risk, horizontal lines indicate the 95% CI

Fig. 5

This image depicts a giant tumor of the left breast with bleeding and ulcers from the case with the worst prognosis. The gross picture of giant tumor with internal necrosis, 23 × 19 × 13 cm in size

Fig. 6

CT scan of the breast tumor. Breast CT revealed an irregular mass (12.0 × 11.3 × 11.7 cm) with local mixed echoes and marginal vessels formation. Left axillary lymph nodes are enlarged to 2.5 × 1.2 × 0.8 cm

Fig. 7

Gross picture and microphotograph of the giant tumor. A Gross image of the giant tumor with internal necrosis, 23 × 19 × 13 cm in size. B Histopathology of a core needle biopsy of the tumor revealed multiple fusiform atypical tumor cells (Hematoxylin and eosin, original magnification, 100 ×). ER (-), PR (-). C A pathological microphotograph revealed irregular fusiform tumor cells with a variable nucleus and numerous microcapillaries. (Hematoxylin and eosin, original magnification, 200 ×). Mitotic 8/10HPF

Fig. 8

Hematoxylin and eosin staining of the giant sarcoma (original magnification, 200 ×). A Immunohistochemistry staining revealed positive of Ki67. B SMA with weak positive staining. C Vimentin with positive staining. D Bcl-2 with negative result