Melton, L. Joseph

Abstract Background: Solitary plasmacytoma of bone (SBP) is a localized collection of monoclonal plasma cells that is potentially curable with local radiation therapy but associated with a high risk of progression to multiple myeloma. We hypothesized that an abnormal immunoglobulin free light (FLC) ratio at diagnosis may be a prognostic indicator of transformation risk. Methods: We identified a cohort of 133 patients with SBP for whom stored serum taken at the time of diagnosis was available. The diagnosis was ascertained and serum FLC determined in 126 patients. Results: From this cohort, 48 patients have progressed to myeloma and the median time to progression among those who progressed was 1.9 years. On univariate analysis, age (p<0.001), gender (p=0.035), abnormal FLC ratio at diagnosis (p=0.009) and persistence of serum or urine M-protein after therapy (p=0.0070 were all associated with a shorter overall survival (OS) and time to progression to multiple myeloma. Progression by Normal FLC(0.26–1.65) Progression by Normal FLC(0.26–1.65) On multivariate analysis, an abnormal FLC ratio retained its independence in a model that includes age at diagnosis but lost its significance when combined with persistence of the serum or urine M-protein. However, serum or urine M-proteins are not detectable in a significant number of patients with SBP and therefore not informative. Conclusion: The FLC ratio at the time of diagnosis of SBP is a powerful predictor of risk and a useful aid to management of patients with this condition.

Abstract Smoldering Waldenström’s Macroglobulinemia (SWM) is defined as a serum IgM monoclonal protein ≥3 g/dL and/or ≥10% bone marrow lymphoplasmacytic infiltration but no evidence of constitutional symptoms, symptomatic anemia, or hyperviscosity. Forty-eight patients with SWM were identified at Mayo Clinic from 1974 to 1995. Patients with a diagnosis of chronic lymphocytic leukemia or lymphoma or history of any antineoplastic therapy before diagnosis of SWM were excluded. The median age at diagnosis was 63 years (range 39–87 years). Only one patient (2%) was < 40 years of age, but 14 percent were < 50 years old. Thirty-two (67%) were men, and 16 (33%) were women. At diagnosis, hepatomegaly was noted in 10%, splenomegaly in 4%, and lymphadenopathy in 8%. The initial hemoglobin level ranged from 8.7 to 15.3 g/dL (median 11.8). The anemia in all 4 patients with an initial hemoglobin < 10 g/dL was due to other causes such as myelodysplastic syndrome, bronchopleural fistula, Barrett’s esophagus, and Coumadin administration. The initial leukocyte level ranged from 3.2 to 13.2 × 109/L (median 5.7), and platelets ranged from 101 to 578 × 109/L (median 285.5). Only one patient had a serum creatinine > 2.0 mg/dL and it was unrelated to SWM. The serum monoclonal protein level at the time of diagnosis ranged from 1.5 to 5.2 g/dL (median 3.3); 12 (25%) were < 3 g/dL, while 10 (21%) were ≥4 g/dL. IgM kappa accounted for 75%, IgM lambda 21%, and 2 (4%) were biclonal. Immunofixation of the urine was positive in 97% (kappa 80%, lambda 17%, indeterminate 3%) of those tested. The size of the urine M protein ranged from unmeasurable to 1.4 g/24h (median 0.04 g/24h). Serum albumin ranged from 2.5 to 4.3 g/dL (median 3.6). Five patients (10%) had an albumin value < 3 g/dL. Ten (26%) had a reduction of 1 uninvolved immunoglobulin, while 8 (21%) had a reduction of both IgG and IgA immunoglobulins. Lymphoplasmacytic infiltration of the bone marrow ranged from 3% to 80%, (median 30%). Three (6%) had less than 10% infiltration, while 13 (27%) had 50% or greater infiltration. The 48 patients were followed for a total of 292 (range 0.5 to 22.6 years; median 3.7) person-years, during which time 33 progressed to symptomatic WM and one to AL amyloidosis. The expected number of WM based on the SEER data was 0.004 cases. Thus, relative risk of progression to WM was increased 7,586-fold (95% CI, 5,083 to 10,373). The median time to progression was 4.6 years. The absolute risk of progression to WM was 6% at 1 year, 39% at 3 years, and 55% at 5 years. The median survival after progression to symptomatic WM was 5.1 years. Seventy-three percent of patients died, indicating a robust follow-up. We evaluated sex, hemoglobin level, size of serum M protein, reduction of uninvolved immunoglobulins, presence of urinary monoclonal light chains, serum albumin level, and the proportion of lymphoplasmacytic infiltration of the bone marrow as risk factors for progression. Significant risk factors for progression with univariate analysis included size of the serum M protein, hemoglobin level, reduction in uninvolved immunoglobulins, and degree of bone marrow lymphoplasmacytic cell infiltration. Multivariate modeling revealed that the size of the M protein and the degree of bone marrow infiltration were the most important risk factors. We conclude that smoldering WM is a distinct clinical entity that needs to be differentiated from IgM MGUS and symptomatic Waldenstrom’s Macroglobulinemia.

