Predicting type 2 diabetes risk before and after solid organ transplantation using polygenic scores in a Danish cohort

Type 2 diabetes mellitus (T2DM) can be multifactorial where both genetics and environmental factors play a role. We aimed to investigate the use of polygenic risk scores (PRS) in the prediction of pre-transplant T2DM and post-transplant diabetes mellitus (PTDM) among solid organ transplant (SOT) patients. Using non-genetic risk scores alone; and the combination with PRS, separate logistic regression models were built and compared using receiver operator curves. Patients were assessed pre-transplant and in three post-transplant periods: 0-45, 46-365 and >365 days. A higher PRS was significantly associated with increased odds of pre-transplant T2DM. However, no improvement was observed for pre-transplant T2DM prediction when comparing PRS combined with non-genetic risk scores to using non-genetic risk scores alone. This was also true for predictions of PTDM in all three post-transplant periods. This study demonstrated that polygenic risk was only associated with the risk of T2DM among SOT recipients prior to transplant and not for PTDM. Combining PRS with a clinical model of non-genetic risk scores did not significantly improve the predictive ability, indicating its limited clinical utility in identifying patients at high risk for T2DM before transplantation, suggesting that non-genetic or different genetic factors may contribute to PTDM.

Prediction of Radiation-induced Lymphopenia following Exposure of the Thoracic Region and Associated Risk of Infections and Mortality

AIMS

Large blood volumes are irradiated when the heart is exposed to radiation. The mean heart dose (MHD) may be a good surrogate for circulating lymphocytes exposure. We investigated the association between MHD and radiation-induced lymphopenia and explored the impact of the end-of-radiation-therapy (EoRT) lymphocyte count on clinical outcomes.

MATERIALS AND METHODS

In total, 915 patients were analysed: 303 patients with breast cancer and 612 with intrathoracic tumours: oesophageal cancer (291), non-small cell lung cancer (265) and small cell lung cancer (56). Heart contours were generated using an interactive deep learning delineation process and an individual dose volume histogram for each heart was obtained. A dose volume histogram for the body was extracted from the clinical systems. We compared different models analysing the effect of heart dosimetry on the EoRT lymphocyte count using multivariable linear regression and assessed goodness of fit. We published interactive nomograms for the best models. The association of the degree of EoRT lymphopenia with clinical outcomes (overall survival, cancer treatment failure and infection) was investigated.

RESULTS

An increasing low dose bath to the body and MHD were associated with a low EoRT lymphocyte count. The best models for intrathoracic tumours included dosimetric parameters, age, gender, number of fractions, concomitant chemotherapy and pre-treatment lymphocyte count. Models for patients with breast cancer showed no improvement when adding dosimetric variables to the clinical predictors. EoRT lymphopenia grade ≥3 was associated with decreased survival and increased risk of infections among patients with intrathoracic tumours.

CONCLUSION

Among patients with intrathoracic tumours, radiation exposure to the heart contributes to lymphopenia and low levels of peripheral lymphocytes after radiotherapy are associated with worse clinical outcomes.

Risk of Bacterial, Viral, and Fungal Infections in Patients With Solid Malignant Tumors Treated With Curative Intent Radiation Therapy

Purpose

The incidence, etiology, and association of infections with radiation therapy (RT)-induced lymphopenia in patients with solid tumors is not well elucidated.

Methods and Materials

We identified possible, probable, and definite infections caused by bacteria, fungi, and viruses, combining data on medication, microbiology, and diagnoses. Definite infections had either a diagnosis or a positive microbiological isolation. We analyzed the incidence and adjusted incidence-rate ratio of infections in the year after the start of RT among patients who received RT plus chemotherapy and RT monotherapy, by type of infection and according to the degree of RT-induced lymphopenia.

