Bone marrow Ki-67 index is of prognostic value in newly diagnosed multiple myeloma.

BACKGROUND: Ki-67 is an index of proliferative activity and is an established predictive and prognostic marker in multiple malignancies. However, its prognostic relevance in multiple myeloma (MM) is unclear. We investigated the relationship between Ki-67 expression and survival outcomes in MM in the era of novel therapies. METHODS: We interrogated our database to identify patients with MM, newly diagnosed between July 1, 2013 and December 31, 2020, with Ki-67 expression assessed by immunohistochemistry (IHC) on bone marrow biopsies. Using an established threshold of 5% we defined Ki-67low (≤5%) and Ki-67high (>5%) subgroups for association with progression-free survival (PFS) and overall survival (OS). RESULTS: Of 167 patients included: 53 (31.7%) had Ki-67high and 114 had Ki-67low. More patients with R-ISS 3 had Ki-67high (22.2% vs. 9.7%). The gain of 1q21 was overrepresented in the Ki-67high group (28% vs. 8%). Median PFS in the Ki-67low group was 3.1 years, and in the Ki-67high group 1.6 years (log-rank p < .001, HR: 1.9). Median OS was not reached in the Ki-67low vs. 4.8 years in the Ki-67high cohort (HR: 1.9; log-rank test: p = .018). In the multivariable modeling, after adjusting for other risk factors, HR for Ki-67high versus Ki-67low was 2.4 (p < .001) for PFS and 2.1 (p = .026) for OS. CONCLUSIONS: Our results demonstrate that a high Ki-67 index (>5%) is an independent prognostic marker associated with worse OS and PFS in newly diagnosed MM. IHC staining for Ki-67 on bone marrow biopsies could be easily adopted as a prognostic biomarker for MM in economically constrained healthcare settings.

Standardizing Clinical Workflow for Assessing Minimal Residual Disease by Flow Cytometry in Multiple Myeloma.

INTRODUCTION: Minimal residual disease (MRD) status is an established prognostic biomarker for patients with multiple myeloma. Commonly used MRD testing techniques such as next generation sequencing or next generation flow cytometry can detect as little as one or two multiple myeloma plasma cells in 106 normal bone marrow cells. Early pull of bone marrow aspirates (BMA), necessary to achieve such level of sensitivity, can be difficult to secure in routine clinical practice due to the competing need for early pull samples for clinical response assessment, therefore introducing the risk of analytical interference during MRD testing. METHODS: To overcome this challenge, we standardized our workflow for collecting specimens by using a technical first pull after needle repositioning for MRD testing. To capture a comprehensive picture of MRD assay performance and specimen adequacy, we tested for MRD on 556 technical first pull bone marrow aspirates by next generation flow cytometry. Among the specimens, several key multiple myeloma treatment milestones were represented: end of induction therapy, two to three months post-autologous stem cell transplant, early and late stages of maintenance therapy. RESULTS: By using the technical first pull bone marrow aspirate, we achieved an analytical assay input of 10 million nucleated cells for 97.5% of specimens. Our analytical sensitivity reached 10-6; (i.e., 10 multiple myeloma plasma cells in 10 × 106 bone marrow cells). Twenty-four percent of specimens were significantly hemodiluted. Low assay input or hemodilution quantifiably lowered the assay sensitivity. CONCLUSION: Specimen adequacy is, therefore, an important metric to incorporate into MRD status reporting.

Implementation, adherence, and results of systematic SARS-CoV-2 testing for asymptomatic patients treated at a tertiary care regional radiation oncology network.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus is a current pandemic. We initiated a program of systematic SARS-CoV-2 polymerase chain reaction (PCR) testing in all asymptomatic patients receiving radiotherapy (RT) at a large radiation oncology network in the Charlotte, NC metropolitan region and report adherence and results of the testing program. METHODS: Patients undergoing simulation for RT between May 18, 2020 and July 10, 2020 within the Levine Cancer Institute radiation oncology network who were asymptomatic for COVID-19 associated symptoms, without previous positive SARS-CoV-2 testing, and without recent high-risk contacts were included. PCR testing was performed on nasal cavity or nasopharyngeal swab samples. Testing was performed within 2 weeks of RT start (pre-RT) and at least every 4 weeks during RT for patients with prolonged RT courses (intra-RT). An automated task based process using the oncology electronic medical record (EMR) was developed specifically for this purpose. RESULTS: A total of 604 unique patients were included in the cohort. Details on testing workflow and implementation are described herein. Pre-RT PCR testing was performed in 573 (94.9%) patients, of which 4 (0.7%) were positive. The adherence rate to intra-RT testing overall was 91.6%. Four additional patients (0.7%) tested positive during their RT course, of whom 3 were tested due to symptom development and 1 was asymptomatic and identified via systematic testing. A total of 8 (1.3%) patients tested positive overall. There were no known cases of SARS-CoV-2 transmission from infected patients to clinic staff and/or other patients. CONCLUSIONS: We detailed the workflows used to implement systematic SARS-CoV-2 for asymptomatic patients at a large radiation oncology network. Adherence rates for pre-RT and intra-RT testing were high using this process. This information allowed for appropriate delay in initiating RT, minimizing the occurrence of RT treatment interruptions, and no known cases of transmission from infected patients to clinic staff and/or other patients.

Microgranular acute promyelocytic leukemia presenting with leukopenia and an unusual immunophenotype.

