Endocrine Deficiency As a Function of Radiation Dose to the Hypothalamus and Pituitary in Pediatric and Young Adult Patients With Brain Tumors.

PURPOSE: There are sparse data defining the dose response of radiation therapy (RT) to the hypothalamus and pituitary in pediatric and young adult patients with brain tumors. We examined the correlation between RT dose to these structures and development of endocrine dysfunction in this population. MATERIALS AND METHODS: Dosimetric and clinical data were collected from children and young adults (< 26 years of age) with brain tumors treated with proton RT on three prospective studies (2003 to 2016). Deficiencies of growth hormone (GH), thyroid hormone, adrenocorticotropic hormone, and gonadotropins were determined clinically and serologically. Incidence of deficiency was estimated using the Kaplan-Meier method. Multivariate models were constructed accounting for radiation dose and age. RESULTS: Of 222 patients in the study, 189 were evaluable by actuarial analysis, with a median follow-up of 4.4 years (range, 0.1 to 13.3 years), with 31 patients (14%) excluded from actuarial analysis for having baseline hormone deficiency and two patients (0.9%) because of lack of follow-up. One hundred thirty patients (68.8%) with medulloblastoma were treated with craniospinal irradiation (CSI) and boost; most of the remaining patients (n = 56) received involved field RT, most commonly for ependymoma (13.8%; n = 26) and low-grade glioma (7.4%; n = 14). The 4-year actuarial rate of any hormone deficiency, growth hormone, thyroid hormone, adrenocorticotropic hormone, and gonadotropin deficiencies were 48.8%, 37.4%, 20.5%, 6.9%, and 4.1%, respectively. Age at start of RT, time interval since treatment, and median dose to the combined hypothalamus and pituitary were correlated with increased incidence of deficiency. CONCLUSION: Median hypothalamic and pituitary radiation dose, younger age, and longer follow-up time were associated with increased rates of endocrinopathy in children and young adults treated with radiotherapy for brain tumors.

Medical oncology consultation and minimization of overtreatment in men with low-risk prostate cancer.

PURPOSE: Specialist bias, in which specialists recommend the therapy that they are capable of delivering, is thought to influence the treatment of patients with localized prostate cancer and to contribute to overtreatment of men with limited life expectancy. Consequently, rates of active surveillance, the preferred management modality per the National Comprehensive Cancer Network (NCCN) for patients with low- and very low-risk disease and a life expectancy of less than 10 and less than 20 years, respectively, are low. We sought to determine whether consultation with a medical oncologist is associated with increased rates of active surveillance in men with low-risk prostate cancer. METHODS: We identified 188 patients with low-risk prostate cancer undergoing active surveillance at one of three referral centers in Boston, MA in 2009. Multivariable logistic regression was used to determine whether consultation with a medical oncologist was associated with selection of active surveillance. The data were reanalyzed for patients with low- and very low-risk disease and a life expectancy of less than 10 and less than 20 years, respectively. RESULTS: Consultation with a medical oncologist was associated with increased rates of active surveillance (37% v 21%, P = .01), an association that remained significant on multivariable logistic regression (odds ratio [OR] = 2.70; 95% CI, 1.27 to 5.75; P = .01). When applied to patients with limited life expectancy, this finding remained significant (OR = 4.74; 95% CI, 1.17 to 19.25; P = .03). CONCLUSION: Consultation with a medical oncologist is associated with increased rates of active surveillance, adherence to NCCN guidelines, and minimization of overtreatment in men with early prostate cancer and limited life expectancy.

Models of care and NCCN guideline adherence in very-low-risk prostate cancer.

NCCN Guidelines recommend active surveillance as the primary management option for patients with very-low-risk prostate cancer and an expected survival of less than 20 years, reflecting the favorable prognosis of these men and the lack of perceived benefit of immediate, definitive treatment. The authors hypothesized that care at a multidisciplinary clinic, where multiple physicians have an opportunity to simultaneously review and discuss each case, is associated with increased rates of active surveillance in men with very-low-risk prostate cancer, including those with limited life expectancy. Of 630 patients with low-risk prostate cancer managed at 1 of 3 tertiary care centers in Boston, Massachusetts in 2009, 274 (43.5%) had very-low-risk classification. Patients were either seen by 1 or more individual practitioners in sequential settings or at a multidisciplinary clinic, in which concurrent consultation with 2 or more of the following specialties was obtained: urology, radiation oncology, and medical oncology. Patients seen at a multidisciplinary prostate cancer clinic were more likely to select active surveillance than those seen by individual practitioners (64% vs 30%; P<.001), an association that remained significant on multivariable logistic regression (odds ratio [OR], 4.16; P<.001). When the analysis was limited to patients with an expected survival of less than 20 years, this association remained highly significant (72% vs 34%, P<.001; OR, 5.19; P<.001, respectively). Multidisciplinary care is strongly associated with selection of active surveillance, adherence to NCCN Guidelines and minimization of overtreatment in patients with very-low-risk prostate cancer.

