Time to revise classification of phyllodes tumors of breast? Results of a French multicentric study

Marie-José Adam (1) , Sofiane Bendifallah , Négar Kalhorpour , Camille Cohen-Steiner , Laetitia Ropars (2) , Asma Mahmood , Chloé Rousseau (3) , Jean Leveque (4) , Krystel Nyangoh Timoh (1) , Adolphe Der Some (1) , Lobna Ouldamer , Guillaume Legendre , Marcos Ballester , Emile Daraï , Geoffroy Canlorbe , Vincent Lavoue (4)

1 Centre Hospitalier Universitaire de Rennes [CHU Rennes] = Rennes University Hospital [Ponchaillou]
2 CHU Angers - Centre Hospitalier Universitaire d'Angers
3 CIC - Centre d'Investigation Clinique [Rennes]
4 COSS - Chemistry, Oncogenesis, Stress and Signaling

Objective - To assess prognostic factors of recurrence of phyllodes tumors (PT) of the breast. Methods - We performed a retrospective, multicentric cohort study, including all patients who underwent breast surgery for grade 1 (benign), 2 (borderline) or 3 (malignant) PT between 2000 and 2016 in five tertiary University hospitals, diagnosed according to World Health Organisation classification. Results - 230 patients were included: 144 (63%), 60 (26%) and 26 (11%) with grade 1, 2 and 3 PT, respectively. Recurrence occurred in 10 (7%), 7 (12%) and 5 (19%) patients with grade 1, 2 and 3 PT, respectively. In univariate analysis, moderate to severe nuclear stromal pleomorphism (HR 8.00 [95% CI: 1.65-38.73], p < 0.009) was correlated with recurrence in all groups including grade 1 (HR 14.3 [95% CI: 1.29-160], p = 0.031). In multivariate analysis, surgical margin >5 mm, (HR 0.20 [95% CI: 0.06-0.63], p = 0.013) were significantly correlated with less recurrence in all PT grades. For grade 1 PT, there was also significantly less recurrence with surgical margin >5 mm, (HR 0.09 [95% CI: 0.01-0.85], p = 0.047) in multivariate analysis. Conclusion - The surgical margin should be at least 5 mm whatever the grade of PT. Moderate to severe nuclear stromal pleomorphism identified a subgroup of grade 1 PT with a higher rate of recurrence. This suggests that the WHO classification could be revised with the introduction of nuclear stromal pleomorphism to tailor PT management.

Mots clés: Benign; Malignant; Borderline; Surgery; Prognostic factors; Phyllodes breast tumor

Domaines: Sciences du Vivant [q-bio]

Marie-José Adam, Sofiane Bendifallah, Négar Kalhorpour, Camille Cohen-Steiner, Laetitia Ropars, et al.. Time to revise classification of phyllodes tumors of breast? Results of a French multicentric study. EJSO - European Journal of Surgical Oncology, 2018, 44 (11), pp.1743-1749. ⟨10.1016/j.ejso.2018.08.007⟩. ⟨hal-01880076⟩