Concurrent Lapatinib With Brain Radiation Therapy in Patients With HER2+ Breast Cancer With Brain Metastases: NRG Oncology-KROG/RTOG 1119 Phase 2 Randomized Trial.

PURPOSE: Lapatinib plus whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS) was hypothesized to improve the 12-week intracranial complete response (CR) rate compared with either option of radiation therapy (RT) alone for patients with brain metastases (BM) from human epidermal growth factor receptor 2-positive (HER2+) breast cancer. METHODS AND MATERIALS: This study included patients with HER2+ breast cancer with ≥1 measurable, unirradiated BM. Patients were randomized to WBRT (37.5 Gy/3 wk)/SRS (size-based dosing) ± concurrent lapatinib (1000 mg daily for 6 weeks). Secondary endpoints included objective response rate (ORR), lesion-specific response, central nervous system progression-free survival, and overall survival. RESULTS: From July 2012 to September 2019, 143 patients were randomized, with 116 analyzable for the primary endpoint. RT + lapatinib did not improve 12-week CR (0% vs 6% for RT alone, 1-sided P = .97), or ORR at 12 weeks. At 4 weeks, RT + lapatinib showed higher ORR (55% vs 42%). Higher graded prognostic assessment and ≤10 lesions were associated with higher 12-week ORR. Grade 3 and 4 adverse event rates were 8% and 0% for RT and 28% and 6% for RT + lapatinib. CONCLUSIONS: The addition of 6 weeks of concomitant lapatinib to WBRT/SRS did not improve the primary endpoint of 12-week CR rate or 12-week ORR. Adding lapatinib to WBRT/SRS showed improvement of 4-week ORR, suggesting a short-term benefit from concomitant therapy.

Comparison of initial and sequential salvage brain-directed treatment in patients with 1-4 vs. 5-10 brain metastases from breast cancer (KROG 16-12).

PURPOSE: We aimed to compare the initial and salvage brain-directed treatment and overall survival (OS) between patients with 1-4 brain metastases (BMs) and those with 5-10 from breast cancer (BC). We also organized a decision tree to select the initial whole-brain radiotherapy (WBRT) for these patients. METHODS: Between 2008 and 2014, 471 patients were diagnosed with 1-10 BMs. They were divided into two groups based on the number of BM: 1-4 BMs (n = 337) and 5-10 BMs (n = 134). Median follow-up duration was 14.0 months. RESULTS: Stereotactic radiosurgery (SRS)/fractionated stereotactic radiotherapy (FSRT) was the most common treatment modality (n = 120, 36%) in the 1-4 BMs group. In contrast, 80% (n = 107) of patients with 5-10 BMs were treated with WBRT. The median OS of the entire cohort, 1-4 BMs, and 5-10 BMs was 18.0, 20.9, and 13.9 months, respectively. In the multivariate analysis, the number of BM and WBRT were not associated with OS, whereas triple-negative BC and extracranial metastasis decreased OS. Physicians determined the initial WBRT based on four variables in the following order: number and location of BM, primary tumor control, and performance status. Salvage brain-directed treatment (n = 184), mainly SRS/FSRT (n = 109, 59%), prolonged OS by a median of 14.3 months. CONCLUSION: The initial brain-directed treatment differed notably according to the number of BM, which was chosen based on four clinical factors. In patients with ≤ 10 BMs, the number of BM and WBRT did not affect OS. The major salvage brain-directed treatment modality was SRS/FSRT and increased OS.

A Phase II Study of Preoperative Chemoradiotherapy with Capecitabine Plus Simvastatin in Patients with Locally Advanced Rectal Cancer.