Pancreatic neuroendocrine tumors with involved surgical margins: prognostic factors and the role of adjuvant radiotherapy.

PURPOSE: Pancreatic neuroendocrine tumors (pNET) are rare neoplasms associated with poor outcomes without resection, and involved surgical margins are associated with a worse prognosis. The role of adjuvant radiotherapy (RT) in these patients has not been characterized. METHODS AND MATERIALS: We retrospectively evaluated 46 consecutive patients with positive or close (<1 mm) margins after pNET resection, treated from 1983 to 2010, 16 of whom received adjuvant RT. Median RT dose was 50.4 Gy in 1.8-Gy fractions; half the patients received concurrent chemotherapy with 5-fluorouracil or capecitabine. No patients received adjuvant chemotherapy. Cox multivariate analysis (MVA) was used to analyze factors associated with overall survival (OS). RESULTS: Median age at diagnosis was 56 years, and 52% of patients were female. Median tumor size was 38 mm, 57% of patients were node-positive, and 11% had a resected solitary liver metastasis. Patients who received RT were more likely to have larger tumors (median, 54 mm vs. 30 mm, respectively, p = 0.002) and node positivity (81% vs. 33%, respectively, p = 0.002) than those not receiving RT. Median follow-up was 39 months. Actuarial 5-year OS was 62% (95% confidence interval [CI], 41%-77%). In the group that did not receive RT, 3 patients (10%) experienced local recurrence (LR) and 5 patients (18%) developed new distant metastases, while in the RT group, 1 patient (6%) experienced LR and 5 patients (38%) developed distant metastases. Of all recurrences, 29% were LR. On MVA, male gender (adjusted hazard ratio [AHR] = 3.81; 95% CI, 1.21-11.92; p = 0.02) and increasing tumor size (AHR = 1.02; 95% CI, 1.01-1.04; p = 0.007) were associated with decreased OS. CONCLUSIONS: Long-term survival is common among patients with involved-margin pNET. Despite significantly worse pathologic features among patients receiving adjuvant RT, rates of LR between groups were similar, suggesting that RT might aid local control, and merits further evaluation.

Do the dietary supplements epigallocatechin gallate or vitamin e cause a radiomodifying response on tumors in vivo? A pilot study with murine breast carcinoma.

The primary aim of this study was to evaluate a systematic and reproducible assay to examine the potential radiomodifying effects of vitamin E (VE) or epigallocatechin gallate (EGCG), antioxidants commonly consumed by cancer patients as dietary supplements, on tumor control. C3H mice were randomized to a control diet or to the control diet supplemented with VE or EGCG. A tumor control dose 50% (TCD(50)) assay was used to evaluate for a radiomodifying response in stage IV murine cancer (MCa-IV) tumors, implanted in the hindleg of mice, and allowed to grow to 8 mm before receiving a single dose of radiation. The effects of VE and EGCG on intratumoral angiogenesis and apoptosis were evaluated in a group of nonirradiated mice using immunohistochemical staining. Cell proliferation assays were conducted on MCa-IV tumors in vitro. EGCG slowed tumor growth rate by 10%. EGCG and VE slowed tumor regrowth by 24 to 25%. There were no significant differences in TCD(50) values between the groups (control = 73.9 Gy, VE = 77.2 Gy, EGCG = 76.4 Gy); however, normal tissues were protected from late radiation effects (autoamputations) in the VE group. VE and EGCG increased tumor cell apoptosis and decreased tumor cell proliferation but had no effect on microvessel density. In this pilot study, neither VE nor EGCG exerted a significant radiomodifying effect on the MCa-IV tumor. Nonetheless, the suggestion of a small degree of tumor radioprotection by these antioxidant compounds warrants further research. As supplementation with VE radioprotected normal tissue, additional studies on this putative benefit are recommended.