A combinatorial system to examine the enzymatic repair of multiply damaged DNA substrates.

DNA damage drives genetic mutations that underlie the development of cancer in humans. Multiple pathways have been described in mammalian cells which can repair this damage. However, most work to date has focused upon single lesions in DNA. We present here a combinatorial system which allows assembly of duplexes containing single or multiple types of damage by ligating together six oligonucleotides containing damaged or modified bases. The combinatorial system has dual fluorescent labels allowing examination of both strands simultaneously, in order to study interactions or competition between different DNA repair pathways. Using this system, we demonstrate how repair of oxidative damage in one DNA strand can convert a mispaired T:G deamination intermediate into a T:A mutation. We also demonstrate that slow repair of a T:G mispair, relative to a U:G mispair, by the human methyl-binding domain 4 DNA glycosylase provides a competitive advantage to competing repair pathways, and could explain why CpG dinucleotides are hotspots for C to T mutations in human tumors. Data is also presented that suggests repair of closely spaced lesions in opposing strands can be repaired by a combination of short and long-patch base excision repair and simultaneous repair of multiply damage sites can potentially lead to lethal double strand breaks.

De-escalation of Post-mastectomy Irradiation in Hormone Receptor-Positive Breast Cancer with One to Three Positive Nodes.

BACKGROUND: The 21-gene recurrence score (RS) is used to predict benefit from chemotherapy in hormone receptor (HR)-positive breast cancer with one to three positive lymph nodes. Prospective-retrospective studies have shown that the RS is prognostic for both systemic and locoregional recurrence in tamoxifen-treated patients. We aimed to assess whether RS could be utilized to predict a survival benefit from postmastectomy radiation therapy (PMRT). PATIENTS AND METHODS: The National Cancer Database (NCDB) was used to identify women ≤ 75 years of age with HR+, HER2-negative, T1-3, N1, M0 breast cancer who underwent mastectomy and axillary staging with available RS during the years 2010-2016. Kaplan-Meier and Cox proportional hazards models were used to identify association between treatment and overall survival (OS). Univariate and multivariate analyses were used to identify variables correlating with PMRT and OS. RESULTS: A total of 8907 patients were identified. Of the total, 3203 (36%) patients received adjuvant PMRT and 5704 (64%) did not. Across the entire cohort, 5-year OS was 97.5% for patients receiving PMRT and 96.8% for those who did not (P = 0.063). After adjusting for all covariates, in patients with RS ≤ 25, there was no statistically significant improvement in 5-year OS with the addition of adjuvant PMRT (97.5% versus 98.1% P = 0.093). Moreover, no survival benefit was seen with axillary node dissection (P = 0.58) or with the addition of chemotherapy (P = 0.312). CONCLUSIONS: In our cohort of patients with one to three positive nodes and a RS ≤ 25, omission of post-mastectomy radiation therapy had no impact on OS. Our results suggest that RS may be utilized in the individualized decision making on PMRT.

Adjuvant chemotherapy in patients with invasive lobular carcinoma and use of the 21-gene recurrence score: A National Cancer Database analysis.

BACKGROUND: Invasive lobular carcinoma (ILC) is traditionally considered less responsive to chemotherapy. Although the Oncotype recurrence score (RS) has been validated to identify high-risk patients who benefit from chemotherapy, some studies have questioned its relevance in patients with ILC. The objective of this study was to better characterize potential use of the RS in these patients. METHODS: The National Cancer Database was used to identify women with stage I through III, T1 through T3, N0 or N1, hormone receptor-positive, HER2-negative ILC or invasive ductal carcinoma (IDC) who had an available RS between 2010 and 2016. Multivariable Cox regression was used to model the effect of variables on 5-year overall survival (OS). The Kaplan-Meier method was used to estimate OS according to the RS, nodal status, and chemotherapy. RESULTS: In total, 15,763 patients with ILC and 100,070 with IDC were identified. The mean age of patients with ILC and IDC was 59.2 ± 9.1 and 57.2 ± 9.8, respectively. A lower percentage of patients with ILC versus those with IDC had a high RS, defined as >25 (6.6% vs 16.0%; P < .0001). ILC patients with a high RS who had N0 or N1 disease received approximately 10% less chemotherapy compared with similar patients who had IDC. The results indicated that the RS had statistically significant prognostic value for patients with ILC. In addition, an absolute OS advantage was correlated with the receipt of chemotherapy by patients with ILC who had a high RS with N0 or N1 disease. CONCLUSIONS: Patients with ILC who have a high RS are treated less often with chemotherapy compared with similar patients who have IDC. Nevertheless, the RS has a prognostic as well as a predictive value in ILC, with an association between OS benefit and chemotherapy receipt in patients who have ILC with a high RS, especially if they have N1 disease. LAY SUMMARY: Invasive lobular carcinoma (ILC) is a subtype of breast cancer comprising about 15% of cases. The Oncotype recurrence score (RS) is a genetic test of breast tumors that helps predict which patients might benefit from chemotherapy. Some have doubted the relevance of the RS for patients with ILC. In this study, the authors show that the RS is relevant for patients who have ILC. The RS has the potential of predicting the risk of recurrence and identifying patients with ILC who might benefit from chemotherapy.

