A case of metastatic lymphoepithelial carcinoma of parotid gland identified on 68gallium DOTA-[Tyr3] octreotate PET CT

The authors present the case of a 59-year-old lady diagnosed with lymphoepithelial carcinoma (LEC) of the left parotid gland. The primary tumour was identified using contrast-enhanced CT, and diagnosis was confirmed via fine needle aspiration cytology and immunohistochemistry. Staging using fluorine-18 fluorodeoxyglucose PET CT revealed regional nodal metastases, while no distant metastasis was evident. Following radical radiotherapy, a favourable locoregional response was observed on MRI, yet the patient's plasma Epstein-Barr virus load continued to rise. Given her primary tumour's somatostatin receptor type 2 (SSTR2) positivity, gallium-68 DOTA-[Tyr3] octreotate PET CT (68Ga-DOTATATE PET CT) was performed, revealing multiple distant metastases with DOTATATE avidity. Despite attempts at palliative chemotherapy and immunotherapy, disease progression led to the decision for the best supportive care. The unique presentation of metastatic LEC on 68Ga-DOTATATE PET CT suggests a potential role for SSTR2-targeted imaging in diagnosis and management.

68 Ga-DOTATATE PET/CT of Metastatic Lymphoepithelial Carcinoma of Parotid Gland

ABSTRACT

We present a case of a 59-year-old woman with lymphoepithelial carcinoma of left parotid gland. She was treated with radical radiotherapy, but her plasma Epstein-Barr virus DNA load continued to increase despite good locoregional response. As her primary tumor was positive for somatostatin receptor type 2, we performed 68 Ga-DOTATATE PET/CT, which revealed multiple DOTATATE-avid distant metastases.

A Systematic Review and Meta-Analysis of Mapping Biopsy for Primary Extramammary Paget's Disease in Reducing Recurrence Following Surgical Excision

Objective

To examine the association between the performance of mapping biopsies and surgical outcomes postexcision of extramammary Paget's disease (EMPD).

Background

Primary EMPD is a rare entity associated with poorly defined surgical margins and difficult-to-access sites of lesions. Surgical resection with clear margins remains the preferred management method. The use of mapping biopsies might be beneficial, particularly in lowering disease recurrence.

Methods

Available literature was reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology before a fixed-effect meta-analysis was performed to identify the presence of a correlation between performing mapping biopsies and positive margins on permanent sections as well as disease-free survival. Additional study results not included in the quantitative assessment were qualitatively assessed and reported.

Results

A total of 12 studies were shortlisted for final analysis. 294 patients who underwent mapping biopsies and 48 patients who did not undergo mapping biopsies were included in the assessment. Forest plot analysis revealed a pooled rate ratio of 0.50 (95% CI, 0.32-0.77) in the prevalence of positive margins in patients with mapping biopsies performed as compared to patients without. The pooled rate ratio of the prevalence of disease-free survival in patients with mapping biopsies performed as compared to patients without was 1.38 (95% CI, 1.03-1.84). Qualitative assessment of the remaining selected studies revealed equivocal results.

Conclusions

Mapping biopsies are able to improve EMPD surgical excision outcomes but given the rarity of the disease and heterogeneity of mapping biopsy procedures, further confirmation with randomized controlled trials or a larger patient pool is necessary.

Inferring cancer disease response from radiology reports using large language models with data augmentation and prompting

OBJECTIVE

To assess large language models on their ability to accurately infer cancer disease response from free-text radiology reports.

MATERIALS AND METHODS

We assembled 10 602 computed tomography reports from cancer patients seen at a single institution. All reports were classified into: no evidence of disease, partial response, stable disease, or progressive disease. We applied transformer models, a bidirectional long short-term memory model, a convolutional neural network model, and conventional machine learning methods to this task. Data augmentation using sentence permutation with consistency loss as well as prompt-based fine-tuning were used on the best-performing models. Models were validated on a hold-out test set and an external validation set based on Response Evaluation Criteria in Solid Tumors (RECIST) classifications.

