Purpose: The partner and localizer of breast cancer 2 (PALB2) mutation is a predisposition to breast cancer development. However, limited clinical data are available for the Korean population. Therefore, this study aimed to compare the characteristics and oncological outcomes of patients with PALB2-mutated and non-mutated PALB2 in Korea. Methods: A total of 1,463 breast cancer (BRCA) 1/2 mutation-negative breast cancer underwent comprehensive multigene sequencing between 2016 and 2019 at Severance Hospital, Seoul, Korea. Clinicopathological data and oncological results of PALB2 mutated patients were prospectively collected and compared with those of the non-mutated group. Results: PALB2 mutations were identified in 1.2% (17/1,463) of the patients. The median age at diagnosis was 46 (30–73) years, and the median tumor size was 1.8 (0.05–3.5) cm. All patients with PALB2 mutations had histologic grades II–III, and a triple-negative subtype was found in 23.5% (4/17); however, there were no significant differences in clinicopathological data between the groups. During the median follow-up time of 38.5 months, locoregional recurrence occurred in 4.2% (44/1,043), distant recurrence was reported in 3.0% (31/1,043), and contralateral breast cancer was diagnosed in 0.8% (9/1,043) of patients, with no significant difference observed between the groups. All-cause mortality was observed in 1.8% (19/1,028) of the non-mutated group and none in the PALB2 mutation group. However, survival analyses demonstrated no significant differences in all-cause mortality (p = 0.524) and recurrence-free survival (p = 0.319). Conclusion Clinicopathological features and oncological outcomes of PALB2 mutated breast cancer were not significantly different from those of non-mutated breast cancer in the Korean population.

Purpose: The partner and localizer of breast cancer 2 (PALB2) mutation is a predisposition to breast cancer development. However, limited clinical data are available for the Korean population. Therefore, this study aimed to compare the characteristics and oncological outcomes of patients with PALB2-mutated and non-mutated PALB2 in Korea. Methods: A total of 1,463 breast cancer (BRCA) 1/2 mutation-negative breast cancer underwent comprehensive multigene sequencing between 2016 and 2019 at Severance Hospital, Seoul, Korea. Clinicopathological data and oncological results of PALB2 mutated patients were prospectively collected and compared with those of the non-mutated group. Results: PALB2 mutations were identified in 1.2% (17/1,463) of the patients. The median age at diagnosis was 46 (30–73) years, and the median tumor size was 1.8 (0.05–3.5) cm. All patients with PALB2 mutations had histologic grades II–III, and a triple-negative subtype was found in 23.5% (4/17); however, there were no significant differences in clinicopathological data between the groups. During the median follow-up time of 38.5 months, locoregional recurrence occurred in 4.2% (44/1,043), distant recurrence was reported in 3.0% (31/1,043), and contralateral breast cancer was diagnosed in 0.8% (9/1,043) of patients, with no significant difference observed between the groups. All-cause mortality was observed in 1.8% (19/1,028) of the non-mutated group and none in the PALB2 mutation group. However, survival analyses demonstrated no significant differences in all-cause mortality (p = 0.524) and recurrence-free survival (p = 0.319). Conclusion Clinicopathological features and oncological outcomes of PALB2 mutated breast cancer were not significantly different from those of non-mutated breast cancer in the Korean population.

