Post-Mastectomy Implant Complications in the Hispanic Breast Cancer Patient Population.

BACKGROUND/AIM: The purpose was to analyze the impact of post-mastectomy radiation therapy (PMRT) on implant-based breast reconstruction (IBR) in self-identified Hispanic patients compared to non-Hispanic counterparts. PATIENTS AND METHODS: We retrospectively reviewed patients who underwent IBR between January 1, 2017 and December 31, 2019 at a single hospital system. Patients were cisgender women, assigned female at birth, 18 years or older, and underwent mastectomy with immediate IBR +/- PMRT. We compared characteristics between Hispanic and non-Hispanic patients, assessing capsular contracture and implant loss rates. Multivariable analysis was performed to identify factors associated with complications. RESULTS: A total of 317 patients underwent mastectomy and reconstruction. Of these patients, 302 underwent a total of 467 mastectomies with IBR, and these 467 procedures were included in the analysis of complications. Complications occurred in 175 breasts (37.5%), regardless of PMRT. Seventy-two of the 302 patients (24%) received PMRT to one breast. The overall rates of capsular contracture, implant loss, and overall complications did not vary significantly between Hispanic and non-Hispanic patients (p=0.866, 0.974, and 0.761, respectively). When comparing only irradiated patients, there was a trend towards increased implant loss and overall complication rates in Hispanic versus non-Hispanic patients (p=0.107 and 0.113, respectively). Following PMRT the rate of any complication was 71% in Hispanic women and 53% in non-Hispanic women. CONCLUSION: Our study illuminates a trend towards higher complication rates after PMRT in Hispanic versus non-Hispanic patients. Further studies are needed to understand why Hispanic patients may have more side effects from radiation therapy.

Genomic Characterization of Aggressive Breast Cancer in Younger Women.

PURPOSE: Although breast cancer (BC) risk increases with age, BC in younger women is more aggressive with higher mortality compared with older women. We characterize the genomic landscape of BCs in younger women. METHODS: Clinicopathologic, molecular, and genomic differences across age groups (< 40 years, 40-60 years, > 60 years) in female BC patients were investigated in two large cohorts [AACR-GENIE8.1 (n = 11,594) and METABRIC (n = 2509)]. Cox-proportional regression analyzed the prognostic impact of age groups for disease-specific survival (DSS) and recurrence-free survival (RFS) in METABRIC and progression-free survival (PFS) in GENIE cohorts. Chi-squared test was used to assess statistical associations between genomic alterations and age groups. RESULTS: Survival analysis showed that women < 40 years had shorter DSS [hazard ratio (HR): 1.52, p = 0.005], RFS (HR: 1.4, p = 0.006), and PFS (HR: 1.82, p = 0.0003) compared with women 40-60 years, and shorter RFS (HR: 1.5, p = 0.001) and PFS (HR: 2.95, p < 0.0001) compared with women > 60 years. Molecular subtypes in the METABRIC cohort showed women < 40 years were enriched with basal, and HER2+ subtypes, and less enriched with luminal A and B subtype (p < 0.0001). Characterization of genomic alterations in both cohorts demonstrated that BCs in women < 40 years were more enriched with TP53 mutations (FDR < 0.0001), BRCA1 mutations (FDR = 0.01), ERBB2 amplifications (FDR < 0.001), CDK12 amplifications (FDR < 0.001), and PPM1D amplifications (FDR < 0.001). In contrast, BCs in older women (> 60 years) were more enriched with PIK3CA, KMT2C, and CDH1 mutations (FDR < 0.0001). CONCLUSIONS: BCs in young women are associated with shorter survival and more aggressive genomic features, including mutations in TP53 and BRCA1, and amplifications in ERBB2 and CDK12. These findings have the potential to impact clinical trial design and treatment.

Erring Characteristics of Deformable Image Registration-Based Auto-Propagation for Internal Target Volume in Radiotherapy of Locally Advanced Non-Small Cell Lung Cancer.