RESULTS

The best-performing model was the GatorTron transformer which achieved an accuracy of 0.8916 on the test set and 0.8919 on the RECIST validation set. Data augmentation further improved the accuracy to 0.8976. Prompt-based fine-tuning did not further improve accuracy but was able to reduce the number of training reports to 500 while still achieving good performance.

DISCUSSION

These models could be used by researchers to derive progression-free survival in large datasets. It may also serve as a decision support tool by providing clinicians an automated second opinion of disease response.

CONCLUSIONS

Large clinical language models demonstrate potential to infer cancer disease response from radiology reports at scale. Data augmentation techniques are useful to further improve performance. Prompt-based fine-tuning can significantly reduce the size of the training dataset.

Imaging and treatment with 68Gallium and 177Lutetium-DOTATATE in a rare SSTR2 and ESWR1-CREM fusion positive undifferentiated round cell tumour of the lung

The authors present a 45-year-old lady with a rare undifferentiated round cell tumour of the lung with a ESWR1-CREM fusion gene that progressed despite multiple lines of therapy. The tumour was Somatostatin Receptors Type 2 (SSTR2) positive and avid on ⁶⁸Gallium-DOTATATE imaging. This allowed for novel treatment with Peptide Receptor Radionuclide Therapy (PRRT) using ¹⁷⁷Lutetium-DOTATATE after all other standard of care options were exhausted.

Treatment Response of Sacrococcygeal Chordoma to Palliative Stereotactic Body Radiotherapy: A Case Report

Chordomas are rare and locally aggressive tumours that arise from embryonic remnants of the notochord, with a predilection for the skull base, mobile spine, and sacrum. Sacral or sacrococcygeal chordomas can be particularly difficult to manage because of their large size at presentation and involvement of adjacent organs and neural structures. Although the recommended definitive therapy for such tumours is either en bloc resection with or without adjuvant radiotherapy (RT) or definitive fractionated RT with charged particle therapy, older and/or less-fit patients may not necessarily be accepting of said approaches due to the potential morbidities and challenging logistic requirements. Here, we report a case of a 79-year-old male presenting with intractable lower limb pain and neurologic deficits due to a large de novo sacrococcygeal chordoma. The patient was successfully treated with a 5-fraction course of stereotactic body radiotherapy (SBRT), given with palliative intent, with complete relief of his symptoms achieved approximately 21 months after RT and without the development of any iatrogenic toxicities. In view of this case, ultra-hypofractionated SBRT may be a suitable option for the palliation of large de novo sacrococcygeal chordomas for selected patients to reduce their symptom burden and improve their quality of life.

Evaluation of inter- and intra-observer variations in prostate gland delineation using CT-alone versus CT/TPUS

Background

This study aims to explore the role of four-dimensional (4D) transperineal ultrasound (TPUS) in the contouring of prostate gland with planning computed tomography (CT) images, in the absence of magnetic resonance imaging (MRI).

Materials and methods

Five radiation oncologists (ROs) performed two rounds of prostate gland contouring (single-blinded) on CT-alone and CT/TPUS datasets obtained from 10 patients who underwent TPUS-guided external beam radiotherapy. Parameters include prostate volume, DICE similarity coefficient (DSC) and centroid position. Wilcoxon signed-rank test assessed the significance of inter-modality differences, and the intraclass correlation coefficient (ICC ) reflected inter- and intra-observer reliability of parameters.

Results

Inter-modality analysis revealed high agreement (based on DSC and centroid position) of prostate gland contours between CT-alone and CT/TPUS. Statistical significant difference was observed in the superior-inferior direction of the prostate centroid position (p = 0.011). All modalities yielded excellent inter-observer reliability of delineated prostate volume with ICC > 0.9, mean DSC > 0.8 and centroid position: CT-alone (ICC = 1.000) and CT/TPUS (ICC = 0.999) left-right (L/R); CT-alone (ICC = 0.999) and CT/TPUS (ICC = 0.998) anterior-posterior (A/P); CT-alone (ICC = 0.999) and CT/TPUS (ICC = 1.000) superior-inferior (S/I). Similarly, all modalities yielded excellent intra-observer reliability of delineated prostate volume, ICC > 0.9 and mean DSC > 0.8. Lastly, intra-observer reliability was excellent on both imaging modalities for the prostate centroid position, ICC > 0.9.