PURPOSE: The purpose of this phase II trial was to evaluate whether the addition of simvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, to preoperative chemoradiotherapy (CRT) with capecitabine confers a clinical benefit to patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Patients with LARC (defined by clinical stage T3/4 and/or lymph node positivity) received preoperative radiation (45-50.4 Gy in 25-28 daily fractions) with concomitant capecitabine (825 mg/m2 twice per day) and simvastatin (80 mg, daily). Curative surgery was planned 4-8 weeks after completion of the CRT regimen. The primary endpoint was pathologic complete response (pCR). The secondary endpoints included sphincter-sparing surgery, R0 resection, disease-free survival, overall survival, the pattern of failure, and toxicity. RESULTS: Between October 2014 and July 2017, 61 patients were enrolled; 53 patients completed CRT regimen and underwent total mesorectal excision. The pCR rate was 18.9% (n=10) by per-protocol analysis. Sphincter-sparing surgery was performed in 51 patients (96.2%). R0 resection was achieved in 51 patients (96.2%). One patient experienced grade 3 liver enzyme elevation. No patient experienced additional toxicity caused by simvastatin. CONCLUSION: The combination of 80 mg simvastatin with CRT and capecitabine did not improve pCR in patients with LARC, although it did not increase toxicity.

Dummy run quality assurance study in the Korean Radiation Oncology Group 19 - 09 multi-institutional prospective cohort study of breast cancer.

BACKGROUND: The Korean Radiation Oncology Group (KROG) 19 - 09 prospective cohort study aims to determine the effect of regional nodal irradiation on regional recurrence rates in ypN0 breast cancer patients. Dosimetric variations between radiotherapy (RT) plans of participating institutions may affect the clinical outcome of the study. We performed this study to assess inter-institutional dosimetric variations by dummy run. METHODS: Twelve participating institutions created RT plans for four clinical scenarios using computed tomography images of two dummy cases. Based on a reference structure set, we analyzed dose-volume histograms after collecting the RT plans. RESULTS: We found variations in dose distribution between institutions, especially in the regional nodal areas. Whole breast and regional nodal irradiation (WBI + RNI) plans had lower inter-institutional agreement and similarity for 95% isodose lines than WBI plans. Fleiss's kappa values, which were used to measure inter-institutional agreement for the 95% isodose lines, were 0.830 and 0.767 for the large and medium breast WBI plans, respectively, and 0.731 and 0.679 for the large and medium breast WBI + RNI plans, respectively. There were outliers in minimum dose delivered to 95% of the structure (D95%) of axillary level 1 among WBI plans and in D95% of the interpectoral region and axillary level 4 among WBI + RNI plans. CONCLUSION: We found inter-institutional and inter-case variations in radiation dose delivered to target volumes and organs at risk. As KROG 19 - 09 is a prospective cohort study, we accepted the dosimetric variation among the different institutions. Actual patient RT plan data should be collected to achieve reliable KROG 19 - 09 study results.

Suggestion for the omission of post-mastectomy chest wall radiation therapy in patients who underwent skin-sparing/nipple-sparing mastectomy.

AIM: Both skin-sparing mastectomy (SSM) and nipple-sparing mastectomy (NSM) have been widely adopted. Although postmastectomy radiation therapy (PMRT) can improve clinical outcomes, it can worsen cosmesis following reconstruction. Therefore, identifying risk factors of ipsilateral breast tumor recurrence (IBTR) could help de-escalate PMRT after NSM/SSM in patients with pT1-2 disease. METHODS: We retrospectively reviewed patients treated with SSM (N = 400) and NSM (N = 156) in patients with pT1-2N0-1 disease between 2009 and 2016. Seventy-four patients received PMRT with 50-50.4 Gy in 25-28 fractions. The Cox proportional hazards model was used to analyze the prognostic factors of IBTR. RESULTS: With a median follow-up of 66.2 months, 17 IBTR events were observed, with 5-year IBTR-free rate of 97.2%. Although only one IBTR was observed after PMRT, there was no statistical difference in the 5-year IBTR-free rate (PMRT vs. no PMRT, 98.6% vs. 97.0%, p = 0.360). Multivariable analyses demonstrated that age ≤45 years and lymphovascular invasion (LVI) were adverse features of IBTR. The low-risk group (0 risk factor) showed a better 5-year IBTR-free rate than the high-risk group (≥1 risk factor) (100.0% vs. 95.8%, p = 0.003). In the high-risk group, PMRT slightly improved 5-year IBTR-free rate compared with no PMRT (98.6% vs. 95.2%, p = 0.166). In addition, PMRT increased 5-year cumulative incidence of reconstruction failure (10.0% vs. 2.8%, p = 0.001). CONCLUSION: We identified risk factors (age and LVI) related to IBTR following upfront SSM/NSM with pT1-2 disease. As a hypothesis-generating study, de-escalation of PMRT by omitting chest wall irradiation in selective patients could improve reconstruction-related complications without compromising oncologic outcomes.

