Radioresistant Pulmonary Oligometastatic and Oligoprogressive Lesions From Nonlung Primaries: Impact of Histology and Dose-Fractionation on Local Control After Radiation Therapy.

Purpose: We investigated whether pulmonary metastases from historically considered radioresistant primaries would have inferior local control after radiation therapy than those from nonradioresistant nonlung primaries, and whether higher biologically effective dose assuming alpha/beta=10 (BED10) would be associated with superior local control. Methods and Materials: We identified patients treated with radiation therapy for oligometastatic or oligoprogressive pulmonary disease to 1 to 5 lung metastases from nonlung primaries in 2013 to 2020 at a single health care system. Radioresistant primary cancers included colorectal carcinoma, endometrial carcinoma, renal cell carcinoma, melanoma, and sarcoma. Nonradioresistant primary cancers included breast, bladder, esophageal, pancreas, and head and neck carcinomas. The Kaplan-Meier estimator, log-rank test, and multivariable Cox proportional hazards regression were used to compare local recurrence-free survival (LRFS), new metastasis-free survival, progression-free survival, and overall survival. Results: Among 114 patients, 73 had radioresistant primary cancers. The median total dose was 50 Gy (IQR, 50-54 Gy) and the median number of fractions was 5 (IQR, 3-5). Median follow-up time was 59.6 months. One of 41 (2.4%) patients with a nonradioresistant metastasis experienced local failure compared with 18 of 73 (24.7%) patients with radioresistant metastasis (log-rank P = .004). Among radioresistant metastases, 12 of 41 (29.2%) patients with colorectal carcinoma experienced local failure compared with 6 of 32 (18.8%) with other primaries (log-rank P = .018). BED10 ≥100 Gy was associated with decreased risk of local recurrence. On univariable analysis, BED10 ≥100 Gy (hazard ratio [HR], 0.263; 95% CI, 0.105-0.656; P = .004) was associated with higher LRFS, and colorectal primary (HR, 3.060; 95% CI, 1.204-7.777; P = .019) was associated with lower LRFS, though these were not statistically significant on multivariable analysis. Among colorectal primary patients, BED10 ≥100 Gy was associated with higher LRFS (HR, 0.266; 95% CI, 0.072-0.985; P = .047) on multivariable analysis. Conclusions: Local control after radiation therapy was encouraging for pulmonary metastases from most nonlung primaries, even for many of those classically considered to be radioresistant. Those from colorectal primaries may benefit from testing additional strategies, such as resection or systemic treatment concurrent with radiation.

Dose-Volume Predictors of Radiation Pneumonitis After Thoracic Hypofractionated Radiation Therapy.

PURPOSE: Hypofractionated radiation therapy (HFRT) is a common treatment for thoracic tumors, typically delivered as 60 Gy in 15 fractions. We aimed to identify dosimetric risk factors associated with radiation pneumonitis in patients receiving HFRT at 4 Gy per fraction, focusing on lung V20, mean lung dose (MLD), and lung V5 as potential predictors of grade ≥2 pneumonitis. METHODS AND MATERIALS: All patients were treated with thoracic HFRT to 60 Gy in 15 fractions or 72 Gy in 18 fractions at a single health care system from 2013 to 2020. Tumors near critical structures (trachea, proximal tracheobronchial tree, esophagus, spinal cord, or heart) were considered central (within 2 cm), and those closer were classified as ultracentral (within 1 cm). The primary endpoint was grade ≥2 pneumonitis. Logistic regression analyses, adjusting for target size and dosimetric variables, were used to establish a dose threshold associated with <20% risk of grade ≥2 pneumonitis. RESULTS: During a median 24.3-month follow-up, 18 patients (16.8%) developed grade ≥2 radiation pneumonitis, with no significant difference between the 2 dose regimens (17.3% vs 16.3%, P = .88). Four patients (3.7%) experienced grade ≥3 pneumonitis, including 2 grade 5 cases. Patients with grade ≥2 pneumonitis had significantly higher lung V20 (mean 23.4% vs 14.5%, P < .001), MLD (mean 13.0 Gy vs 9.5 Gy, P < .001), and lung V5 (mean 49.6% vs 40.6%, P = .01). Dose thresholds for a 20% risk of grade ≥2 pneumonitis were lung V20 <17.7%, MLD <10.6 Gy, and V5 <41.3%. Multivariable analysis revealed a significant association between lung V20 and grade ≥2 pneumonitis (adjusted odds ratio, 1.48, P = .03). CONCLUSIONS: To minimize the risk of grade ≥2 radiation pneumonitis when delivering 4 Gy per fraction at either 60 Gy or 72 Gy, it is advisable to maintain lung V20<17.7%. MLD <10.6 Gy and V5<41.3% can also be considered as lower-priority constraints. However, additional validation is necessary before incorporating these constraints into clinical practice or trial planning guidelines.