Conclusion

TPUS does not add significantly to the amount of anatomical information provided by CT images. However, TPUS can supplement planning CT to achieve a higher positional accuracy in the S/I direction if access to CT/MRI fusion is limited.

Multi-center evaluation of artificial intelligent imaging and clinical models for predicting neoadjuvant chemotherapy response in breast cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) plays an important role in the management of locally advanced breast cancer. It allows for downstaging of tumors, potentially allowing for breast conservation. NAC also allows for in-vivo testing of the tumors' response to chemotherapy and provides important prognostic information. There are currently no clearly defined clinical models that incorporate imaging with clinical data to predict response to NAC. Thus, the aim of this work is to develop a predictive AI model based on routine CT imaging and clinical parameters to predict response to NAC.

METHODS

The CT scans of 324 patients with NAC from multiple centers in Singapore were used in this study. Four different radiomics models were built for predicting pathological complete response (pCR): first two were based on textural features extracted from peri-tumoral and tumoral regions, the third model based on novel space-resolved radiomics which extract feature maps using voxel-based radiomics and the fourth model based on deep learning (DL). Clinical parameters were included to build a final prognostic model.

RESULTS

The best performing models were based on space-resolved and DL approaches. Space-resolved radiomics improves the clinical AUCs of pCR prediction from 0.743 (0.650 to 0.831) to 0.775 (0.685 to 0.860) and our DL model improved it from 0.743 (0.650 to 0.831) to 0.772 (0.685 to 0.853). The tumoral radiomics model performs the worst with no improvement of the AUC from the clinical model. The peri-tumoral combined model gives moderate performance with an AUC of 0.765 (0.671 to 0.855).

CONCLUSIONS

Radiomics features extracted from diagnostic CT augment the predictive ability of pCR when combined with clinical features. The novel space-resolved radiomics and DL radiomics approaches outperformed conventional radiomics techniques.

A comparative analysis between low-dose-rate brachytherapy and external beam radiation therapy for low- and intermediate-risk prostate cancer in Asian men

OBJECTIVE

To report the long-term clinical outcomes of low-risk (LR) and intermediate-risk (IR) prostate cancer patients treated with low-dose-rate brachytherapy (LDR-BT) and external beam radiation therapy (EBRT).

PATIENTS AND METHODS

Men with biopsy-proven low- and intermediate-risk prostate cancer received EBRT and LDR-BT in an Asian academic center from 2000 to 2019 were reviewed. Kaplan-Meier survival analysis was performed to compare biochemical failure-free survival (bFFS) and overall survival (OS) between LDR and EBRT in the low- and intermediate-risk cohorts.

RESULTS

642 patients (521 EBRT and 121 LDR-BT) with low- and intermediate-risk prostate cancer were included for analysis. In the intermediate-risk group, 5- and 10-year bFFS was 96%, 89% and 86%, 61% for LDR-BT and EBRT, respectively. LDR-BT was associated with a statistically significant improvement of bFFS in the intermediate-risk cohort (HR 2.7, p = 0.02). In the low-risk cohort, no difference of bFFS was found between LDR-BT and EBRT (HR 1.9, p = 0.08). Hormone therapy was more common in EBRT than LDR-BT for intermediate-risk group (71% versus 44%, p < 0.05). Prostate cancer-specific mortality was low in both EBRT (1%) and LDR-BT (2%) cohorts. No significant difference in OS was found between LDR-BT and EBRT in low- and intermediate-risk group (HR 2.1, p = 0.2 and HR = 1.7, p = 0.3).

CONCLUSION

In our retrospective study, LDR-BT is associated with superior bFFS compared with EBRT in Asian men with intermediate-risk prostate cancer.

