No Association of Positive Superficial and/or Deep Margins with Local Recurrence in Invasive Breast Cancer Treated with Breast-Conserving Surgery

Assessment of Eligibility and Utilization of Accelerated Partial Breast Irradiation in Korean Breast Cancer Patients (KROG 22-15)

PURPOSE

We investigated the proportions of patients eligible for accelerated partial breast irradiation (APBI) among those with pT1-2N0 breast cancer, based on the criteria set by the American Society for Radiation Oncology (ASTRO), the Groupe Européen de Curiethérapie and the European Society for Radiotherapy and Oncology (GEC-ESTRO), the American Brachytherapy Society (ABS), and the American Society of Breast Surgeons (ASBS). Additionally, we analyzed the rate of APBI utilization among eligible patients.

MATERIALS AND METHODS

Patients diagnosed with pT1-2N0 breast cancer in 2019 were accrued in four tertiary medical centers in Korea. All patients had undergone breast conserving surgery followed by radiotherapy, either whole breast irradiation or APBI. To determine which guideline best predicts the use of APBI in Korea, the F1 score and Matthews Correlation Coefficient (MCC) were determined for each guideline.

RESULTS

A total of 1,251 patients were analyzed, of whom 196 (15.7%) underwent APBI. The percentages of eligible patients identified by the ASTRO, GEC-ESTRO, ABS, and ASBS criteria were 13.7%, 21.0%, 50.5%, and 63.5%, respectively. APBI was used to treat 54.4%, 37.2%, 27.1%, and 23.7% of patients eligible by the ASTRO, GEC-ESTRO, ABS, and ASBS criteria, respectively. The ASTRO guideline exhibited the highest F1 score (0.76) and MCC (0.67), thus showing the best prediction of APBI utilization in Korea.

CONCLUSION

The proportion of Korean breast cancer patients who are candidates for APBI is substantial. The actual rate of APBI utilization among eligible patients may suggest there is a room for risk-stratified optimization in offering radiation therapy.

Margin status and survival outcomes after breast cancer conservation surgery: prospectively registered systematic review and meta-analysis

OBJECTIVE

To determine if margin involvement is associated with distant recurrence and to determine the required margin to minimise both local recurrence and distant recurrence in early stage invasive breast cancer.

DESIGN

Prospectively registered systematic review and meta-analysis of literature.

DATA SOURCES

Medline (PubMed), Embase, and Proquest online databases. Unpublished data were sought from study authors.

ELIGIBILITY CRITERIA

Eligible studies reported on patients undergoing breast conserving surgery (for stages I-III breast cancer), allowed an estimation of outcomes in relation to margin status, and followed up patients for a minimum of 60 months. Patients with ductal carcinoma in situ only or treated with neoadjuvant chemotherapy or by mastectomy were excluded. Where applicable, margins were categorised as tumour on ink (involved), close margins (no tumour on ink but <2 mm), and negative margins (≥2 mm).

RESULTS

68 studies from 1 January 1980 to 31 December 2021, comprising 112 140 patients with breast cancer, were included. Across all studies, 9.4% (95% confidence interval 6.8% to 12.8%) of patients had involved (tumour on ink) margins and 17.8% (13.0% to 23.9%) had tumour on ink or a close margin. The rate of distant recurrence was 25.4% (14.5% to 40.6%) in patients with tumour on ink, 8.4% (4.4% to 15.5%) in patients with tumour on ink or close, and 7.4% (3.9% to 13.6%) in patients with negative margins. Compared with negative margins, tumour on ink margins were associated with increased distant recurrence (hazard ratio 2.10, 95% confidence interval 1.65 to 2.69, P<0.001) and local recurrence (1.98, 1.66 to 2.36, P<0.001). Close margins were associated with increased distant recurrence (1.38, 1.13 to 1.69, P<0.001) and local recurrence (2.09, 1.39 to 3.13, P<0.001) compared with negative margins, after adjusting for receipt of adjuvant chemotherapy and radiotherapy. In five studies published since 2010, tumour on ink margins were associated with increased distant recurrence (2.41, 1.81 to 3.21, P<0.001) as were tumour on ink and close margins (1.44, 1.22 to 1.71, P<0.001) compared with negative margins.

CONCLUSIONS

Involved or close pathological margins after breast conserving surgery for early stage, invasive breast cancer are associated with increased distant recurrence and local recurrence. Surgeons should aim to achieve a minimum clear margin of at least 1 mm. On the basis of current evidence, international guidelines should be revised.

