High dose intensity doxorubicin in aggressive non-Hodgkin's lymphoma: a literature-based meta-analysis

BACKGROUND

Aggressive non-Hodgkin's lymphoma (NHL) represents approximately 60% of lymphomas in the West and even more in the developing world. cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) is recognized as the standard chemotherapy regimen and the addition of rituximab to B-cell subtypes has been shown to significantly improve treatment outcomes. Nevertheless, still a significant fraction of patients is not offered rituximab due to economic reasons. Thus, CHOP is still offered to these patients as well as those with T-cell subtypes. Data from the early 1990s have indicated that the dose intensity (DI) of doxorubicin is a key factor in predicting survival.

METHODS

A Medline and Cochrane library search was carried out using the search terms 'CHOP', 'lymphoma' and 'randomized trials'. Eligible trials had CHOP as a control arm and any regimen administering doxorubicin at a higher DI (16.6 mg/m(2)/week) as the investigational arm. Pooling of data was carried out using the mixed effect model.

RESULTS

Eight trials were eligible. Patients receiving DI doxorubicin-based regimens had a significantly better overall survival [summary hazard ratio (SHR) 0.82; 95% confidence interval (CI) 0.71-0.96], event-free survival (SHR 0.86; 95% CI 0.75-0.99) and higher complete response rate (summary odds ratio 0.91; 95% CI 0.67-0.97).

CONCLUSION

High DI doxorubicin based should be considered in patients with aggressive NHL.

High-dose intense doxorubicin-based regimens in aggressive non-Hodgkin's lymphoma: A systematic overview

e19528

Background: Aggressive non-Hodgkin's lymphoma represents around 60% of lymphomas in the Western world and even more in Egypt. CHOP has been long been recognized as the standard chemotherapy regimen in this disease. The addition of rituximab (R) to CHOP in the treatment of B-cell subtypes has resulted in a significant improvement in all treatment endpoints. Nevertheless, still a significant fraction of patients in the developing world are not offered R due to economical reasons. Thus CHOP is still offered to these patients as well as those with T-cell subtypes. Data from the early 1990s have suggested that the dose intensity (DI) of doxorubicin may have a prognostic value. Hence we conducted a metaanalysis on chemotherapy regimens incorporating higher DI doxorubicin and compare them to CHOP in terms of complete response (CR) rate, event free survival (EFS) and overall survival (OAS). Methods: A MEDLINE and COCHRANE library search was performed using the search terms ‘CHOP‘, ‘lymphoma‘ and ‘randomized trials‘. Eligible trials were randomized trials, having CHOP as a control arm and any chemotherapy regimen administering doxorubicin at a higher DI than that of CHOP (16mg/m2/week) as the investigational arm. Pooling of data was performed using the mixed effect model. The outcome measure for pooling the CR rate was the odds ratio (OR) while the hazard ratio (HR) was the outcome measure for EFS and OAS. Confidence intervals were estimated according to the method developed by Parmar. Results: Eight trials published until February 2008 met the inclusion criteria. They included 3,668 patients randomly assigned to either CHOP (1,660 patients) or DI doxorubicin-based regimen (2008 patients). Patients receiving DI doxorubicin-based regimen had a significantly better overall survival (HR; 0.79; 95% CI: 0.66–0.94). As for the EFS and CR analyses, there was a trend in favor of patients who received the DI regimens; however the difference was not statistically significant (HR: 0.86; 95% CI: 0.71–1.03 & OR: 0.8; 95% CI: 0.63–1.02 respectively). Conclusions: High DI doxorubicin-based regimens are associated with a better OAS compared to CHOP. Such approach should be considered in patients with aggressive B-cell lymphomas not offered R as well as those with T-cell lymphomas.

No significant financial relationships to disclose.

Primary diffuse large B-cell lymphoma of the breast: prognostic factors and outcomes of a study by the International Extranodal Lymphoma Study Group

BACKGROUND

Primary diffuse large B-cell lymphoma (DLBCL) of breast is rare. We aimed to define clinical features, prognostic factors, patterns of failure, and treatment outcomes.