SSTR2 in Nasopharyngeal Carcinoma: Relationship with Latent EBV Infection and Potential as a Therapeutic Target

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor, most commonly located in the pharyngeal recess and endemic to parts of Asia. It is often detected at a late stage which is associated with poor prognosis (5-year survival rate of 63%). Treatment for this malignancy relies predominantly on radiotherapy and/or systemic chemotherapy, which can be associated with significant morbidity and impaired quality of life. In endemic regions NPC is associated with infection by Epstein-Barr virus (EBV) which was shown to upregulate the somatostatin receptor 2 (SSTR2) cell surface receptor. With recent advances in molecular techniques allowing for an improved understanding of the molecular aetiology of this disease and its relation to SSTR2 expression, we provide a comprehensive and up-to-date overview of this disease and highlight the emergence of SSTR2 as a key tumor biomarker and promising target for imaging and therapy.

The outcomes of cutaneous head and neck angiosarcoma with different treatment modalities and correlation with inflammatory markers

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Background: Head and neck angiosarcoma (HN-AS) is a distinct entity that commonly arises from the scalp of elderly Asian males. We strive to study the impact of different treatment modalities and explore correlation with blood inflammatory markers. Methods: A prospectively maintained database was queried for patients with biopsy-confirmed HN-AS treated in a single tertiary institution from 2000 to 2018. Results: Eight-eight patients were analyzed. Median age is 73.5 (IQR 66-81.2). Fifty-five (64%) were non-metastatic at diagnosis, seventy-four (84.1%) arose from the scalp and 70.5% were males. Of the 55 non-metastatic patients, 21 received curative surgery and 7 patients received adjuvant radiotherapy. Patients who had curative surgery had smaller tumors (p < 0.001). Local relapses were 57.1% vs 35.7% without and with radiotherapy (p = 0.34). Five patients were still alive at time of analysis but only 1 with a follow up of more than 5 years. In this group, 2-year and 5-year locoregional progression free survival (PFS) were 56.0% and 26.1%, distant PFS were 73.7% and 41.4%, OS were 48.6% and 17.7%. In the group that was metastatic at presentation (n = 31), 17 patients received palliative chemotherapy with 7 patients documented as partial response. 17 patients received palliative radiotherapy with largely good symptomatic relief. Six patients received photodynamic therapy: with 1 documented abscopal response. The median survival is 6.9 months. Overall, 64 patients received palliative chemotherapy and 42 received palliative radiotherapy (in the metastatic or inoperable setting). The most common chemotherapy regimen was single agent paclitaxel (56.3%). In the first line setting, 66.7% experienced at least a partial response to chemotherapy. Comparing the 3 different treatment groups (metastastic vs curative surgery vs non-metastatic/no curative surgery), patient with curative surgery had the best OS (p = 0.007) but worse PFS compared to non-metastatic but no curative surgery patients (p = 0.03). Using full blood count at diagnosis, hazard ratio for neutrophil lymphocyte ratio (NLR) and lymphocyte monocyte ratio (LMR) were 1.02 (p = 0.06) and 0.80 (p = 0.02) respectively for OS. In multivariate analysis, age, stage and LMR were the only 3 significant predictors for OS. Conclusions: Cutaneous HN-AS is an aggressive disease. Although patients who had curative surgery had better overall survival which could be confounded by smaller tumours, and they also had earlier documented relapses possibly due to closer surveillance or tumor growth promotion from post-surgical inflammatory response. The value of adjuvant radiotherapy is unknown. Palliative radiotherapy is useful, and a more hypo-fractionated approach should be favored. Palliative single-agent paclitaxel is effective although overall survival remains grave. Blood inflammatory indicators correlate with survival.