Determining Which Patients Require Preoperative Pelvic Radiotherapy Before Curative-Intent Surgery and/or Ablation for Metastatic Rectal Cancer.

BACKGROUND: The aim of this study is to determine the optimal indications for preoperative pelvic radiotherapy (RT) in patients with metastatic rectal cancer who underwent curative-intent surgical resection and/or ablation. METHODS: Between January 2000 and October 2019, 246 patients who met our inclusion criteria were enrolled. Preoperative RT was performed in 22 patients (8.9%). Lower margin below the peritoneal reflection (p < 0.001), mesorectal fascia (MRF) invasion (p = 0.02), and lateral pelvic lymph node (LPLN) involvement (p = 0.005) were more frequent in the preoperative RT group. RESULTS: During the median follow-up period of 13.3 months (interquartile range [IQR]: 6.0-36.3 months), local recurrence (LR) was identified in 60 patients (24.4%). It was the first site of recurrence in 45 of them (18.3%). Among them, three patients were in the preoperative RT group. On multivariable analysis, lower margin below the peritoneal reflection, MRF invasion, LPLN involvement, carcinoembryonic antigen (CEA) level ≥ 10 ng/mL before treatment, and preoperative RT were significant prognostic factors for LR-free survival (LRFS). In the patient group without any risk factors, the 2-year LRFS rate was 94.9% without preoperative RT. In the patient group with one or more risk factors, the 2-year LRFS was 64.4% without and 95.2% with preoperative RT. CONCLUSION: LR developed in about 25% of patients within 2 years. Preoperative RT should be considered, especially in patients with a risk factor for LR, including lower margin below the peritoneal reflection, MRF invasion, LPLN involvement, or CEA ≥ 10 ng/mL before treatment.

Immediate breast reconstruction has no impact on the oncologic outcomes of patients treated with post-mastectomy radiation therapy: a comparative analysis based on propensity score matching.

PURPOSE: To investigate the impact of immediate breast reconstruction (iBR) on patients treated with post-mastectomy radiation therapy (PMRT) using propensity score matching (PSM). METHODS: After a retrospective review of patients treated with PMRT between 2008 and 2017, we included 153 patients who underwent iBR and 872 patients who did not undergo iBR. Among the 153 patients who underwent iBR, 34 received one-stage iBR with autologous tissue and 119 received two-stage iBR. Conventional fractionated PMRT with a total dose of 50-50.4 Gy in 25-28 fractions was performed in all patients. Propensity scores were calculated via logistic regression. RESULTS: Patients who underwent iBR were younger, had early stage disease, and had more frequent hormone receptor-positive tumor than those who did not undergo iBR. After PSM, 127 patients from each group with well-balanced characteristics were selected. With a median follow-up of 67.5 months, iBR led to better 6-year disease-free survival rates compared to no iBR before PSM (84.8% vs. 71.4%, p = 0.003); after PSM, there was no significant difference (84.8% vs. 75.5%, p = 0.130). On multivariable analysis in the matched cohort, iBR was not associated with inferior disease-free survival (hazard ratio, 0.67; p = 0.175). In the sensitivity analysis, iBR was not associated with a lower disease-free survival across all prognostic groups. The 5-year cumulative incidence of iBR failure was 15.0%. CONCLUSION: In patients with adverse pathologic factors planning to receive PMRT, iBR did not compromise oncologic outcomes. In addition, iBR can be considered in patients treated with PMRT with several clinicopathologic risk factors.

The Pattern of Care for Brain Metastasis from Breast Cancer over the Past 10 Years in Korea: A Multicenter Retrospective Study (KROG 16-12).

