Radiological, pathological and surgical outcomes after neoadjuvant endocrine treatment in patients with ER-positive/HER2-negative breast cancer with a clinical high risk and a low-risk 70-gene signature

OBJECTIVE

This study aims to evaluate the response to and surgical benefits of neoadjuvant endocrine therapy (NET) in ER+/HER2-breast cancer patients who are clinically high risk, but genomic low risk according to the 70-gene signature (MammaPrint).

METHODS

Patients with ER+/HER2-invasive breast cancer with a clinical high risk according to MINDACT, who had a genomic low risk according to the 70-gene signature and were treated with NET between 2015 and 2023 in our center, were retrospectively analyzed. RECIST 1.1 criteria were used to assess radiological response using MRI or ultrasound. Surgical specimens were evaluated to assess pathological response. Two breast cancer surgeons independently scored the eligibility of breast conserving therapy (BCS) pre- and post- NET.

RESULTS

Of 72 included patients, 23 were premenopausal (100% started with tamoxifen of which 4 also received OFS) and 49 were postmenopausal (98% started with an aromatase inhibitor). Overall, 8 (11%) showed radiological complete response. Only 1 (1.4%) patient had a pathological complete response (RCB-0) and 68 (94.4%) had a pathological partial response (RCB-1 or RCB-2). Among the 26 patients initially considered for mastectomy, 14 (53.8%) underwent successful BCS. In all 20 clinical node-positive patients, a marked axillary lymph node was removed to assess response. Four out of 20 (20%) patients had a pathological complete response of the axilla.

CONCLUSION

The study showed that a subgroup of patients with a clinical high risk and a genomic low risk ER+/HER2-breast cancer benefits from NET resulting in BCS instead of a mastectomy. Additionally, NET may enable de-escalation in axillary treatment.

Real-world data on malignant and borderline phyllodes tumors of the breast: A population-based study of all 921 cases in the Netherlands (1989 -2020)

AIM

The aim of our study is to analyze patterns in treatment and outcome in a population-based series of patients with borderline and malignant phyllodes tumors (PT).

MATERIAL AND METHODS

Data on all patients with a borderline or malignant PT (1989-2020) were extracted from the Netherlands Cancer Registry and the Dutch nationwide pathology databank (Palga) and retrospectively analyzed.

RESULTS

We included 921 patients (borderline PT n = 452 and malignant PT n = 469). Borderline PT patients more often had breast-conserving surgery (BCS) as final surgery (81 vs. 46%). BCS rates for borderline PT increased over time (OR 1.08 per year, 95%CI 1.04 - 1.13, P < 0.001). In malignant PT adjuvant radiotherapy was given in 14.7%; this rate increased over time (OR 1.07 per year, 95%CI 1.02 - 1.13, P = 0.012). Local recurrence rate (5-year estimate of cumulative incidence) was 8.7% (95%CI 6.0-11.4) for borderline PT and 11.7% (95%CI 8.6-14.8) for malignant PT (P = 0.187) and was related to tumor size ≥ 20 mm (HR 10.6 (95%CI 1.5-76.8) and positive margin (HR 3.0 (95%CI 1.6-5.6), p < 0.001), but not to negative margin width (HR 1.3 ( 95%CI 0.7-2.3), p = 0.350)). Distant metastasis occurred only in malignant PT with a 5-year cumulative incidence of 4.7% (95%CI 3.3 - 6.1).

CONCLUSION

This population-based series showed an increase in BCS in borderline PT and an increase in adjuvant radiotherapy in malignant PT over time. We identified malignant PT, BCS, larger tumor size and positive final margins as possible risk factors for local recurrence. Small but negative margins can be accepted.

Management of Benign Phyllodes Tumors: A Dutch Population-Based Retrospective Cohort Between 1989 and 2022

BACKGROUND

Phyllodes tumors (PTs) are rare tumors of the breast. The current National Comprehensive Cancer Network (NCCN) guidelines recommend excision of benign PTs, accepting close or positive margins. Controversy about the optimal treatment for benign PTs remains, especially regarding the preferred margin width after surgical excision and the need for follow-up evaluation.

METHODS

A nationwide retrospective study analyzed the Dutch population from 1989 to 2022. All patients with a diagnosis of benign PT were identified through a search in the Dutch nationwide pathology databank (Palga). Information on age, year of diagnosis, size of the primary tumor, surgical treatment, surgical margin status, and local recurrence was collected.