Somatostatin receptor 2 expression in nasopharyngeal cancer is induced by Epstein Barr virus infection: impact on prognosis, imaging and therapy

Nasopharyngeal cancer (NPC), endemic in Southeast Asia, lacks effective diagnostic and therapeutic strategies. Even in high-income countries the 5-year survival rate for stage IV NPC is less than 40%. Here we report high somatostatin receptor 2 (SSTR2) expression in multiple clinical cohorts comprising 402 primary, locally recurrent and metastatic NPCs. We show that SSTR2 expression is induced by the Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) via the NF-κB pathway. Using cell-based and preclinical rodent models, we demonstrate the therapeutic potential of SSTR2 targeting using a cytotoxic drug conjugate, PEN-221, which is found to be superior to FDA-approved SSTR2-binding cytostatic agents. Furthermore, we reveal significant correlation of SSTR expression with increased rates of survival and report in vivo uptake of the SSTR2-binding 68Ga-DOTA-peptide radioconjugate in PET-CT scanning in a clinical trial of NPC patients (NCT03670342). These findings reveal a key role in EBV-associated NPC for SSTR2 in infection, imaging, targeted therapy and survival.

Baseline Plasma EGFR Circulating Tumour DNA Levels in a Pilot Cohort of EGFR-Mutant Limited-Stage Lung Adenocarcinoma Patients Undergoing Radical Lung Radiotherapy

The use of circulating cell-free tumour DNA (ctDNA) is established in metastatic lung adenocarcinoma to detect and monitor sensitising EGFR mutations. In early-stage disease, there is very little data supporting its role as a potential biomarker. We report on a prospective cohort of 9 limited-stage EGFR mutant lung cancer patients who were treated with radical radiotherapy. We looked at baseline plasma EGFR ctDNA and noted the detection rates to be higher in locally advanced disease. At a median follow-up of 13.5 months, an association between a detectable pre-radiotherapy plasma EGFR ctDNA and early tumour relapse (155 days vs. NR, p = 0.004) was noted. One patient with persistent plasma EGFR ctDNA predated radiological progression. The role of ctDNA in early-stage lung cancer is developing. Plasma EGFR ctDNA could be a useful biomarker in lung cancer patients undergoing radical treatments for staging, prognostication, and follow-up. These preliminary findings should be explored in larger studies.

Preliminary outcomes of a prospective observational study of combinatorial abiraterone acetate/enzalutamide (AA/Enz) and radical radiotherapy (RT) in nonmetastatic node-positive (N+M0) prostate cancer (PCa)

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Background: Treatment paradigm for N+M0 PCa has evolved, with the advent of multiple options for upfront AA/Enz or RT in combination with conventional hormonal therapy (HT). However, the optimal treatment protocol remains undefined. We therefore conducted a prospective observational study of combination AA/Enz+RT in N+M0 PCa patients. Methods: Patients with biopsy-proven adenocarcinoma of the prostate and N+M0 by imaging (68Ga-PSMA-PET or whole body MRI) were included. Exclusion criteria were 1) ECOG ≥2; 2) severe comorbidities; 3) cardiac event of <6 mo interval. Treatment protocol involved 18 mo of AA (1000 mg with 5 mg prednisolone once daily)/Enz (160 mg once daily)+HT (LHRH agonist/antagonist) in combination with RT to pelvis (54 Gy with simultaneous boost of 60-66 Gy in 27 fr) and prostate (78 Gy/39 fr); RT commenced 1-3 mo upon initiation of AA/Enz. Primary endpoint of this analysis was PSA of ≤0.1 ng/ml at 12 mo. Results: From Jun 2017-Sep 2019, 13 men were recruited; median follow-up duration was 14.0 mo (range 3.0-28.0 mo). Median age of the cohort was 67.0 y (IQR 61.0 – 69.0 y); 84.0% of men had GS8-10 disease, and median number of cN+ nodes was 2 (range 1-5 nodes). 11 received AA, and 2 received Enz. 53.8% (N = 7) and 69.2% (N = 9) of patients achieved a PSA nadir of ≤0.1 ng/ml at 6.0 and 12.0 mo, respectively; this contrasts against a propensity-matched cohort (N = 27) treated by HT+RT alone (33.3% and 51.9%, respectively). No biochemical recurrence was recorded at the time of analysis. 3 and 2 acute ≥G2 GU and GI toxicities were reported during RT. Late ≥G2 GU toxicities were observed in 2 men (G2 frequency). 2 patients experienced G2 fatigue and one with G2 transaminitis secondary to AA, with dose reduction. Germline genetic profiling with whole exome sequencing revealed two patients (15.4%) with BRCA2 frameshift mutations; interestingly, GU/GI RT toxicities were not observed in these patients. Conclusions: Our preliminary results suggest that combinatorial AA/Enz and high dose RT is tolerated and can induce a pronounced PSA response in low volume N+M0 PCa.