Making National Cancer Institute-Designated Comprehensive Cancer Center Knowledge Accessible to Community Oncologists via an Online Tumor Board: Longitudinal Observational Study.

BACKGROUND: Expert knowledge is often shared among multidisciplinary academic teams at tumor boards (TBs) across the country, but these conversations exist in silos and do not reach the wider oncology community. OBJECTIVE: Using an oncologist-only question and answer (Q&A) website, we sought to document expert insights from TBs at National Cancer Institute-designated Comprehensive Cancer Centers (NCI-CCCs) to provide educational benefits to the oncology community. METHODS: We designed a process with the NCI-CCCs to document and share discussions from the TBs focused on areas of practice variation on theMednet, an interactive Q&A website of over 13,000 US oncologists. The faculty translated the TB discussions into concise, non-case-based Q&As on theMednet. Answers were peer reviewed and disseminated in email newsletters to registered oncologists. Reach and engagement were measured. Following each Q&A, a survey question asked how the TB Q&As impacted the readers' practice. RESULTS: A total of 23 breast, thoracic, gastrointestinal, and genitourinary programs from 16 NCI-CCC sites participated. Between December 2016 and July 2021, the faculty highlighted 368 questions from their TBs. Q&As were viewed 147,661 times by 7381 oncologists at 3515 institutions from all 50 states. A total of 277 (75%) Q&As were viewed every month. Of the 1063 responses to a survey question on how the Q&A affected clinicians' practices, 646 (61%) reported that it confirmed their current practice, 163 (20%) indicated that a Q&A would change their future practice, and 214 (15%) reported learning something new. CONCLUSIONS: Through an online Q&A platform, academics at the NCI-CCCs share knowledge outside the walls of academia with oncologists across the United States. Access to up-to-date expert knowledge can reassure clinicians' practices, significantly impact patient care in community practices, and be a source of new knowledge and education.

Radiation Oncologists' Views on Breast Radiation Therapy Guidelines: Utilizing an Online Q&A Platform to Assess Current Views on Whole-Breast Irradiation Therapy.

INTRODUCTION: Poor adherence to the 2011 American Society for Radiation Oncology (ASTRO) evidence-based guideline on whole-breast irradiation (WBI) has been reported. We utilized theMednet to assess the views of the updated 2018 guideline among radiation oncologists (ROs). METHODS: We identified 11 questions asked by community ROs on theMednet, a web-based platform, between October 27, 2014 and May 2, 2017 that were updated in the 2018 guideline. New answers provided by senior authors of the 2018 guideline, cited guidelines, and polls to survey ROs were disseminated in 3 theMednet's newsletters between March 16, 2018 and May 1, 2018. Any question with less than 60% consensus was resubmitted on October 9, 2019 and assessed on February 13, 2020. RESULTS: A total of 792 ROs responded to the initial surveys. In each survey, the answer choice(s) that received the majority of the votes aligned with the 2018 guideline. The strongest consensus was for the use of hypofractionated (HF)-WBI regardless of histology (97%), followed by HF-WBI boost dose (92%), molecular subtype (90%), grade (88%), and concurrent use of trastuzumab (87%). The least consensus was for age at which HF-WBI should be offered with 53% of respondents, specifically 73% of academic ROs versus 47% of community ROs (P = .001), agreeing with the guideline. The re-submitted survey 19 months later showed 77% of 287 new respondents now agreed with the guideline regarding age. CONCLUSION: The majority of ROs concur with the 2018 WBI guideline in theMednet surveys, with better agreement among academic ROs than community ROs for certain components of the guideline. Further research into the different practice patterns may optimize patient care.