Purpose: Respiratory motion of locally advanced non-small cell lung cancer (LA-NSCLC) adds to the challenge of targeting the disease with radiotherapy (RT). One technique used frequently to alleviate this challenge is an internal gross tumor volume (IGTV) generated from manual contours on a single respiratory phase of the 4DCT via the aid of deformable image registration (DIR)-based auto-propagation. Through assessing the accuracy of DIR-based auto-propagation for generating IGTVs, this study aimed to identify erring characteristics associated with the process to enhance RT targeting in LA-NSCLC. Methods: 4DCTs of 19 patients with LA-NSCLC were acquired using retrospective gating with 10 respiratory phases (RPs). Ground-truth IGTVs (GT-IGTVs) were obtained through manual segmentation and union of gross tumor volumes (GTVs) in all 10 phases. IGTV auto-propagation was carried out using two distinct DIR algorithms for the manually contoured GTV from each of the 10 phases, resulting in 10 separate IGTVs for each patient per each algorithm. Differences between the auto-propagated IGTVs (AP-IGTVs) and their corresponding GT-IGTVs were assessed using Dice coefficient (DICE), maximum symmetric surface distance (MSSD), average symmetric surface distance (ASSD), and percent volume difference (PVD) and further examined in relation to anatomical tumor location, RP, and deformation index (DI) that measures the degree of deformation during auto-propagation. Furthermore, dosimetric implications due to the analyzed differences between the AP-IGTVs and GT-IGTVs were assessed. Results: Findings were largely consistent between the two algorithms: DICE, MSSD, ASSD, and PVD showed no significant differences between the 10 RPs used for propagation (Kruskal-Wallis test, ps > 0.90); MSSD and ASSD differed significantly by tumor location in the central-peripheral and superior-inferior dimensions (ps < 0.0001) while only in the central-peripheral dimension for PVD (p < 0.001); DICE, MSSD, and ASSD significantly correlated with the DI (Spearman's rank correlation test, ps < 0.0001). Dosimetric assessment demonstrated that 79% of the radiotherapy plans created by targeting planning target volumes (PTVs) derived from the AP-IGTVs failed prescription constraints for their corresponding ground-truth PTVs. Conclusion: In LA-NSCLC, errors in DIR-based IGTV propagation present to varying degrees and manifest dependences on DI and anatomical tumor location, indicating the need for personalized consideration in designing RT internal target volume.

Disparities in Primary Breast Cancer Stage at Presentation Among Hispanic Subgroups.

BACKGROUND: Although the United States (US) Hispanic population consists of diverse communities, prior breast cancer studies often analyze this group in aggregate. Our aim was to identify differences in breast cancer stage at presentation in the US population, with a particular focus on Hispanic subgroups. METHODS: Data from the National Cancer Database (NCDB) from 2004 to 2017 were used to select women with primary breast cancer; individuals were disaggregated by racial and ethnic subgroup and Hispanic country of origin. Ordinal logistic regression was used to create adjusted odds ratios (aORs) with 95% confidence intervals (CIs), with higher odds representing presentation at later-stage breast cancer. Subgroup analysis was conducted based on tumor receptor status. RESULTS: Overall, among 2,282,691 women (5.2% Hispanic), Hispanic women were more likely to live in low-income and low-educational attainment neighborhoods, and were also more likely to be uninsured. Hispanic women were also more likely to present at later-stage primary breast cancer when compared with non-Hispanic White women (aOR 1.19, 95% CI 1.18-1.21; p < 0.01). Stage disparities were demonstrated when populations were disaggregated by country of origin, particularly for Mexican women (aOR 1.55, 95% CI 1.51-1.60; p < 0.01). Disparities worsened among both racial and country of origin subgroups in women with triple-negative disease. CONCLUSION: Later breast cancer stage at presentation was observed among Hispanic populations when disaggregated by racial subgroup and country of origin. Socioeconomic disparities, as well as uncaptured disparities in access and/or differential care, may drive these observed differences. Future studies with disaggregated data are needed to characterize outcomes in Hispanic communities and develop targeted interventions.

Prophylactic Radiotherapy for Prevention of Heterotopic Ossification After Periacetabular Fractures: A Review of Efficacy and Associated Conditions.

Prophylactic radiotherapy (XRT) is a commonly used treatment to decrease heterotopic ossification (HO) in patients with traumatic hip injuries. We conducted a retrospective review of patients at risk for HO who underwent XRT. Of the patients reviewed, 27.3% developed radiographic HO, 11.2% developed symptoms, and 2.0% required resection surgery. Patients were divided into primary (n = 71) and secondary prophylaxis (n = 27) cohorts. In the primary group, 25.0% developed radiographic HO, 5.6% developed symptoms, and 0 required surgery. In the secondary cohort, 33.3% of patients developed new radiographic HO, and 25.9% were symptomatic: four had a Brooker score of 3, and three had a score of 4 (p = 0.03), and 7.4% required surgical resection. (Journal of Surgical Orthopaedic Advances 31(2):113-118, 2022).