De-escalation of Endocrine Therapy in Early Hormone Receptor-positive Breast Cancer: When Is Local Treatment Enough?

OBJECTIVE: To identify subgroups of hormone receptor-positive (HR+) breast cancer patients that might not benefit from adding endocrine therapy (ET) to their local treatment. BACKGROUND: De-escalation in breast cancer treatment has included surgery, radiation, and chemotherapy and has often focused on older patient populations. Systemic ET has yet to be de-escalated, though it carries serious side-effects, decreasing quality of life over 5 to 10 years. We hypothesize the 21-gene recurrence score (RS) could identify subgroups of younger patients whose long-term survival is unaffected by adjuvant ET. METHODS: The National Cancer Database was used to identify women aged ≥50, with HR+, HER2-negative tumors, ≤3 cm in size, N0 status, and a RS≤25, who underwent breast-conserving surgery in 2010 to 2016. Kaplan-Meier and Cox proportional hazards models were used to identify association between treatment and overall survival (OS). RESULTS: Of the 45,217 patients identified, 80.6% were 50 to 69 years old. 42,632 (94.3%) patients received ET and 2585 (5.7%) did not. The 5-year OS was 96.4% for patients receiving ET and 93.1% for those who did not (P < 0.001). After adjusting for all covariates, patients aged 50 to 69 with RS < 11 showed no statistically significant improvement in OS when adding ET to surgery, with or without radiation (P = 0.40). With RS 11 to 25, there was a significant improvement of OS with ET plus radiation (P < 0.001). CONCLUSIONS: Local treatment only, with de-escalation of long-term ET, for patients aged 50 to 69 with RS < 11, seems not to impact OS and should have an anticipated quality of life improvement. Prospective studies investigating this approach are warranted.

The 21-gene recurrence score in node-positive, hormone receptor-positive, HER2-negative breast cancer: a cautionary tale from an NCDB analysis.

PURPOSE: The 21-gene recurrence score assay (RS) has not been prospectively validated to predict adjuvant chemotherapy benefit in hormone receptor-positive (HR+), HER2-negative (HER2-), node-positive breast cancer patients. Nevertheless, de-escalation based on RS has been demonstrated and partially advocated by retrospective data. The purpose of this study was to identify subgroups of node-positive patients with low to intermediate RS who still benefit from adjuvant chemotherapy. METHODS: The National Cancer Database was used to identify 28,591 women with stage I-III, T1-T3, N1, HR+, HER2- breast cancer and a RS ≤ 25 between 2010 and 2016. Univariate and multivariate analyses were used to identify variables correlating with chemotherapy use and 5-year survival. Subgroup analysis was performed to discern patients in whom the use of adjuvant chemotherapy correlated with better survival. RESULTS: A 35% decline in chemotherapy use was observed from 2010 to 2016. Patients with younger age, higher RS, larger tumors and more positive lymph nodes, and those treated by mastectomy, axillary lymph node dissection and radiation, were more likely to receive chemotherapy. Chemotherapy use was associated with an improved 5-year survival (HR = 1.63, 95% CI 1.28-2.07). Upon subgroup analysis, this association was lost in patients > 70 years and those with a RS ≤ 11, while patients ≤ 70 with a RS of 12-25 treated with chemotherapy had an absolute 5-year survival advantage of 3.0% (HR = 1.91, 95% CI 1.42-2.57). CONCLUSION: Clinicians should be cautious when considering omission of adjuvant chemotherapy in patients ≤ 70 years, with HR+, HER2-, N1 tumors and a RS 12-25, at least until the results of the anticipated RxPONDER trial become available.

Prognosis and Chemotherapy Use in Breast Cancer Patients with Multiple Lymphatic Micrometastases: An NCDB Analysis.

