Rethinking on the management strategy of malignant phyllodes tumor of the breast: An analysis based on the SEER database

A case report of a patient with ductal carcinoma and a malignant phyllodes tumor in situ in 2 separate breasts

RATIONALE

Breast malignant phyllodes tumors (MPT) are quite uncommon. It is rarely reported that they occur in conjunction with breast cancer. We detailed a case in which an MPT and ductal carcinoma in situ carcinoma occurred simultaneously in 2 different breasts.

PATIENT CONCERNS

A 79-year-old female patient was seen for a rapidly growing lump in the upper left quadrant of her breast. The lump was described as huge, hard, irregular, and palpable. MRI of the breasts revealed a big mass in the left breast and a smaller lump in the right.

DIAGNOSIS

Ductal carcinoma in situ with breast MPT.

INTERVENTIONS

We performed a double mastectomy. Post-operative endocrine treatment was suggested.

OUTCOMES

During the 18-month follow-up period, no signs of recurrence or metastasis were seen. The ultrasound examination of the chest wall showed no abnormality. Bilateral axillary and supraclavicular ultrasonography showed no lymphadenectasis and a CT scan of the lungs showed no suspicious cancer nodules.

LESSONS

It is possible for MPT and ductal carcinoma in situ to occur simultaneously in different breasts. Surgeons need to integrate clinical observations, imaging tools, and patient history to make an early diagnosis. Before undergoing surgery, a thorough examination of both breasts is required.

[Rare tumours of the breast]

Breast tumours are the most common tumours in women but represent a very heterogeneous group. On the one hand, there are ductal and lobular carcinomas of the breast, representing 90% of tumours, whose clinicopathologic characteristics are well known. On the other hand, there are rare breast tumours, each of which represents less than 1% that limits their study through large cohorts. The objective of this work was to collect, update and synthesize knowledge on these rare tumours. A literature review was performed on the Medline and Google Scholar databases. We present here a selection of several rare tumours, providing updated data at the epidemiological, histopathological, genetic, clinical and radiographic, prognostic and therapeutic levels, taking into account the place of radiotherapy. Each tumour histology is unique and has its own characteristics, the management must therefore be adapted as much as possible and decided in a multidisciplinary meeting.

Real-world efficacy of postoperative radiotherapy with a moderate dose-escalation for phyllodes tumors of the breast

Background

Phyllodes tumors are rare breast tumors comprising less than 1% of cases, categorized as benign, borderline, or malignant. Treatment typically involves complete surgical excision with wide margins. Adjuvant radiotherapy may be recommended for borderline or malignant tumors, or when clear margins cannot be achieved through surgery alone.

Methods

We conducted a retrospective review of 14 women diagnosed with phyllodes tumors between 2015 and 2023. Among them, 36% had benign tumors and 64% had borderline/malignant tumors. The majority (86%) underwent breast-conserving surgery. Postoperative radiation therapy was delivered to the whole breast/chest wall, with a median biologically effective dose (BED) of 92.7 Gy (90.0-102.6 Gy), representing a moderate dose-escalation over conventional breast cancer schedules.

Results

After a median follow-up of 48.5 months, no local or distant recurrence were observed. Mild to moderate skin toxicity occurred in all patients: 36% reported grade 1, 43% grade 2, and 21% grade 3 toxicity. One patient developed grade 2 fibrosis during follow-up. No significant correlations were found between the severity of acute/late toxicity and tumor size, surgical approach, or the radiation field's planning target volume (PTV).

Conclusions

Adjuvant radiation therapy appears to be well tolerated and feasible for high-risk phyllodes tumors. However, the decision to utilize radiotherapy should be personalized, considering tumor characteristics and the risks and benefits associated with treatment.