PATIENTS AND METHODS

A retrospective international study of 204 eligible patients presenting to the International Extranodal Lymphoma Study Group-affiliated institutions from 1980 to 2003.

RESULTS

Median age was 64 years, with 95% of patients presenting with unilateral disease. Median overall survival (OS) was 8.0 years, and median progression-free survival 5.5 years. In multifactor analysis, favourable International Prognostic Index score, anthracycline-containing chemotherapy, and radiotherapy (RT) were significantly associated with longer OS (each P < or = 0.03). There was no benefit from mastectomy, as opposed to biopsy or lumpectomy only. At a median follow-up time of 5.5 years, 37% of patients had progressed--16% in the same or contralateral breast, 5% in the central nervous system, and 14% in other extranodal sites.

CONCLUSIONS

The combination of limited surgery, anthracycline-containing chemotherapy, and involved-field RT produced the best outcome in the pre-rituximab era. A prospective trial on the basis of these results should be pursued to confirm these observations and to determine whether the impact of rituximab on the patterns of relapse and outcome parallels that of DLBCL presenting at other sites.

Effect of addition of rituximab to CHOP on survival of patients in both the GCB and non-GCB subgroups of diffuse large B-cell lymphoma

8040

Background: Diffuse large B-cell lymphoma (DLBCL) includes at least two prognostically important subgroups, i.e. germinal center B-cell (GCB) and activated B-cell (ABC) DLBCL, which were initially characterized by gene expression profiling and subsequently validated by immunostaining. Bcl-2 has also been identified as a prognostic indicator in the ABC subgroup. However, with the addition of rituximab (R) to standard chemotherapy, the prognostic significance of this subclassification of DLBCL is unclear. Methods: We studied 119 cases of de novo DLBCL including 70 cases treated with R-CHOP and 49 cases treated with CHOP. The cases were assigned to either the GCB or non-GCB subgroups using the methodology described by Hans et al (Blood 2004; 103:275). Characteristics of the patients were compared using the Chi-square test. Overall survival (OS) and event-free survival (EFS) were estimated using the Kaplan Meier method and compared with the log-rank test. Results: The median age of the 119 patients was 67 years, ranging from 20 to 90 years, and there were 62 males and 57 females. The clinical characteristics of patients treated with CHOP versus R-CHOP, including the IPI, were comparable. R-CHOP was more effective than CHOP with improved 5-year EFS (63% vs 41%, p=0.013) and OS (78% vs 47%, p<0.001). In both patient groups treated with R-CHOP or CHOP, the GCB subgroup had a significantly better 5-year EFS and OS compared to the non-GCB subgroup (OS: 91% vs 64% for R-CHOP, p=0.0073; 67% vs 31% for CHOP, p=0.034, respectively). Additionally, both the GCB and non-GCB subgroups treated with R-CHOP had a significantly improved OS compared to their respective subgroups receiving CHOP alone (GCB, p=0.015; non-GCB, p=0.019). Bcl-2 expression was not a significant predictor in either the GCB or non-GCB subgroups treated with R-CHOP (OS, GCB: p=0.32; non-GCB: p=0.43). Conclusions: In this retrospective study, we demonstrate that subclassification based on the cell of origin continues to have prognostic significance in patients with DLBCL treated with R-CHOP. Addition of rituximab to CHOP improves the overall survival of patients with DLBCL in both the GCB and non-GCB subgroups.

No significant financial relationships to disclose.

Advance care planning (ACP) prior to hematopoeitic stem cell transplantation (HSCT) in patients with cancer is associated with improved survival

