Improvements in the radiochemical method for separating 226Ra in solid samples through coprecipitation with BaSO4

The aim of this work was to improve the commonly used method for ²²⁶Ra determination in water and to establish its application in solid samples. This method is based on the coprecipitation of Ra with BaSO₄ and gross alpha counting of the precipitate. An exhaustive study of the coprecipitation behaviour of the most abundant cations present in solid samples was performed to avoid incorrect radiochemical yields. As a result, it was considered necessary to introduce two new purification steps into the conventional method. Likewise, two nuclides, ²⁴¹Am and ²²⁶Ra, were compared to obtain the mass efficiency curve given their different behaviour in the coprecipitation process. While Ra behaves similarly to Ba, Am coprecipitates, forming mixed crystals that may behave differently in the self-absorption process. The influence of the cations on the chemical yield with no precipitate purification was: Sr²⁺≫Fe³⁺>Mg²⁺≈Ca²⁺>K⁺≈Na⁺. The method was successfully applied to soil, sediment, and plant ash samples.

Abstract P3-05-02: Immune profiling of paired primary and recurrent triple negative breast cancer

Background: Triple negative breast cancer (TNBC) is a heterogeneous disease with several molecular subtypes: basal-like1 (BL-1), basal-like 2 (BL-2), mesenchymal (M), and luminal androgen receptor (LAR). Molecular evolution of TNBC through chemotherapy selection pressure is well recognized but poorly understood. In addition, approximately 20% of TNBCs respond to PD-1 or PD-L1 inhibitors. It has been observed that heavily pre-treated patients may not respond well to immunotherapy. This study was carried out to perform immune profiling of paired primary and recurrent TNBC. Here we report the result of the first 10 paired tissue pilot analysis.

Methods: Twenty specimens were identified through an IRB-approved protocol via the City of Hope Biospecimen Repository (2002-2015). Two brain and one bone metastasis specimens were not included due to technical difficulty. Formalin-fixed paraffin embedded (FFPE) sample blocks were cut into 5-mm thick slides and labeled with the following antibodies: CD4, CD8, CD3, FOXP3, CD20, CD33, Pan-CK, and PD-1 using the multiplex IHC opal method. Image acquisition and cell counting were carried out using PerkinElmer Vectra automated quantitative pathology imaging system and inForm software analysis (PerkinElmer, Waltham, MA). mRNA expression profiling was performed using Affymetrix Human Genechip 2.0. Raw data were normalized and processed using Expression Console. Using Vanderbilt TNBC sub-classification tool, we have sub-classified the 20 primary and recurrent TNBC specimens. Tumor mutation burden (TMB) was generated through FoundationOne® platform.

Result: A total of 17 samples were analyzed (M, 5; LAR, 3; BL-1, 4; BL-2, 5). M-subtype had a significantly lower tumor-infiltrating CD3+ T cells (p=0.005), CD8+ T cells (p=0.024), CD4+ T cells (p=0.065) and CD4+FOXP3+ Treg cells (p=0.054), irrespective of the site of metastasis. CD20+ B cells were particularly enriched in BL-1 subtype (p=0.0013, 23.5% of 17 samples). Of 17 samples, 8 had TMB. Seven had low TMB (<10 mut/Mb) and one had intermediate TMB (11 mut/Mb, LAR subtype). The tumor with intermediate TMB had the highest quantity of tumor-infiltrating CD3+ T cells, CD8+ T cells, CD8+PD1+ T cells, and CD4+FOXP3+PD1+ Treg cells compared to the 7 tumors with low TMB. Compared with recurrent tumors, primary tumors had a significantly higher percentage of tumor-infiltrating T cells (TIL). To validate multiplexed IHC results, these samples were evaluated by a licensed pathologist at City of Hope using the International TILs Working Group 2014 guidelines, and there was a good correlation between percent of TILs and CD3+ T cells by IHC approach.

Conclusion: To our knowledge, this is the first study linking tumor immune cell profiles with the TNBC 4 subtypes. Distinctive immune cell patterns were observed among 4 TNBC subtypes. M subtype had significantly lower TILs, which may indicate poor response to checkpoint inhibitors. Further analysis of a total of 50 paired TNBCs is currently underway.

Contact information: Yuan Yuan MD PhD, Email: yuyuan@coh.org

Citation Format: He T-F, Yost S, Schmolze D, Wang R, Rosario A, Tu T, Chu P, Lee P, Yuan Y. Immune profiling of paired primary and recurrent triple negative breast cancer [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 P3-05-02.

Managing patients with pancreatic cancer

The diagnosis of pancreatic cancer is devastating for patients and family members because of the high morbidity and mortality rates associated with the disease. Regardless of the stages of their illnesses or the treatments they receive, only 3% of patients diagnosed with pancreatic cancer survive five years or more after diagnosis. Compassionate, knowledgeable, supportive nursing care is necessary throughout all stages of pancreatic cancer. This article provides perioperative nurses with information about the diagnosis, treatment, and palliative care for patients diagnosed with pancreatic cancer.

Achilles tendon repair with an absorbable polymer-carbon fiber composite

Twenty-seven patients were surgically treated for Achilles tendon rupture using a composite implant. The implant is ribbon-like in configuration and composed of filamentous carbon fiber coated with an absorbable polymer. When used to secure an Achilles repair, the implant acts as a scaffold for the regrowth of collagenous tissue. Rapid attachment of host tissue assures good, early repair strengths which allows for a more vigorous rehabilitation program. Fourteen patients have at least 9 months of follow-up (average follow-up, 14.4 months) and have been objectively and subjectively evaluated on a temporal basis for return of function. To date, complications have been minimal. Results have been very encouraging with 90% return of function at 18 months.

Organic versus functional etiology in catatonia: case report

The case of an illegal alien brought to the emergency room in a catatonic stupor is described. The patient's condition worsened following the administration of a high-potency neuroleptic, and it was later learned that he had a history of epileptic seizures. This case emphasizes the importance of ruling out organic causes in patients presenting with catatonic symptoms.