Abstract Background: Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell proliferative disorder with a high risk of progression to symptomatic multiple myeloma. Identification of risk factors that predict progression of SMM to symptomatic MM could identify higher risk patients who might benefit from chemoprevention or more intensive surveillance. We hypothesized that increased monoclonal free kappa or lambda immunoglobulin light chains in smoldering myeloma (SMM), as detected by the serum free light chain (FLC) assay, indicates an increased the risk of progression to active myeloma. Methods: Of 276 pathologically confirmed SMM patients seen at the Mayo Clinic from 1970 to 1995, baseline serum samples obtained within 30 days of diagnosis were available in 273. Results: At a median follow-up of surviving patients of 12.4 years, transformation to active disease has occurred in 161 (59%) patients. An abnormal FLC ratio was present at baseline in 90% of patients. The best break-point for predicting risk of progression was a FLC ratio less than or equal to 0.125 or greater than or equal to 8 (hazard ratio, 2.3; 95% CI, 1.6–3.2) [Figure 1]. The extent of abnormality of FLC ratio was independent of SMM risk categories defined by number of plasma cells in the bone marrow and size of serum M-proteins (bone marrow plasma cells ≥ 10% and serum M protein ≥ 3 g/dL; bone marrow plasma cells ≥ 10% but serum M protein < 3 g/dL; and serum M protein ≥ 3 g/dL but bone marrow plasma cells < 10%). Incorporating the FLC ratio into the risk model, the division of patients into high-, intermediate-, and low-risk groups is 28, 42, and 30% with 5 year progression rates of 76, 51, and 25%, respectively [Figure 2]. Conclusions: The serum immunoglobulin FLC ratio is an important additional determinant of clinical outcome in patients with SMM. Figure Figure Figure Figure

Abstract Background: Active cancer without or with chemotherapy is associated with a 4- to 6.5-fold increased risk for VTE 1. However, cancer-associated VTE incidence may be under- or overestimated by reports that linked cancer registry data to an anticoagulation clinic database or to hospital discharge diagnosis codes 2–5. Objective: To estimate the incidence of VTE in active cancer in a well-defined geographic population that includes the full spectrum of VTE events (including rapidly fatal events) occurring in the community. Methods: Using the longitudinal resources of the Rochester Epidemiology Project and Mayo Clinic Tumor Registry, we identified all Olmsted County, MN residents with incident VTE by review of their complete medical records in the community 6, and all residents with active cancer (by cancer site), over the 28-year period, 1973–2000. Using residents with active cancer within the three months prior or subsequent to incident VTE as the numerator, and all residents with active cancer as the denominator, we estimated the incidence of VTE in active cancer, both overall and for the subsets of pancreatic cancer, brain cancer and lymphoma. Results: Over 78,236 active-cancer person-years, 595 Olmsted County residents developed incident VTE. The overall active cancer-associated VTE incidence was 760 per 100,000 person-years (95% CI: 701, 824), about 6.5-fold higher than the general population 7. Over 473, 983 and 4,258 pancreatic cancer, brain cancer and lymphoma person-years, respectively, 51, 18 and 46 residents developed incident VTE. The pancreatic cancer-, brain cancer- and lymphoma-associated VTE incidence rates were 10,784 (95% CI: 8029, 14,179), 1,831 (95% CI: 1085, 2,893) and 1,080 (95% CI: 791, 1,441) per 100,000, respectively. Overall, cancer-associated VTE incidence increased with age, and for all ages, men had a higher VTE rate than women. We observed a much higher pancreatic cancer-associated VTE incidence than previously reported. Conclusions: The incidence of VTE in individuals with active cancer (especially pancreatic cancer) is higher than the general population. The incidence of VTE in patients with pancreatic cancer is higher than previously estimated.