9026

Background: HSCT carries an increased risk of mortality. Thus, patients are encouraged to have ACP. However, discussions about ACP is not a casual process since it may elicit undue anxiety to the patients and their families. Anecdotally, pts fear that discussion of the possibility of death is inconsistent with hoping for the best outcome. We therefore compared the outcomes of pts with or without ACP who received HSCT for cancer. Methods: ACP was defined as having living will, power of attorney for health care, or life-support instructions conducted prior to transplant. ACP were reviewed in pts who were at least 19 yo and received first allogeneic or autologous HSCT for cancer between 2001 and 2003. Pts were classified into: 1) No ACP, 2) ACP prior to cancer dx, 3) ACP after cancer dx but prior to HSCT. Multivariate analysis (MVA) was done to evaluate the relative risk of mortality at 1 year according to ACP while adjusting for other prognostic factors. Results: 343 pts were included in the study: 172 (50%) did not have ACP, while 171 (50%) pts had ACP. Of those with ACP, 127 pts (74%) were available for review. Characteristics were similar between pts with and without reviewable ACP. 28 pts had ACP prior to cancer dx, 87 had ACP prior to HSCT, while 12 had ACP after HSCT. 64% of pts with ACP had both power of attorney and a living will, 16% had a living will alone and 19% had power of attorney alone. Older pts (p <0.001) and Caucasians (p = 0.04) were more likely to have ACP. MVA were confined to the 172 pts with no ACP and 115 who had ACP before HSCT and showed that pts with ACP prior to HSCT had a significantly lower risk of mortality (see table ). Conclusions: Despite a diagnosis of cancer and hospitalization for HSCT, only 50% of patients had engaged in ACP. ACP at any time before HSCT was associated with higher one-year survival. Engagement in ACP is not necessarily inconsistent with hoping for the best outcome in HSCT. Further study is warranted to explore the reasons for engaging or not in ACP.

No significant financial relationships to disclose.

[Table: see text]

Addition of tumor bulk to the International Prognostic Index (IPI) does not improve prognostication in diffuse large B-cell Lymphoma (DLBCL)

7585

Background: Bulky disease in DLBCL has been linked to adverse outcomes. Tumor bulk was not included in the IPI due to lack of uniform data availability. Radiation to sites of bulky disease may result in improved outcomes. We evaluated the impact of tumor bulk as a prognostic factor combined with the IPI in predicting overall survival in DLBCL. Methods: A retrospective review of adult patients with newly diagnosed DLBCL from October 1982 through February 2000 was done, and data pertaining to tumor size, age, Ann Arbor stage, performance status (PS), lactate dehydrogenase level (LDH), extranodal involvement, radiation therapy and overall survival was collected. Surviving patients were followed through December 2005. Bulky disease was defined as largest tumor mass of ≥10 cm. Statistical analysis was performed using Cox proportional hazards regression. Results: Complete data was available on 669 patients. All patients received anthracycline or mitoxantrone based chemotherapy. Bulky disease was found in 27% of patients, while radiation was employed in 22% of patients. There was no significant association between use of radiation and tumor bulk. IPI was calculated as low risk—37%, low-intermediate—28%, high-intermediate—20% and high—14%. Median follow-up of survivors was 100 months (range <1 - 263). In univariate analysis, bulky disease alone was a significant predictor of inferior survival (RR 1.27, p = 0.044), however when combined with the IPI it was not a significant predictor of poorer overall survival as compared with non-bulky disease (RR 1.10, p = 0.36). Radiation therapy was associated with a significant increase in overall survival (RR 0.70, p = 0.005). Conclusions: Bulky disease is an important independent prognostic factor for overall survival in patients with DLBCL, however when combined with IPI it does not result in improved prediction. It is unclear whether this is due to insufficient power or due to possible inter-relation between tumor size, LDH and PS, the latter of which are included in the IPI. Radiation therapy to some patients with bulky disease may also have mitigated the adverse effect. Larger prospective studies may shed light on the utility of tumor bulk combined with IPI and possible alterations in management.

No significant financial relationships to disclose.

Effect of follow-up provider source on outcomes of patients with hematologic malignancies receiving hematopoietic stem cell transplantation