SYSTEMATIC REVIEW REGISTRATION

CRD42021232115.

Comparison of Recurrence Rate Between Re-Excision With Radiotherapy and Radiotherapy-Only Groups in Surgical Margin Involvement of In Situ Carcinoma

Purpose

Surgical margin status is a surrogate marker for residual tumors after breast-conserving surgery (BCS). A comparison of ipsilateral breast tumor recurrence (IBTR) rates between re-excision combined with radiotherapy (excision with RTx) and RTx alone, following the confirmation of ductal carcinoma in situ (DCIS) in the resection margin after BCS, has not been reported previously. Therefore, in the present study, the clinical characteristics of DCIS involvement in the surgical resection margin between excision with RTx and RTx alone were investigated, and the IBTR rate was compared.

Methods

We analyzed 8,473 patients treated with BCS followed by RTx between January 2013 and December 2019. Patients were divided into 2 groups based on surgical resection margin status in permanent pathology, and superficial and deep margins were excluded. Patients who underwent re-excision with DCIS confirmed in the resection margin were identified and the IBTR rate was examined.

Results

Among 8,473 patients treated with BCS, 494 (5.8%) had positive surgical resection margins. The median follow-up period was 47 months. Among the 494 patients with a positive resection margin, 368 (74.5%) had residual DCIS at the surgical resection margin in the final pathology. Among those with confirmed DCIS at the resection margin, 24 patients (6.5%) were re-excised, and 344 patients (93.5%) underwent RTx after observation. The IBTR rates were 4.2% and 1.2% in the re-excision and observation groups, respectively. IBTR-free survival analysis revealed no significant difference between the excision with RTx and RTx-only groups (p = 0.262).

Conclusion

The IBTR rate did not differ between the excision with RTx and RTx-only groups when DCIS was confirmed at the resection margins. This suggests that RTx and close observation without re-excision could be an option, even in cases where minimal involvement of DCIS is confirmed on surgical resection.

Usefulness of 3D-surgical guides in breast conserving surgery after neoadjuvant treatment

We used 3D printed-breast surgical guides (3DP-BSG) to designate the original tumor area from the pre-treatment magnetic resonance imaging (MRI) during breast-conserving surgery (BCS) in breast cancer patients who received neoadjuvant systemic therapy (NST). Targeting the original tumor area in such patients using conventional localization techniques is difficult. For precise BCS, a method that marks the tumor area found on MRI directly to the breast is needed. In this prospective study, patients were enrolled for BCS after receiving NST. Partial resection was performed using a prone/supine MRI-based 3DP-BSG. Frozen biopsies were analyzed to confirm clear tumor margins. The tumor characteristics, pathologic results, resection margins, and the distance between the tumor and margin were analyzed. Thirty-nine patients were enrolled with 3DP-BSG for BCS. The median nearest distance between the tumor and the resection margin was 3.9 cm (range 1.2–7.8 cm). Frozen sections showed positive margins in 4/39 (10.3%) patients. Three had invasive cancers, and one had carcinoma in situ; all underwent additional resection. Final pathology revealed clear margins. After 3-year surveillance, 3/39 patients had recurrent breast cancer. With 3DP-BSG for BCS in breast cancer patients receiving NST, the original tumor area can be identified and marked directly on the breast, which is useful for surgery. Trial Registration: Clinical Research Information Service (CRIS) Identifier Number: KCT0002272. First registration number and date: No. 1 (27/04/2016).

Breast-conserving surgery with 3D-printed surgical guide: a single-center, prospective clinical study

To facilitate precise tumor resection at the time of breast-conserving surgery (BCS), we developed and implemented a magnetic resonance imaging (MRI)-based three-dimensional-printed (3DP) breast surgical guide (BSG). This prospective cohort study was conducted at a single institution from July 2017 to February 2019 on women with breast cancer who underwent partial breast resection using patient-specific 3DP BSGs. Eighty-eight patients with invasive cancer were enrolled, of whom 1 patient had bilateral breast cancer. The mean size of the tumor long-axis on MRI before surgery was 2.8 ± 0.9 cm, and multiple tumors were observed in 34 patients. In 16 cases (18.0%), the resection margin was tumor-positive according to intraoperative frozen biopsy; all of these tumors were ductal carcinoma in situ and were re-excised intraoperatively. In 93.3% of the cases, the resection margin was tumor-free in the permanent pathology. The mean pathological tumor size was 1.7 ± 1.0 cm, and the mean distance from the tumor to the border was 1.5 ± 1.0 cm. This exploratory study showed that the tumor area on the MRI could be directly displayed on the breast when using a 3DP BSG for BCS, thereby allowing precise surgery and safe tumor removal.