Using a Collaborative, Virtual Discussion Platform to Mobilize Oncologic Expertise for the COVID-19 Pandemic.

PURPOSE: COVID-19 is a rapidly emerging worldwide pandemic that has drastically changed health care across the United States. Oncology patients are especially vulnerable. Novel point-of-care resources may be useful to rapidly disseminate peer-reviewed information from oncology experts nationwide. We describe our initial experience with distributing this information through a private, curated, virtual collaboration question-and-answer (Q&A) platform for oncologists. METHODS: The Q&A database was queried for a 2-month period from March 12 to May 12, 2020. We collected the total number of views and unique viewers for the questions. We classified the questions according to their emphasis (practice management, clinical management, both) and disease type across radiation oncology, medical oncology, gynecologic oncology, and pediatric oncology. RESULTS: Seventy-nine questions were approved, 67 of which were answered and generated 49,494 views with 5,148 unique viewers. Most discussions covered clinical management, with breast cancer being the most active disease site. Ten questions covered pediatric oncology and gynecologic oncology. Forty-seven percent of the 11,010 users of the platform visited the website during the 2-month period. CONCLUSION: Discussions on the Q&A platform reached a substantial number of oncologists throughout the nation and may help oncologists to modify their treatment in real time with the rapidly evolving COVID-19 pandemic.

Strategies for Translating Evidence-Based Medicine in Lung Cancer into Community Practice.

The landscape of non-small cell lung cancer (NSCLC) treatment has rapidly evolved over the past decade. This is exemplified by the use of molecular targeted agents, immunotherapies, and newer technologies such as stereotactic body radiotherapy (SBRT). As the translation of preclinical discoveries into clinical practice continues, the effective dissemination and implementation of evidence-based treatment of NSCLC will remain a foremost challenge for oncologists. To further extend evidence-based medicine into the community setting, community oncologists are being engaged on multiple fronts including leadership and participation in national clinical trials and utilization of internet-based resources.

Racial Disparities in Hypofractionated Radiotherapy Breast Cancer Clinical Trials.

There is a paucity of data regarding factors affecting enrollment onto radiation oncology clinical trials. The purpose of this study was to determine patients and tumor characteristics that influenced enrollment of breast cancer patients onto hypofractionated breast radiotherapy trials (HBRTs) at a single institution. In this retrospective cohort study, patients enrolled on HBRTs at the Rutgers Cancer Institute of New Jersey (n = 132) were compared with a cohort of breast cancer patients eligible for, but not enrolled onto HBRTs treated during the same time period (n = 132). Charts were retrospectively reviewed to determine patients' demographics, clinico-pathologic factors, and treatment characteristics. Statistical analysis was performed to analyze variables affecting enrollment onto HBRTs between the two groups. Over a 42-month time period, 132 patients treated on HBRTs received 2,475-4,995 cGy over 3 to 15 fractions. When compared with patients treated off trial, there was no statistically significant effect of age, family history, lymph node positivity, tumor grade, estrogen or Her-2 receptor status, use of chemotherapy or hormones, use of brachytherapy, or the site of initial consultation on HBRT enrollment. Non-White women were less likely to enroll in HBRT's when compared with White women (25.7% versus 40.1%, p = 0.0129), though this was found to be a nonsignificant trend when taking stage into consideration on multivariate analysis (OR for lower T-stage: 0.281, p = 0.003, OR 1.839 for white race, p = 0.076). Consistent with previous studies, non-White women were less likely to enroll in HBRTs than White women. However, disease stage accounted for these racial disparities. Further studies must be performed to determine if race is an independent factor determining radiation oncology clinical trial enrollment.