Abstract Introduction: Diabetes mellitus is often cited as a VTE risk factor. However, persons with diabetes are frequently hospitalized for medical illness or undergo surgery, both major VTE risk factors. Thus, the association of VTE with diabetes independent of surgery or hospitalization is uncertain. Methods: Using longitudinal, population-based Rochester Epidemiology Project resources, we identified all Olmsted County, MN residents who met objective criteria for incident VTE over the 25-year period, 1976–2000 (n=1922), and one to two controls per case, matched on age, gender, Olmsted County residency, and length of medical history (n=2115). For cases and controls, we reviewed their complete medical history in the community for baseline characteristics previously identified as independent VTE risk factors, including clinically-diagnosed diabetes mellitus. We tested diabetes as a potential VTE risk factor both alone and after adjusting for other baseline characteristics, and in the subset of cases with idiopathic VTE, using conditional logistic regression. Results: Among all cases and controls, 231 (12%) and 199 (9.4%) had diabetes, respectively. Univariately, diabetes was associated with overall VTE (odds ratio [OR]=1.32; 95% CI: 1.07, 1.62; p=0.009). However, after controlling for body mass index (OR=1.04, p<0.001), hospitalization with major surgery (OR=25.2, p<0.001) or hospitalization for medical illness (OR=7.3, p<0.001), active cancer (OR=8.3, p<0.001) and varicose veins (OR=1.3, p=0.003), diabetes was no longer associated with VTE (OR=1.09; 95% CI: 0.85, 1.41; p=0.49). Among 458 idiopathic VTE cases and 518 matched controls, 43 (9.4%) and 46 (8.9%) had diabetes, respectively. Diabetes was not associated with idiopathic VTE (OR=1.07, 95% CI: 0.69, 1.67; p=0.76). Conclusions: Diabetes mellitus is not an independent risk factor for overall or idiopathic incident VTE.