Impact of genomic assays on treatment and outcomes in locally advanced breast cancer.

PURPOSE: Genomic profiling in early-stage breast cancer provides prognostic and predictive information. Genomic profiling assays have not been validated in locally advanced breast cancer (LABC). We examined a large cancer registry to evaluate genomic profiling in LABC and its effect on treatment decisions and survival. METHODS: Females with ER+/HER2- LABC who did not receive neoadjuvant therapy were selected from the National Cancer Database 2004-2017. We compared characteristics between patients with and without genomic profiling and with low genomic risk, 21-gene recurrence score ≤ 25 or low-risk 70-gene signature, treated with endocrine therapy ± chemotherapy. Propensity score methods were utilized to account for covariates that may have predicted treatment. Univariable and multivariable survival analyses were performed. RESULTS: Of 18,437 patients with LABC, 1258 (7%) had genomic profiling and 1022 (81%) had low genomic risk results. 562 patients (55%) with low genomic risk received chemotherapy and endocrine therapy (chemoendocrine). Patients who received chemoendocrine therapy were younger, had fewer comorbidities, presented with higher stage disease, had higher grade tumors, more frequently had partial mastectomy, and more often received radiation than those who received endocrine therapy alone. On multivariable analysis, endocrine therapy alone was associated with worse OS compared to chemoendocrine therapy (HR 1.77, 95% CI 1.13-2.78, p = 0.013). CONCLUSION: In women with LABC and low genomic risk, endocrine therapy alone was associated with worse OS compared to chemoendocrine therapy. This suggests that genomic profiling is not predictive in LABC. Accordingly, genomic profiling should not be routinely utilized to make adjuvant treatment decisions in LABC in the absence of further data which shows a benefit.

Neoadjuvant Chemoradiation Impacts the Prognostic Effect of Surgical Margin Status in Pancreatic Adenocarcinoma.

BACKGROUND: Many studies show significantly improved survival after R0 resection compared with R1 resection in pancreatic adenocarcinoma (PAC); however, the effect of neoadjuvant chemoradiation (NACRT) on this association is unknown. OBJECTIVE: The aim of this study was to evaluate the prognostic significance of positive surgical margins (SMs) after NACRT compared with upfront surgery + adjuvant therapy in PAC. METHODS: All cases of surgically resected PAC at a single institution were reviewed from 1996 to 2014; patients treated with palliative intent, metastatic disease, and biliary/ampullary tumors were excluded. The primary endpoint was overall survival (OS). RESULTS: Overall, 300 patients were included; 134 patients received NACRT with concurrent 5-fluorouracil or gemcitabine followed by surgery, and 166 patients received upfront surgery (+ adjuvant chemotherapy in 72% of patients and RT in 65%); 31% of both groups had a positive SM (+SM). The median OS for patients with a +SM or negative SM (-SM) was 26.6 and 31.6 months, respectively for NACRT, and 12.0 and 24.5 months, respectively, for upfront surgery. OS was significantly improved with -SM compared with +SM in both groups (p = 0.006). When resection yielded +SM, NACRT patients had improved OS compared with upfront surgery patients (p < 0.001). On multivariable analysis, +SM in the upfront surgery group (hazard ratio [HR] 2.94, 95% confidence interval [CI] 2.04-4.24; p < 0.001) and older age (HR 1.01, 95% CI 1.00-1.03, per year; p = 0.007) predicted worse OS. +SM in the NACRT group was not associated with worse OS (HR 1.09, 95% CI 0.72-1.65; p = 0.70). CONCLUSION: Patients with a positive margin after NACRT and surgery had longer survival compared with patients with a positive margin after upfront surgery. NACRT should be strongly considered for patients at high risk of R1 resections.

Primary Versus Secondary Radiotherapy for Heterotopic Ossification Prevention About the Elbow.