PURPOSE: We aimed to investigate manifestations and patterns of care for patients with brain metastasis (BM) from breast cancer (BC) and compared their overall survival (OS) from 2005 through 2014 in Korea. MATERIALS AND METHODS: We retrospectively reviewed 600 BC patients with BM diagnosed between 2005 and 2014. The median follow-up duration was 12.5 months. We categorized the patients into three groups according to the year when BM was initially diagnosed (group I [2005-2008], 98 patients; group II [2009-2011], 200 patients; and group III [2012-2014], 302 patients). RESULTS: Over time, the median age at BM diagnosis increased by 2.2 years (group I, 49.0 years; group II, 48.3 years; and group III, 51.2 years; p=0.008). The percentage of patients with extracranial metastasis was 73.5%, 83.5%, and 86.4% for group I, II, and III, respectively (p=0.011). The time interval between BC and BM was prolonged in patients with stage III primary BC (median, 2.4 to 3 years; p=0.029). As an initial brain-directed treatment, whole-brain radiotherapy alone decreased from 80.0% in 2005 to 41.1% in 2014. Meanwhile, stereotactic radiosurgery or fractionated stereotactic radiotherapy alone increased from 13.3% to 34.7% during the same period (p=0.005). The median OS for group I, II, and III was 15.6, 17.9, and 15.0 months, respectively, with no statistical significance. CONCLUSION: The manifestations of BM from BC and the pattern of care have changed from 2005 to 2014 in Korea. However, the OS has remained relatively unchanged over the 10 years.

Distribution of tumor subtypes in bilateral breast cancer: Comparison between synchronous and metachronous cancer.

AIM: This study was performed to evaluate patterns of breast cancer subtypes in Korean patients with synchronous (SBC) or metachronous bilateral breast cancer (MBC). METHODS: We retrospectively reviewed records of 302 patients with SBC (n = 161) or MBC (n = 141) who received curative surgery at our hospital between 1995 and 2013. Expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) was determined by immunohistochemistry (IHC) staining. We categorized breast cancers into the following subtypes: ER+ or PR+, HER2- (i.e., luminalA); ER+ or PR+, HER2+ (i.e., luminalB HER2+); ER-, PR- and HER2+ (i.e., HER2-enriched); ER-, PR- and HER2- (i.e., triple negative, TN). RESULTS: More patients with MBC were ≤40 years at the time of breast cancer diagnosis than patients with SBC (34.6% vs. 19.3%, P < 0.01). The proportion of subtypes in SBC and MBC were as follows: luminalA, 65.8% vs. 45.0%; luminalB, HER2+, 9.0% vs. 8.5%; HER2-enriched, 4.1% vs. 12.1%; and TN, 11.2% vs. 31.2%, respectively (P < 0.01). The 10-year overall survival rate in patients with SBC and MBC was 89.0% and 93.6%, respectively. The 10-year disease-free survival rate in patients with SBC and MBC was 79.6% and 80.9%, respectively. Locoregional recurrence was found in 2.5% of patients with SBC and 9.9% of patients with MBC. Distant metastasis occurred in 8.7% of patients with SBC and 4.9% of patients with MBC. CONCLUSION: The distribution of breast cancer subtypes was different between SBC and MBC. TN-subtype was profoundly more frequent in MBC whereas luminal-subtype was most frequently found among SBC.

Quantitative Changes in Skin Composition Parameters after Radiation Therapy According to Surgery Types Among Patients with Breast Cancer: A Prospective Study.

BACKGROUND: In the current study, we sought to evaluate and compare the objective changes in biophysical parameters and patient-reported outcomes following radiation therapy (RT) in patients with breast cancer who underwent breast-conserving surgery (BCS) or modified radical mastectomy (MRM). MATERIALS AND METHODS: Patients older than 18 years, with stage I to III breast cancer, who were expected to receive RT were recruited between August 2015 and March 2019. Skin hydration, sebum content, pigmentation, and elasticity of the irradiated and unirradiated breast or chest wall were assessed using a noninvasive bioengineering device. Assessments were performed before the initiation of RT (T0); after the 5th (T1), 15th (T2), and 25th (T3) fractions; and 1 (T4) and 3 months (T5) after the completion of RT. Patient-reported outcomes were also evaluated using Radiation Dermatitis Assessment for Breast Cancer 11. RESULTS: Hydration and sebum levels on the irradiated breast decreased during RT and had not returned to baseline at T5. Erythema on the irradiated breast increased two-fold between T0 and T3, and melanin levels were significantly higher than those at baseline and those of the contralateral unirradiated breast until T5 (106.0 vs. 115.8, P = .03). More than half of the patients continued to report skin color changes, dryness, and pain after RT. The erythema in the irradiated site at T1 was significantly higher in the MRM group than in the BCS group (P for interaction = .04), while there were no significant differences in the changes of the other parameters. CONCLUSION: RT-induced changes in hydration, sebum, and melanin, and the majority of patient-reported pain, color changes, and dryness, even 3 months after the completion of treatment. There were no remarkable differences in the measurable skin parameters according to the surgery type, with the exception of erythema, which was higher in the MRM group 1 week after the start of RT.