BACKGROUND: The number of involved lymph nodes negatively affects prognosis in breast cancer patients. Nevertheless, current staging and treatment recommendations do not distinguish between patients with single versus multiple lymphatic micrometastases. In this study, we aim to better characterize these patients. METHODS: The National Cancer Database was retrospectively queried to identify 486,800 women with stage I-III, estrogen receptor-positive/progesterone receptor-positive/human epidermal growth factor receptor 2-negative (ER+/PR+/HER2-) breast cancer and nodal status of N0, N1mi with 1 (Nmic1) or more (Nmic > 1) involved nodes, and N1 with 1 involved node (N1.1), from 2010 to 2016. Patients with different nodal statuses were compared regarding treatment characteristics, survival, and benefit from chemotherapy by their 21-gene recurrence score (RS). RESULTS: Of the 23,072 N1mi patients, 88.3% were Nmic1 and 11.7% were Nmic > 1. Nmic > 1 patients were younger, had larger and higher-grade tumors, with more lymphovascular invasion, and were more commonly treated by axillary dissection, radiation, and chemotherapy than Nmic1 patients. In that, they were comparable with N1.1 patients. Five-year survival of Nmic > 1 patients (88.1%) was worse than Nmic1 patients (90.1%; p = 0.02), but similar to N1.1 patients (87.9%). Nmic1, Nmic > 1, and N1.1 patients with RS 11-25 exhibited a < 2% absolute survival benefit associated with chemotherapy. With RS > 25, Nmic > 1 patients showed a 3.5% benefit, similar to Nmic1 (4.8%) and lower than N1.1 (10.9%) patients. CONCLUSIONS: Nmic > 1 breast cancer patients have worse prognoses than Nmic1 patients, similar to N1.1 patients. Our data suggest those patients with RS 11-25 have minimal benefit from chemotherapy. These findings should be taken into account when discussing prognosis and considering chemotherapy in patients with lymphatic micrometastases.

The impact of HER2-directed targeted therapy on HER2-positive DCIS of the breast.

BACKGROUND: In invasive breast cancer, HER2 is a well-established negative prognostic factor. However, its significance on the prognosis of ductal carcinoma in situ (DCIS) of the breast is unclear. As a result, the impact of HER2-directed therapy on HER2-positive DCIS is unknown and is currently the subject of ongoing clinical trials. In this study, we aim to determine the possible impact of HER 2-directed targeted therapy on survival outcomes for HER2-positive DCIS patients. MATERIALS AND METHODS: The National Cancer Data Base (NCDB) was used to retrieve patients with biopsy-proven DCIS diagnosed from 2004-2015. Patients were divided into two groups based on the adjuvant therapy they received: systemic HER2-directed targeted therapy or no systemic therapy. Statistics included multivariable logistic regression to determine factors predictive of receiving systemic therapy, Kaplan-Meier analysis to evaluate overall survival (OS), and Cox proportional hazards modeling to determine variables associated with OS. RESULTS: Altogether, 1927 patients met inclusion criteria; 430 (22.3%) received HER2-directed targeted therapy; 1497 (77.7%) did not. Patients who received HER2-directed targeted therapy had a higher 5-year OS compared to patients that did not (97.7% vs. 95.8%, p = 0.043). This survival benefit remained on multivariable analysis. Factors associated with worse OS on multivariable analysis included Charlson-Deyo Comorbidity Score ≥ 2 and no receipt of hormonal therapy. CONCLUSION: In this large study evaluating HER2-positive DCIS patients, the receipt of HER2-directed targeted therapy was associated with an improvement in OS. The results of currently ongoing clinical trials are needed to confirm this finding.

Effects of adjunct testosterone on cardiac morphology and function in advanced cancers: an ancillary analysis of a randomized controlled trial.