Trial Registration Clinical Research Information Service (CRIS) Identifier (No. KCT0002375, KCT0003043).

Feasibility and safety of breast-conserving surgery via a periareolar incision for cancers located far from the nipple-areolar complex: a retrospective study

Purpose

We performed breast-conserving surgery (BCS) using periareolar incisions for cancers located far from the nipple–areolar complex (NAC) and examined if BCS via a periareolar incision maximized cosmesis and maintained oncologic safety. One of the most important goals of BCS is to improve cosmesis after surgery and quality of life, but the skin incision can affect cosmesis based on the tumor location.

Methods

Fifty-five patients with breast cancers located far from the NAC underwent BCS via periareolar incisions between January 2017 and April 2018. If a sentinel lymph node biopsy was required, another skin incision was created in the axilla using the conventional technique. Medical records of patients were reviewed retrospectively.

Results

The mean patient age was 48.1 ± 10.6 years. The mean tumor size was 1.8 ± 1.0 cm (range 0.2–4.5 cm) on preoperative magnetic resonance imaging (MRI); the mean distance from the NAC to the tumor was 5.9 ± 1.9 cm (range 4.0–12.3 cm). Patients with cancers in the subareolar area were excluded even though the distance from the nipple was > 4 cm on MRI. Negative microscopic margins were obtained in all patients. There was no surgical complication such as seroma, bleeding, or infection. Re-operation was not needed. All patients received whole breast radiation therapy. After surgery and radiation therapy, periareolar incision scars were nearly invisible.

Conclusion

For cancers located far from the NAC, BCS via periareolar incisions is feasible and leads to superior cosmesis in selective patients. Moreover, BCS seems oncologically safe, although long-term outcomes need to be evaluated.

Magnetic resonance imaging based 3-dimensional printed breast surgical guide for breast-conserving surgery in ductal carcinoma in situ: a clinical trial

Breast-conserving surgery (BCS) is performed in patients with ductal carcinoma in situ (DCIS) because of the small size of the tumor. It is essential to know the quantitative extent of the tumor before performing this precise partial resection surgery. A three-dimensional printed (3DP) breast surgical guide (BSG) was developed using information obtained from supine magnetic resonance imaging (MRI) and 3D printing technology and it was used for treating patients with breast cancer. Here, we report our experience with the application of the BSG for patients with DCIS. Patients with breast cancer who underwent BCS from July 2017 to February 2019 were included in this study. The patients underwent partial resection with a supine-MRI based 3DP-BSG. A total of 102 BCS using 3DP-BSG were conducted, and 11 cases were DCIS. The patients’ median age was 56 years (range, 38–69 years). The mean tumor diameter was 1.3 ± 0.9 cm. The median surgical time was 70 min (range, 40–88 min). All patients had tumor-free resection margins. The median distance from the tumor to the margin was 11 mm (range, 2–35 mm). Direct demarcation of the tumor extent in the breast and a pain-free procedure are the advantages of using 3DP-BSG in patients with DCIS.

Trial registration: Clinical Research Information Service (CRIS) Identifier Number: KCT0002375, KCT0003043.

Impact of Oncotype DX Recurrence Score on the Patterns of Locoregional Recurrence in Breast Cancer (Korean Radiation Oncology Group 19-06)

The current study evaluated the impact of the Oncotype DX recurrence score (RS) on the patterns of locoregional recurrence (LRR) in node-negative, hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. Totally, 339 patients from 4 institutions were enrolled and analyzed retrospectively. All patients underwent breast-conserving surgery followed by whole-breast irradiation; only 2 patients received regional nodal irradiation (RNI). The RS was < 11 in 55 patients, 11–25 in 241, and > 25 in 43. Sixty-two patients received adjuvant chemotherapy. All patients except 4 received hormonal therapy. During a 62-month median follow-up, local recurrence was observed in 1 patient; regional recurrence, 3; and distant metastasis, 7. All LRRs were observed among patients with a RS > 25, resulting in a 5-year LRR rate of 7.3% in this subgroup. Regional recurrences developed in patients did not receive RNI initially. Thus, RNI might be effective for patients with a high RS.