6112

Background: Studies have shown that involvement of trained physicians is associated with favorable outcomes of patients receiving hematopoietic stem cell transplantation (HSCT). At the University of Nebraska Medical Center (UNMC), most patients are shifted back to the care of their referring physicians in the first 100 days. We evaluated whether the practice of shifting care of patients from specialists to primary care providers (PCP), referred to as patient care oscillation, in HSCT results in optimal outcomes. Methods: Data from 666 patients who underwent HSCT for malignant hematologic disorders between 2000 and 2003 were analyzed. Cox proportional hazards regression analyses were done to compare the relative risk of relapse/progression and mortality at 100-days and 1-year between patients whose care remained with specialists (transplant MDs at UNMC or community oncologist) versus those who were transferred back to the care of referring PCPs while adjusting for patient and disease factors. Results: Rate of patient care oscillation varies according to type of transplant. In allo-HSCT, 50% of patients received follow-up care from PCPs, 30% from community oncologists, while 20% remain at UNMC for follow-up. In auto-HSCT, 70% of patients received follow-up care from PCPs, 20% from community oncologists, while 10% remain at UNMC for follow-up with transplanting physicians. Outcomes after HSCT according to type of transplant is shown in the table. Conclusions: These preliminary findings suggest that in both allogeneic and autologous HSCT, the risk of disease progression/relapse and mortality may be independent of the type of follow-up care provider. However, further studies are needed to determine whether the practice of shifting the care of HSCT patients results in similar medical care utilization, post-transplant complications, re-hospitalizations and patient satisfaction. Patients likely to benefit from specialized versus primary care should be identified.

[Table: see text]

No significant financial relationships to disclose.

Patients with grade 3 follicular lymphoma have prolonged relapse-free survival following anthracycline-based chemotherapy: the Nebraska Lymphoma Study Group Experience

BACKGROUND

The aim of the study was to determine the outcome and clinical features predictive of survival in patients with follicular lymphoma (FL) treated aggressively and to determine the rate of disease-specific mortality in patients with grade 3 FL (FL3).

MATERIALS AND METHODS

Four hundred and twenty-one patients with FL who were treated with various anthracycline-based chemotherapy regimens were included in this retrospective study.

RESULTS

Patients with FL3 and a diffuse component of >50% had the worst outcome, with a hazard ratio of dying of 2.2 (95% CI 1.4-3.4) compared with patients with FL1 or FL2, and a ratio of 1.6 (95% CI 1.02-2.5) compared with FL3 with a diffuse component of < or =50% by multivariate analysis (P = 0.0026). Patients with FL3a had an outcome similar to those with FL3b. In patients with FL3 and a diffuse component of < or =50%, the overall and event-free survival curves showed a plateau for patients younger than 60 years of age. However, there were no differences in the cumulative incidence of relapse/progression or lymphoma-specific/treatment-related mortality between the two age groups.

CONCLUSIONS

Less than half of the patients with FL3 and a diffuse component of < or =50% treated with anthracycline-based combination chemotherapy will relapse and relapses are uncommon after 6 years. Older patients should be offered the same aggressive chemotherapy as younger patients.

Hematopoietic stem cell transplantation in mantle cell lymphoma

BACKGROUND

Patients with mantle cell lymphoma (MCL) have in general, lower response rates and overall survival (OS) than those with other B-cell non-Hodgkin's lymphomas. The role of hematopoietic stem cell transplantation (HSCT) in MCL is unclear. Hence we decided to study the clinical course of patients who received autologous and allogeneic HSCT for MCL.

METHODS

Ninety-seven patients, (80 patients-autologous; 17 patients-allogeneic) who received a HSCT for mantle cell lymphoma were included in the study.

RESULTS

The complete response rates at day 100 between the two groups were similar (73% vs. 62%). Day-100 mortality was higher in the allogeneic HSCT group (19% vs. 0%) (P < 0.01). The estimated 5-year relapse rates, 5-year event-free survival (EFS) and 5-year OS among the allogeneic HSCT patients were 21%, 44% and 49%, respectively, similar to 56%, 39% and 47% in the autologous group. Ten patients received HyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone + high-dose methotrexate and cytarabine) +/- rituximab prior to transplant. There have been no relapses or deaths amongst these patients at a median follow-up of 16 months.

CONCLUSIONS

Patients treated with allogeneic HSCT had a lower relapse rate, but similar EFS and OS to autologous HSCT. Treatment of MCL with HyperCVAD +/- rituximab followed by HSCT seems promising.