BACKGROUND: Adjunct testosterone therapy improves lean body mass, quality of life, and physical activity in patients with advanced cancers; however, the effects of testosterone on cardiac morphology and function are unknown. Accordingly, as an ancillary analysis of a randomized, placebo-controlled trial investigating the efficacy of testosterone supplementation on body composition in men and women with advanced cancers, we explored whether testosterone supplementation could prevent or reverse left ventricular (LV) atrophy and dysfunction. METHODS: Men and women recently diagnosed with late stage (≥IIB) or recurrent head and neck or cervical cancer who were scheduled to receive standard of care chemotherapy or concurrent chemoradiation were administered an adjunct 7 week treatment of weekly intramuscular injections of either 100 mg testosterone (T, n = 1 M/5F) or placebo (P, n = 6 M/4F) in a double-blinded randomized fashion. LV morphology (wall thickness), systolic function (ejection fraction, EF), diastolic function (E/A; E'/E), arterial elastance (Ea), end-systolic elastance (Ees), and ventricular-arterial coupling (Ea/Ees) were assessed. RESULTS: No significant differences were observed in LV posterior wall thickness in placebo (pre: 1.10 ± 0.1 cm; post: 1.16 ± 0.2 cm; p = 0.11) or testosterone groups (pre: 0.99 ± 0.1 cm; post: 1.14 ± 0.20 cm; p = 0.22). Compared with placebo, testosterone significantly improved LVEF (placebo: - 1.8 ± 4.3%; testosterone: + 6.2 ± 4.3%; p < 0.05), Ea (placebo: 0.0 ± 0.2 mmHg/mL; testosterone: - 0.3 ± 0.2 mmHg/mL; p < 0.05), and Ea/Ees (placebo: 0.0 ± 0.1; testosterone: - 0.2 ± 0.1; p < 0.05). CONCLUSIONS: In patients with advanced cancers, testosterone was associated with favorable changes in left ventricular systolic function, arterial elastance, and ventricular-arterial coupling. Given the small sample size, the promising multisystem benefits of testosterone warrants further evaluation in a definitive randomized trial. TRIAL REGISTRATION: This study was prospectively registered on ClinicalTrials.gov (NCT00878995; date of registration: April 9, 2009).

The impact of molecular status on survival outcomes for invasive micropapillary carcinoma of the breast.

Invasive micropapillary carcinoma (IMPC) is an uncommon variant of breast cancer. Previous studies demonstrated this subtype is often hormone receptor (HR)-positive, resulting in survival outcomes similar to invasive ductal carcinoma. However, many of these studies were conducted prior to HER2 testing availability. We aim to determine the impact of molecular marker status (including HER2 status) on IMPC survival outcomes. The National Cancer Data Base (NCDB) was used to retrieve patients with biopsy-proven IMPC from 2007 to 2012. Only patients with known HR and HER2 status were included. Cox multivariate regression was used to determine prognostic factors. In total, 865 patients were included; median follow-up was 2.5 years. Overall, 651 patients (75.3%) had HR + HER2- disease, 128 (14.8%) had HR + HER2+ disease, 41 (4.7%) had HR-HER2 + disease, and 45 (5.2%) had triple negative disease. Patients with triple negative disease were more likely to have poorly differentiated histology (66.7%), lymphovascular invasion (73.3%), stage 3 disease (37.8%), undergone mastectomy (68.9%), and positive surgical margins (15.6%). On Cox multivariate regression, those with triple negative disease had worse overall survival (hazard ratio [HR] 7.28, P < 0.001). Other adverse prognostic factors included African-American descent (HR 2.24, P = 0.018), comorbidity score of 1 (HR 2.50, P = 0.011), comorbidity score ≥2 (HR 3.27, P = 0.06), and ≥3 positive lymph nodes (HR 3.23, P = 0.007). Similar to invasive ductal carcinoma, triple negative disease in IMPC results in worse survival outcomes. This is the largest and first study to characterize molecular status (including HER2 status) in patients with IMPC and its impact on survival outcomes.

Omission of radiation therapy following breast conservation in older (≥70 years) women with T1-2N0 triple-negative breast cancer.

BACKGROUND: Although randomized data support omitting adjuvant radiotherapy (RT) following breast conservation for T1-2N0 estrogen receptor positive breast cancer in ≥70-year-old women, there remains a knowledge gap regarding its omission for triple-negative BC (TNBC). METHODS AND MATERIALS: The National Cancer Database (NCDB) was queried for ≥70-year-old females with newly diagnosed T1-2N0M0 TNBC treated with breast conservation. Multivariable logistic regression ascertained factors associated with adjuvant RT administration. Overall survival (OS) between patients treated with or without adjuvant RT was estimated using the Kaplan-Meier method. Cox proportional hazards modeling determined variables associated with OS. RESULTS: Of 8526 patients, 6283 (74%) patients received adjuvant RT, and 2243 (26%) did not. RT was more frequently withheld in older patients, those with higher comorbidities, lower income, pT2 disease, following margin-positive resection, receipt of chemotherapy, and at academic centers (P < 0.05 for all). Median follow-up was 38.0 months. Five-year OS was greater in the adjuvant RT group (77.2% vs 55.3%, P < 0.001); these differences persisted when stratifying for age, T stage, and chemotherapy utilization (P < 0.001 for all). Omission of RT was also independently associated with poorer OS on multivariate analysis (P < 0.001). CONCLUSIONS: This investigation, the largest known such study to date, observed that omission of adjuvant RT for elderly women with T1-2N0 TNBC was associated with poorer OS; this was observed across a range of age groups, as well as following stratification by T stage and chemotherapy usage. Although these results do not imply causation, caution must be exercised when considering omission of adjuvant RT in node-negative TNBC patients.

