Prognostic Factors of Phyllodes Tumors of the Breast: Analysis of 170 Cases

Background: Phyllodestumors (PT) of the breast are rare and their prognosis and treatment are still subject of discussion. The purpose of this study is to determine the prognostic factors of this rare tumor.
Patients and Methods: We retrospectively reviewed the medical records of 170 patients who had histologically confirmed PT, collected over a period of 24 years in one single Institute (Salah Azaiz Institute).
Results: The mean age was of 38.7 years (14-75 years). The mean tumor size was 82.6 mm (15-300). According to criteria of WHO classification, tumors were classified into three groups: benign (97 cases, 57.1%), borderline (22 cases, 12.9%) and malignant (51 cases, 30%). One hundred and twenty eight patients (75.2%) were treated conservatively (96 benign, 17 borderline and 15 malignant) and 42 (24.7%) by radical surgery (6 borderline and 36 malignant). For malignant PT treated by local excision with or without reexcision of the tumor bed, the 5-year overall and recurrence free survivals were 46.2% and 44.2% vs. 55 and 63.8% when the surgery was radical (mastectomy with or without axillary dissection) (P=not significant and P=0.01). The rate of recurrence was 15.3 % (26) after a mean follow-up of 40 months (6 benign, 6 borderline and 14 malignant). Twelve patients developed metastases (7%). The 5-year overall and recurrence free survivals were 92.8% and 91.7%, respectively. In univariate analysis, age and recurrences are not of prognostic value for survival, while tumor size, histotype, necrosis, stromal overgrowth, cytonuclearatypia, tumor margins and number of mitosis were significant prognostic factors for survival. In multivariate study, stromal overgrowth and cytonuclearatypia remained independent predictors for survival. The tumor size and margins status were independent predictors for local recurrence.
Conclusion: According to our results, the most important factor for local recurrence is the tumor size and the margins status and for the overall survival is the stromal overgrowth and the cytonuclearatypia. The best treatment remains wide local excision for the benign forms while total mastectomy appears to be correlated to better recurrence free survival in large malignant PT.