Results

A total of 4450 of 6334 (70.3%) patients experienced 11264 infections overall; 1424 (22.5%) patients developed 2104 definite infections in the first year after RT. Infections were more frequent among patients who received RT plus chemotherapy (2590 of 3469; incidence: 16.5 [95% confidence interval {CI}, 16.1-17.0], per 100 patient-years) compared with patients who received RT monotherapy (1860 of 2865; incidence: 12.7 [95% CI, 12.3-13.2]). The incidence of infection was highest in the first 3 months overall (28.2 vs 18.0 in patients who received RT plus chemotherapy compared with those who received RT monotherapy) and for definite infections (4.7 vs 3.8). The proportion of specific bacterial infections were similar among patients who received RT plus chemotherapy versus those who received RT monotherapy. Urinary tract infections were the most frequent (51.2% vs 56.2%), followed by pneumonias (24.1% vs 22.4%). Viral and fungal infections were more frequent among patients who received RT plus chemotherapy, but they were uncommon. In multivariable analyses, patients who received RT plus chemotherapy with a lymphopenia grade of 1-2 or ≥3 versus no lymphopenia at end of RT had an increased risk of bacterial infections 0 to 3 months after RT (incidence rate ratio, 1.45 [95% CI, 1.06-1.97] and 1.71 [95% CI, 1.26-2.34], respectively). Limiting to definite bacterial infections, the incidence rate ratio for lymphopenia grade ≥3 versus no lymphopenia was 2.66 (95% CI, 1.40-5.03).

Conclusions

The incidence of bacterial infections 0 to 3 months after RT plus chemotherapy for solid tumors was high, especially among patients with RT-induced lymphopenia grade 1-2 and ≥3.

Posttransplantation Diabetes Mellitus Among Solid Organ Recipients in a Danish Cohort

Post-transplant diabetes mellitus (PTDM) is associated with a higher risk of adverse outcomes. We aimed to describe the proportion of patients with diabetes prior to solid organ transplantation (SOT) and post-transplant diabetes mellitus (PTDM) in three time periods (early-likely PTDM: 0–45 days; 46–365 days and >365 days) post-transplant and to estimate possible risk factors associated with PTDM in each time-period. Additionally, we compared the risk of death and causes of death in patients with diabetes prior to transplant, PTDM, and non-diabetes patients. A total of 959 SOT recipients (heart, lung, liver, and kidney) transplanted at University Hospital of Copenhagen between 2010 and 2015 were included. The highest PTDM incidence was observed at 46–365 days after transplant in all SOT recipients. Age and the Charlson Comorbidity Index (CCI Score) in all time periods were the two most important risk factors for PTDM. Compared to non-diabetes patients, SOT recipients with pre-transplant diabetes and PTDM patients had a higher risk of all-cause mortality death (aHR: 1.77, 95% CI: 1.16–2.69 and aHR: 1.89, 95% CI: 1.17–3.06 respectively). Pre-transplant diabetes and PTDM patients had a higher risk of death due to cardiovascular diseases and cancer, respectively, when compared to non-diabetes patients.

RootPainter3D: Interactive-machine-learning enables rapid and accurate contouring for radiotherapy

PURPOSE

Organ-at-risk contouring is still a bottleneck in radiotherapy, with many deep learning methods falling short of promised results when evaluated on clinical data. We investigate the accuracy and time-savings resulting from the use of an interactive-machine-learning method for an organ-at-risk contouring task.

METHODS

We implement an open-source interactive-machine-learning software application that facilitates corrective-annotation for deep-learning generated contours on X-ray CT images. A trained-physician contoured 933 hearts using our software by delineating the first image, starting model training, and then correcting the model predictions for all subsequent images. These corrections were added into the training data, which was used for continuously training the assisting model. From the 933 hearts, the same physician also contoured the first 10 and last 10 in Eclipse (Varian) to enable comparison in terms of accuracy and duration.

RESULTS

We find strong agreement with manual delineations, with a dice score of 0.95. The annotations created using corrective-annotation also take less time to create as more images are annotated, resulting in substantial time savings compared to manual methods. After 923 images had been delineated, hearts took 2 min and 2 s to delineate on average, which includes time to evaluate the initial model prediction and assign the needed corrections, compared to 7 min and 1 s when delineating manually.

CONCLUSIONS

Our experiment demonstrates that interactive-machine-learning with corrective-annotation provides a fast and accessible way for non computer-scientists to train deep-learning models to segment their own structures of interest as part of routine clinical workflows.

Hematological toxicity in patients with solid malignant tumors treated with radiation - Temporal analysis, dose response and impact on survival

PURPOSE

To describe the kinetics of the peripheral blood components after radiotherapy, to examine radiation exposure vs. End-of-Radiation-Therapy (EoRT) counts and to associate the EoRT lymphocyte count with death and cancer treatment failure.

MATERIALS AND METHODS

Cohort study of patients who received curative intent radiotherapy for solid tumor diagnoses from 2009-2016 at Rigshospitalet, Copenhagen and had available 3D radiation exposure data. We illustrated peripheral blood count kinetics within 12 months before and after radiotherapy start and analyzed the impact of the irradiated body volume. We investigated overall survival and cancer treatment failure according to EoRT lymphopenia using Cox regression analyses.