Novel prognostic classification predicts overall survival of patients receiving salvage whole-brain radiotherapy for recurrent brain metastasis from breast cancer: A recursive partitioning analysis (KROG 16-12).

BACKGROUND: To investigate outcomes of salvage whole-brain radiotherapy (WBRT) for recurrent brain metastases (BM) from breast cancer (BC), to identify prognostic factors of overall survival (OS), and to propose a novel prognostic classification for OS in these patients. MATERIALS AND METHODS: We identified 54 patients who had received salvage WBRT as the second brain-focused treatment for recurrent BM from BC (2000-2014). The median follow-up duration was 4.9 months. A recursive partitioning analysis (RPA) was conducted to develop a model to predict OS at the time of salvage WBRT. RESULTS: The median OS was 6.8 months. OS according to BC-specific graded prognostic assessment (breast-GPA), modified breast-GPA, and updated breast-GPA did not represent our cohort. In the multivariate analysis, a long time before salvage WBRT (≥16 months), control of primary BC or extracranial metastases, systemic treatment after salvage WBRT, and administration of a biologically effective dose for an α/ß of 10 Gy (BED10) of salvage WBRT >37.5 Gy showed superior OS. We proposed three RPA classes based on the control of both primary BC and extracranial metastasis and BED10 of salvage WBRT: class I, class II, and class III. In this model, patients with class I experienced the best OS (34.6 months; class II, 5.0 months; class III, 2.4 months; P < 0.001). CONCLUSIONS: In our RPA classification according to the control of both primary BC and extracranial metastasis and the dose of salvage WBRT, significant differences in OS were observed. The subsequent use of a systemic treatment showed better OS.

Prognosis of patients with axillary lymph node metastases from occult breast cancer: analysis of multicenter data.

PURPOSE: This study was conducted to evaluate prognosis of patients with level I/II axillary lymph node metastases from occult breast cancer (OBC). MATERIALS AND METHODS: Data of 53 patients with OBC who received axillary lymph node dissection (ALND) positive/negative (+/-) breast-conserving surgery between 2001 and 2013 were retrospectively collected at seven hospitals in Korea. The median number of positive lymph nodes (+LNs) was 2. Seventeen patients (32.1%) had >3 +LNs. A total of 48 patients (90.6%) received radiotherapy. Extents of radiotherapy were as follows: whole-breast (WB; n = 11), regional lymph node (RLN; n = 2), and WB plus RLN (n = 35). RESULTS: The median follow-up time was 85 months. Recurrence was found in four patients: two in the breast, one in RLN, and one in the breast and RLN. The 5-year and 7-year disease-free survival (DFS) rates were 96.1% and 93.5%, respectively. Molecular subtype and receipt of breast radiotherapy were significantly associated with DFS. Patients with estrogen receptor negative, progesterone receptor negative, and human epidermal growth factor receptor 2 negative (ER-/PR-/HER2-) subtype had significantly lower 7-year DFS than those with non-ER-/PR-/HER2- tumor (76.9% vs. 100.0%; p = 0.03). Whole breast irradiation (WBI) was significantly associated with a higher 7-year DFS rate (94.7% for WBI group vs. 83.3% for non-WBI group; p = 0.01). Other factors including patient's age, number of +LNs, taxane chemotherapy, and RLN irradiation were not associated with DFS. CONCLUSION: Patients with OBC achieved favorable outcome after ALND and breast-targeting treatment. Molecular subtype and receipt of WBI was significant factors for DFS.

