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Hypercalcemia in HL is rare and its incidence has been reported as 0.9, 1.6 and 5.4 % in different series

Hypercalcemia of malignancy involves three mechanisms: 1. Humoral hypercalcemia mediated by PTHrP—seen in solid tumors like breast cancer and adult T cell leukemia/lymphoma (ATLL), 2. Direct osteoclast mediated bone resorption due to bony metastasis—seen in solid tumors and multiple myeloma, 3. Calcitriol mediated hypercalcemia—seen in Hodgkin’s and non-Hodgkin’s lymphoma as well as granulomatous disorders like tuberculosis, sarcoidosis, leprosy and disseminated Candidiasis

Mechanism of hypercalcemia in HL has long been suggested to involve extra-renal activation of 1α-hydroxylase leading to production of 1, 25(OD)2 Vitamin D3 or Calcitriol, an active metabolite of Vitamin D, which leads to increased re-absorption of calcium and phosphate from intestine, increased osteoclast activation and bone resorption as well as increased phosphate re-absorption in renal tubules

The source of 1α-hydroxylase in HL has been postulated as monocytes and macrophages infiltrating the tumor akin to tuberculosis or sarcoidosis and is stimulated by IFN-γ secreted by T-lymphocytes

Like sarcoidosis, patients with HL exhibit increased sensitivity to Vitamin D supplements and sunlight, which have been found to precipitate hypercalcemia in these patients

Classical biochemical profile in Calcitriol mediated hypercalcemia include: an elevated calcium, normal/slightly elevated phosphate, normal 25(OH) Vitamin D, suppressed PTHrP and PTH, elevated Calcitriol and a normal/increased tubular reabsorption of phosphate

not been associated with a poorer prognosis and tends to subside after treatment of the underlying disease

Non-recombinant urate oxidase (Uricozyme®)

recombinant urate oxidase (Rasburicase®)

urine alkalisation may induce calcium phosphate deposition

renal replacement therapy should be started on an emergency basis when hydration fails to produce a prompt metabolic improvement or when ARF develops

Up to 50% of patients with newly diagnosed multiple myeloma have renal failure and up to 10% require dialysis

renal ultrasonography remains the method of choice for investigating extra-renal obstruction

The relief of the obstruction, either by percutaneous nephrostomy or through a ureteral stent, is the cornerstone of treatment

TMA may be associated with the cancer itself, with cancer chemotherapy, or with allogeneic BMT

thrombotic microangiopathy (TMA)

it may be as high as 5%

Most of the cases occur in patients with solid tumours, the most common type being adenocarcinoma (stomach, breast and lung)

The pathophysiology of the TMA-malignancy association remains controversial, although many studies suggest an insult to the vascular endothelium

mitomycin C. Subsequently, TMA has been reported with many anti-cancer agents, including gemcita-bine, bleomycin, cisplatin, CCNU, cytosine arabinoside, daunorubicin, deoxycoformycin, 5-FU, azathioprine and interferon α

Plasma exchanges have been shown to improve prognosis in the general population of patients with TMA

Causative factors should be looked for and antihypertensive treatment given. Lastly, in the absence of guidelines, we believe that plasma exchange should be proposed in patients with severe cancer treatment-associated TMA

The most widely used protective measure is saline infusion to induce solute diuresis

During methotrexate infusion and elimination, fluids should be given to maintain a high urinary output and urinary alkalisation should be performed to keep the urinary pH above 7.5. Rescue with folinic acid (50 mg four times a day) should be started 24 hours after each high-dose metho-trexate infusion and serum methotrexate concentrations should be measured every day

cyclophosphamide and ifosfamide