Purpose: The partner and localizer of breast cancer 2 (PALB2) mutation is a predisposition to breast cancer development. However, limited clinical data are available for the Korean population. Therefore, this study aimed to compare the characteristics and oncological outcomes of patients with PALB2-mutated and non-mutated PALB2 in Korea. Methods: A total of 1,463 breast cancer (BRCA) 1/2 mutation-negative breast cancer underwent comprehensive multigene sequencing between 2016 and 2019 at Severance Hospital, Seoul, Korea. Clinicopathological data and oncological results of PALB2 mutated patients were prospectively collected and compared with those of the non-mutated group. Results: PALB2 mutations were identified in 1.2% (17/1,463) of the patients. The median age at diagnosis was 46 (30–73) years, and the median tumor size was 1.8 (0.05–3.5) cm. All patients with PALB2 mutations had histologic grades II–III, and a triple-negative subtype was found in 23.5% (4/17); however, there were no significant differences in clinicopathological data between the groups. During the median follow-up time of 38.5 months, locoregional recurrence occurred in 4.2% (44/1,043), distant recurrence was reported in 3.0% (31/1,043), and contralateral breast cancer was diagnosed in 0.8% (9/1,043) of patients, with no significant difference observed between the groups. All-cause mortality was observed in 1.8% (19/1,028) of the non-mutated group and none in the PALB2 mutation group. However, survival analyses demonstrated no significant differences in all-cause mortality (p = 0.524) and recurrence-free survival (p = 0.319). Conclusion Clinicopathological features and oncological outcomes of PALB2 mutated breast cancer were not significantly different from those of non-mutated breast cancer in the Korean population.

Purpose: The use of advanced energy devices for mastectomy and axillary lymph node dissection can reduce perioperative blood loss, seroma formation, and drainage duration/volume. Retraction using fiberoptic retractors can help visualize deep and narrow surgical fields. We aimed to compare the postoperative outcomes between single-incision breast-conserving surgery (SIBCS) and conventional breast-conserving surgery (CBCS) with axillary staging using advanced energy devices and conventional equipment, respectively. Materials and Methods: We retrospectively reviewed the medical records of 244 patients who underwent BCS with axillary surgery between March 2018 and September 2019 at Severance Hospital. The patients were grouped based on the device used to aid in axillary staging: CBCS group (n=117) used conventional electrocautery; and SIBCS group (n=127) used advanced energy devices and fiberoptic retractors. The two groups were compared for postoperative outcomes. Results: The mean patient age was 55.9 and 53.1 years in the CBCS and SIBCS groups, respectively. Incision size was significantly smaller in the SIBCS group than in the CBCS group (6.3±2.1 cm vs. 7.5±2.5 cm, p=0.044). There were no significant differences between the two groups in terms of operating time (126.0±40.0 min vs. 127.0±63.0 min, p=0.828), operative blood loss (11.0±31.0 mL vs. 7.0±18.0 mL, p=0.100), drainage duration (7.0±3.0 d vs. 8.0±4.0 d, p=0.288), and complications (1.70% vs. 2.36%, p=0.523). Conclusion Using advanced energy devices for SIBCS with axillary staging reduced incision size and provided better cosmetic outcomes compared to those using the conventional method. Advanced energy devices may offer better surgical outcomes in patients who undergo BCS with axillary staging.

Background: Axillary evaluation is unnecessary for pure ductal carcinoma in situ (DCIS);however, it is performed because of the risk of upstaging to invasive cancer. We assessed the role of intraoperative frozen section (IOF) biopsy in reducing invasive cancer upstaging and axillary evaluation in preoperative DCIS patients. Methods: We reviewed patients with preoperative DCIS who underwent breast-conserving surgery (BCS) with IOF biopsy. Positive IOF biopsy findings were defined as the presence of invasive or micro-invasive cancer. The IOF biopsy and permanent pathology findings were compared. Results: Seventy-eight patients underwent BCS with IOF biopsy. Six patients showed positive IOF biopsy findings; five of these patients showed concordant permanent pathology findings.Sentinel lymph node biopsy (SLNB) was positive in one patient. Thirteen patients with invasive breast cancer were missed by IOF biopsy; they underwent SLNB during the second surgery. None of them had metastatic lymph nodes. The sensitivity and specificity of IOF biopsy were 27.7% and 98.3%, respectively, with 82.1% accuracy. None of the other factors showed statistically significant relationships with the permanent pathology findings, except for the IOF biopsy findings. Conclusion IOF evaluation can aid in detecting the invasiveness of tumors in patients with preoperative DCIS.