Abstract Background: Monoclonal gammopathy of undetermined significance (MGUS) affects 3% of persons age 50 yrs or greater. Reliable predictors of progression of MGUS to myeloma or related malignancy are needed. We hypothesized that the presence of monoclonal unbound (free) kappa or lambda immunoglobulin light chains in MGUS, as detected by an abnormal serum kappa/lambda free light chain (FLC) ratio would indicate clonal evolution in the neoplastic plasma cell and increase risk of progression to malignancy. Methods: Patients (pts) from Southeastern Minnesota with MGUS seen at the Mayo Clinic from Jan 1, 1960 through Dec 31, 1994 who had baseline serum samples collected and stored at the time MGUS was first recognized were studied. Free kappa and lambda chains were measured using the serum FLC assay (FREELITETM, The Binding Site Ltd). Results: Of 1384 pts with MGUS during the defined time period, baseline serum samples obtained within 30 days of diagnosis of MGUS were available in 1148 pts. At a median follow-up of 15 yrs, malignant progression has occurred in 87 (7.6%) pts: myeloma (53 pts), IgM lymphoma (17), primary amyloidosis (6), macroglobulinemia (6), chronic lymphocytic leukemia (3) and plasmacytoma (2). An abnormal kappa/lamda FLC ratio (kappa/lambda ratio <0.26 or >1.65) indicating presence of monoclonal FLC was detected in 379 (33%) pts. In a Cox proportional hazards model, the risk of progression in pts with an abnormal kappa/lamda FLC ratio was significantly higher (hazard ratio 3.5, 95% CI 2.3–5.5; p<0.001) compared to pts with a normal ratio. After adjusting for the size of the serum monoclonal (M) protein by multivariate analysis, the hazard ratio was only slightly reduced to 2.8, p<0.001. The risk of progression to myeloma or related malignancy at 10 years was 17% with an abnormal kappa/lambda FLC ratio versus 5% with a normal ratio; corresponding rates at 20 years were 35%, and 13%, respectively. MGUS pts with both an abnormal serum FLC ratio and high serum M protein had a risk of progression at 20 years of 46% (high-risk), versus 26% with one of two risk factors (intermediate-risk) and 7% with no risk factors (low-risk) (Table). The true life-time (28 year) risk of myeloma or related malignancy in the low-risk group was only 5.3% when other competing causes of death were taken into account. Conclusions: Presence of monoclonal FLC in the serum as detected by an abnormal kappa/lamda FLC ratio is a major independent risk factor for progression of MGUS to myeloma or a related malignancy. The new risk-stratification identifies a low-risk subset with a remarkably small life-time risk of progression, a finding of significant importance for the management of MGUS. Risk-stratification of MGUS using the size of the serum M spike and free light chain ratio Risk Group No. of patients Hazard ratio Absolute risk of progression at 20 years Low-risk (Serum M protein <1.5 gm/dL and normal FLC ratio [0.26–1.65]) 606 1 7% Intermediate-risk (Either risk factor present) 373 3.5 26% High-risk (Serum M protein >/=1.5 gm/dL and abnormal FLC ratio [<0.26 or >1.65]) 169 6.8 46%

Abstract If the observed dramatic increase in VTE incidence with advancing age is due to increased VTE risk factor exposure (i.e., secondary VTE), the incidence of idiopathic VTE should not vary with age or calendar year. Objective: To estimate the incidence of idiopathic and secondary VTE by age and by calendar year. Methods: Using the resources of the Rochester Epidemiology Project, we identified the inception cohort of Olmsted County, MN, residents with a first lifetime VTE during the 30-year period, 1966–1995 (n=2761). For each case, we reviewed the complete medical records in the community for 48 baseline clinical characteristics that are commonly-accepted risk factors for VTE. We categorized VTE cases as idiopathic (n=305) if no such characteristics were present; the remaining cases were categorized as secondary. Age- and sex-specific incidence rates were calculated using idiopathic or secondary VTE cases as the numerator, and age-, sex- and calendar year-specific estimates of the population of Olmsted County as the denominator. Results: The incidence of both idiopathic and secondary VTE increased exponentially with age for both men and women (p<0.001). Over the 30-year study period, the age-adjusted incidence of idiopathic VTE was essentially constant among men (from 19.0 to 17.1 per 100,000 men-years for 1966–70 and 1990–95, respectively), but decreased markedly among women (from 18.5 to 3.6 per 100,000 woman-years for 1966–70 and 1990–95, respectively; p=0.005 for the interaction). Conclusions: The dramatic increase in VTE incidence with age likely reflects the biology of aging, although as yet unidentified VTE risk factors cannot be excluded. The reason for the decreased incidence of idiopathic VTE over the last 30 years among women is unclear.