What Is High-risk Breast Cancer With Pathologically Negative Lymph Nodes for Regional Recurrence?

PURPOSE: This study aimed to identify high-risk factors for regional recurrence in patients with breast cancer with pathologically negative lymph nodes. METHODS AND MATERIALS: We retrospectively analyzed 3800 patients with stage pT1-pT3 breast cancer and pathologically negative lymph nodes between 2004 and 2012. All patients underwent upfront surgery with curative intent. Adjuvant systemic treatments were administered to most patients (96.7%) based on contemporary guidelines. RESULTS: After a median follow-up of 83 months (range, 7-175 months), the estimated 10-year cumulative incidence rate of regional recurrence was 2.0%. Multivariate competing risk analysis revealed that high histologic grade, positive lymphovascular invasion, and stage pT2-3 were significant risk factors for any regional recurrence. Patients with ≥2 risk factors showed a significantly higher 10-year cumulative incidence rate of any regional recurrence than those with 1 or no risk factors (5.5% vs 1.2%; P < .001). When the number of retrieved lymph nodes was less than 10, the difference in the incidence rate of regional recurrence between patients with ≥2 risk factors and those with 1 or no risk factors was greater (6.6% vs 1.3%, respectively; P < .001). The 10-year disease-free survival was worse in patients with ≥2 risk factors than in those with 1 or no risk factors (84.7% vs 90.0%, respectively; P < .001). Patients with ≥2 risk factors also showed worse 10-year overall survival than did those with 1 or no risk factors (91.3% vs 97.0%, respectively; P < .001). CONCLUSIONS: Overall, the cumulative incidence rate of any regional recurrence was low at 10 years. However, patients with ≥2 risk factors showed an increased risk of any regional recurrence and worse disease-free survival, particularly when the number of retrieved lymph nodes was less than 10.

Internal mammary node irradiation in node-positive breast cancer treated with mastectomy and taxane-based chemotherapy.

BACKGROUND: It is important to continually reevaluate the risk/benefit calculus of internal mammary node irradiation (IMNI) in the era of modern systemic therapy. We aimed to investigate the effect of IMNI on survival in node-positive breast cancer treated with mastectomy and anthracycline plus taxane-based chemotherapy. METHODS: We analyzed 348 patients who underwent mastectomy and anthracycline plus taxane-based chemotherapy for node-positive breast cancer between January 2006 and December 2011. All patients received postoperative radiation therapy (RT) with IMNI (n = 105, 30.2%) or without IMNI (n = 243, 69.8%). The benefit of IMNI for disease-free survival (DFS) and overall survival (OS) was evaluated using multivariate analysis and inverse probability of treatment weighting (IPTW) to adjust for unbalanced covariates between the groups. RESULTS: After a median follow-up of 95 months, the 10-year locoregional recurrence-free survival rate, DFS, and OS in all patients were 94.8%, 77.4%, and 86.2%, respectively. The IPTW-adjusted hazard ratio (HR) for the association of IMNI (vs. no IMNI) with DFS and OS was 0.208 (95% confidence intervals (CI) 0.045-0.966) and 0.460 (95% CI, 0.220-0.962), respectively. In multivariate analysis, IMNI was a favorable factor for DFS (HR, 0.458; P = 0.021) and OS (HR 0.233, P = 0.018). CONCLUSIONS: IMNI was associated with improved DFS and OS in node-positive patients treated with mastectomy, post-mastectomy RT, and taxane-based chemotherapy, although the rate of locoregional recurrence was low.

Dynamics of circulating tumor DNA during postoperative radiotherapy in patients with residual triple-negative breast cancer following neoadjuvant chemotherapy: a prospective observational study.