RESULTS

The study enrolled 1908 patients with benign PT. The median age at diagnosis was 43 years (interquartile range [IQR], 34-52 years), and the median tumor size was 30 mm (IQR, 19-40 mm). Most of the patients (95%) were treated with breast-conserving surgery (BCS). The overall local recurrence rate was 6.2%, and the median time to local recurrence was 31 months (IQR, 15-61 months). Local recurrence was associated with bilaterality of the tumor (odds ratio [OR], 4.91; 95% confidence interval [CI], 2.95-28.30) and positive margin status (OR, 2.51; 95% CI 1.36-4.63). The local recurrence rate was 8.9% for the patients with positive excision margins and 4.0% for the patients with negative excision margins. Notably, for 27 patients (22.6%) who experienced a local recurrence, histologic upgrading of the recurrent tumor was reported, 7 (5.9%) of whom had recurrence as malignant lesions.

CONCLUSIONS

This nationwide series of 1908 patients showed a low local recurrence rate of 6.2% for benign PT, with higher recurrence rates following positive margins.

De-ESCAlating RadioTherapy in breast cancer patients with pathologic complete response to neoadjuvant systemic therapy: DESCARTES study

PURPOSE

Neoadjuvant systemic therapy (NST) is increasingly used in breast cancer patients and depending on subtype, 10-89% of patients will attain pathologic complete response (pCR). In patients with pCR, risk of local recurrence (LR) after breast conserving therapy is low. Although adjuvant radiotherapy after breast conserving surgery (BCS) reduces LR further in these patients, it may not contribute to overall survival. However, radiotherapy may cause early and late toxicity. The aim of this study is to show that omission of adjuvant radiotherapy in patients with a pCR after NST will result in acceptable low LR rates and good quality of life.

METHODS

The DESCARTES study is a prospective, multicenter, single arm study. Radiotherapy will be omitted in cT1-2N0 patients (all subtypes) who achieve a pCR of the breast and lymph nodes after NST followed by BCS plus sentinel node procedure. A pCR is defined as ypT0N0 (i.e. no residual tumor cells detected). Primary endpoint is the 5-year LR rate, which is expected to be 4% and deemed acceptable if less than 6%. In total, 595 patients are needed to achieve a power of 80% (one-side alpha of 0.05). Secondary outcomes include quality of life, Cancer Worry Scale, disease specific and overall survival. Projected accrual is five years.

CONCLUSION

This study bridges the knowledge gap regarding LR rates when adjuvant radiotherapy is omitted in cT1-2N0 patients achieving pCR after NST. If the results are positive, radiotherapy may be safely omitted in selected breast cancer patients with a pCR after NST.

TRIAL REGISTRATION

This study is registered at ClinicalTrials.gov on June 13th 2022 (NCT05416164). Protocol version 5.1 (15-03-2022).

Clinicopathological Parameters in Patient Selection for Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Cancer Metastases: A Meta-analysis

OBJECTIVE

To improve patient selection for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) by evaluating various preoperatively assessable clinicopathological parameters as markers for survival after CRS and HIPEC.

SUMMARY BACKGROUND DATA

Peritoneal metastases (PMs) originating from colorectal cancer are treated with CRS and HIPEC. Despite increasing survival, high morbidity and mortality warrant selection of patients with optimal benefit from this treatment. Many studies report a number of variables to be associated with survival after CRS and HIPEC, but no definitive analysis has been made to validate various markers.

METHODS

In concordance with PRISMA guidelines, we performed a literature search encompassing 4110 articles to select 50 articles that reported the influence of 1 or more clinicopathological variables on overall survival after CRS and HIPEC. In absence of RCTs, 25 cohort studies could be used to perform a meta-analysis on 10 prognostic variables.

RESULTS

We determined that concurrent liver metastasis, lymph node metastasis, Eastern Cooperative Oncology Group score, tumor differentiation, and signet ring cell histology are all negative prognostic variables on overall survival after CRS and HIPEC. Conversely, sex and location of primary could not be validated as prognostic markers. More research is required to make definitive conclusions about neoadjuvant chemotherapy, onset of PMs, and mucinous histology.

CONCLUSIONS

Current clinical practice, which selects patients based on extraperitoneal metastasis, lymph node stage, performance status, and tumor histology, is validated by our pooled analysis. Our data merit further research into neoadjuvant chemotherapy in the setting of CRS and HIPEC for PMs.