Real-world prevalence of PD-L1 expression in non-small cell lung cancer: an Australia-wide multi-centre retrospective observational study.

An investigator-initiated, Australia-wide multi-centre retrospective observational study was undertaken to investigate the real-world prevalence of programmed death ligand-1 (PD-L1) expression in non-small cell lung carcinoma (NSCLC). Multiple centres around Australia performing PD-L1 immunohistochemistry (IHC) were invited to participate. Histologically confirmed NSCLC of any stage with a PD-L1 IHC test performed for persons aged ≥18 years between 1 January 2018 and 1 January 2020, and eligible for review, were identified at each centre, followed by data extraction and de-identification, after which data were submitted to a central site for collation and analysis. In total data from 6690 eligible PD-L1 IHC tests from histologically (75%) or cytologically (24%) confirmed NSCLC of any stage were reviewed from persons with a median age of 70 years, 43% of which were female. The majority (81%) of tests were performed using the PD-L1 IHC SP263 antibody with the Ventana BenchMark Ultra platform and 19% were performed using Dako PD-L1 IHC 22C3 pharmDx assay. Reported PD-L1 tumour proportion score (TPS) was ≥50% for 30% of all tests, with 62% and 38% scoring PD-L1 ≥1% and <1%, respectively. Relative prevalence of clinicopathological features with PD-L1 scores dichotomised to <50% and ≥50%, or to <1% and ≥1%, were examined. Females scored ≥1% slightly more often than males (64% vs 61%, respectively, p=0.013). However, there was no difference between sexes or age groups (<70 or ≥70 years) where PD-L1 scored ≥50%. Specimens from patients with higher stage (III/IV) scored ≥1% or ≥50% marginally more often compared to specimens from patients with lower stage (I/II) (p≤0.002). Proportions of primary and metastatic specimens did not differ where PD-L1 TPS was ≥1%, however more metastatic samples scored TPS ≥50% than primary samples (metastatic vs primary; 34% vs 27%, p<0.001). Cytology and biopsy specimens were equally reported, at 63% of specimens, to score TPS ≥1%, whereas cytology samples scored TPS ≥50% slightly more often than biopsy samples (34% vs 30%, respectively, p=0.004). Resection specimens (16% of samples tested) were reported to score TPS ≥50% or ≥1% less often than either biopsy or cytology samples (p<0.001). There was no difference in the proportion of tests with TPS ≥1% between PD-L1 IHC assays used, however the proportion of tests scored at TPS ≥50% was marginally higher for 22C3 compared to SP263 (34% vs 29%, respectively, p<0.001). These real-world Australian data are comparable to some previously published global real-world data, with some differences noted.

Genomic stratification and liquid biopsy in a rare adrenocortical carcinoma (ACC) case, with dual lung metastases.

Adrenocortical carcinoma is a rare malignancy with a poor prognosis and few treatment options. Molecular characterization of this cancer remains limited. We present a case of an adrenocortical carcinoma (ACC) in a 37-yr-old female, with dual lung metastases identified 1 yr following commencement of adjuvant mitotane therapy. As standard therapeutic regimens are often unsuccessful in ACC, we undertook a comprehensive genomic study into this case to identify treatment options and monitor disease progress. We performed targeted and whole-genome sequencing of germline, primary tumor, and both metastatic tumors from this patient and monitored recurrence over 2 years using liquid biopsy for ctDNA and steroid hormone measurements. Sequencing revealed the primary and metastatic tumors were hyperhaploid, with extensive loss of heterozygosity but few structural rearrangements. Loss-of-function mutations were identified in MSH2, TP53, RB1, and PTEN, resulting in tumors with mismatch repair signatures and microsatellite instability. At the cellular level, tumors were populated by mitochondria-rich oncocytes. Longitudinal ctDNA mutation and hormone profiles were unable to detect micrometastatic disease, consistent with clinical indicators of disease remission. The molecular signatures in our ACC case suggested immunotherapy in the event of disease progression; however, the patient remains free of cancer. The extensive molecular analysis presented here could be applied to other rare and/or poorly stratified cancers to identify novel or repurpose existing therapeutic options, thereby broadly improving diagnoses, treatments, and prognoses.

