Risk of acute myeloid leukemia and myelodysplastic syndrome among older women receiving anthracycline-based adjuvant chemotherapy for breast cancer on Modern Cooperative Group Trials (Alliance A151511)

PURPOSE

We examined acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) events among 9679 women treated for breast cancer on four adjuvant Alliance for Clinical Trials in Oncology trials with >90 months of follow-up in order to better characterize the risk for AML/MDS in older patients receiving anthracyclines.

METHODS

We used multivariable Cox regression to examine factors associated with AML/MDS, adjusting for age (≥65 vs. <65 years; separately for ≥70 vs. <70 years), race/ethnicity, insurance, performance status, and anthracycline receipt. We also examined the effect of cyclophosphamide, the interaction of anthracycline and age, and outcomes for those developing AML/MDS.

RESULTS

On Cancer and Leukemia Group B (CALGB) 40101, 49907, 9344, and 9741, 7290 received anthracyclines; 15% were in the age ≥65 and 7% were ≥70. Overall, 47 patients developed AML/MDS (30 AML [0.3%], 17 MDS [0.2%]); 83% of events occurred within 5 years of study registration. Among those age ≥65 and ≥70, 0.8 and 1.0% developed AML/MDS (vs. 0.4% for age <65), respectively. In adjusted analyses, older age and anthracycline receipt were significantly associated with AML/MDS (adjusted hazard ratio [HR] for age ≥65 [vs. <65] = 3.13, 95% confidence interval [CI] 1.18-8.33; HR for anthracycline receipt [vs. no anthracycline] = 5.16, 95% CI 1.47-18.19). There was no interaction between age and anthracycline use. Deaths occurred in 70% of those developing AML/MDS.

CONCLUSIONS

We observed an increased risk for AML/MDS for older patients and those receiving anthracyclines, though these events were rare. Our results help inform discussions surrounding anticipated toxicities of adjuvant chemotherapy in older patients.

Influence of age on receipt of chemotherapy for adult Medicaid beneficiaries with metastatic colorectal cancer

9548

Background: Although advances in systemic treatment for metastatic colorectal cancer (CRC) have improved survival, it is unclear if this treatment is administered routinely among vulnerable individuals. Our objective was to describe treatment patterns for low income individuals with metastatic CRC and evaluate the influence of age on delivery of treatment in the context of patient, community, and health care setting characteristics. Methods: Matched North Carolina Cancer Registry and Medicaid claims data were used to identify a cohort of 390 patients with metastatic CRC diagnosed between 1999 and 2002. We assessed the relationship between treatment delivered within one year of diagnosis and characteristics of the patient (age, gender, race/ethnicity, comorbidity), community (percent poverty, percent rural), and health care setting (academic medical center, surgery volume). Treatment delivery was categorized into: 1) receipt of any chemotherapy, 2) local therapy only, and 3) no treatment. We fit a logistic regression model comparing receipt of any chemotherapy to local treatment only and another comparing receipt of any chemotherapy to no treatment. Results: Patients' mean age was 65.1±14.6 years; 56.0% were female and 45.5% were non-white. Only 27.7% received chemotherapy, while 50.3% received local therapy only and 22.0% received no treatment. After adjusting for comorbidity and all other covariates, patients aged <75 years were more likely to receive chemotherapy than patients ≥75 (versus local treatment only, OR=3.2, 95% CI=1.7–6.1; versus no treatment, OR=3.9, 95% CI=1.9–8.3). Absence of significant comorbidity was associated with use of chemotherapy only when compared to those who received no treatment (OR=3.1, 95% CI=1.6–5.9). Race/ethnicity, community, and health care setting characteristics were not associated with treatment. Conclusions: Use of chemotherapy in this low income cohort was low compared to published reports in other populations. Younger age was the only characteristic in this analysis which was consistently associated with receipt of chemotherapy. These results suggest that older low income patients may represent a particularly vulnerable population with regard to treatment disparity.

No significant financial relationships to disclose.

Receipt of chemotherapy among Medicaid-enrolled patients diagnosed with regional colon cancer

e15016

Background: Although overall improvements in colon cancer mortality have been observed, persistent disparities marked by socioeconomic inequality remain. Inadequate treatment received by the poor leads to disparities in overall and disease-free survival. This paper evaluates the patient, health services, and community characteristics associated with receipt of chemotherapy among poor Medicaid beneficiaries diagnosed with SEER-staged regional colon cancer. Methods: A dataset was constructed from Medicaid-enrolled patients diagnosed with colon cancer from 1999 to 2002 (n=692). Using claims data, North Carolina Central Cancer Registry data, and U.S. Census data, multivariable models were constructed to evaluate the association between patient, health services, and community characteristics and adjuvant chemotherapy. Results: Characteristics of the study population include: 66% female; 25% ages 65–74 and 46% ages 75+; and 42% African American. 1 in 4 of individuals with regional stage colon cancer had a Medicaid or Medicare claim for chemotherapy within 12 months of diagnosis. Individuals under age 65 (OR 6.4, CI 3.6–11.1) and ages 65- 74 (OR 4.4, CI 2.6–7.7) were significantly more likely to receive chemotherapy than individuals 75 and older in the multivariable model. Although non-cancer related comorbidity, class of case, and poverty were significantly associated with received chemotherapy in unadjusted models, their effects were no longer significant after controlling for age. Conclusions: A substantial percentage of Medicaid enrollees do not receive recommended adjuvant chemotherapy. The poor elderly may be especially at risk for under treatment.

No significant financial relationships to disclose.