Duration-dependent margins for prostate radiotherapy-a practical motion mitigation strategy

BACKGROUND AND OBJECTIVE

The magnitude of intra-fractional prostate displacement (change from initial position over time) is associated with the duration of the patient lying on the radiotherapy treatment couch. This study reports a minute-by-minute association and calculates the impact of this displacement on duration-dependent margins using real-time intra-fractional position data monitored by four-dimensional transperineal ultrasound (4D TPUS).

MATERIALS AND METHODS

A total of 55 patients were recruited prospectively. Intra-fractional position of the prostate was monitored in real-time using a 4D TPUS Clarity® system. A total of 1745 monitoring sessions were analysed. Van Herk's margin recipe (2.5∑ + 1.64((σ² + σ_p²)^1/2 - σ_p)) was used to estimate the duration-dependant margins for every minute, up to the 15th minute. Linear regression analysis was then performed on the overall margins against time and direction.

RESULTS

The mean intra-fractional position was 0.76 mm Inferior (Inf), 0 mm Lateral (Lat) and 0.94 mm Posterior (Post) at the 15th minute. A minimum margin expansion of 2.42 mm (Superior/Inf), 1.02 mm (Left/Right) and 2.65 mm (Anterior/Post) was required for an 8‑minute treatment compared to 4.29 mm (Sup/Inf), 1.84 mm (Lt/Rt) and 4.63 mm (Ant/Post) for a 15-minute treatment. The required margin expansion increased linearly (R² = 0.99) in all directions (p < 0.01). However, while there was no statistically significant difference (p = 0.10) in the required margin expansion in the Sup/Inf and Ant/Post directions respective of the time duration, the margins were much bigger compared to those in the Lt/Rt direction (p < 0.01).

CONCLUSION

We report our experience in deriving the minimum duration-dependant margin to generate the required planning target volume for prostate radiotherapy. The required margin increases linearly in all directions within the 15-min duration; thus, the margin will depend on the duration of the technique chosen (IMRT/VMAT/3DCRT/proton).

Immune dysregulation underpins radioresistance in nasopharyngeal carcinoma (NPC)

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Background: Radiotherapy (RT) is a primary modality in the treatment of NPC. However, 30% of patients present with disease recurrence following RT of this radiosensitive tumor. Here, we investigated the molecular and immune profiles associated with radioresistant (RR) NPC. Additionally, we investigated for aberrant molecular pathways in paired recurrences of patients to uncover new drivers underpinning radioresistance. Methods: We prospectively recruited a cohort of 100 NPC patients who completed definitive RT/chemoRT; including 30 cases who were recruited at recurrence. Whole exome sequencing (WES) at 200x was performed to identify low frequencies ( < 1%) of true somatic nucleotide variants (SNVs) and copy number alterations (CNAs). Transcriptomic profiles from RNAseq were interrogated using supervised and unsupervised statistical approaches to determine aberrant pathways that were significantly associated with RR. Results: Genomic instabilityas characterized by percentage genome alteration (PGA) was comparable in our cohort. Additionally, we did not observe any common or exclusive CNAs between RR- and nr-NPC cases. Based on a constellation of immune-related signatures, we observed an “immune-cold” profile that is associated with RR-NPC compared to nr-NPC controls, which is characterized by low expression of CD8+ T cell infiltration and interferon-γ response. Expectedly, pathways relating to angiogenesis, hypoxia and NOTCH signaling were upregulated in the RR-NPC cohort. Interestingly, we observed a reversal of the immune phenotype from “cold” to an enrichment of effector T cell infiltration in the paired recurrences. Conclusions: Here, we present a comprehensive mutational landscape of RR-NPC, which revealed the potential role of the immune environment in modulating RR. The longitudinal immune dysregulation of the tumor microenvironment between the de novo tumors and recurrences could be a driver or passenger event during the onset of recurrence.

