Abstract P3-12-10: Utilization patterns and temporal trends of internal mammary nodal irradiation (IMNI) at a tertiary cancer centre

Purpose: Despite data from multiple randomized trials, the role and uptake of internal mammary nodal irradiation (IMNI) is variable. This study was designed to quantify the rates and determinants of IMNI at a tertiary cancer centre.

Methods: Treatment records of consecutively treated breast cancer (BC) patients receiving adjuvant locoregional (LR) radiotherapy (RT) from January 1, 2012 to October 31, 2017 was studied. LR-RT and use of IMNI as a function of clinicopathological factors, use of deep inspiratory breath-hold (DIBH) and dosimetric parameters were retrieved. Patients were divided into two groups:Group1 received LR-RT that included the IMN's, supraclavicular (SCLV) ± axillary regions,Group2 received LR-RT directed only to the SCLV±axillary areas. For the purpose of utilization analysis and temporal trends, early(2012-2015) and late(2016-2017) cohorts were examined based on the year of RT delivery. To determine if the use of IMNI was dependent on BC risk, we defined 3 risk categories:1) pT1/2, N0); 2)pT1/2, N1; and 3) pT3/4, N2/3 disease. Differences between the risk categories and groups were evaluated using chi-square/ Fisher's and Mann Whitney test for categorical and continuous variables, respectively. Univariable and multivariable logistic regression analysis was done to determine factors associated with the receipt of IMNI.

Results:A total of 1566 patients met eligibility (Group 1=376; Group 2=1190). Of these patients, the percentage receiving LR-RT remained constant (17%) over the study period but the proportion of patients receiving IMNI increased significantly each year (p<0.0001), and was higher in the late vs. early treatment cohort (55% vs 8%, p<0.0001).On univariable analysis, younger age, LVI positivity, medial/central location, increasing stage, PR negativity, mastectomy, axillary dissection ,receipt of chemotherapy and increasing number of positive nodes had higher odds of receiving IMNI. Radiation oncologists with < or ≥5 years of practice was predictive of IMNI (31.3% vs 20.5%, p<0.0001),staff having <5years in practice being more likely to recommend IMNI. The distribution of patients in the different risk categories was similar between Groups 1 and 2 (p=0.097), and identified that the majority of patients receiving IMNI were in risk category 2(83%). Further comparison of risk categories suggested that the odds of receiving IMNI was lower in risk category 3 vs. category 1 (p=0.033). On multivariable analysis, decreasing age age (p=<0.001) , medial quadrant(p=0.0026),PR negative(p=0.0011), mastectomy(p=0.0055) , increasing nodal positivity (p<0.0001)and late RT cohort (p=0.001) had increased odds of IMNI. Overall use of DIBH was significantly higher in those receiving IMNI (45% vs 26%, p<0.0001). Mean heart (2.2vs1.7Gy, p<0.0001) and total lung doses (7.8vs6.6Gy,p<0.0001) were also significantly higher with IMNI.

Conclusion: There was a significant increase in utilization of IMNI from 2012 to 2017. Younger age, medial location, PR negativity and increasing number of positive nodes predicted for receipt of IMNI. Staff with<5years in practice were more likely to recommend LR-RT that included the IMNs. The use of DIBH significantly increased with IMNI and allowed for acceptable dosimetric constraints.

Citation Format: Misra S, Lee G, Maganti M, Koch CA. Utilization patterns and temporal trends of internal mammary nodal irradiation (IMNI) at a tertiary cancer centre [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-10.

Adverse effects of anti-epileptics in trigeminal neuralgiform pain

BACKGROUND

Side effects of anti-epileptic drugs (AEDs) have not been adequately documented in trigeminal neuralgia and its variants. The aim of this observational cross-sectional study was to compare the A-B Neuropsychological Assessment Schedule (ABNAS), which measures cognitive side effects to the Adverse Events Profile (AEP), which looks at a broader range of side effects, and to investigate drug/dosage relationships with questionnaire scores to help determine a point at which a drug change would be indicated.

METHODS

One hundred five patients were recruited from a facial pain clinic, over a 10-month period. Self-complete questionnaire scores were compared between patients using different AEDs.

