Leung, Nelson

Renal impairment is a common complication of multiple myeloma (MM). The estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease formula is the recommended method for the assessment of renal function in patients with MM with stabilized serum creatinine. In acute renal injury, the RIFLE (risk, injury, failure, loss and end-stage kidney disease) and Acute Renal Injury Network criteria seem to be appropriate to define the severity of renal impairment. Novel criteria based on eGFR measurements are recommended for the definition of the reversibility of renal impairment. Rapid intervention to reverse renal dysfunction is critical for the management of these patients, especially for those with light chain cast nephropathy. Bortezomib with high-dose dexamethasone is considered as the treatment of choice for such patients. There is limited experience with thalidomide in patients with myeloma with renal impairment. Thus, thalidomide can be carefully administered, mainly in the context of well-designed clinical trials, to evaluate if it can improve the rapidity and probability of response that is produced by the combination with bortezomib and high-dose dexamethasone. Lenalidomide is effective in this setting and can reverse renal insufficiency in a significant subset of patients, when it is given at reduced doses, according to renal function. The role of plasma exchange in patients with suspected light chain cast nephropathy and renal impairment is controversial. High-dose melphalan (140 mg/m2) and autologous stem-cell transplantation should be limited to younger patients with chemosensitive disease.

Abstract Immunoglobulin free light chains (FLCs) are the precursors of amyloid fibrils in primary amyloidosis (AL). We studied the relationship between FLC levels and clinical features in 730 patients with newly diagnosed AL. The plasma cell clone was λ in 72% patients, and κ in 28% patients. κ-AL had more GI tract and liver involvement, where as renal involvement was more with λ-AL. While the overall survival (OS) was similar for κ and λ-AL, the median OS for those without an identifiable serum heavy chain was significantly shorter (12.6 vs 29.9 months; P = .02). The OS was shorter among those with a higher dFLC (involved FLC−uninvolved FLC; κ > 29.4 mg/dL or λ > 18.2 mg/dL using median for cutoff); 10.9 vs 37.1 months; P < .001. In multivariate analysis, dFLC was independent of other prognostic factors. The type of light chain impacts the spectrum of organ involvement and the FLC burden correlates with survival in AL.

Objective: To describe a case of acquired Fanconi syndrome after treatment with capecitabine, irinotecan, and bevacizumab. Case Summary: A 77-year-old female with metastatic colon cancer presented with vomiting and diarrhea. The patient had been diagnosed with stage IIIC (T3, N2, M0) colon cancer 18 months earlier and was initially treated with FOLFOX6 (regimen of oxaliplatin, fluorouracil, and leucovorin) after her hemicolectomy. She was switched to a capecitabine/oxaliplatin regimen after 4 cycles due to central access problems. She did well until 10 months after her cancer diagnosis, when metastasis was discovered. She was started on reduced doses of capecitabine, irinotecan, and bevacizumab. After her eleventh cycle, she presented to the hospital with the above symptoms. Laboratory test results showed hypokalemia, hypocalcemia, hypophosphatemia, and hypouricemia. The patient had not been started on any new medications other than chemotherapy for over 1 year. The electrolyte derangements were new, since the patient had laboratory values checked every 3 weeks. Despite daily intravenous replacements, the electrolyte abnormalities persisted. Laboratory evaluations demonstrated the presence of euglycemic glucosuria and a high fractional excretion of phosphorus in the setting of hypophosphatemia. Fanconi syndrome was confirmed by demonstration of aminoaciduria. Discussion: Fanconi syndrome is a disorder characterized by proximal tubular dysfunction resulting in electrolyte wasting. In the acquired form, medications and multiple myeloma are the most common causes. Based on the Naranjo probability scale, a drug was the probable cause of Fanconi syndrome in our patient. However, because multiple drugs were involved, it was not possible to determine which one was the culprit. Conclusions: This is the first case of Fanconi syndrome reported after the administration of capecitabine, irinotecan, and bevacizumab. More studies are needed to confirm this association.

Abstract Myeloid cell leukemia-1 (Mcl-1) is an antiapoptotic member of the Bcl-2 protein family. Increased Mcl-1 expression is associated with failure to achieve remission after treatment with fludarabine and chlorambucil in patients with chronic lymphocytic leukemia (CLL). However, the influence of Mcl-1 expression has not been examined in CLL trials using chemoimmunotherapy. We investigated Mcl-1 protein expression prospectively as part of a phase 2 study evaluating the efficacy of pentostatin, cyclophosphamide, and rituximab in patients with untreated CLL. No significant difference by Mcl-1 expression was noted in pretreatment or response parameters. However, in patients with higher Mcl-1 expression, both minimal residual disease-negative status and progression-free survival was found to be significantly reduced (57% vs 19%, P = .01; 50.8 vs 18.7 months; P = .02; respectively). Mcl-1 expression may therefore be useful in predicting poor response to chemoimmunotherapy. These findings further support pursuing treatment strategies targeting this important antiapoptotic protein. (Because the trials described were conducted before the requirement to register them was implemented, they are not registered in a clinical trial database.)

AbstractHigh-dose melphalan followed by stem cell transplantation (HDM-SCT) has become the treatment of choice for patients with immunoglobulin light chain amyloidosis (AL). Unfortunately, treatment mortality can be excessive in certain subpopulations. We have noted that patients who gained more than 2% body weight during mobilization had a poorer outcome following HDM-SCT. Excluding 2 patients for lack of weight record and denial of consent, 126 patients between July 1997 and June 2003 were retrospectively studied. Weight increased more than 2.0% during mobilization in 51.6% of the patients. Patients who accumulated more than 2.0% tended to have more proteinuria, more organs involved, lower serum albumin, more diuretic use, and dosage adjustment during mobilization. First-year mortality was significantly higher in those with more than 2% weight gain (33.9% versus 9.8%, P = .002). Multivariate analysis showed weight gain, glomerular filtration rate, and septal thickness to be independent predictors of first-year mortality. The increase in mortality was noted even after the excess weight was diuresed prior to conditioning. The impact on mortality dissipated after the first year. Weight gain during mobilization appears to be a new marker of adverse outcome following HDM-SCT. Better prognostication may improve the treatment mortality rate of these patients.