GWAS of 972 autologous stem cell recipients with multiple myeloma identifies 11 genetic variants associated with chemotherapy-induced oral mucositis.

PURPOSE: High-dose chemotherapy and autologous stem cell transplant (ASCT) to treat multiple myeloma (MM) and other cancers carries the risk of oral mucositis (OM) with sequelae including impaired nutritional and fluid intake, pain, and infectious complications. As a result of these problems, cancer treatment may have to be interrupted or delayed. In this study, we looked beyond OM's known risk factors of renal function and melphalan dose with a genome-wide association study (GWAS) to evaluate whether genetic variants in conjunction with clinical risk factors influence predisposition for OM. METHODS: Genotyping was performed using Illumina HumanOmni1-Quad v1.0 BeadChip and further assessed for data quality. We tested 892,589 germline single-nucleotide polymorphisms (SNPs) for association with OM among 972 Caucasian patients treated with high-dose melphalan and ASCT in Total Therapy clinical trials (TT2, TT3, TT4) for newly diagnosed MM. Statistical analyses included t tests, stepwise regression modeling, and logistic regression modeling to find baseline clinical factors and genotypes associated with OM. RESULTS: We found that 353 (36.3 %) patients had grades 2-4 OM. Type of treatment protocol, baseline estimated glomerular filtration rate, and melphalan dose along with baseline serum albumin and female gender predicted 43.6 % of grades 2-4 OM cases. Eleven SNPs located in or near matrix metalloproteinase 13, JPH3, DHRS7C, CEP192, CPEB1/LINC00692, FBN2, ALDH1A1, and DMRTA1/FLJ35282 were associated with grades 2-4 OM. The addition of these SNPs increased sensitivity in detecting grades 2-4 OM cases to 52 %. CONCLUSIONS: These SNPs may be important for their roles in inflammatory pathways, epithelial healing, and chemotherapy detoxification.

Extensive extramedullary disease involving the colon in multiple myeloma: a case report and review of literature.

INTRODUCTION: Organ involvement in multiple myeloma (MM) is characterized by infiltrative disease or by a myelomatous mass known as a plasmacytoma. We present a patient with MM who had extensive extramedullary involvement of the colon and a review of the literature on colon plasmacytomas. CASE REPORT: A 57-year-old male with MM presented with disease relapse in 2007, workup showing biopsy confirmed left perinephric extra-medullary disease involving the adjacent colon. Positron emission-tomography (PET) exhibited intense pan-colonic fluoro-deoxyglucose (FDG) uptake and computed-tomography confirmed extensive infiltrating soft tissue thickening in the ascending, transverse, and descending colon representing plasmacytomas. The patient underwent an autologous hematopoietic stem cell transplantation after conditioning with high-dose melphalan. Restaging PET-scan showed complete resolution of colonic extra-medullary plasmacytomas. Extramedullary plasmacytomas (EMP) are rare and constitute 4% of all plasma cell tumors. DISCUSSION AND CONCLUSION: Colonic plasmacytoma is an extremely rare site, with fewer than 25 cases reported in the literature. Colonic plasmacytomas have different presentations depending on the size and location. Treatment options for primary EMPs include surgical resection, radiotherapy, and chemotherapy. The primary treatment option for secondary EMP is systemic chemotherapy. This rare pan-colonic plasmacytoma, as a part of extramedullary myeloma, showed an impressive response to chemotherapy.

Incidence and risk factors for lower alimentary tract mucositis after 1529 courses of chemotherapy in a homogenous population of oncology patients: clinical and research implications.

BACKGROUND: Lower alimentary tract mucositis is a serious complication of chemotherapy. The aim of the study was to determine the incidence, risk factors, and mortality of lower alimentary tract mucositis in a homogeneous population of patients with newly diagnosed myeloma receiving similar antineoplastic therapy and standardized supportive care. METHODS: Lower alimentary tract mucositis was evaluated among 303 consecutive patients with myeloma (2004-2007) enrolled in a clinical trial consisting of induction chemotherapy, tandem melphalan-based autologous stem cell transplantation (ASCT), and consolidation. Lower alimentary tract mucositis was defined as neutropenia-associated grade II-IV enteritis/colitis. Pretreatment risk factors were examined including body surface area (BSA), serum albumin (albumin), and estimated creatinine clearance (CrCl). Multiple logistic regression model was used to compute adjusted odds ratio (OR) and 95% confidence intervals (CI). RESULTS: Forty-seven (15.5%) patients developed lower alimentary tract mucositis during 1529 courses of chemotherapy (including 536 melphalan-based ASCT). Pre-enrollment BSA <2 m² (OR, 2.768; 95% CI, 1.200-6.381; P = .0169) increased the risk for lower alimentary tract mucositis, whereas higher albumin was protective (OR, 0.698; 95% CI, 0.519-0.940; P = .0177). Pretransplant variables associated with lower alimentary tract mucositis were BSA <2 m² (OR, 4.451; 95% CI, 1.459-13.58, P = .0087) and estimated CrCl <60 mL/min (OR, 3.493; 95% CI, 1.173-10.40; P = .0246). Higher albumin level conferred protection (OR, 0.500; 95% CI, 0.304-0.820; P = .0061). No lower alimentary tract mucositis-related death was observed. CONCLUSIONS: Lower alimentary tract mucositis is not uncommon among a homogenous population of oncology patients undergoing sequential courses of chemotherapy including melphalan-based ASCT but does not contribute to mortality. Lower BSA, renal function, and albumin are associated with increased risk for lower alimentary tract mucositis.