Development and validation of algorithms to differentiate ductal carcinoma in situ from invasive breast cancer within administrative claims data.

BACKGROUND: Overtreatment is a common concern for patients with ductal carcinoma in situ (DCIS), but this entity is difficult to distinguish from invasive breast cancers in administrative claims data sets because DCIS often is coded as invasive breast cancer. Therefore, the authors developed and validated algorithms to select DCIS cases from administrative claims data to enable outcomes research in this type of data. METHODS: This retrospective cohort using invasive breast cancer and DCIS cases included women aged 66 to 70 years in the 2004 through 2011 Texas Cancer Registry (TCR) data linked to Medicare administrative claims data. TCR records were used as "gold" standards to evaluate the sensitivity, specificity, and positive predictive value (PPV) of 2 algorithms. Women with a biopsy enrolled in Medicare parts A and B at 12 months before and 6 months after their first biopsy without a second incident diagnosis of DCIS or invasive breast cancer within 12 months in the TCR were included. Women in 2010 Medicare data were selected to test the algorithms in a general sample. RESULTS: In the TCR data set, a total of 6907 cases met inclusion criteria, with 1244 DCIS cases. The first algorithm had a sensitivity of 79%, a specificity of 89%, and a PPV of 62%. The second algorithm had a sensitivity of 50%, a specificity of 97%. and a PPV of 77%. Among women in the general sample, the specificity was high and the sensitivity was similar for both algorithms. However, the PPV was approximately 6% to 7% lower. CONCLUSIONS: DCIS frequently is miscoded as invasive breast cancer, and thus the proposed algorithms are useful to examine DCIS outcomes using data sets not linked to cancer registries. Cancer 2018;124:2815-2823. © 2018 American Cancer Society.

Response rates and pathologic complete response by breast cancer molecular subtype following neoadjuvant chemotherapy.

PURPOSE: This is the largest study to date evaluating response rates and pathologic complete response (pCR) and predictors thereof, based on molecular subtype, in women with breast cancer having undergone neoadjuvant chemotherapy (NC). METHODS: The National Cancer Database was queried for women with cT1-4N1-3M0 breast cancer having received NC. Patients were divided into four subtypes: luminal A, luminal B, Her2, or triple negative (TN). Multivariable logistic regression ascertained factors associated with developing pCR. Kaplan-Meier analysis evaluated overall survival (OS) between patients by degree of response to NC when stratifying patients by subtype. RESULTS: Of a total of 13,939 women, 322 (2%) were luminal A, 5941 (43%) luminal B, 2274 (16%) Her2, and 5402 (39%) TN. Overall, 19% of all patients achieved pCR, the lowest in luminal A (0.3%) and the highest in Her2 (38.7%). Molecular subtype was an independent predictor of both pCR and OS in this population. Clinical downstaging was associated with improved survival, mostly in women with luminal B, Her2, and TN subtypes. Subgroup analysis of the pCR population demonstrated 5-year OS in the luminal B, Her2, and TN cohorts of 93.0, 94.2, and 90.6%, respectively (Her2 vs. TN, p = 0.016). CONCLUSIONS: Assessing nearly 14,000 women from a contemporary United States database, this is the largest known study examining the relationship between response to NC and molecular subtype. Women with luminal A disease are the least likely to undergo pCR, with the highest rates in Her2 disease. Degree of response is associated with OS, especially in luminal B, Her2, and TN patients. Despite the comparatively higher likelihood of achieving pCR in TN cases, this subgroup may still experience a survival detriment, which has implications for an ongoing national randomized trial.

Addition of chemotherapy to definitive radiotherapy for IB1 and IIA1 cervical cancer: Analysis of the National Cancer Data Base.