RESULTS

We analyzed 4055 patients with both pre-treatment and EoRT platelet counts and 2318 patients who also had neutrophil and lymphocyte counts. Only the lymphocyte decline after radiotherapy start was clinically relevant and remained low one year after radiotherapy. The higher the volume of the body exposed to radiation, the lower the EoRT blood counts. Female gender (p < 0.001), number of fractions (p = 0.010), dose-volume (p < 0.001) and concomitant use of chemotherapy, particularly the platinum compounds (p < 0.001) were independently associated with a lower EoRT lymphocyte count. Patients with head and neck cancer had the lowest EoRT lymphocyte count. Patients with lymphopenia had a higher risk of death in the year after radiotherapy, compared with patients with no lymphopenia.

CONCLUSION

Radiation schemes with fewer fractions and radiation techniques allowing reduction of the volume of the body exposed to radiation could be expected to better preserve patients' immune function.

252. Increased incidence rates of positive blood cultures shortly after chemotherapy treatment initiation among individuals treated for solid malignant tumours

Background

Cancer treatments suppress immune function and are associated with increased risk of infections, but the overall burden of serious infectious diseases in treated patients has not been clearly elucidated.

Methods

All patients treated for solid malignant tumours with curative intent radiotherapy (RT) and/or standard first line chemotherapy (C) at the Department of Oncology at Rigshospitalet between 01/1/2010 to 31/12/2016 were included. Patients were followed from treatment initiation to new cancer treatment, end of follow up or death whichever came first. We calculated incidence rates (IR) of positive blood culture (PBC) per 1000 person years follow up using Kaplan-Meier methods, and examined the proportion who died within 30 days of PBC.

Results

13,275 individuals were included, 4,372 (33%), 6,349 (48%), and 2,554 (19%) treated with RT, C, or concomitant RT&C, respectively, contributing 21,493 person years follow-up. 6,930 (52%) were female, the median (IQR) age was 63 (53, 70), and the most common cancer diagnoses were breast (n = 2,593 [19%]), colorectal (n=1,422 [11%]), and stomach (n=1,246 [9%]).

Overall, 564 individuals (4%) experienced 746 unique episodes of PBC, 188, 408, and 150 events in 143, 311 and 110 individuals treated with RT, C, and RT&C, of which 49 (26%), 104 (25%), 38 (25%) died within 30 days of PBC, respectively. IR of PBC significantly varied by treatment: 13.0 (95% confidence interval 11.1, 15.4), 43.9 (39.3, 49.0) and 32.0 (26.5, 38.5) per 1000 person-years follow up in the RT, C and RT&C groups, respectively (IR ratio = 3.36 (2.75, 4.10) and 2.45 (1.91, 3.14) for C and RT&C compared to RT, respectively) and time since treatment (figure). Escherichia coli (n=185, 25%), Staphylococcus aureus (n=102, 14%), Klebsiella pneumoniae (n=76, 10%), Enterococcus faecium (n=48, 6%), and Enterococcus faecalis (n= 37, 5%) were the top 5 microorganisms identified and did not vary by treatment category, p = 0.11, there were 31 (4%) cases of Candida.

Incidence rate of positive blood culture (PBC) by time since treatment initiation (0–3 months, 0–6 months and >6 months) and the proportion who died within 30 days of PBC by treatment type among individuals treated for solid malignant tumours with radiotherapy [RT], chemotherapy [C] and concomitant RT&C at Department of Oncology at Rigshospitalet, University of Copenhagen between 01/1//2010 to 31/12/2016.

Conclusion

PBCs are seen more often within 3 – 6 months after C than after RT alone. PBCs are not common, but when they occur, mortality is high. More precise risk factors for PBC and prophylactic means and empiric treatments in selected high-risk patients should be investigated.

Disclosures

All Authors: No reported disclosures

[Atypic toxocariasis: a case report from the Peruvian north coast]

We present the case of a 4.5 years old boy with atypic toxocariasis, from La Matanza, Morropon, Piura. The patient had non-specific symptoms during 9 days. Suspicion of Toxocariasis was supported by marked eosinophilia in the cell blood count (15% or 1470 cells/μL). Diagnosis was confirmed by laboratory with ELISA serology demonstrating the presence of IgG and IgM anti-Toxocara antibodies. Symptoms receded before the patient received a five-day treatment with albendazol 15mg/kg/day.