RESULTS

A-B Neuropsychological Assessment Schedule score correlated well with AEP indicating that cognitive side effects were a significant burden. Toxic range on the ABNAS was estimated to occur when scores were >43/72 (95% CI: 37.4-48.6). Polytherapy is weakly associated with the higher scores. Oxcarbazepine dosage was found to linearly correlate with AEP and ABNAS scores, better than carbamazepine dosage. Memory alteration was least common with lamotrigine and oxcarbazepine, and there was less association between fatigues with oxcarbazepine/pregabalin.

CONCLUSION

Anti-epileptic drugs have significant side effects. The ABNAS questionnaire is a useful tool along with the AEP to recognize and monitor AEDs' side effects and to help to adjust medications to optimal dosage.

Abstract P3-07-10: Modulation of FASN under obese conditions

Introduction: Obesity is known to be associated with a worse breast cancer prognosis, in part through altering metabolism in cells of the tumor microenvironment. In particular, changes in metabolism associated with fatty acid utilization have been noted in not only breast cancer, but also several other cancer types. This includes changes to both expression and activity of the Fatty Acid Synthase enzyme (FASN), which is responsible for production of long chain fatty acids, including palmitate. These changes in long chain fatty acid production can modulate tumor behavior through modulation of energy utilization such as beta-oxidation, as well as plasma membrane modulation with phospholipids. Our previous studies have demonstrated that exposure to obese conditions induces significant changes in breast cancer cell proliferation. Additionally, obesity modulates activity of other cells within the tumor microenvironment, including adipocytes, which might influence the cancer cell itself. We hypothesize one particular mechanism that supports these changes is obesity-induced upregulation of FASN and that FASN may be a viable target to limit obesity-induced progression.

Methods and Results: FASN has been shown to promote cancer cell proliferation through generating fatty acid precursors required for cell proliferation, altering membrane fluidity, and activating oncogenic signaling pathways. To determine if modulation of FASN is an important mechanism by which obesity promotes disease progression, MCF-7 breast cancer cells and human pre-adipocyte cells (ASC) were exposed to 2% sera from obese postmenopausal women and 2% sera from non-obese (control) women. Preliminary quantitative PCR results demonstrated that exposure to the obese sera resulted in increased expression of FASN in both the cancer cells as well as the ASC. Current studies are on-going to determine if 1) FASN up-regulation results in increased long-chain and free fatty acid production in both the cancer and adipocyte cells, 2) whether changes in long chain and free fatty acid production results in altered metabolism and plasma membrane status and 3) whether targeting FASN with a new generation of FASN inhibitors currently being investigated in the clinic can modulate obesity-induced disease progression.

Conclusions: Our findings indicate that obesity promotes upregulation of FASN in several cells within the tumor microenvironment, including adipocytes and the cancer cell itself. We have also found that using a FASN inhibitor is effective in limiting cancer cell viability and proliferation. Our on-going studies will confirm if this is an important mechanism by which obesity promotes disease progression. Since FASN inhibitors are currently being investigated in the clinic, the results of these studies will provide a better understanding of how obesity alters the biology of the disease, and may identify a novel target for improving patient outcomes.

Citation Format: Pham T, Oberman A, Kim I, Lee G, Quach D, Galván G, Jolly C, Cavazos D, Brenner A, deGraffenried L. Modulation of FASN under obese conditions [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-07-10.

Polyamine patterns in plasma of patients with systemic lupus erythematosus and fever

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with various clinical manifestations and serologic markers. In this study, we analyzed nine polyamine (PA) profiles of plasma from patients with SLE and healthy controls (HCs), and the relationship between the PA profiles and disease activity. PA alterations in plasma of 44 patients with SLE and fever were investigated using gas chromatography mass spectrometry (GC-MS) in selected ion monitoring mode using N-ethoxycarbonyl/ N-pentafluoropropionyl derivatives, and compared with those of 43 HCs. Patients with SLE and HCs showed differences in five of nine PA profiles. Among five changed PA levels, four PAs, namely N¹-acetylcadaverine, spermidine, N¹-acetylspermidine, and spermine, were dramatically decreased. However, the level of cadaverine was increased in patients with SLE. In the partial correlation with PA profiles and disease activity markers of SLE, several disease activity markers and nutritional markers were correlated with cadaverine, spermidine, and N ⁸-acetylspermidine. Thus, our results provide a comprehensive understanding of the relationship between PA metabolomics and disease activity markers in patients with SLE.