Electronic medical record: a balancing act of patient safety, privacy and health care delivery.

With almost $35 billion appropriated in government incentives and additional funds spent in development by institutions, the concept of an electronic patient record (EPR) within integrated health information technology (HIT) systems has taken the United States by storm. However, the United Kingdom's expensive struggle to implement a seamless EPR highlights the variety of pitfalls and unforeseen complications ranging from recognizing the importance of accurately assessing EPR-related patient risks to understanding the difficulties in the exchange of information across a gradient of distinct interfaces. Furthermore, the tenuous relationship between HIT implementation and patient outcomes in the short-term draws into question the value of EPR construction costs along with the ethical and privacy issues they create. Nonetheless, experts agree that with future software advances and physician familiarization, a robust HIT will be an important asset to patient autonomy, epidemiologic and clinical research, evidence-based error reduction and the potential for cost reduction. This article seeks to review the current status of this initiative and potential pitfalls that remain.

Ethics and the law: is there common ground on informed consent for disparities in hospital outcomes?

The association between procedure volume at institutions and outcomes of cancer surgeries has been widely published in the medical literature; discussed in the lay press; and, during the past 15 years, incorporated into quality improvement endeavors. In certain cases, institutional volume has become a proxy for quality. Despite the vast amount of retrospective data on this topic, physicians generally have been unsure how to approach the information and interpret it for their patients. Even more challenging to some physicians has been deciding whether the data oblige them to either direct patients with cancer to high-volume centers for care or discuss the data with these patients as part of informed consent. An additional challenge is that physicians must understand laws related to these issues and that these laws are unclear. This article reviews the ethical arguments for including disparities in hospital outcomes as part of informed consent and examines whether legal precedent can shed light on this debate.

Parameters favorable to intraprostatic radiation dose escalation in men with localized prostate cancer.

PURPOSE: To identify , within the framework of a current Phase I trial, whether factors related to intraprostatic cancer lesions (IPLs) or individual patients predict the feasibility of high-dose intraprostatic irradiation. METHODS AND MATERIALS: Endorectal coil MRI scans of the prostate from 42 men were evaluated for dominant IPLs. The IPLs, prostate, and critical normal tissues were contoured. Intensity-modulated radiotherapy plans were generated with the goal of delivering 75.6 Gy in 1.8-Gy fractions to the prostate, with IPLs receiving a simultaneous integrated boost of 3.6 Gy per fraction to a total dose of 151.2 Gy, 200% of the prescribed dose and the highest dose cohort in our trial. Rectal and bladder dose constraints were consistent with those outlined in current Radiation Therapy Oncology Group protocols. RESULTS: Dominant IPLs were identified in 24 patients (57.1%). Simultaneous integrated boosts (SIB) to 200% of the prescribed dose were achieved in 12 of the 24 patients without violating dose constraints. Both the distance between the IPL and rectum and the hip-to-hip patient width on planning CT scans were associated with the feasibility to plan an SIB (p = 0.002 and p = 0.0137, respectively). CONCLUSIONS: On the basis of this small cohort, the distance between an intraprostatic lesion and the rectum most strongly predicted the ability to plan high-dose radiation to a dominant intraprostatic lesion. High-dose SIB planning seems possible for select intraprostatic lesions.

Radiotherapy for patients with the human immunodeficiency virus: are special precautions necessary?