BACKGROUND: This study was performed to evaluate circulating tumor DNA (ctDNA) kinetics during postoperative radiotherapy (PORT) in patients with residual triple-negative breast cancer (TNBC) at surgery following neoadjuvant chemotherapy (NAC). METHODS: Stage II/III patients with post-NAC residual TNBC who required PORT were prospectively included in this study between March 2019 and July 2020. For 11 TNBC patients, next-generation sequencing targeting 38 genes was conducted in 55 samples, including tumor tissue, three plasma samples, and leukocytes from each patient. The plasma samples were collected at three-time points; pre-PORT (T0), after 3 weeks of PORT (T1), and 1 month after PORT (T2). Serial changes in ctDNA variant allele frequency (VAF) were analyzed. RESULTS: Somatic variants were found in the tumor specimens in 9 out of 11 (81.8%) patients. Mutated genes included TP53 (n = 7); PIK3CA (n = 2); and AKT1, APC, CSMD3, MYC, PTEN, and RB1 (n = 1). These tumor mutations were not found in plasma samples. Plasma ctDNA variants were detected in three (27.3%) patients at T0. Mutations in EGFR (n = 1), CTNNB1 (n = 1), and MAP2K (n = 1) was identified with ctDNA analysis. In two (18.2%) patients, the ctDNA VAF decreased through T1 and T2 while increasing at T2 in one (9.1%) patient. After a median follow-up of 22 months, no patient showed cancer recurrence. CONCLUSION: Among patients with post-NAC residual TNBC, more than a quarter exhibited a detectable amount of ctDNA after curative surgery. The ctDNA VAF changed variably during the course of PORT. Therefore, ctDNA kinetics can serve as a biomarker for optimizing adjuvant treatment.

Clinical and dosimetric risk factors for vertebral compression fracture after single-fraction stereotactic body radiation therapy for spine metastases.

OBJECTIVES: This analysis was performed to evaluate the incidence of vertebral compression fracture (VCF) and determine the contributing factors for VCF in patients undergoing single-fraction stereotactic body radiotherapy (SBRT) for spinal bone metastases (SBM). METHODS: A retrospective review of medical records was conducted for patients undergoing SBRT for SBM at our institution between January 2010 and December 2018. Patients who had undergone neither pre-SBRT surgical excision nor post-SBRT prophylactic fixation were included. The effects of clinical and dosimetric parameters were analyzed with respect to VCF risk. The following dosimietric parameters of the planning target volume (PTV) were calculated: mean/minimum/maximum dose, radiation dose to 10-90% volume, and irradiated volume receiving more than 10-25 Gy (PTV_V10 - 25 Gy). RESULTS: Among 163 patients (179 vertebrae), 21 (12.8%) experienced VCF. The 1-year and 2-year VCF rates were 12.1% and 13.2%, respectively. Among dosimetric parameters, PTV_V15 Gy was the most significant for VCF prediction. In a univariate analysis, breast or prostate primary, no vertebral body collapse, and PTV_V15 Gy ≤42 cm3 were significantly associated with a lower incidence rate of VCF. In a multivariate analysis, PTV_V15 Gy was the only significant factor for VCF risk. The 1-year VCF rate was 3.8% in patients with PTV_V15 Gy ≤42 cm3, while it was 22.1% in those with PTV_V15 Gy > 42 cm3 (p < 0.01). CONCLUSIONS: SBRT-related VCF was found in 12% of patients in our institution. The PTV_V15 Gy is a significant factor for VCF prediction.

Chronological Skin Changes Through Postmastectomy Radiotherapy Based on Radiotherapy Techniques: Using Quantitative Dermatological Measurements.

BACKGROUND: There has been few research on how to measure skin status quantitatively throughout the course of radiotherapy (RT). We evaluated the changes in the skin induced by 2 different RT techniques using objective measurements in breast cancer patients. METHODS: In this prospective study, between August 2015 and March 2019, serial measurements of the dermatological factors during and after postmastectomy radiotherapy (PMRT) were made in 40 breast cancer patients. PMRT was performed using the conventional photon tangential technique (PTT) or patient-tailored bolus technique (PTB). We analyzed these measurements using a mixed effect model and compared the clinically evaluated radiation dermatitis and patient-reported outcomes (PROs). RESULTS: The trend of changes in melanin and erythema was significantly different between the PTB and PTT groups (p = 0.045 and 0.016, respectively). At the 3-month follow-up erythema intensity and melanin were higher in the PTB group than in PTT group (both p < 0.001). Eight patients (40% in the PTB group) reported grade 2 radiation dermatitis and 1 patient (5% in the PTB group) reported grade 3 radiation dermatitis. No grade 2 or higher radiation dermatitis was found in the PTT group. Ten patients (50%) in the PTB group and 3 patients (15%) in the PTT group reported severe erythema likely due to questionable clinical evaluation, but hyperpigmentation was rarely reported at the follow-up visits. CONCLUSION: The PTB group showed higher intensity of erythema at the end of RT than the PTT group and the increase in melanin lasted until the 3-month follow-up visits in the PTB group. Moreover, patients subjectively appealed more severe symptoms following PTB in PROs.