OBJECTIVES: To examine the efficacy and safety of radiotherapy for the prevention of heterotopic ossification (HO) about the elbow. DESIGN: Retrospective chart review. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: Two hundred and twenty-nine patients who received prophylactic radiotherapy (XRT) over a 15-year period were identified. Patients were included if they received XRT to the elbow joint and had at least 12 weeks of follow-up after XRT. Fifty-four patients were ultimately included. INTERVENTION: All patients were treated with a single dose of 7 Gy. Ninety-eight percentage of patients received XRT within 24 hours after surgery, and all patients received XRT within 72 hours after surgery. MAIN OUTCOMES MEASUREMENTS: The primary study measures evaluated were the presence or absence of clinically symptomatic HO and the presence of radiographic HO after XRT to the elbow joint. RESULTS: Eighteen patients were treated with XRT after a traumatic injury requiring surgery (primary prophylaxis), and 36 were treated with XRT after excision surgery to remove HO which had already formed (secondary prophylaxis). In the primary cohort, 16.7% developed symptomatic HO after XRT and 11.1% required surgery to resect the heterotopic bone. In the secondary cohort, 11.1% developed symptomatic HO after surgery and XRT and 5.5% required resection surgery. No secondary malignancies were identified. CONCLUSIONS: Our findings suggest that XRT for elbow HO may be safe and effective for both primary and secondary HO. XRT for HO was not shown to be associated with radiation-induced sarcoma in this series, at least in the short term. Further study in a large patient population with extended follow-up is required to better characterize populations at high risk for development of HO and secondary malignancy. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Radiomics Predicts for Distant Metastasis in Locally Advanced Human Papillomavirus-Positive Oropharyngeal Squamous Cell Carcinoma.

(1) Background and purpose: clinical trials have unsuccessfully tried to de-escalate treatment in locally advanced human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC) with the goal of reducing treatment toxicity. The aim of this study was to explore the role of radiomics for risk stratification in this patient population to guide treatment. (2) Methods: the study population consisted of 225 patients with locally advanced HPV+ OPSCC treated with curative-intent radiation or chemoradiation therapy. Appearance of distant metastasis was used as the endpoint event. Radiomics data were extracted from the gross tumor volumes (GTVs) identified on the planning CT, with gray level being discretized using three different bin widths (8, 16, and 32). The data extracted for the groups with and without distant metastasis were subsequently balanced using three different algorithms including synthetic minority over-sampling technique (SMOTE), adaptive synthetic sampling (ADASYN), and borderline SMOTE. From these different combinations, a total of nine radiomics datasets were derived. Top features that minimized redundancy while maximizing relevance to the endpoint were selected individually and collectively for the nine radiomics datasets to build support vector machine (SVM) based predictive classifiers. Performance of the developed classifiers was evaluated by receiver operating characteristic (ROC) curve analysis. (3) Results: of the 225 locally advanced HPV+ OPSCC patients being studied, 9.3% had developed distant metastases at last follow-up. SVM classifiers built for the nine radiomics dataset using either their own respective top features or the top consensus ones were all able to differentiate the two cohorts at a level of excellence or beyond, with ROC area under curve (AUC) ranging from 0.84 to 0.95 (median = 0.90). ROC comparisons further revealed that the majority of the built classifiers did not distinguish the two cohorts significantly better than each other. (4) Conclusions: radiomics demonstrated discriminative ability in distinguishing patients with locally advanced HPV+ OPSCC who went on to develop distant metastasis after completion of definitive chemoradiation or radiation alone and may serve to risk stratify this patient population with the purpose of guiding the appropriate therapy.

Predictors of Hematologic Toxicity and Chemotherapy Dose Intensity in Patients Undergoing Chemoradiation for Pancreatic Cancer.