Abstract If the incidence of VTE varies by season, then the etiology of VTE could be related to seasonal exposures. However, the few studies that estimated VTE incidence by season reached conflicting conclusions. Objective: To estimate the incidence of VTE by month and by season of the year. Methods: Using the resources of the Rochester Epidemiology Project, we identified the inception cohort of Olmsted County, MN, residents with a first lifetime VTE over the 30-year period, 1966–1995 (n=2761). For each case, we reviewed the complete medical records in the community for the date of VTE onset, date of birth, gender and 48 baseline clinical characteristics commonly accepted as risk factors for VTE. We categorized cases as idiopathic (n=305) if no such characteristics were present; remaining cases were categorized as secondary. Incidence rates were calculated using the number of overall, idiopathic or secondary VTE cases by month of onset as the numerator, and age- and sex-specific estimates of the monthly population of Olmsted County as the denominator (yearly population estimates divided by 12). Results: The incidence of VTE did not vary appreciably by month of the year for overall, idiopathic or secondary VTE (all p-values >0.2). However, the overall incidence of VTE was higher in the 3 summer months (June, July, August) compared to the 3 winter months (December, January, February; 132.6 vs. 116.9 per 100,000 person-years, respectively, both age- and sex-adjusted to year 2000 U.S. Whites; p-value = 0.026). The same general pattern was true for both idiopathic and secondary VTE, but separately neither was statistically significant (p-value=0.48 and 0.15, respectively). Conclusions: The incidence of VTE is higher in the summer compared to the winter months, suggesting the hypothesis that vector-borne (e.g., mosquito, tick) and/or enteroviral infection may play a role in the etiology of VTE.

Abstract Chronic Idiopathic Bence Jones Proteinuria (first reported in 1982) is an asymptomatic plasma cell proliferative disorder that is associated with a risk of progression to symptomatic multiple myeloma (MM) or primary amyloidosis (AL). We defined it as the presence of a monoclonal light chain in the urine, absence of an intact immunoglobulin M protein (IgH expression) in the serum, fewer than 10% bone marrow plasma cells (if done), and no evidence of MM, AL or other related plasma cell proliferative disorders. Following approval by the Mayo Clinic Institutional Review Board, we searched a computerized database and reviewed the records of all patients who were seen at Mayo Clinic within 30 days of the recognition of a monoclonal light chain (Bence Jones protein) in the urine between 1960 and 1996. Patients found to have end-organ damage at diagnosis as the result of the plasma cell proliferative disorder (including MM or AL), received chemotherapy, or had a nephrotic syndrome were excluded. Follow-up included review of each subject’s medical record at Mayo Clinic as well as review of death certificates for patients who died. Patients were sent letters of inquiry if they had not visited Mayo Clinic in the preceding year. The risk of progression to MM and AL was compared to those expected on the basis of Surveillance, Epidemiology and End Results (SEER) rates for MM in Iowa and the prevalence of AL in Olmsted County, Minnesota. Two-hundred twenty-three patients fulfilled the criteria for Idiopathic Bence Jones Proteinuria during the 37-year period (1960 – 1996). The median age at diagnosis was 69 yrs (range, 36–90 yrs) and only 1% were < 40 years of age. Sixty-seven percent were male. The urine M protein ranged from unmeasurable to 4.7 g/24h. The median was 0.09 g/24h and only 8% were > 1 g/24h. Kappa light chain accounted for 57% while lambda was present in 43%. Eighty-one percent of patients died during follow-up. Twenty-six percent had a monoclonal light chain in the serum on immunofixation. Concentrations of uninvolved (normal, polyclonal or background) immunoglobulins were reduced in 45%. During 1408 person years of follow-up, 11 patients developed symptomatic MM (relative risk 28.5; 95% CI, 14.3 – 51.1) and an additional 9 patients developed AL (relative risk 61.8; 95% CI, 28.3 – 117.4). The cumulative probability of progression to active MM or AL was 7% at 5 yrs, 13.5% at 10 yrs., and 18% at 15 yrs. The factors evaluated with respect to predicting progression to MM or AL included sex, hemoglobin value, serum albumin, amount of urine M protein/24h, type of urine light chain (kappa or lambda), reduction of uninvolved (background) immunoglobulins, and elevation of serum calcium or creatinine. The amount of the urine M protein/24h was the only significantly predictive parameter for progression. As a continuous variable, a higher urine M protein was associated with an increased risk of progression (hazard ratio = 2.1 for a 1g increase, p=0.003). The amount of the urine M protein was also significant as a dichotomous variable. Patients who had a urine M protein ≥ 1g/24h had an increased risk of progression (hazard ratio = 3.6, p=0.007). We conclude that patients with Idiopathic Bence Jones Proteinuria are at risk for the development of MM or AL and need to be followed indefinitely.