Shortly after the onset of the acquired immunodeficiency syndrome (AIDS) epidemic in the 1980s, reports of radiation-associated toxicity in patients with the human immunodeficiency virus (HIV) and AIDS began to appear in the medical literature. Although the majority of reports have focused on AIDS-defining malignancies such as Kaposi sarcoma, greater-than-expected toxicity after a course of radiotherapy or chemoradiotherapy has also been documented in cancers not generally classified as being related to HIV. With improved antiretroviral therapies, HIV patients are living longer and have the potential to develop a variety of HIV-associated and nonassociated malignancies that require treatment, including radiotherapy. This review reports the published data regarding the interactions of HIV, AIDS, and antiretroviral therapy with radiotherapy and implications for the management of malignancies in patients with HIV.

Outcomes of malignant CNS ependymomas: an examination of 2408 cases through the Surveillance, Epidemiology, and End Results (SEER) database (1973-2005).

BACKGROUND: Determine the role of surgery and radiation therapy for patients with malignant CNS ependymomas. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database (1973-2005) was queried. RESULTS: Overall, a total of 2408 cases of malignant ependymomas were identified. Of these, 2132 cases (88.5%) were identified as WHO grade II ependymomas and 276 cases (11.5%) as WHO grade III (anaplastic) ependymomas. The annual incidence of ependymomas was approximately 1.97 cases per million in 2005. Overall median survival for all patients was 230 mo, with a significant difference between women and men (262 mo versus196 mo, respectively) (P=0.004). Median age at diagnosis was 37 y among females and 34 y in males. Patients who successfully underwent surgical resection had a considerably longer median survival (237 mo versus 215 mo, P<0.001) as well as a significantly improved five-year survival (72.4% versus 52.6%, P<0.001). Univariate analysis demonstrated that age, gender, ethnicity, primary tumor site, WHO grade and surgical resection were significant predictors of improved survival for ependymoma patients. Multivariate analysis identified that a WHO grade III tumor, male gender, patient age, intracranial tumor locations and failure to undergo surgical resection were independent predictors of poorer outcomes. Multivariate analysis of partially resection cases revealed that lack of radiation was a sign of poor prognosis (HR 1.748, P=0.024). CONCLUSION: Surgical extirpation of ependymomas is associated with significantly improved patient survival. For partially resected tumors, radiation therapy provides significant survival benefit.

Surgery does not adversely affect survival in primary gastrointestinal lymphoma.

OBJECTIVE: To evaluate the impact of surgery on gastrointestinal lymphoma. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was queried from 1973 to 2005. RESULTS: A total of 17,222 cases of PGIL were identified. The overall incidence of PGIL was approximately 1.505 cases per 100,000. A significantly increasing incidence for PGIL was observed (APC = +4.67, P < 0.05). In the cases for which treatment data was available, resection occurred in roughly half of the patients. In univariate analysis, surgical extirpation did not improve survival (47 months vs. 76 months, P < 0.001), while radiation treatment improved median survival (77 months vs. 59 months, P < 0.001). Multivariate analysis revealed increasing age and male gender as independent predictors of decreased overall survival. Tumor location also was a significant predictor of outcome. Large B-cell lymphoma type PGIL had a poorer prognosis than marginal zone B-cell lymphoma. By multivariate analysis, surgery was not found to increase the risk of death (HR = 0.99). CONCLUSIONS: No associated survival benefit for surgery in the treatment in gastrointestinal lymphoma was observed. Determination of lymphoma should preclude surgical resection. Nonetheless, inadvertent extirpative surgery or in association with perforation does not appear to increase mortality.

Malignant abdominal mesothelioma: defining the role of surgery.