Partial chest wall radiation therapy for positive or close surgical margins after modified radical mastectomy for breast cancer without lymph node metastasis

Aim

Whole‐breast radiation therapy after breast‐conserving surgery can control local recurrence with a long‐term survival rate equivalent to that of radical mastectomy for patients with early breast cancer. However, the significance of radiation therapy for patients with positive/close margins after mastectomy remains controversial. Following radical mastectomy, no residual breast parenchyma remains, and thus radiation therapy of the entire chest wall may represent overtreatment in the patients, especially those without lymph node metastasis (N0). We therefore implemented partial chest wall radiation therapy for patients with N0 breast cancer and positive and/or close margins after mastectomy.

Methods

A total of 22 patients with N0 status but positive/close margins underwent partial chest wall radiation therapy to irradiate the predetermined clinical target volume, which had margins of at least 2 cm medial, lateral, superior, and inferior to the primary tumor bed. With reference to chest wall thickness, 4‐10‐MV photons or 5‐8‐MeV electrons with/without a bolus were delivered. The total dose was 50‐66 Gy. We compared the results with those from 18 nonradiation therapy patients using Pearson's χ² test.

Results

All patients in the partial chest wall radiation therapy group achieved good local control despite having a significantly higher proportion of positive margins (77.3%) compared with the nonradiation therapy group (27.8%) (P = 0.002). Both groups showed 100% recurrence‐ and disease‐free survival.

Conclusion

Partial chest wall radiation therapy may offer recurrence‐ and disease‐free survival without local recurrence in N0 mastectomy patients with positive/close surgical margins.

Therapy of isolated locoregional recurrent carcinoma of the breast

PURPOSE

There is widespread consent that isolated locoregional recurrence (ILRR) in breast cancer should be treated surgically. On searching literature and guidelines most studies include ipsilateral recurrence in breast tissue or on thoracic wall post-mastectomy, recurrence in scar tissue as well as in ipsilateral axillary lymph nodes. Some studies discuss metachronous contralateral breast cancer as ILRR. About 10-35% of women with primary breast cancer suffer from ILRR. The existing data concerning the role of systemic therapy in the treatment of ILRR are insufficient. We investigated the influence of chemotherapy on disease-free- (DFS) and overall-survival (OS).

METHODS

Retrospective analysis of all patients with ILRR and without distant metastasis was done, which were treated at the Department of Gynecology, Obstetrics and Reproductive Medicine, Saarland University between 2005 and 2013. Data collection used patients' database system and was followed via patient questionnaires.

RESULTS

In total, we collected data of 93 patients with locally recurrent breast cancer and observed a 72.6% questionnaire response rate. Average timeline accounted for 99 months between primary diagnosis and local recurrence; average age of patients at diagnosis of local recurrence was 60.6 years. After a median follow-up of 63 months DFS reached 76% with and 73% without chemotherapy, and after 74 months overall survival amounted to 94% and 70%, respectively.

CONCLUSION

Almost all patients with ILRR were operated. Especially patients with hormone receptor-negative recurrent breast cancer seemed to show a benefit having been treated with chemotherapy. Most patients were without recurrence after their particular therapies.

Comparing long-term local recurrence rates of surgical and non-surgical management of close anterior margins in breast conserving surgery

PURPOSE

While it is known that histologically involved margins lead to a higher local recurrence rate, re-excision of anterior margins is less common than that of radial margins. However, there are minimal long-term data on the oncological safety of non-surgical management of anterior margins.

PATIENTS AND METHODS

A retrospective study was performed of all patients who underwent breast conserving surgery for breast cancer between 2000 and 2008 at two tertiary referral centres. A close margin was defined as disease within two mm of the resection margin (including disease at the margin).

RESULTS

6922 patients underwent surgery for invasive or in situ breast cancer of whom 277 patients had a close anterior margin alone after breast conserving surgery. Two hundred and twenty patients had non-surgical management of their margins, while 57 had re-excision surgery. Overall, there were 4/57 local recurrences in the surgical management group and 12/220 in the non-surgical management group. The local recurrence-free survival rate at 5 years was 98.2% (1 recurrence, 95% CI 87.8-99.7) in the surgical management group and 97.2% (6 recurrences, 95% CI 93.8-98.7) in the non-surgical management group. At 10 years, the rates were 92.2% (4 recurrences, 95% CI 80.3-97.0) in the surgical management group and 93.9% (12 recurrences, 95% CI 89.4-96.5) in the non-surgical management group. There was no significant difference found in the local recurrence rate between management groups (HR 1.24, 95% CI 0.40, 3.85; p = 0.71).

CONCLUSIONS

Local recurrence rates are acceptable and similar in both the surgically and non-surgically managed groups. Non-surgical management of close anterior margins appears oncologically safe when combined with appropriate adjuvant therapy.