PURPOSE: The standard treatment for stage IB1 and IIA1 cervical carcinoma is surgery. For non-operative cases, the National Comprehensive Cancer Network recommends definitive radiotherapy (RT) with or without chemotherapy. This study sought to determine whether the addition of chemotherapy to RT improved overall survival (OS) for patients with stage IB1 and IIA1 cervical cancer. METHODS: We used the National Cancer Data Base to identify patients with stage IB1 or stage IIA1 cervical cancer diagnosed in 2004 to 2012 who received definitive RT with or without chemotherapy. Patient, tumor, and treatment facility characteristics were assessed. Kaplan-Meier analysis was performed to compare overall survival (OS) between groups. Cox regression analysis was performed to identify factors associated with survival. Propensity-score matching was used to compare survival outcomes while accounting for indication bias. RESULTS: 825 patients met the specified criteria. 275 (33.3%) of patients received treatment with RT alone, whereas 550 (66.7%) were treated with CRT. The median OS in patients treated with RT alone was 121.1months, while the median OS for patients treated with CRT was not reached (hazard ratio [HR]=0.719; 95% confidence interval [CI] 0.549-0.945). Propensity-score matched analysis confirmed that CRT was superior to RT alone (HR=0.701; 95% CI 0.509 to 0.963). CONCLUSIONS: Our study suggests the addition of chemotherapy to definitive RT in patients with stage IB1 or stage IIA1 cervical cancer is associated with an improvement in OS. Prospective studies are recommended to validate these results and to further investigate the quality of life differences associated with chemotherapy use.

The role of the lung microbiome in health and disease. A National Heart, Lung, and Blood Institute workshop report.

Study of the human lung microbiome in the context of pulmonary health and disease is an area of emerging research interest that is being driven by several contributing factors. These factors include increased recognition of the diversity of human-associated microbiota, their roles in health and in diseases associated with chronic inflammation, and advancements in technologies and tools that have facilitated such discoveries about the microbiota in organ systems outside of the lung. Therefore, the overarching goals of lung microbiome research are: to identify and characterize microbial populations associated with the respiratory tract and lungs; to understand their roles in lung health and disease; and, we hope, to allow the development of improved approaches for diagnosing and treating chronic respiratory diseases in which the microbiome has a role. Recent studies of the lung microbiome have yielded a number of interesting findings but also highlighted questions and challenges for researchers and clinicians. In December 2011, the National Heart, Lung, and Blood Institute convened a workshop to identify key issues and areas for further attention or development to advance research on the lung microbiome. Current knowledge and the state of research on the lung and related areas of human microbiome investigation were reviewed and discussed.

Lymph node involvement in immunohistochemistry-based molecular classifications of breast cancer.

BACKGROUND: Prognosis and treatment options differ for each molecular subtype of breast cancer, but risk of regional lymph node (LN) metastasis for each subtype has not been well studied. Since LN status is the most important predictor for prognosis, the aim of this study is to investigate the propensity for LN metastasis in each of the five breast cancer molecular subtypes. METHODS: Under an institutional review board-approved protocol, we retrospectively reviewed the charts of all pathologically confirmed breast cancer cases from January 2004 to June 2012. Five subtypes were defined as luminal A (hormone receptor positive, Ki-67 low), luminal B (hormone receptor positive, Ki-67 high), luminal human epidermal growth factor receptor 2 (HER2), HER2-enriched (hormone receptor negative), and triple negative (TN). RESULTS: A total of 375 patients with complete data were classified by subtype: 95 (25.3%) luminal A, 120 (32%) luminal B, 69 (18.4%) luminal HER2, 26 (6.9%) HER2-enriched, and 65 (17.3%) TN. On univariate analysis, age (<50), higher tumor grade, HER2+ status, tumor size, and molecular subtype were significant for LN positivity. Molecular subtype correlated strongly with tumor size (χ(2); P = 0.0004); therefore, multivariable logistic regression did not identify molecular subtype as an independent variable to predict LN positivity. CONCLUSIONS: Luminal A tumors have the lowest risk of LN metastasis, whereas luminal HER2 subtype has the highest risk of LN metastasis. Immunohistochemical-based molecular classification can be readily performed and knowledge of the factors that affect LN status may help with treatment decisions.

Role of 21-Gene Recurrence Score in Predicting Prognostic Benefit of Radiation Therapy After Breast-Conserving Surgery for T1N0 Breast Cancer.