Impact of Breast Reconstruction on Biophysical Parameters of Mammary Skin in Patients Receiving Postmastectomy Radiotherapy for Breast Cancer.

PURPOSE: In this study, we examined the impact of reconstruction using tissue expander insertion (TEI) on the risk of radiation dermatitis in patients undergoing postmastectomy radiotherapy (PMRT). METHODS: Between August 2015 and March 2019, patients with breast cancer who had received systemic chemotherapy and PMRT were prospectively included. Skin parameters, including melanin, erythema, hydration, sebum, and elasticity, were measured using a multi-probe instrument at 6 time points: before the initiation of radiotherapy (pre-RT), at weeks 1, 3, and 5 during radiotherapy (weeks 1-5), and 1 and 3-month after radiotherapy (post-RT-1m and post-RT-3m). Patient-reported outcomes (PROs) were assessed at each time point. Changes in biophysical parameters and PRO were compared between patients with and without TEI (TEI+ vs. TEI-). RESULTS: Thirty-eight patients, including 18 with TEI+ and 20 with TEI-, were analyzed. The pattern of time-course changes in biophysical parameters and PRO did not differ between TEI+ and TEI- patients. The melanin index was highest at post-RT-1m, while the erythema index was highest at week 5. At post-RT-3m, TEI+ patients presented higher melanin values than TEI- patients, with no statistical significance (coefficient, 47.9 vs. 14.2%; p = 0.07). In all patients, water content decreased throughout the measurement period. At post-RT-3m, TEI+ patients demonstrated a further decrease in water content, while the TEI- group nearly recovered the water content to pre-RT status (coefficient, -17.1, -2.5; p = 0.11). The sebum and elasticity levels were not altered by TEI. CONCLUSION: In patients undergoing PMRT, TEI did not significantly affect the changing patterns of skin biophysical parameters and PRO during radiotherapy.

Analysis of BRCA1/2 variants of unknown significance in the prospective Korean Hereditary Breast Cancer study.

Genetic testing for BRCA1 and BRCA2 is crucial in diagnosing hereditary breast and ovarian cancer syndromes and has increased with the development of multigene panel tests. However, results classified as variants of uncertain significance (VUS) present challenges to clinicians in attempting to choose an appropriate management plans. We reviewed a total of 676 breast cancer patients included in the Korean Hereditary Breast Cancer (KOHBRA) study with a VUS on BRCA mutation tests between November 2007 and April 2013. These results were compared to the ClinVar database. We calculated the incidence and odds ratios for these variants using the Korean Reference Genome Database. A total of 58 and 91 distinct VUS in BRCA1 and BRCA2 were identified in the KOHBRA study (comprising 278 and 453 patients, respectively). A total of 27 variants in the KOHBRA study were not registered in the Single Nucleotide Polymorphism database. Among BRCA1 VUSs, 20 were reclassified as benign or likely benign, four were reclassified as pathogenic or likely pathogenic, and eight remained as VUSs according to the ClinVar database. Of the BRCA2 VUSs, 25 were reclassified as benign or likely benign, two were reclassified as pathogenic or likely pathogenic, and 33 remained as VUS according to the ClinVar database. There were 12 variants with conflicting interpretations of pathogenicity for BRCA1 and 18 for BRCA2. Among them, p.Leu1780Pro showed a particularly high odds ratio. Six pathogenic variants and one conflicting variant identified using ClinVar could be reclassified as pathogenic variants in this study. Using updated ClinVar information and calculating odds ratios can be helpful when reclassifying VUSs in BRCA1/2.