OBJECTIVES: Intensity-modulated radiation therapy (IMRT) has been shown to decrease abdominal toxicity in patients undergoing chemoradiation (CRT) for pancreatic cancer. We evaluated whether IMRT impacts the rates of hematologic toxicity and chemotherapy dose intensity in patients undergoing CRT. METHODS: We retrospectively reviewed patients with borderline resectable or locally advanced pancreatic cancer undergoing CRT between 2006 and 2012. Exclusion criteria included receipt of non-gemcitabine therapy, chemotherapy before CRT, or abnormal baseline hematologic indices. Endpoints included total gemcitabine dose received, dose intensity, unplanned dose reductions, and hematologic toxicity (WBC, ANC, platelet, and hemoglobin). Patient/treatment factors were evaluated for their relationship to the above endpoints during CRT and within the first 3 months post-CRT. Statistical analysis was performed using the Fisher exact test and regression models. Because of the multiple comparisons in the presented analysis, a false discovery rate adjustment was performed at the 5% false discovery rate level. RESULTS: Eighty-five patients met the inclusion criteria. Fifty-eight (68.2%) patients received treatment with IMRT, and 27 (31.8%) patients were treated with 3D-conformal radiation. During CRT, there was no relationship between radiation technique and gemcitabine dose received, dose intensity, or hematologic grade 3+ toxicity. Post-CRT, there was no relationship between radiation technique and total gemcitabine dose received, dose intensity, or dose reduction. Patients receiving IMRT were more likely to have ANC grade 3+ toxicity (P=0.007) post-CRT, although this was no longer statistically significant after correction. There were no other relationships between treatment technique and hematologic toxicity. CONCLUSIONS: IMRT technique may be associated with higher hematologic toxicity in patients undergoing CRT for pancreatic cancer. Given the expanding use of CRT, additional study is needed to identify the impact of IMRT on myelosuppression in these patients.

Lymph-node-positive cutaneous nonmelanoma skin cancer: A poor-prognosis disease in need of treatment intensification.

Locoregionally advanced nonmelanoma skin cancer (NMSC) has an aggressive clinical course characterized by high rates of treatment failure and poor survival compared with localized skin cancers. Our goal was to investigate multimodal therapy for lymph-node-positive NMSC. Data from patients with lymph-node-positive NMSC who underwent surgery and adjuvant therapy at a single tertiary center from 2002 to 2012 were retrospectively reviewed. Median follow-up was 1.8 years (range: 0.5 to 8.5). Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method. The chi-square test and logistic regression were used to determine the association between locoregional control (LRC) and the following variables: evidence of extracapsular extension, number of lymph nodes positive, largest involved lymph node, presence of a positive margin, and use of concurrent chemoradiation (CRT). Forty-six patients were evaluated, 13 (28%) of whom received adjuvant CRT. CRT patients were younger (p < 0.001) and had a significantly greater number of positive lymph nodes (p = 0.016) than patients who received adjuvant radiation alone. At 5 years, LRC was 76%, PFS was 65%, and OS was 49%. Univariate analysis demonstrated that CRT (p = 0.006), largest lymph node measurement (p = 0.039), and ≥3 involved lymph nodes (p = 0.001) predicted local recurrence. CRT (p = 0.035, odds ratio [OR] 0.20 [95% confidence interval 0.05 to 0.90]) and ≥3 involved lymph nodes (p = 0.017, OR 0.07 [95% confidence interval 0.01 to 0.62]) remained significant on multivariate analysis. CRT was well tolerated. No grade ≥3 toxicities were observed except for 1 asymptomatic grade-4 thrombocytopenia. Patients with lymph-node-positive NMSC do poorly. Patient selection for intensification of adjuvant therapy needs clarification.

Long-Term Patient-Reported Outcomes From a Phase 3 Randomized Prospective Trial of Conventional Versus Hypofractionated Radiation Therapy for Localized Prostate Cancer.

PURPOSE: To assess the long-term quality of life (QoL) outcomes from a phase 3 trial comparing 2 modes of intensity modulated radiation therapy (IMRT): conventional IMRT (CIMRT) versus hypofractionated IMRT (HIMRT) in patients with localized prostate cancer. METHODS AND MATERIALS: Between 2002 and 2006, 303 men with low-risk to high-risk prostate cancer were randomized to 76 Gy in 38 fractions (CIMRT) versus 70.2 Gy in 26 fractions (HIMRT). QoL was compared by use of the Expanded Prostate Cancer Index Composite (EPIC), the International Prostate Symptom Score (IPSS), and EuroQoL (EQ5D) questionnaires. The primary outcome of the QoL analysis was a minimum clinically important difference defined as a 0.5 standard deviation change from baseline for each respective QoL parameter. Treatment effects were evaluated with the use of logistic mixed effects regression models. RESULTS: A total of 286, 299, and 218 patients had baseline EPIC, IPSS, or EQ5D data available and were included in the analysis. Overall, there was no statistically significant difference between the 2 treatment arms in terms of EPIC, IPSS, or EQ5D scores over time, although there was a trend toward lower EPIC urinary incontinence scores in the HIMRT arm. More patients in the HIMRT arm had a lower EPIC urinary incontinence score relative to baseline versus patients in the CIMRT arm with long-term follow-up. On multivariable analysis, there was no association between radiation fractionation scheme and any QoL parameter. When other clinical factors were examined, lymph node radiation was associated with worse EPIC hormonal scores versus patients receiving no lymph node radiation. In general, QoL outcomes were generally stable over time, with the exception of EPIC hormonal and EQ5D scores. CONCLUSIONS: In this randomized prospective study, there were stable QoL changes in patients receiving HIMRT or CIMRT. Our results add to the growing body of literature suggesting that HIMRT may be an acceptable treatment modality in clinically localized prostate cancer.