Extraprostatic extension (EPE) of prostatic carcinoma: is its proximity to the surgical margin or Gleason score important?

OBJECTIVE: To examine the association between histopathological factors of extraprostatic prostate cancer and outcome. PATIENTS AND METHODS: Patients with extraprostatic extension (EPE) without positive margins, seminal vesicle or lymph node involvement were analysed from a consecutive radical prostatectomy cohort of 1136 (2002-2006) for: (i) distance of EPE from the margin; (ii) Gleason score of the EPE; and (iii) extent of EPE. Log-rank, Kaplan-Meier, and Cox regression analyses were performed. RESULTS: The study included 194 pT3a, pN0, R0 patients with a median follow-up of 5.4 years, with 37 (19%) patients experiencing biochemical relapse (BCR). On univariable analysis, patients with a Gleason score of ≥8 in the extraprostatic portion showed increased incidence of BCR compared with those with Gleason scores of ≤7 (P = 0.03). The proximity of the EPE to the margin (0.01-7.5 mm) did not correlate with BCR. On multivariable analysis, the extent of EPE, the Gleason score of the dominant nodule or of the EPE portion did not correlate with BCR. CONCLUSION: Data from this study using current International Society of Urological Pathology Gleason scoring and EPE criteria indicate that close proximity of EPE to the margin is not associated with recurrence. Gleason score ≥8 within EPE is associated with an increased BCR risk on univariable analysis, but larger studies are required to confirm whether extensive Gleason pattern 4 in an EPE indicates increased risk in an otherwise overall Gleason score 7 cancer.

Selective analysis of cell-free DNA in maternal blood for evaluation of fetal trisomy.

OBJECTIVE: To develop a novel prenatal assay based on selective analysis of cell-free DNA in maternal blood for evaluation of fetal Trisomy 21 (T21) and Trisomy 18 (T18). METHODS: Two hundred ninety-eight pregnancies, including 39 T21 and seven T18 confirmed fetal aneuploidies, were analyzed using a novel, highly multiplexed assay, termed digital analysis of selected regions (DANSR™). Cell-free DNA from maternal blood samples was analyzed using DANSR assays for loci on chromosomes 21 and 18. Products from 96 separate patients were pooled and sequenced together. A standard Z-test of chromosomal proportions was used to distinguish aneuploid samples from average-risk pregnancy samples. DANSR aneuploidy discrimination was evaluated at various sequence depths. RESULTS: At the lowest sequencing depth, corresponding to 204,000 sequencing counts per sample, average-risk cases where distinguished from T21 and T18 cases, with Z statistics for all cases exceeding 3.6. Increasing the sequencing depth to 410,000 counts per sample substantially improved separation of aneuploid and average-risk cases. A further increase to 620,000 counts per sample resulted in only marginal improvement. This depth of sequencing represents less than 5% of that required by massively parallel shotgun sequencing approaches. CONCLUSION: Digital analysis of selected regions enables highly accurate, cost efficient, and scalable noninvasive fetal aneuploidy assessment.

Reactive angioendotheliomatosis in the setting of antiphospholipid syndrome.

A 31-year-old man with systemic lupus erythematosus and antiphospholipid syndrome developed erythematous purpuric plaques distributed over the lower chest, abdomen and upper thighs. Biopsy of lesional skin revealed intravascular proliferation of endothelial cells with associated microthrombi formation. The histological pattern was consistent with reactive angioendotheliomatosis, a rare reactive pattern seen associated with disparate medical conditions. The pathogenesis of the reactive angioendotheliomatosis in our patient was suspected to be related to his procoagulant state; thrombi formed despite a therapeutic international normalized ratio while on warfarin. His lesions began to resolve with the cessation of warfarin and commencement of subcutaneous enoxaparin, oral clopidogrel and oral aspirin. The skin biopsy findings were pivotal in influencing the change of therapy in this patient and decreasing his immunosuppression.