Purpose: There is a potential risk that lobular carcinoma in situ (LCIS) on preoperative biopsy might be diagnosed as ductal carcinoma in situ (DCIS) or invasive carcinoma in the final pathology. This study aimed to evaluate the rate of upgrade of LCIS on preoperative biopsy to DCIS or invasive carcinoma. Materials and Methods: Data of 55 patients with LCIS on preoperative biopsy were analyzed. All patients underwent surgery between 1991 and 2016 at Severance Hospital in Seoul, Korea. We analyzed the rate of upgrade of preoperative LCIS to DCIS or invasive cancer in the final pathology. The clinicopathologic features related to the upgrade were evaluated. Results: The rate of upgrade of LCIS to DCIS or invasive carcinoma was 16.4% (9/55). In multivariate analysis, microcalcification and progesterone receptor expression were significantly associated with the upgrade of LCIS (p=0.023 and p=0.044, respectively). Conclusion The current study showed a relatively high rate of upgrade of LCIS on preoperative biopsy to DCIS or invasive cancer. The presence of microcalcification and progesterone receptor expression may be potential predictors of upgradation of LCIS on preoperative biopsy. Surgical excision of the LCIS during preoperative biopsy could be a management option to identify the concealed malignancy.

Purpose: Advanced energy devices, including electrosurgical bipolar systems or ultrasonic shears, are widely used in various surgeries. An electrosurgical bipolar device allows surgeons to grasp and dissect tissues, as well as simultaneously ligate and cut vessels and lymphatics during surgery. This study aimed to evaluate the effects of advanced bipolar energy devices on the reduction in seroma formation during mastectomy, axillary staging, and/or reconstruction. Methods: This prospective randomized clinical trial with a 1:1 ratio compared the use of an electrosurgical bipolar device, LigaSureTM (LGS), against conventional cut-and-ligate techniques in mastectomy with axillary procedures for patients with breast cancer. A total of 82 patients with breast cancer who underwent definitive surgery were enrolled in this study. The primary endpoint was the total drainage volume after surgery. Results: The clinicopathological characteristics of the two groups were not significantly different. The total postoperative drainage volume was significantly lower in the LGS group than in the control group (756.26 mL vs. 1,167.74 mL, p = 0.009). The actual postoperative drainage volume and duration also decreased significantly in the LGS group compared with those in the control group (all p < 0.05). The rate of postoperative complications was lower in the LGS group than in the control group (9.8% vs. 27.5%, p = 0.05). Conclusion Electrosurgical bipolar devices showed better performance in terms of decreasing postoperative drainage during mastectomy and axillary staging and/or reconstruction.

Purpose: Nipple-sparing mastectomy (NSM) includes various techniques, including conventional or endoscopic mastectomies. Since the introduction of robot-assisted NSM (RANSM) in 2015, 2 main methods have been used: gasless and gas-inflated techniques. The aim of this study was to compare clinicopathologic characteristics, surgical outcomes, and postoperative complications between patients treated with gasless RANSM and those treated with gas-inflated RANSM. Methods: We conducted a retrospective study of women who underwent gasless or gasinflated RANSM with immediate breast reconstruction between November 2016 and May 2019. The indications for RANSM were early breast cancer, interstitial mastopathy, or BRCA1/2 mutation carriers. Clinicopathologic characteristics, surgical outcomes, and postoperative complications were analyzed. The severity of complications was graded using the Clavien-Dindo system. Results: A total of 58 RANSM procedures were performed in 46 women: 15 cases of gasless RANSM and 43 cases of gas-inflated RANSM. The proportion of node-negative disease was higher in the gas-inflated group (97.1%) than in the gasless group (69.2%, p = 0.016).Adjuvant radiotherapy was administered in 30.6% of the cases in the gasless group and only 5% of the cases in the gas-inflated group. Other clinicopathological factors were not significantly different between the groups. Regarding surgical outcomes, the initial incision was 1 cm longer in the gasless group (5.17 ± 0.88 cm) than that in the gas-inflated group (4.20 ± 1.05 cm; p = 0.002). The final incision was also longer in the gasless group (5.17 ± 0.88 cm) than that in the gas-inflated group (4.57 ± 1.07 cm; p = 0.040). Operation time, complication rate, and complication grade were not significantly different between the 2 groups. Conclusion In this study, there were no significant differences in surgical outcomes or postoperative complications between gasless and gas-inflated RANSM, except for a longer incision with the gasless technique. Both techniques are reasonable options for RANSM followed by immediate reconstruction.

