Longitudinal post-radiotherapy plasma Epstein-Barr virus DNA trends inform on optimal risk stratification in endemic nasopharyngeal carcinoma

OBJECTIVES

To characterize longitudinal changes in Epstein-Barr virus (EBV) DNA post-radiotherapy in nasopharyngeal carcinoma (NPC) patients, and investigate whether an early (0-2 weeks) or delayed (8-12 weeks) EBV DNA result better predicts for disease-free survival (DFS).

MATERIALS AND METHODS

Histologically-confirmed NPC patients with ≥1 EBV DNA test quantified using the harmonized BamHI-W polymerase chain reaction-based assay at 0-2 and 8-12 weeks post-radiotherapy were included.

RESULTS

We identified 302 patients with EBV DNA measured at 0-2 weeks post-radiotherapy; of which, 110 (36.4 %) underwent a repeat test at 8-12 weeks post-treatment. Patients harboring a detectable EBV DNA at 0-2 weeks experienced an inferior DFS (adjusted HR1-264 copies 1.72 [95 %CI: 1.05-2.83], P = 0.031; AHR≥265 copies 4.39 [95 %CI: 1.68-11.44], P = 0.002 relative to 0 copies/mL). At 8-12 weeks, we observed substantial shifts in EBV DNA readings from 0 to 2 weeks; 76/110 (69.1 %) and 34/110 (30.9 %) patients at 0-2 weeks versus 90/110 (81.8 %) and 20/110 (18.2 %) at 8-12 weeks recorded undetectable and detectable EBV DNA, respectively. Positive EBV DNA at 8-12 weeks was strongly associated with relapse (73.3 % [11/15] for 1-264; 80.0 % [4/5] for ≥265 subgroups had relapses versus 15.6 % [14/90] for 0 copies/mL). Area under receiver operating curve values for 2-year relapse rates were 0.817 (95 %CI: 0.725-0.909) for stage + EBV DNA8-12w versus 0.654 (95 %CI: 0.542-0.765) for stage + EBV DNA0-2w. CONCLUSION: EBV DNA is dynamic post-radiotherapy, and delayed EBV DNA testing better enriched for higher-risk NPC patients. This implicates trials investigating adjuvant chemotherapy intensification based on early EBV DNA testing.

Efficacy, toxicity, and quality-of-life outcomes of ultrahypofractionated radiotherapy in patients with localized prostate cancer: A single-arm phase 2 trial from Asia

AIMS

Ultra-hypofractionated radiotherapy (UHF-RT) is widely utilized in men with localized prostate cancer (PCa). There are limited data in Asian cohorts. We report the outcomes of a single-arm, phase II trial of UHF-RT from an Asian center.

METHODS

We recruited men with histologically confirmed, nonmetastatic localized PCa. UHF-RT regimens were 36.25 Gy (Cohort A) and 37.5 Gy (Cohort B) delivered in five fractions every other day over 1.5-2.5 weeks. Primary endpoint was physician-scored late genitourinary (GU) and gastrointestinal (GI) adverse events (AEs). Quality-of-life (QoL) was assessed by Expanded Prostate Cancer Index Composite (EPIC) at baseline, 1- and 2-year post-UHF-RT.

RESULTS

Between March 2014 and August 2019, 105 men were recruited; four were subsequently excluded from analysis. Median age was 68.0 (Interquartile range (IQR): 63.8-73.0) years. 26 (24.8%) and 68 (64.8%) men had NCCN-defined low-and intermediate-risk PCa, respectively. No late ≥G3 GU or GI toxicities were reported in both cohorts. Peak incidence of acute ≥G2 GU AEs at 14 days post-UHF-RT was 23.6% (17/72) and 24.0% (6/25) in Cohorts A and B, respectively; ≥G2 GI AEs were observed in 9.7% (7/72) and 36.0% (9/25), respectively. Late ≥G2 GU and GI AEs occurred in 4.7% and 3.1% of Cohort A patients, and 5.0% in Cohort B at 12 months, with no AEs at 24 months. EPIC scores changed minimally across all domains. At a median follow-up of 44.9 months, we recorded one (1.3%) biochemical relapse by the Phoenix criteria (Cohort A).

CONCLUSION

UHF-RT is well tolerated in Asian men and can be a recommended fractionation schema for localized PCa.