OBJECTIVE: Determine the role of surgery for patients with malignant abdominal mesotheliomas (MAMs). METHODS: The Surveillance, Epidemiology, and End Results (SEER) database (1973-2005) was queried. RESULTS: Overall, 10,589 cases of malignant mesotheliomas were identified. Of these, 9,211 cases were thoracic (TM) and 1,112 cases were MAM (10.5%). Patients with TM presented with more localized disease than those patients with MAM (P < 0.001). MAM more often affected younger patients (63 years vs. 71 years) (P < 0.001). The annual incidence of MAM was approximately 1.00 case per 100,000 in 2005. Overall median survival for MAM patients was 8 months, with a significant difference between women and men (13 months vs. 6 months, respectively) (P < 0.001). Patients who successfully underwent surgical resection had a considerably longer median survival (20 months vs. 4 months, P < 0.001) as well as a significantly higher 5-year survival (28% vs. 12%, P < 0.001). Multivariate analysis identified that a poorly differentiated tumor grade, failure to undertake surgical resection, advanced age, and male gender were all independent predictors of poorer outcome. CONCLUSION: Surgical extirpation of MAM may be associated with significantly improved survival. All patients with MAM should be evaluated for potential surgical resection.

Should informed consent for cancer treatment include a discussion about hospital outcome disparities?

BACKGROUND TO THE DEBATE: Several studies have found disparities in the outcome of medical procedures across different hospitals--better outcomes have been associated with higher procedure volume. An Institute of Medicine workshop found such a "volume-outcome relationship" for two types of cancer surgery: resection of the pancreas and esophagus (http://www.iom.edu/?id=31508). This debate examines whether physicians have an ethical obligation to inform patients of hospital outcome disparities for these cancers.

SUS/AAS abstracts: what is the scientific impact?

AIM: To evaluate the scientific impact of presentations at the annual meetings of the Society of University Surgeons (SUS) and the Association for Academic Surgery (AAS). METHODS: All Abstracts presented at the 2002-2004 annual conferences were examined for publication rate (PR), publication citation (PC) and journal impact factor (IF). RESULTS: Overall, 1200 abstracts from the SUS (n = 543,45%) and AAS (n = 657,55%) were reviewed. One way ANOVA analysis of SUS results across session types demonstrated significant differences in PR (89% plenary, 81% parallel, 100% basic science, 47% resident conference, poster 76%, p < 0.0001), but no difference in PC (12.96 plenary, 9.66 parallel, 7.77 basic science, 8.23 resident conference, 8.21 poster, p = 0.25561) or IF (4.17 plenary, 3.50 parallel, 2.66 basic science, 3.12 resident conference 3.13 poster, p = 0.3947). AAS results demonstrated significant differences for PR (81% plenary, 62% parallel and 43% poster, p < 0.0001), CR (8.33 plenary, 4.81 parallel, and 4.78 poster, p = 0.006) and IF (3.75 plenary, 2.64 parallel, and 2.73 poster, p = 0.0124). Comparison of abstracts between meetings demonstrated a higher overall PR, CR and IF for SUS publications (p < 0.0001). CONCLUSION: These data suggest that SUS and AAS presentations constitute high-quality research, Trends towards higher PR, PC and IF for plenary sessions indicate that the review process properly stratifies research. Statistically higher impact measures for SUS presentations are consistent with the more mature research careers of SUS members.

Are many community hospitals undertreating breast cancer?: lessons from 24,834 patients.

OBJECTIVE: To compare treatment patterns and long-term outcomes between teaching and community hospitals treating patients with infiltrating ductal carcinoma (IDC). METHODS: All IDCs from the Florida Cancer Data System from 1994 to 2000 were examined. RESULTS: Overall, 24,834 operative cases of IDC were identified. Teaching hospitals treated 11.3% of patients with a larger proportion of stage III and IV disease (39.8% vs. 33.0%). Five- and 10-year overall survival rates at teaching hospitals were 84% and 72%, compared with 81% and 69% at high-volume community hospitals and 77% and 63% at low-volume hospitals (P < 0.001). The greatest differences on survival were observed in patients with advanced IDC. Examination of practice patterns demonstrated that multimodality therapy was most frequently administered in teaching hospitals. Breast-conserving surgery was more frequently performed at teaching hospitals (41.5% vs. 38.9% P = 0.008). On multivariate analysis, it was found that treatment at a teaching hospital was a significant independent predictor of improved survival (hazard ratio = 0.763, P < 0.001). This survival benefit was greater and independent of high-volume center status (hazard ratio = 0.903, P < 0.02). CONCLUSIONS: Patients with IDC treated at teaching hospitals have significantly better survival than those treated at high-volume centers or community hospitals, particularly in the setting of advanced disease. Poorer long-term outcomes for IDC at community hospitals seem to be, at least in part, because of decreased use of proven life-extending adjuvant therapies. These results should encourage community hospitals to institute changes in treatment approaches to invasive breast cancer to optimize patient outcomes.