Abstract Background: Recent trends in the incidence of venous thromboembolism (VTE), including idiopathic vs. non-idiopathic VTE, have not been well described. Objective: To estimate the incidence of deep vein thrombosis (DVT) and pulmonary embolism with or without DVT (PE), and describe trends in incidence. Methods: Using the resources of the Rochester Epidemiology Project, we identified all Olmsted County, MN residents with an incident DVT and PE over the 35-year period, 1966–2000 (n=3342). For all cases, the complete medical records in the community were reviewed for demographic and baseline characteristics previously identified as risk factors for VTE. Generalized linear models assuming a Poisson error structure, and using a log link function, and a log (population) offset will be used to assess the relationship of crude incidence rates to gender, year of diagnosis and age at diagnosis. Results: The overall average age- and sex-adjusted annual VTE incidence was 122 per 100,000 person-years (DVT, 56 per 100,000; PE, 66 per 100,000), with higher age-adjusted rates among men than women (134 versus 115 per 100,000, respectively). VTE incidence rates increased exponentially with age for both genders, ranging from 4 to 1110 per 100,000 for age groups 0–19 to 90–110 years. Compared to the 5-year period, 1981–85 (when non-invasive diagnostic testing became routinely available), the overall VTE incidence through 2000 remains unchanged. However, the DVT incidence and the PE incidence significantly increased and decreased, respectively, adjusting for age and gender (p<0.001 for both). The overall age- and sex-adjusted annual incidence of idiopathic VTE was 11.7 per 100,000 person-years (DVT, 6.6 per 100,000; PE, 5.1 per 100,000), with age-adjusted rates also higher among men than women (15.1 vs. 9.1 per 100,000). Interestingly, again compared to 1981–85, idiopathic VTE incidence decreased for 1991–95 (p=0.001) and 1996–2000 (p=0.32), adjusting for age and gender. Idiopathic DVT incidence decreased for 1991–95 (p=0.09), and idiopathic PE incidence decreased for both 1991–95 (p=0.004) and 1996–2000 (p=0.03). The overall age- and sex-adjusted annual incidence of non-idiopathic VTE was 109.4 per 100,000 (DVT, 48.4 per 100,000; PE, 60.7 per 100,000), again, with age-adjusted rates higher in men than women (115.1 vs. 106.8 per 100,000). Non-idiopathic DVT incidence increased steadily since 1981–85 (p=0.006, p<0.001, and p<0.001 for increasing DVT incidence for 1986–1990–1991–1995–1996–2000, respectively, adjusting for age and gender). Non-idiopathic PE incidence, however, remained unchanged for 1986–2000. Conclusions: VTE remains a major national health problem, especially among the elderly. Despite improved VTE prophylaxis efficacy and utilization, the overall incidence of VTE remains unchanged. However, the decreasing incidence of idiopathic DVT, and particularly idiopathic PE (with its associated poor survival) raises the possibility that the total number of VTE(PE)-related deaths may also be decreasing, albeit slightly. This hypothesis requires formal testing. The increasing or steady incidence of non-idiopathic DVT and PE, respectively, suggests the need for more widespread, effective VTE prophylaxis.