Surgery and Adjuvant Radiation for High-risk Skin Adnexal Carcinoma of the Head and Neck.

OBJECTIVES: Skin adnexal carcinoma (SAC) is a rare cutaneous malignancy that arises from sebaceous and sweat glands. These carcinomas are believed to behave more aggressively than cutaneous squamous cell carcinomas (SCC) with a propensity for local recurrence. The role of adjuvant radiotherapy in SAC is undefined. METHODS: We retrospectively reviewed all cases of head and neck SAC treated with surgery and adjuvant radiation from 2000 to 2012 at a single institution. RESULTS: Nine cases were identified. Median age was 67 (range, 52 to 88) years. The histologies were: adnexal carcinoma (n=1), adnexal carcinoma with sebaceous differentiation (n=1), adnexal carcinoma with squamous differentiation (n=1), skin appendage carcinoma (n=1), sclerosing sweat duct carcinoma (n=1), mucinous carcinoma (n=1), ductal eccrine adenocarcinoma (n=1), porocarcinoma (n=1), and trichilemmal carcinoma (n=1). All tumors were reviewed by a dermatopathologist to confirm the SAC diagnosis.All patients had undergone surgery. Indications for adjuvant radiation included involved lymph nodes (n=4), perineural invasion (n=2), nodal extracapsular extension (n=2), positive margin (n=1), high-grade histology (n=6), multifocal disease (n=2), and/or recurrent disease (n=5). Radiation was delivered to the primary site alone (n=3), to the draining lymphatics alone (n=2), or to both (n=4). One patient received concurrent cisplatin. Median dose to the primary site was 60 Gy and to the neck was 50 Gy.Median follow-up was 4.0 years (range, 0.6 to 11.4 y). Locoregional control was 100%. Five-year progression-free survival was 89%. There was 1 acute grade 3 toxicity and no greater than or equal to grade 2 late toxicities were recorded. CONCLUSIONS: Surgery and adjuvant radiation for high-risk SAC offers excellent locoregional control with acceptable toxicity.

Dosimetric predictors of hematologic toxicity in patients undergoing concurrent gemcitabine-based chemoradiation for localized pancreatic cancer.

PURPOSE: This study was undertaken to identify parameters associated with hematologic toxicity or chemotherapy dose modification in patients undergoing concurrent chemoradiation (CRT) with gemcitabine for localized pancreatic cancer. METHODS AND MATERIALS: We reviewed patients with localized pancreatic cancer undergoing CRT between 2006 and 2012. Exclusion criteria included receipt of nongemcitabine therapy, chemotherapy before CRT, or abnormal baseline hematologic indices. The T11-L3 vertebrae were contoured as bone marrow region at risk. Linear and logistic regression models were used to test associations between dosimetric parameters and gemcitabine dose modification or hematologic toxicity during or within 3 months following CRT. Receiver operator curves were generated to identify threshold doses for hematologic toxicity. RESULTS: Forty-nine patients were included. During CRT, the maximum thoracolumbar dose was associated with grade 2+ neutropenia during CRT (P = .017) and the volume receiving 5 Gy (V5) was associated with grade 2+ leukopenia (P = .041). Post-CRT, thoracolumbar mean dose (P = .015), V5 (P = .01), and V10 (P = .012) were associated with increased grade 2+ neutropenia. On multivariable analysis, the thoracolumbar maximum dose (P = .045) and V5 (P = .045) were associated with grade 2+ neutropenia and grade 2+ leukopenia during CRT, respectively. Post-CRT, the mean dose (P = .046), V5 (P = .019), and V10 (P = .037) were associated with increased grade 2+ neutropenia. A maximum dose of 48.02 Gy and V5 of 57.6% were identified as predictors of toxicity during CRT. A V5 of 56.6%, V10 of 47.05%, and mean dose of 11.67 Gy were identified as predictors of post-CRT hematologic toxicity. Post-CRT, there was a trend toward increased dose modifications with increased V5 (P = .065). CONCLUSIONS: In our dataset, the thoracolumbar mean dose, maximum dose, V5, and V10 correlated with hematologic toxicity during CRT and post-CRT in patients with localized pancreatic cancer. Because of the high rates of distant failure and importance of systemic therapy in these patients, this may be an important consideration during treatment planning.