Scientific impact of women in academic surgery.

OBJECTIVE: To evaluate the scientific impact of women in the surgical literature. METHODS: Gender of the principal investigator of every abstract presented at the 2002, 2003, and 2004 annual meetings of the Association for Academic Surgery and Society of University Surgeons was identified by internet search. Resulting publications were identified using PubMed. Journal impact factor and number of article citations were determined using ISI Web of Knowledge. RESULTS: The principal investigator's gender was identified for 649 (98.8%) of the 657 abstracts presented at the 2002--2004 AAS meetings. Women authored 9.1% of abstracts and 11.8% of total resulting publications. The publication rate of abstracts by women was significantly higher than that of men (69.5% versus 52.4%, P = 0.0132). There was a trend toward higher average impact factors of journals in which female authors published (3.265 versus 2.673, P = 0.0626). There was no significant difference in mean number of citations per publication. The principal investigator's gender was identified for all 337 (100%) abstracts presented at the 2002--2004 SUS meetings. Women authored 11.0% of abstracts and 11.2% of resulting publications. Publication rates and average citation numbers were similar for female and male authors. The average impact factors of journals in which women published were significantly higher (4.741 versus 3.348, P = 0.0082). CONCLUSIONS: Although women comprise a small proportion of principal investigators on abstracts presented at these conferences, the quality of their presented work is equal to or better than those of their male counterparts.

Malignant breast cancer in children: a review of 75 patients.

OBJECTIVE: To determine incidence trends and outcomes for pediatric patients with malignant breast disease. METHODS: The Surveillance, Epidemiology, and End Results registry was examined for all females 19 years of age and younger diagnosed with a malignant breast tumor between 1973 and 2004. RESULTS: A total of 75 patients with malignant breast tumors were identified. Overall, 14.5% of patients had in situ tumors, and 85.5% had invasive disease. Tumors were classified as being either carcinomas (n = 41, 54.7%) or sarcomas (n = 34, 45.3%). The majority of sarcomatous lesions were phyllodes tumors (n = 29, 85.5%), whereas most carcinomas were of a ductal etiology (n = 19, 46.3%). The age-adjusted incidence of all malignant pediatric breast tumors in 2003 was 0.08 cases per 100,000 people (0.03 carcinoma and 0.06 sarcoma cases per 100,000 people). In the carcinoma group, regionally advanced disease was present in 11 patients (26.8%), whereas only 3 patients (7.3%) presented with metastatic disease. All patients with sarcomatous tumors presented with localized disease. Adjuvant radiation therapy was administered in only 9.8% of carcinomas and 8.8% of sarcomas, and 85.4% of carcinoma patients and 97.1% of sarcoma patients underwent surgical resection for their primary disease. Subgroup analysis revealed 5- and 10-year survival rates of 89.6% for patients with sarcomatous tumors and 63.1% and 54.3% for carcinomas. CONCLUSIONS: Malignant pediatric breast malignancies remain relatively rare. The two most common histologies of breast neoplasms in children are malignant carcinomas followed by sarcomas. Although uncommon, malignant disease must be considered in the differential diagnosis of the pediatric patient with a breast mass.