PURPOSE: The 21-gene RT-PCR recurrence score (RS) is performed in patients with hormone receptor-positive (ER+, PR+), human epidermal growth factor receptor 2 (HER2)-negative, N0 breast cancer to determine which patients will likely benefit from chemotherapy after breast-conserving surgery (BCS). The purpose of this study was to evaluate whether the RS can predict for patients likely to benefit from radiation therapy (RT) after BCS. METHODS AND MATERIALS: The National Cancer Database was queried (2004-2017) for female patients with pT1N0 ER+ PR+ HER2-negative breast cancer treated with BCS who had an available RS. Patients were stratified based on their RS (low risk [LR], 1-10; intermediate risk [IR], 11-25; high risk [HR], 26-100). For each RS cohort, propensity score matching was conducted to create 1:1 matched cohorts of patients who received RT and patients who did not. Kaplan-Meier analysis evaluated overall survival (OS). Univariable and multivariable (MVA) Cox proportional hazard analysis identified clinical and treatment factors prognostic for OS. RESULTS: A total of 79,040 patients met the selection criteria: 18,823 in the LR cohort, 52,341 in the IR cohort, and 7876 in the HR cohort. A total of 92% of patients received RT: 91% in the LR cohort, 93% in the IR cohort, and 92% in the HR cohort. After propensity score matching, the 5-year OS in the LR cohort was 95% for those who received RT and 93% for those who did not (P = .184). In the IR cohort, the 5-year OS was 95% for those who received RT and 93% for those who did not (P = .001). In the HR cohort, the 5-year OS was 95% for those who received RT and 84% for those who did not (P < .001). MVA demonstrated that RT was a positive prognostic factor for OS in both the IR cohort (P = .001) and HR cohort (P < .001). On MVA in the LR cohort, RT (P = .186) was not predictive of improved OS. CONCLUSIONS: An OS benefit was observed with the use of RT in patients with IR or HR RS but not in patients with LR RS. Future prospective evaluation is warranted.

21-Gene recurrence score predictive for prognostic benefit of radiotherapy in patients age ≥ 70 with T1N0 ER/PR + HER2- breast cancer treated with breast conserving surgery and endocrine therapy.

PURPOSE: Based on the results of the Cancer and Leukemia Group B (CALGB) 9343 trial, patients age ≥70 with T1N0 hormone receptor positive (ER/PR+), human epidermal growth factor receptor-2 negative (HER2-) breast cancer who are treated with breast conserving surgery (BCS) and endocrine therapy (ET) are candidates for omission of radiotherapy (RT). Because the CALGB 9343 trial did not stratify based on recurrence score (RS) test (Oncotype Dx), we conducted the present retrospective study to determine whether RS is predictive of who may benefit from RT following BCS in this cohort. MATERIALS AND METHODS: The National Cancer Database (NCDB) was queried (2004-2017) for patients age ≥ 70 with pT1N0 ER+/PR + HER2- breast cancer treated with BCS and ET. Patients were stratified based on their RS (low risk [LR] = 1-10, intermediate risk [IR] = 11-25, high risk [HR] = 26-99). Propensity score matching (PSM) created 1:1 matched cohorts of patients who received radiotherapy and those who did not. Kaplan-Meier analysis evaluated overall survival (OS). Univariable (UVA) and multivariable (MVA) Cox proportional hazard analyses identified clinical and treatment factors prognostic for OS. RESULTS: A total of 11,891 patients met the selection criteria: 3364 in the LR cohort, 7305 in the IR cohort, and 1222 in the HR cohort. A total of 79 % received RT: 77 % in the LR cohort, 79 % in the IR cohort, and 85 % in the HR cohort. Because PSM could not be efficiently performed in the HR cohort alone, the IR and HR cohort were merged (IRHR) for matching. After PSM, the 5-year OS in the LR cohort was 91 % for those who received RT and 89 % for those who did not (p = 0.605). In the IRHR cohort, the 5-year OS was 91 % for those who received RT and 87 % for those who did not (p = 0.003). On MVA in the LR cohort, RT (p = 0.727) was not predictive of improved OS. On MVA in the IRHR cohort, RT (p = 0.010) was a positive prognostic factor for OS. CONCLUSION: In this older cohort of patients, there is an OS benefit with the use of RT in patients with IRHR RS but not in patients with LR RS. Pending prospective evaluation, assessment of RS in this older subset of patients is recommended with consideration of RT when RS is ≥11.

Prognostic Impact of Radiation Therapy in Pure Mucinous Breast Carcinoma.