68Gallium-labelled PSMA-PET/CT as a diagnostic and clinical decision-making tool in Asian prostate cancer patients following prostatectomy

Objective

Prostate cancers (PCa) in Asian individuals are molecularly distinct from those found in their Caucasian counterparts. There is no risk stratification tool for Asian men with rapid biochemical recurrence (BCR) following radical prostatectomy (RadP). This study aims to assess the detection rate of ⁶⁸Ga-prostate-specific membrane antigen-positron emission tomography/computed tomography (PSMA-PET/CT) for diagnosis of clinical recurrence and as a treatment decision making tool in Asian patients with BCR post-RadP.

Methods

⁶⁸Ga PSMA-PET and CT body with/without bone scan [conventional workup (CWU)] were performed in 55 Asian patients with BCR within 36 months post-RadP. Two blinded reviewers assessed the images. Detection rates of ⁶⁸Ga PSMA-PET/CT were evaluated, and impact on management was reviewed by comparison with CWU.

Results

Median time to BCR post-RadP was 8.1 months. Detection rate for ⁶⁸Ga PSMA-PET/CT was 80% (44/55). A positive scan was significantly associated with increasing prostate-specific antigen (PSA) level [odds ratio (OR) = 1.13 (95% CI 1.05–1.30), P = 0.017], but not with higher Gleason grade or shorter PSA doubling time. Compared to CWU, ⁶⁸Ga PSMA-PET/CT detected an additional 106 lesions in 33/44 patients with a positive scan, resulting in a change in management in 25/44 (56.8%) patients: 10 to hormonal therapy (HT) and whole pelvis radiotherapy (RT) in addition to bed RT, and 15 to palliative HT alone.

Conclusions

In the present report, we demonstrated the diagnostic and treatment decision utility of ⁶⁸Ga PSMA-PET/CT in Asian men with rapid BCR. Detection of small volume nodal and systemic recurrences at low PSA levels (< 1.0 ng/mL) highlights the role of the tool in assigning patients to treatment intensification with HT-RT or palliative HT in polymetastatic disease.

Exploiting molecular genomics in precision radiation oncology: a marriage of biological and physical precision

Achieving local tumour control is paramount for cure in head and neck and prostate cancers. With the transition to precision radiotherapy (RT) techniques, survival rates have improved in the majority of these cancers, but a substantial proportion of 30-40% still relapse following primary treatment. Recent large-scale molecular profiling studies have revealed unique biological events that could explain for tumour aggression and resistance to therapies, redefining the molecular taxonomy of head and neck and prostate cancers. Here, we reviewed the key findings from these studies, highlighting those relevant for clinical stratification. We also proposed novel combinatorial clinicomolecular models to identify subsets of patients with aggressive localised tumours and limited metastases, and to inform on the optimal management of these patients using molecular targeted agents, immunotherapy, and RT.

Mobile cauda equina schwannomas

Although very rare, cases of cauda equina tumours migrating several levels have been known to occur. We report two cases of cauda equina schwannomas which migrated from its primary site, one caudally and the other one rostrally as confirmed by magnetic resonance imaging perioperatively. The first patient was a 27-year-old man and the second a 41-year-old man; both presented with back pain. This report aims to remind clinicians that certain tumours attached to the roots in the lumbar spinal canal may migrate.

Microsurgical treatment for spinal tumours

INTRODUCTION

Although spinal tumours are amenable to total surgical excision, the factors determining the outcome are diverse. This study re-evaluates aspects of the disease that contribute to their outcome.

METHODS

Ninety-three consecutive patients with spinal cord tumours that underwent microsurgical excision between February 1992 and February 2002 were retrospectively studied. All patients underwent magnetic resonance imaging and had histological confirmation of spinal tumours.

RESULTS

There were 44 men and 49 women with a mean age of 49.05 years (range 6 to 83 years). The location of the tumours was cervical in 37 cases, thoracic in 41 cases, lumbosacral in 13 cases, and multilevel in two cases. The mean tumour size was 2.2 cm (range 0.8 to 7 cm) and mean duration of symptoms was 10.8 months. Complete excision was achieved in 72 cases and incomplete removal in 15 cases. The mean follow-up period was 21.45 months (range 3 days to 8 years). Immediate post-operative improvement was noted in 40 (43 percent) patients, 24 (25.4 percent) improved within six months, 13 (14 percent) improved after six months, 12 (12.9 percent) had no improvement and four patients died. The duration of symptoms and the completeness of excision were factors that correlated with post-operative improvement (p-value is less than 0.05). Age, gender, size, histological type, presenting symptoms, spinal level affected and axial location of tumour did not correlate with the outcome.

CONCLUSION

Microsurgical excision of spinal cord tumours is a safe and effective procedure, and post-operative outcome is correlated to duration of symptoms and the extent of tumour resection.