The microgranular variant (M3v) of acute promyelocytic leukemia (APL) is rare, and the diagnosis can be delayed due to variability in how this condition presents. M3v blasts often have folded nuclei, but unlike traditional APL blasts, they often possess faint granules without Auer rods. In addition, microgranular APL often presents with an elevated or normal white blood cell count in contrast with the leukopenia seen in traditional APL. In APL, delayed diagnosis can lead to early death from disseminated intravascular coagulation (DIC), which is the main cause of mortality in an otherwise treatable, and often curable, leukemia. We describe a 19-year-old male with microgranular APL who presented with leukopenia and many blasts resembling non-APL AML blasts with an unexpected immunophenotypic pattern. He was treated for DIC and initiated on all-trans-retinoic acid and arsenic trioxide; he achieved complete molecular remission after induction therapy. Suspicion for APL should always remain high in the presence of clinical manifestations of the disease in order that appropriate treatment can be initiated rapidly to prevent early death.

Accurate detection of BRAF p.V600E mutations in challenging melanoma specimens requires stringent immunohistochemistry scoring criteria or sensitive molecular assays.

Malignant melanoma patients require BRAF mutation testing prior to initiating BRAF inhibitor therapy. Molecular testing remains the diagnostic gold standard, but recent work suggests that BRAF immunohistochemistry (IHC) confers comparable results. Sample attributes and scoring criteria that may affect BRAF IHC interpretation, however, are poorly defined. We investigated formalin-fixed, paraffin-embedded samples with variable challenging interpretative attributes: metastases, core needle biopsies, sample tissues less than 60 mm(2), samples with greater than 50% necrosis, and/or samples with greater than 10% melanin pigmentation. Three pathologists independently scored 122 BRAF V600E IHC-labeled melanoma samples for percentage (0%-100%) of staining intensity (0-3+). Interscorer BRAF IHC discrepancies were resolved by consensus review. Lenient (≥1+, >0%) and stringent (≥2+, ≥10%) IHC scoring criteria were compared to BRAF V600 mutation (cobas) results (n = 118). Specimens with greater than 10% melanin pigmentation and metastatic samples produced the majority of interobserver IHC and IHC/cobas scoring discrepancies. Consensus review using stringent scoring criteria decreased the number of discrepant results, yielded very good interobserver reproducibility, and improved specificity and positive predictive value for BRAF p.V600E detection. BRAF p.V600K mutations accounted for 57.1% of false-negative IHC results when stringent, consensus criteria scoring were used. The cobas test detected 75.0% (8/12) of BRAF IHC-negative BRAF p.V600K mutations confirmed by next-generation sequencing. Molecular BRAF testing is the preferred screening test for BRAF inhibitor therapy eligibility because of superior sensitivity in challenging interpretative melanoma specimens. However, BRAF V600E IHC has excellent specificity and positive predictive value when stringent, consensus scoring criteria are implemented. To decrease IHC scoring discrepancies, pathologists should interpret metastatic and pigmented samples with caution.

Application of subcutaneous talc after axillary dissection in a porcine model safely reduces drain duration and prevents seromas.

BACKGROUND: Talc, the most common pleurodesis agent, has recently been shown to prevent seromas and decrease drain duration when placed subcutaneously after large subcutaneous dissection accompanying open ventral hernia repair. We hypothesized that talc would decrease drain duration and prevent seromas after axillary dissection without local or systemic side effects. STUDY DESIGN: Six pigs underwent full, bilateral axillary dissection (n 12 dissections). Three animals each had aerosolized small particle (SP) talc and large particle (LP) talc sprayed unilaterally (TALC) before closure, with the contralateral axillary dissection serving as the control (NOTALC). Functional status, wound complications, and drain duration were recorded. Local neurovascular structures and systemic organs were harvested at 28 days, processed with hematoxylin and eosin, and examined under normal and polarized light microscopy by blinded physicians. RESULTS: All pigs were back to baseline functional status by 72 hours. Two seromas (33%) were noted in the NOTALC dissections vs 0 in the TALC group (0%). Drain duration was significantly decreased in TALC vs NOTALC dissections (8.3 ± 2.7 vs 12.0 ± 3.2 days, p = 0.03), as was total drain volume (222.5 ± 127.1 mL vs 334.2 ± 137.9 mL, p = 0.02). Gross and histologic evaluation revealed neurovascular structures to be intact. Minimal splenic deposition of talc within macrophages without evidence of injury was identified in all specimens, with fewer deposits in the large particle talc group. Serum laboratory examination at time of harvest revealed all animals to have normal values. CONCLUSIONS: Direct application of talc throughout the wound after axillary dissection in pigs decreased drain duration and drain volume and prevented seroma formation. Gross, histologic, and serum laboratory evaluation demonstrated no talc-related local or systemic complications. Aerosolized talc is an effective and safe pretreatment to prevent seromas and hasten drain removal after axillary dissection.

Comparison of thermal spread after ureteral ligation with the Laparo-Sonic ultrasonic shears and the Ligasure system.

BACKGROUND AND PURPOSE: The extent of lateral spread of tissue injury is important in the success of a primary anastomosis. We compared the injury produced by the Laparo-sonic Coagulation Shears and the Ligasure system. MATERIALS AND METHODS: Ureters were harvested from domestic farm pigs and ligated with the Laparo-sonic (N = 13) or Ligasure (N = 9) system. The tissues were then fixed, stained, and examined by two pathologists without knowledge of the type of treatment. RESULTS: The mean length of thermal damage from the Ligasure was 2.11 mm (range 1.0-4.0 mm) whereas it was 1.92 (range 0.5-4.25 mm) from the Laparo-sonic system. The difference is not statistically significant. CONCLUSION: Debridement of as much as 5 mm of each cut end produced by the Laparo-sonic or Ligasure system may be beneficial in reducing stricture and leak.