Autologous transplantation in elderly patients with multiple myeloma: are we asking the right questions?

Multiple myeloma is a disease of the elderly. Survival outcomes remain unacceptably low in older adults with multiple myeloma. To date, no obvious difference in tumor biology has been elucidated to explain the survival disparity between older and younger patients. Multiple factors including comorbidity, performance status, decreased physiologic reserve and potentially undertreatment contribute to poor outcomes in elderly patients with multiple myeloma. High-dose chemotherapy with autologous stem cell transplantation (ASCT) is increasingly being used to treat elderly patients with multiple myeloma in an effort to improve survival outcomes. Recent case comparison studies, and preliminary transplant registry data suggest that selected older patients can be treated with high-dose chemotherapy effectively with similar toxicity and survival benefits compared to younger patients. Traditional upper age limits for autologous transplantation are being challenged along with the definition of 'elderly' itself. Ultimately, the role of high-dose chemotherapy with stem cell rescue in the upfront treatment of older adults with multiple myeloma can only be established by prospective randomized trials. In the process of designing studies to investigate the use of ASCT in older patients, multiple issues unique to the elderly population will need to be considered. First, it will be critical to develop and validate patient selection algorithms that incorporate measures of comorbidity, cognitive function, physiologic reserve and psychosocial function to identify patients most likely to tolerate and benefit from ASCT. Second, preparative and conditioning regimens will need to be further tailored to maximize the benefit to risk ratio. Finally, outcome measures in clinical trials should include disability and quality of life measures, which may be equally important in making treatment decisions for older patients. The future application and study of autologous transplantation in older patients with multiple myeloma provides a unique opportunity to challenge ageism and serve as a model for development of tailored assessments and interventions in this population.

Predictors of autologous stem cell transplant related mortality in older adults

16509

Background: Autologous stem cell transplantation (ASCT) is increasingly performed in older adults. Predictors of transplant related mortality (TRM) are not well established in this population. Our objective was to identify characteristics associated with TRM in older adults treated with ASCT. Methods: A retrospective chart review was conducted to identify all patients ≥ 60 years of age treated with ASCT at our institution between July 1990 and July 2005. We used logistic regression to investigate the effect of baseline characteristics and of transplant complications on TRM. Results: 143 patients met eligibility criteria of whom 139 were evaluable for the 100 day mortality outcome. The median age was 64.5 (range 60–76.6) years, 34% were female. Primary diagnoses included non-Hodgkin’s lymphoma (55%), multiple myeloma (29%), acute myelogenous leukemia (8%), breast cancer (5%), and Hodgkin’s lymphoma (3%). 100 day TRM was 7.9%. The mean time to engraftment (absolute neutrophil count >1000) was 12.2 ± 5.5 days. Complications included bacteremia (26.3%), cardiac events (myocardial infarction, congestive heart failure or arrhythmia) (11.5%), renal failure (7.4%), and respiratory failure (6.7%). Multivariate analysis including age, sex, diagnosis, number of comorbidities, number of medications, congestive heart failure, coronary artery disease, diabetes mellitus, hemoglobin, and creatinine at the time of transplant did not identify any baseline predictors of 100 day TRM (p > .05 for all). Development of renal failure or respiratory failure during transplantation was associated with increased TRM with an odds ratio of 11.2 (CI 2.5, 49.2) and 13.6 (CI 3.0, 62.2) respectively. Peritransplant cardiac events or bacteremia were not associated with increased TRM. Conclusions: Development of renal failure or respiratory failure is associated with increased TRM in this study. However, age and baseline comorbidities are not predictive of TRM. Future prospective studies should incorporate specific measures of functional and cognitive status which may be more reflective of decreased physiologic reserve in older adults being considered for ASCT.

No significant financial relationships to disclose.

DNA helicases in recombination and repair: construction of a delta uvrD delta helD delta recQ mutant deficient in recombination and repair

DNA helicases play pivotal roles in homologous recombination and recombinational DNA repair. They are involved in both the generation of recombinogenic single-stranded DNA ends and branch migration of synapsed Holliday junctions. Escherichia coli helicases II (uvrD), IV (helD), and RecQ (recQ) have all been implicated in the presynaptic stage of recombination in the RecF pathway. To probe for functional redundancy among these helicases, mutant strains containing single, double, and triple deletions in the helD, uvrD, and recQ genes were constructed and examined for conjugational recombination efficiency and DNA repair proficiency. We were unable to construct a strain harboring a delta recQ delta uvrD double deletion in a recBC sbcB(C) background (RecF pathway), suggesting that a delta recQ deletion mutation was lethal to the cell in a recBC sbcB(C) delta D background. However, we were able to construct a triple delta recQ delta uvrD Delta helD mutant in the recBC sbcB(C) background. This may be due to the increased mutator frequency in delta uvrD mutants which may have resulted in the fortuitous accumulation of a suppressor mutation(s). The triple helicase mutant recBC sbcB(C) delta uvrD delta recQ delta helD severely deficient in Hfr-mediated conjugational recombination and in the repair of methylmethane sulfonate-induced DNA damage. This suggests that the presence of at least one helicase--helicase II, RecQ helicase, or helicase IV--is essential for homologous recombination and recombinational DNA repair in a recBC sbcB(C) background. The triple helicase mutant was recombination and repair proficient in a rec+ background. Genetic analysis of the various double mutants unmasked additional functional redundancies with regard to conjugational recombination and DNA repair, suggesting that mechanisms of recombination depend both on the DNA substrates and on the genotype of the cell.