Purpose: According to the American Joint Committee on Cancer’s 8th Edition Manual, lobular carcinoma in situ (LCIS) is no longer considered a malignant disease, although it may be a precursor to the development of breast cancer. The present study aimed to evaluate the clinicopathological features and prognosis of LCIS. Methods: This study retrospectively analyzed clinicopathological features and prognosis data of LCIS among patients who underwent breast surgery at Severance Hospital, Seoul, South Korea from 1991 to 2016. Results: Of the 47 patients, 49 cases of LCIS were confirmed by postoperative pathology. The mean patient age was 48.15±8.34 years. Most patients (81.6%) did not have palpable tumors at diagnosis, and 51.0% showed no microcalcification on mammography. Breast-conserving surgery was performed more frequently than total mastectomy (77.6% vs. 22.4%). The mean tumor size was 1.63±2.11 cm. There were only 3 cases of pleomorphic LCIS. Hormone receptor-positive tumors were noted in 47 cases, however, the hormone receptor status was unknown in the other 2 cases. There were no LCIS recurrences or deaths during the follow-up period (mean 56 months). Conclusion LCIS is often incidentally diagnosed without clinical symptoms, especially in women aged <50 years. The prognosis of LCIS is excellent in cases that are surgically treated.

Purpose: Nipple-sparing mastectomy (NSM) includes various techniques, including conventional or endoscopic mastectomies. Since the introduction of robot-assisted NSM (RANSM) in 2015, 2 main methods have been used: gasless and gas-inflated techniques. The aim of this study was to compare clinicopathologic characteristics, surgical outcomes, and postoperative complications between patients treated with gasless RANSM and those treated with gas-inflated RANSM. Methods: We conducted a retrospective study of women who underwent gasless or gasinflated RANSM with immediate breast reconstruction between November 2016 and May 2019. The indications for RANSM were early breast cancer, interstitial mastopathy, or BRCA1/2 mutation carriers. Clinicopathologic characteristics, surgical outcomes, and postoperative complications were analyzed. The severity of complications was graded using the Clavien-Dindo system. Results: A total of 58 RANSM procedures were performed in 46 women: 15 cases of gasless RANSM and 43 cases of gas-inflated RANSM. The proportion of node-negative disease was higher in the gas-inflated group (97.1%) than in the gasless group (69.2%, p = 0.016).Adjuvant radiotherapy was administered in 30.6% of the cases in the gasless group and only 5% of the cases in the gas-inflated group. Other clinicopathological factors were not significantly different between the groups. Regarding surgical outcomes, the initial incision was 1 cm longer in the gasless group (5.17 ± 0.88 cm) than that in the gas-inflated group (4.20 ± 1.05 cm; p = 0.002). The final incision was also longer in the gasless group (5.17 ± 0.88 cm) than that in the gas-inflated group (4.57 ± 1.07 cm; p = 0.040). Operation time, complication rate, and complication grade were not significantly different between the 2 groups. Conclusion In this study, there were no significant differences in surgical outcomes or postoperative complications between gasless and gas-inflated RANSM, except for a longer incision with the gasless technique. Both techniques are reasonable options for RANSM followed by immediate reconstruction.