A novel computational OMICS and non-OMICS approach for identifying true pathogenic risk variants for Asian prostate cancer

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Background: Large-scale genome-wide association studies have established germline polygenic risk loci that underpin the susceptibility to prostate cancer (PCa). However, most trials conducted are in men of European ancestry with data missing for Asian male PCa. Here, we report on an in-house multidimensional bioinformatics pipeline that integrates OMICS and non-OMICS approaches in identifying true germline risk-variants for PCa in Asian men. Methods: We utilized a prospective cohort study of Asian men who were newly diagnosed with PCa. Whole exome sequencing (Illumina Hiseq, CA) of blood (100X) was performed. The OMICS-based approach entailed a stepwise screen for hallmarks of cancer-specific pathways. A genome-proteome network was then developed to filter for known pathogenic variants; this was followed by comparison against a large artificial database of aggregated germline variants (N = 95,000) with reported linkage to PCa susceptibility. Finally, mutations were filtered through a non-OMICS pipeline that entailed data synchronization with population-level statistics and clinical outcomes (recurrence and survival). Results: Preliminary analyses were based on 277 PCa cases; of which 50 were M1 cases. Screening using a non-combined unbiased approach yielded 36,157 germline variants. This contrast against our OMICS-based approach, which reduced the variant calls to 6,144 significantly associated mutations. Next, by focusing on pathway-specific genes related to hormonal regulation and known cancer hotspot mutations, we could further tighten our variant calls to 3,562 hormone-related variants (rs9269958 on HLA-DRB1) and 2,125 variants in known cancer genes, notably (rs8176320 on BRCA1/2, rs2555691 on LILRA2, rs8036934 on TP53BP1). Conclusions: Here, we show that application of an OMICS approach that combines pathway-driven analyses and an artificial dataset, along with population-level statistics and clinical relevance resulted in more robust annotation of germline variants that were associated with PCa.

Age exerts a continuous effect in the outcomes of Asian breast cancer patients treated with breast-conserving therapy

Background

Asians are diagnosed with breast cancer at a younger age than Caucasians are. We studied the effect of age on locoregional recurrence and the survival of Asian breast cancer patients treated with breast-conserving therapy.

Methods

Medical records of 2492 patients treated with breast-conserving therapy between 1989 and 2012 were reviewed. The Kaplan–Meier method was used to estimate locoregional recurrence, breast cancer-free survival, and breast cancer-specific survival rates. These rates were then compared using log-rank tests. Outcomes and age were modeled by Cox proportional hazards. Fractional polynomials were then used to test for non-linear relationships between age and outcomes.

Results

Patients ≤ 40 years old were more likely to have locoregional recurrence than were older patients (Hazard ratio [HR] = 2.32, P < 0.001). Locoregional recurrence rates decreased year-on-year by 4% for patients with luminal-type breast cancers, compared with 8% for those with triple-negative cancers. Similarly, breast cancer-free survival rates increased year-on-year by 4% versus 8% for luminal-type and triple-negative cancers, respectively. Breast cancer-specific survival rates increased with age by 5% year-on-year. Both breast cancer-free survival and breast cancer-specific survival rates in patients with luminal cancers exhibited a non-linear (“L-shaped”) relationship—where decreasing age at presentation was associated with escalating risks of relapse and death. The influence of age on overall survival was confounded by competing non-cancer deaths in older women, resulting in a “U-shaped” relationship.

