Abstract PO5-26-01: Assessing the effect of multimodal therapy in massive fungating breast cancers without distant metastasis
Authors: Tamanuki Tamaki , Namura Maki , Aoyagi Tomoyoshi , Sakata Haruhito , Iwai Mika , Shimizu Shinichirou , Matsuzaki Hiroshi 
Published: May 2024

Background: Massive fungating breast cancers (MFBCs), which comprise exudative, foul-smelling tumors, the size of a child’s head or involve extensive ulceration are classified as locally advanced breast cancers. The National Comprehensive Cancer Network guidelines recommend preoperative neoadjuvant chemotherapy in patients with locally advanced breast cancer without distant metastases. However, limited evidence is available regarding the successful treatment of fungating breast cancers. In clinical practice, many fungating breast cancer cases are treated as stage IV tumors. This study aimed to investigate whether multimodal therapy, including surgery for giant breast cancers, can improve survival rates and whether the survival rates are comparable to those of other stage III breast cancers.

Subjects and methods: Out of 1480 cases of primary breast cancer diagnosed at our hospital between June 2012 and March 2020, 123 patients with clinical stages IIIA–IIIC were chosen for analysis. Furthermore, 29 of these patients with MFBC were selected. During multimodal therapy for selected patients with fungating breast cancer, difficulties were encountered in some patients with single-stage skin suturing and closure after standard neoadjuvant chemotherapy. These patients underwent surgery with an additional skin flap or skin grafting. Furthermore, radiation therapy was added as needed. We compared the survival rates of these patients with those of patients who received drug therapy only according to the therapeutic protocol for Stage IV. Survival rates of patients with MFBC and other stage III breast cancers were also compared. Statistical analyses were conducted using the Kaplan–Meier curve and the log-rank test.

Results: Of the 29 patients with MFBC, 22 (75.9%) and seven (24.1%) were treated with multimodal and palliative therapies, respectively. The median age and follow-up period of the multimodal therapy group were 62 (range: 43–94) years and 67 (range, 32–131) months, respectively. The corresponding values for the palliative therapy group were 79 (range: 42–88) years and 31 (range: 2–96) months. All patients in the palliative treatment group were hormone receptor positive and HER2 negative, and treatment with hormone therapy was initiated. The 7-year survival rate was significantly higher in the multimodal therapy group than in the palliative treatment group (92.3% vs. 68.6%, p = 0.0317). Furthermore, the 5-year distant recurrence-free rate was higher in the multimodal treatment group (79.3% vs. 63.5%). Local recurrence did not occur in any patient in the multimodal treatment group. There was no significant difference in the 7-year survival rates between patients with MFBC and those with other stage III breast cancers (86.8% vs. 75.3%; p = 0.239). Triple-negative breast cancer accounted for 20.8% (20 96) of the other stage III breast cancers, but none of these were MFBCs.

Conclusions: Clinically, MFBCs are often palliatively treated as stage IV tumors, even in the absence of distant metastasis. However, the survival rate was significantly higher in the multimodal therapy group than in the palliative treatment group. Furthermore, the survival and distant recurrence-free rates for MFBC were higher than those for other stage III breast cancers. Therefore, patients with MFBCs should be actively treated using curative treatments.

Citation Format: Tamaki Tamanuki, Maki Namura, Tomoyoshi Aoyagi, Haruhito Sakata, Mika Iwai, Shinichirou Shimizu, Hiroshi Matsuzaki. Assessing the effect of multimodal therapy in massive fungating breast cancers without distant metastasis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-26-01.