PURPOSE: Pure Mucinous breast carcinoma (PMBC) is an invasive breast cancer with favorable prognosis. While pathology-specific guidelines exist for PMBC regarding adjuvant chemotherapy and endocrine therapy, no recommendations exist regarding locoregional treatment based on tumor histology. Prognostic impact of radiotherapy for patients with PMBC remains unclear. MATERIALS AND METHODS: The National Cancer Database was queried (2004-2017) for patients with pN0M0 PMBC who underwent lumpectomy. Chi-square testing compared categorical frequencies between patients who received radiotherapy versus those who did not. Propensity score matching created a 1:1 matched cohort of patients who received radiotherapy and patients who didn't. Kaplan-Meier analysis evaluated overall survival (OS). Cox proportional hazard analyses identified clinical and treatment factors prognostic for OS. RESULTS: 17,259 patients met selection criteria; 11,087 (74%) received radiotherapy while 3852 (26%) did not. After PSM, radiotherapy (HR 0.629; 95% CI 0.531-0.746), endocrine therapy (HR 0.676; 95% CI 0.567-0.805), black race (HR 0.703; 95% CI 0.498-0.991), and private insurance (HR 0.184; 95% CI 0.078-0.432) were favorable prognostic factors on multivariate Cox regression analysis while age ≥ 70 years (HR 2.668; 95% CI 1.903-3.740), tumor size > 20 mm (HR 1.964; 95% CI 1.613-2.391), and CDCC score > 0 (HR 1.770; 95% CI 1.474-2.126) were unfavorable prognostic factors. After PSM, 5-year OS was 86% for those who received radiotherapy and 81% for those who did not (P < .001). CONCLUSION: This is the largest study to date on PMBC and the prognostic impact of adjuvant radiotherapy. Radiotherapy is associated with a survival advantage, suggesting omission of radiotherapy is not warranted.

Late GI and bladder toxicities after radiation for uterine cancer.

OBJECTIVE: To determine the impact of radiation treatment for corpus uteri cancer on the development of late gastrointestinal (GI) and bladder toxicities in older women. METHODS: We used a linked database of the Surveillance, Epidemiology and End Results (SEER) program tumor registry records and Medicare claims to estimate the risk of late radiation toxicities in a population based sample of 23,591 women diagnosed with corpus uteri cancer from 1992 to 2005. Gastrointestinal (GI) and bladder diagnoses were included up to 60 months after diagnosis. Cox proportional hazard models were used to estimate risk of any late GI or bladder diagnosis with or without hospitalization, due to radiation. RESULTS: Women treated with radiation had an absolute increase in late GI toxicities of 7.7% and an absolute increase in late bladder toxicities of 3.9%. Most toxicities were not severe. Only 10% of irradiated women with a lower GI diagnosis and less than 1% of irradiated women with a bladder diagnosis, required hospitalization. In the multivariable analysis, advancing age, having chemotherapy, higher comorbidities and prior or early GI and bladder diagnoses were predictive of late toxicities among irradiated women. CONCLUSIONS: Late GI toxicities are more common than previously reported. It is important to analyze late toxicities in population based samples of women with uterine cancer. The results of this and future analyses can be used to identify areas where development of "survivorship plans" will remind and encourage women to report symptoms related to potential toxicities.

Impact of the National Heart, Lung, and Blood Institute's Loan Repayment Program Funding on Retention of the National Institutes of Health Biomedical Workforce.

Background: The National Institutes of Health (NIH) Loan Repayment Programs (LRPs) were established by Congress in 2000 to help attract and retain highly qualified health professionals in biomedical careers by relieving financial pressure incurred from educational loans obtained during medical school and other advanced-degree clinical training programs. In 2019, the NIH LRP Program increased the maximum repayment from $35,000 per year to $50,000 per year for an individual's educational debt in return for two years of research performed in an NIH mission-relevant area (https://www.lrp.nih.gov/eligibility-programs). In addition, in 2020, the National Heart, Lung, and Blood Institute (NHLBI) increased its participation in the LRP by adding the Health Disparities Research Program to Clinical Research and Pediatric Research Programs. Objective: Before these substantive changes took effect, we sought to determine the impact of the NHLBI's participation in the LRP program on retention of scientists in the biomedical research workforce over the past 20 years. Methods: NHLBI LRP applicant cohorts from 2003 and 2008 were carefully examined with a 10-year follow-up period to measure the impact of applying for and obtaining NIH LRP funding on subsequent K- and R-level application and award rates, publication number, and average relative citation ratio as metrics to assess recruitment and retention of scientists in the biomedical research workforce. Results: Obtaining the LRP award was strongly associated with increased submission of and success in obtaining K- and RPG-grant funding and publications for both the 2003 and 2008 NHLBI LRP cohorts. An analysis of subgroups in the 2008 LRP cohort without prior F, K, or RPG funding revealed a consistently strong association between obtaining an LRP award and subsequent K- or RPG-award submission and success as well as potential synergy between obtaining an LRP award and participation on a T grant toward subsequent K- or RPG-award success rates. Conclusion: The LRP award appears to enhance retention in the biomedical research workforce when measured using metrics of grant application and award rates as well as research publications over a 10-year period.