Conclusions

Young Asian breast cancer patients have a continuous year-on-year increase in rates of disease relapse and cancer deaths compared with older patients with no apparent threshold.

Comparison of Circulating Tumour Cells and Circulating Cell-Free Epstein-Barr Virus DNA in Patients with Nasopharyngeal Carcinoma Undergoing Radiotherapy

Quantification of Epstein-Barr virus (EBV) cell-free DNA (cfDNA) is commonly used in clinical settings as a circulating biomarker in nasopharyngeal carcinoma (NPC), but there has been no comparison with circulating tumour cells (CTCs). Our study aims to compare the performance of CTC enumeration against EBV cfDNA quantitation through digital PCR (dPCR) and quantitative PCR. 74 plasma samples from 46 NPC patients at baseline and one month after radiotherapy with or without concurrent chemotherapy were analysed. CTCs were captured by microsieve technology and enumerated, while three different methods of EBV cfDNA quantification were applied, including an in-house qPCR assay for BamHI-W fragment, a CE-IVD qPCR assay (Sentosa ^®) and a dPCR (Clarity™) assay for Epstein-Barr nuclear antigen 1 (EBNA1). EBV cfDNA quantitation by all workflows showed stronger correlation with clinical stage, radiological response and overall survival in comparison with CTC enumeration. The highest detection rate of EBV cfDNA in pre-treatment samples was seen with the BamHI-W qPCR assay (89%), followed by EBNA1-dPCR (85%) and EBNA1-qPCR (67%) assays. Overall, we show that EBV cfDNA outperforms CTC enumeration in correlation with clinical outcomes of NPC patients undergoing treatment. Techniques such as dPCR and target selection of BamHI-W may improve sensitivity for EBV cfDNA detection.

Why are East Asians more susceptible to several infection-associated cancers (carcinomas of the nasopharynx, stomach, liver, adenocarcinoma of the lung, nasal NK/T-cell lymphomas)?

There are at least five cancers with uniquely high incidence amongst East and Southeast Asian ethnic groups - namely nasopharyngeal carcinoma (NPC); gastric carcinoma; hepatocellular carcinoma (HCC); adeno-carcinoma of the lung in female non-smokers and nasal NK/T-cell lymphomas. They all appear to be related to an infective cause (Epstein Barr Virus, Helicobacter pylori, hepatitis B virus). We hypothesize that a genetic bottleneck 30,000years ago at the Last Glacial Maximum could have resulted in unique genetic polymorphisms in Toll-like receptor 8, making East Asians more vulnerable to these infective associated cancers. This bottleneck could have been caused by the presence of malaria in the southern Himalayan conduit between central and East Asia; and only those with an attenuated innate immune response to the malarial parasite (perhaps reflected by the TLR8 polymorphism) were spared the ravages of cerebral malaria; allowing these people to cross into east Asia, but then rendering them susceptible to later endemic infections and their associated cancers.

Why are East Asians more susceptible to several infection-associated cancers (carcinomas of the nasopharynx, stomach, liver, adenocarcinoma of the lung, nasal NK/T-cell lymphomas)?

There are at least five cancers with uniquely high incidence amongst East and Southeast Asian ethnic groups - namely nasopharyngeal carcinoma (NPC); gastric carcinoma; hepatocellular carcinoma (HCC); adeno-carcinoma of the lung in female non-smokers and nasal NK/T-cell lymphomas. They all appear to be related to an infective cause (Epstein Barr Virus, Helicobacter pylori, hepatitis B virus). We hypothesize that a genetic bottleneck 30,000years ago at the Last Glacial Maximum could have resulted in unique genetic polymorphisms in Toll-like receptor 8, making East Asians more vulnerable to these infective associated cancers. This bottleneck could have been caused by the presence of malaria in the southern Himalayan conduit between central and East Asia; and only those with an attenuated innate immune response to the malarial parasite (perhaps reflected by the TLR8 polymorphism) were spared the ravages of cerebral malaria; allowing these people to cross into east Asia, but then rendering them susceptible to later endemic infections and their associated cancers.