Acute myelogenous leukemia in the elderly

Pharmacology of cytotoxic agents: a helpful tool for building dose adjustment guidelines in the elderly

Aging is associated with multidimensional changes, including alterations in physiological functions, co-morbidities and poly-medications. These changes may lead to modifications in the absorption, distribution, metabolism and excretion of drugs. The lack of a scientific basis for optimal drug dosing in the elderly is a major problem. The development and validation of guidelines are therefore essential to improve treatment administration and monitoring in elderly patients. Even though it has been widely demonstrated that standard therapies used in adults may be of great benefit in the elderly, there may be a higher incidence of toxicity. This could be avoided by using dosage individualization based on a sound knowledge of the physiological factors implicated in the pharmacokinetic (PK) characteristics of the drugs administered and in their observed pharmacodynamic (PD) effects in each patient. The so-called "population modeling" approach renders such studies feasible by allowing the analysis of PK-PD relationships from sparse observational data.

Low expression of the myeloid differentiation antigen CD65s, a feature of poorly differentiated AML in older adults: study of 711 patients enrolled in ECOG trials

CD65s appears when the progenitor antigen CD34 disappears, suggesting that this sialylated carbohydrate antigen marks a turning point in normal myeloid differentiation. We characterized acute myeloid leukemia (AML) with low CD65s expression (CD65s(low) AML) in 711 patients entered on seven Eastern Cooperative Oncology Group AML treatment trials (1986-1999). Of those, 198 (28%) qualified as having CD65s(low) AML. Morphologically, CD65s(low) AML was more common in FAB subgroups with minimal differentiation, M0/M1 (P=<0.0001). Early precursor antigens CD34, CD117 and terminal transferase were more frequent in CD65s(low) than CD65s(high) AML (P=<0.0001). Myeloperoxidase was present in fewer CD65s(low) myeloblasts, and the more mature myeloid antigens, CD15 and CD11b, were rarely detected (P=<0.0001). Yet, the two diagnoses did not differ in the distribution of cytogenetic prognostic groups or the occurrence of the multidrug-resistance mediator, P-glycoprotein. CD65s(low) AML patients were significantly older than CD65s(high) cases (P<0.0001). Furthermore, the incidence of CD65s(low) cases increased with age, from 20% in patients under the age of 50 years to 67% in patients older than 80 years (P<0.0001). Overall, complete remission (CR) rate and overall survival were comparable in CD65s(low) and CD65s(high) AML. However, among patients >55 years of age, CD65s(low) AML had a decreased CR rate of 33 vs 44% in CD65s(high) AML (P=0.055). Thus, CD65s(low) AML represents immunophenotypically undifferentiated disease and occurs predominantly in older adults. Although not statistically significant, the observed association between low CD65s expression and decreased CR rate only in patients over the age of 55 is intriguing.

Radiation therapy of the older patient

Radiotherapy has a major role in the multidisciplinary approach to cancer therapy. It is widely used for curative and palliative treatment of cancer involving various sites. Radiotherapy is of particular benefit to older and frail cancer patients as an alternative to surgery and to systemic therapy. The available data on the sensitivity of normal tissues to radiotherapy in elderly patients strongly suggest that older patients with good functional status tolerate radiotherapy as well as younger patients and have comparable tumor response and survival rates. Aggressive radiotherapy should not be withheld from older patients because of chronological age alone.

P-VEBEC: a new 8-weekly schedule with or without rG-CSF for elderly patients with aggressive non-Hodgkin's lymphoma (NHL)

BACKGROUND

Chemotherapy regimens devised for elderly patients with intermediate-high grade NHL are a matter of discussion. The aim is to reduce general toxicity without loosing an antilymphoma effect. The most important limiting factor of chemotherapy is myelotoxicity; for this reason the use of growth factor may be useful in these patients.

PATIENTS AND METHODS

From November '91 to November '92, 67 pts older than 65 years with intermediate-and high-grade advanced-stage NHL were treated with the P-VEBEC regimen, an original scheme with epirubicin 50 mg/m2, cyclophosphamide 350 mg/m2 and etoposide 100 mg/m2 on weeks 1, 3, 5, 7; vinblastine 5 mg/m2 and bleomycin 5 mg/m2 on weeks 2, 4, 6, 8, prednisone 50 mg/m2/day p. os in the first 2 weeks and thereafter every other day. Twenty-eight pts received r-GSF 5 micrograms/kg/day throughout the treatment starting on day 2 of every week for 4 consecutive days. Their median age was 71 years (65-80), 31 pts were male and 36 female, histology according W.F. was D 6; E 17; F 16; G 19; H 9. Twenty-five percent of pts had B symptoms, 35% had bulky disease, 41% LDH level > normal, 44% stage IV and 26% had B.M. involvement.

RESULTS

C.R. was achieved by 66% of pts. Adverse prognostic factors for CR were E histology, stage IV, bone marrow infiltration and LDH above normal. Severe toxicity was never recorded, no toxic death was observed. With a median follow-up of 24 months OS, DFS and EFS were 55%, 52%, and 33%, respectively. EFS was influenced by stage, BM involvement and level of LDH. The relative dose intensity (RDI) was calculated by the method of Hryniuk and Bush. Patients who received rG-CSF had a significantly higher median RDI (94% vs 79%) and lower myelotoxicity (neutrophil nadir < 500 18% vs 56%). The rate of CR was influenced by RDI > 80% (89% vs 56%). EFS was also better in pts who received a RDI higher than 80% (50% vs 18% p = 0.05).

CONCLUSION

P-VEBEC is a feasible cycle in elderly patients; the use of rG-CSF improves RDI. In patients with adverse prognostic factors (BM involvement, poor performance status) a RDI > 0.80 could play a role in improving the outcome.

Acute lymphocytic leukemia (ALL) in elderly patients

OBJECTIVE

To compare the clinical and biologic characteristics, response to therapy and outcome of adult patients with ALL above and below the age of 55.

DESIGN

Retrospective review of clinical and laboratory data.

SETTING

University affiliated Cancer Center and Veteran's Hospital.

PATIENTS

Thirty-three newly diagnosed, consecutive, adults with ALL seen over a nine-year period.

RESULTS

while no differences were demonstrated in the distribution of recognized prognostic indicators (such as cytogenetic abnormalities or immunophenotype), individuals over the age of 55 had significantly lower remission rates and shorter survivals.

CONCLUSIONS

The outcome of elderly patients with ALL is very poor. This is primarily related to an increase in the number of early deaths during induction, as well as a higher prevalence of disease refractory to standard chemotherapy programmes. There is a need for new treatment protocols designed for the elderly ALL patient, as well as a better understanding of the unique biological characteristics of the disease in this age group.