The impact of trainee involvement on outcomes in low-dose-rate brachytherapy for prostate cancer.

PURPOSE: To determine the impact of fellow, resident, or medical student (MS) involvement on outcomes in patients undergoing permanent (125)I prostate seed implant. METHODS AND MATERIALS: The study population consisted of men with clinically localized low/intermediate-risk prostate cancer treated with low-dose-rate permanent interstitial brachytherapy. Cases were stratified according to resident, fellow, MS, or attending involvement. Outcomes were compared using analysis of variance, logistic regression, and log rank tests. RESULTS: A total of 291 patients were evaluated. Fellows, residents, and MS were involved in 47 (16.2%), 231 (79.4%), and 34 (11.7%) cases, respectively. Thirteen (4.4%) cases were completed by an attending physician alone. There was no difference in freedom from biochemical failure when comparing the resident, fellow, or attending alone groups (p = 0.10). There was no difference in V100 (volume of the prostate receiving 100% of the prescription dose) outcomes when comparing resident cases to fellow cases (p = 0.72) or attending alone cases (p = 0.78). There was no difference in D90 (minimum dose covering 90% of the postimplant volume) outcomes when comparing resident cases to fellow cases (p = 0.74) or attending alone cases (p = 0.58). When examining treatment toxicity, fellow cases had higher rates of acute Grade 2 + GU toxicity (p = 0.028). With the exception of higher urethra D90 among PGY 2-3 cases (p = 0.02), dosimetric outcomes were similar to cases with PGY 4-5 resident participation. There was no difference in outcomes for cases with and without MS participation. CONCLUSIONS: Interstitial prostate seed implants can be safely performed by trainees with appropriate supervision. Hands-on brachytherapy training is effective and feasible for trainees.

Survival Impact of Increasing Time to Treatment Initiation for Patients With Head and Neck Cancer in the United States.

PURPOSE: To estimate the overall survival (OS) impact from increasing time to treatment initiation (TTI) for patients with head and neck squamous cell carcinoma (HNSCC). METHODS: Using the National Cancer Data Base (NCDB), we examined patients who received curative therapy for the following sites: oral tongue, oropharynx, larynx, and hypopharynx. TTI was the number of days from diagnosis to initiation of curative treatment. The effect of TTI on OS was determined by using Cox regression models (MVA). Recursive partitioning analysis (RPA) identified TTI thresholds via conditional inference trees to estimate the greatest differences in OS on the basis of randomly selected training and validation sets, and repeated this 1,000 times to ensure robustness of TTI thresholds. RESULTS: A total of 51,655 patients were included. On MVA, TTI of 61 to 90 days versus less than 30 days (hazard ratio [HR], 1.13; 95% CI, 1.08 to 1.19) independently increased mortality risk. TTI of 67 days appeared as the optimal threshold on the training RPA, statistical significance was confirmed in the validation set (P < .001), and the 67-day TTI was the optimal threshold in 54% of repeated simulations. Overall, 96% of simulations validated two optimal TTI thresholds, with ranges of 46 to 52 days and 62 to 67 days. The median OS for TTI of 46 to 52 days or fewer versus 53 to 67 days versus greater than 67 days was 71.9 months (95% CI, 70.3 to 73.5 months) versus 61 months (95% CI, 57 to 66.1 months) versus 46.6 months (95% CI, 42.8 to 50.7 months), respectively (P < .001). In the most recent year with available data (2011), 25% of patients had TTI of greater than 46 days. CONCLUSION: TTI independently affects survival. One in four patients experienced treatment delay. TTI of greater than 46 to 52 days introduced an increased risk of death that was most consistently detrimental beyond 60 days. Prolonged TTI is currently affecting survival.

