AL is caused by deposition in target tissues of amyloid fibrils constituted by immunoglobulin light chains produced by a usually modest bone marrow plasma cell clone. Prognosis and therapeutic strategy depend on the predominant organ involved. A median survival of 17 months was reported by the Mayo Clinic referral Center, while the multicenter Italian AL Study Group, involving 80 clinical centers covering all Italian regions, reported a 40 months median survival. Elucidation of the causes of such discrepancy may lead to & better understanding of the natural history of the disease and at improving the patient care. All patients (pts) initially diagnosed with systemic AL from June 1,1988, through June 30, 1998, at Mayo Clinic or in any of the Italian centers were included in this study. Patients were treated with a melphalan-based chemotherapy. Analysis of variance was used to compare: the two groups, and log-rank test to compare survivals. The Mayo Clinic group was composed of 281 pts, 189 (67%) male and 92 (33%) female with a median age of 67 years (39-89). The Italian group was composed of 209 pts, 119 (57%) male and 90 (43%) female with a median age of 62 years (29-85). The difference in gender and age between the two groups was statistically significant (p=0.02 and <0.001 respectively). Fatigue, weight loss, dyspnea and paresthesias were the most common initial symptoms with weight loss significantly more frequent in the Mayo Clinic group (52% vs 30%, p<0.001). The most common dominant syndromes at diagnosis were due to heart (38% at Mayo Clinic vs 28% in Italy), kidney (28% vs 49%), liver (5% vs 10%), PNS (15% vs 6%) and GI involvement (7% vs 4%). Two-thirds of the Italian pts had nephrotic syndrome versus only one-fifth of the Mayo pts (p<0.001). The inter-ventricular septal thickness was greater than 15 mm in 47% of pts in the Mayo Clinic group and in 33% of pts in the Italian group (p=0.01). There was a higher response rate to chemotherapy in the Italian group (33% vs 20%, p<0.001), presumably related to the higher proportion of renal pts and lower proportion of cardiac pts in this group. Overall median survival was 12 and 30 months in the American and Italian group respectively (p<0.001). Analysis of prognostic factors showed that heart involvement was the main determinant of survival in both groups. These data indicate that AL pts who seek assistance at referral centers tend to be older, with more serious heart involvement, overall lower life expectancy, and reduced possibility to respond to treatment, than pts observed in a multicenter program. This may affect the outcome of clinical trials.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - Dec 1 2000|
ASJC Scopus subject areas
- Cell Biology