Association of Bone Mineral Density Testing With Risk of Major Osteoporotic Fractures Among Older Men Receiving Androgen Deprivation Therapy to Treat Localized or Regional Prostate Cancer.

Importance: Bone health screening is recommended for patients with prostate cancer who are initiating treatment with androgen deprivation therapy (ADT); however, bone mineral density screening rates in the US and their association with fracture prevention are unknown. Objective: To assess dual-energy x-ray absorptiometry (DXA) screening rates and their association with fracture rates among older men with prostate cancer initiating treatment with androgen deprivation therapy. Design, Setting, and Participants: This retrospective nationwide population-based cohort study used data from the Surveillance, Epidemiology, and End Results database and the Texas Cancer Registry linked with Medicare claims. Participants comprised 54 953 men 66 years or older with prostate cancer diagnosed between January 2005 and December 2015 who initiated treatment with ADT. Data were censored at last enrollment in Medicare and analyzed from January 1 to September 30, 2021. Exposures: Dual-energy x-ray absorptiometry screening within 12 months before and 6 months after the first ADT claim. Main Outcomes and Measures: Frequencies of DXA screening and fracture (any fracture and major osteoporotic fracture) and overall survival were calculated. The association between DXA screening and fracture was evaluated using a multivariable Cox proportional hazards model with propensity score adjustment. Results: Among 54 953 men (median age, 74 years; range, 66-99 years) with prostate cancer, 4689 (8.5%) were Hispanic, 6075 (11.1%) were non-Hispanic Black, 41 453 (75.4%) were non-Hispanic White, and 2736 (5.0%) were of other races and/or ethnicities (including 121 [0.2%] who were American Indian or Alaska Native; 1347 [2.5%] who were Asian, Hawaiian, or Pacific Islander; and 1268 [2.3%] who were of unknown race/ethnicity). Only 4362 men (7.9%) received DXA screening. The DXA screening rate increased from 6.8% in 2005 to 8.4% in 2015. Lower screening rates were associated with being single (odds ratio [OR], 0.89; 95% CI, 0.81-0.97; P = .01) and non-Hispanic Black (OR, 0.80; 95% CI, 0.70-0.91; P < .001), living in small urban areas (OR, 0.77; 95% CI, 0.66-0.90; P = .001) and areas with lower educational levels (OR, 0.75; 95% CI, 0.67-0.83; P < .001), and receiving nonsteroidal androgens (OR, 0.57; 95% CI, 0.39-0.84; P = .004). Overall, 9365 patients (17.5%) developed fractures after initial receipt of ADT. The median time to first fracture was 31 months (IQR, 15-56 months). In the multivariable model with propensity score adjustment, DXA screening was not associated with fracture risk at any site (hazard ratio [HR], 0.96; 95% CI, 0.89-1.04; P = .32) among men without previous fractures before receipt of ADT. However, previous DXA screening was associated with a decreased risk of major fractures (HR, 0.91; 95% CI, 0.83-1.00; P = .05) after propensity score adjustment. Conclusions and Relevance: In this study, low DXA screening rates were observed among older men with localized or regional prostate cancer after initiation of treatment with ADT. Despite low rates of screening, evaluation of bone mineral density with a DXA scan was associated with lower risk of major fractures. These findings suggest that DXA screening is important for the prevention of major fractures among older men with prostate cancer and that implementation strategies are needed to adopt bone health screening guidelines in clinical practice.

"Collecting duct carcinoma of the kidney: diagnosis and implications for management".

Collecting duct carcinoma of the kidney is a rare and aggressive subtype of renal cell carcinoma (RCC) arising from the distal convoluted tubules. At the time of diagnosis, patients are more frequently symptomatic, with advanced locoregional stage, and have metastatic disease. The 2016 WHO Classification of Tumours of the Urinary System defined diagnostic criteria for this entity. However, the diagnostic features continue to evolve, with typical, but not entirely specific, histologic and immunophenotypic characteristics. In addition, the lack of consistent molecular alterations makes collecting duct carcinoma a diagnosis of exclusion, with historical cases being re-classified as fumarate hydratase deficient RCC, ALK rearranged RCC, renal medullary carcinoma or high-grade urothelial carcinoma. The rarity and poor prognosis of the tumor makes it difficult to reach consensus guidelines to guide therapy. In this manuscript we review the clinicopathologic features of collecting duct carcinoma including pathologic diagnostic criteria, molecular characteristics and differential diagnosis, and their possible implications for management.

N-Acetylcysteine for Relapsing Thrombotic Thrombocytopenic Purpura: More Evidence of a Promising Drug.

Thrombotic thrombocytopenic purpura (TTP) is a microangiopatic thrombotic state associated with a deficiency on the cleavage function of the Von Willebrand factor polymers by a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13. We report a patient with relapsing TTP successfully treated with N-acetylcysteine (NAC) after failure of plasma exchange (PE) with steroids, rituximab, cyclophosphamide, vincristine, and azathioprine. A 51-year-old male who had an altered mental status while he was on rehabilitation for a previously treated TTP with a subsequent neurologic deficit. He was treated 7 days ago with PE plus steroids and subsequently discharged to our facility for rehabilitation. He was found to have a platelet level of 153,000/mm, hemoglobin decreased from 9.2 to 6.2 g/dL, creatinine raised from 1.0 to 2.4 mg/dL, and the peripheral smear showed schistocytes. A brain computed tomography showed a subacute infarction in the left frontal lobe and an abdominal-pelvic computed tomography disclosed a retroperitoneal hematoma. PE and steroids were started for 14 days. On day 15th, rituximab was added weekly for 10 cycles. A disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 activity level was 95% without platelet count improvement. We started cyclophosphamide, then vincristine, and finally azathioprine. His platelet were maintained above 150,000/mm for a few days. He had several episodes of sepsis after every chemotherapeutic drug. On day 135th, NAC was commenced at 150 mg/kg for 10 days along with PE and low-dose steroids for 10 days. Complete recover of platelet count was achieved and the patient was successfully discharged. Relapsing TTP is often difficult to manage and may last longer than expected carrying several comorbidities and complications. PE plus steroids are the mainstay of TTP treatment and Rituximab is the drug of choice after they have failed. The patient had a complete remission after NAC therapy. Hence, NAC likely can be considered an earlier choice of treatment after rituximab, before the use of chemotherapeutic agents, considering its toxic and adverse effects.