Pre-treatment tumor-specific growth rate as a temporal biomarker that predicts treatment failure and improves risk stratification for oropharyngeal cancer.

PURPOSE: To assess the relationship between tumor-specific growth rate (TSGR) and oropharyngeal cancer (OPC) outcomes in the HPV era. METHODS/MATERIALS: Primary tumor volume differences between a diagnostic and secondary scan separated ⩾7days without interval treatment were used to estimate TSGR, defined as percent volume growth/day derived from primary tumor volume doubling time for 85 OPC patients with known p16 status and smoking pack-years managed with (chemo)radiation. Variables were analyzed using Kruskal-Wallis or Fisher's exact test as appropriate. Log-rank tests and Cox proportional models analyzed endpoints. Using concordance probability estimates (CPE), TSGR was incorporated into RTOG 0129 risk grouping (0129RG) to assess whether TSGR could improve prognostic accuracy. RESULTS: Median time between scans was 35days (range 8-314). Median follow up was 26months (range 1-76). The 0129RG classification was: 56% low, 25% intermediate, and 19% high risk. Median TSGR was 0.74%/day (range 0.01-4.25) and increased with 0129RG low (0.41%), intermediate (0.57%) and high (1.23%) risk, respectively (p=0.015). TSGR independently predicted for TF (TSGR: HR (95%CI)=2.79, 1.67-4.65, p<0.001) in the Cox model. On CPE, prognostic accuracy for TF, disease-free survival and overall survival was improved when 0129RG was combined with TSGR. Dichotomizing 0129RG by median TSGR yielded no observed recurrences in low risk patients with TSGR<0.74% and demonstrated significant difference for intermediate risk (8% vs. 50% for TSGR<0.74% vs. ⩾0.74%, respectively, p<0.001). CONCLUSION: Tumor-specific growth rate correlates with increasing 0129RG and predicts treatment failure, potentially improving the prognostic strength and risk stratification of established 0129 risk groups.

Impact of obesity on outcomes after definitive dose-escalated intensity-modulated radiotherapy for localized prostate cancer.

BACKGROUND: Previous publications have demonstrated conflicting results regarding body mass index (BMI) and prostate cancer (CaP) outcomes after definitive radiotherapy (RT) before the dose escalation era. The goal of the current study was to determine whether increasing BMI was associated with outcomes in men with localized CaP who were treated with dose-escalated RT. METHODS: The authors identified patients with localized (T1b-T4N0M0) CaP who were treated with definitive intensity-modulated RT and image-guided RT from 2001 through 2010. BMI was analyzed as a continuous variable. Adjusting for confounders, multivariable competing risk and Cox proportional hazards regression models were used to assess the association between BMI and the risk of biochemical failure (BF), distant metastases (DM), cause-specific mortality (CSM), and overall mortality. RESULTS: Of the 1442 patients identified, approximately 20% had a BMI <25 kg/m(2) , 48% had a BMI of 25 to 29.9 kg/m(2) , 23% had a BMI of 30 to 34.9 kg/m(2) , 6% had a BMI of 35 to 39.9 kg/m(2) , and 4% had a BMI of ≥40 kg/m(2) . The median follow-up was 47.6 months (range, 1-145 months), with a median age of 68 years (range, 36-89 years). The median dose was 78 grays (range, 76-80 grays) and 30% of patients received androgen deprivation therapy. Increasing BMI was found to be inversely associated with age (P<.001) and pretreatment prostate-specific antigen level (P = .018). On multivariable analysis, increasing BMI was associated with an increased risk of BF (hazard ratio [HR], 1.03; 95% confidence interval [95% CI], 1.00-1.07 [P = .042]), DM (HR, 1.07; 95% CI, 1.02-1.11 [P = .004]), CSM (HR, 1.15; 95% CI, 1.07-1.23 [P<.001]), and overall mortality (HR, 1.05; 95% CI, 1.02-1.08 [P = .004]). CONCLUSIONS: For patients with CaP receiving dose-escalated intensity-modulated RT with daily image-guidance, increasing BMI appears to be associated with an increased risk of BF, DM, CSM, and overall mortality.