Immunological and clinical effects of post-transplant G-CSF versus placebo in T-cell replete allogeneic blood transplant patients: Results from a randomized double-blind study

BACKGROUND

Immunological and clinical effects of post-transplant growth factor administration have not been well studied. This report describes the outcome and immune functions of a total of 50 HLA-matched related donor allogeneic blood stem-cell transplantation patients who received post-transplant G-CSF (10 microg/kg) or placebo.

METHODS

Immune status, including number of lymphocyte subsets and their functions, and serum immunoglobulin levels and clinical status--including GvHD, rate of relapse, event-free survival, and overall survival--were determined in the patients enrolled in this study.

RESULTS

Twenty-eight patients survived 1 year after transplant, and 15 patients had available results to compare immune function by randomization assignment. At 12 months post-transplant, immune parameters in G-CSF versus placebo groups showed no statistically significant differences in number of circulating lymphocyte subsets CD3, CD4, CD8, CD19 and CD56 in the two groups. There was no significant (NS) difference in immunoglobulin IgG, IgA and IgM levels, NK or LAK cell-mediated cytotoxicity levels, and mitogen-induced proliferation between post-transplant G-CSF and placebo group. In addition, the analyses of immune parameters at earlier time-points on Days 28, 100, 180, and 270 revealed that, except for LAK cytotoxicity at Day 100, there was no differences between the two groups. Fourteen of 26 patients are alive in the G-CSF arm and nine of 24 in the placebo arm. Median follow-up of surviving patients is 43 months. Four year overall and event-free survival in the G-CSF and the placebo group were 53% and 35% (NS), and 44% and 36% (NS) respectively. Bacterial or fungal infections were the cause of six of 12 deaths in the G-CSF arm (all bacterial) and of four of 15 deaths in the placebo arm (two deaths from Aspergillus) (P=0.26). Two patients relapsed in the G-CSF arm and three in the placebo arm. Four year cumulative incidences of relapse were 8% versus 13% in G-CSF versus placebo arms, respectively, (NS). Chronic GvHD developed in 14 of 19 100-day survivors after G-CSF (11 extensive stage), and in 17 of 20 (14 extensive stage) in the placebo arm. The 4-year cumulative incidence of chronic GvHD was 56% [95% confidence interval (CI) 24-88%] after G-CSF and 71% (95% CI 48-94%) after placebo; this difference was not statistically significant (log rank P=0.41).

CONCLUSION

In summary, there were no significant immunological or alterations in clinical benefit of post-transplant G-CSF administration in T-replete allotransplant recipients.

The International Prognostic Factors Project score for advanced Hodgkin's disease is useful for predicting outcome of autologous hematopoietic stem cell transplantation

BACKGROUND

The International Prognostic Factors Project on Advanced Hodgkin's Disease developed a seven-factor prognostic score consisting of serum albumin, hemoglobin, gender, stage, age, leukocytosis and lymphocytopenia for newly diagnosed Hodgkin's disease patients who receive chemotherapy. The purpose of this study was to determine whether this prognostic score would also be useful for Hodgkin's disease patients undergoing autologous hematopoietic stem cell transplantation.

PATIENTS AND METHODS

We performed a retrospective review of 379 patients who had autologous transplants for Hodgkin's disease, at the University of Nebraska Medical Center between October 1984 and December 1999. Multivariate analysis was performed to determine whether the prognostic factors identified by the International Prognostic Factors Project adversely influenced event-free survival (EFS) or overall survival (OS).

RESULTS

Low serum albumin, anemia, age and lymphocytopenia were associated with poorer EFS and OS. Gender, stage and leukocytosis were not associated with significantly poorer outcomes. Estimated 10-year EFS was 38%, 23% and 7% for patients with 0-1, 2-3 or > or =4 of the adverse prognostic characteristics identified by the International Prognostic Factors Project, respectively.

CONCLUSIONS

The prognostic score for advanced disease is also useful for relapsed and refractory Hodgkin's disease patients undergoing high-dose therapy followed by autologous hematopoietic stem cell transplantation.

Hodgkin's disease and non-Hodgkin's lymphoma

The development of new classification schemes and prognostic analyses for lymphomas has helped to identify patients at high risk for relapse who may benefit from intensification of primary therapy. Conventional salvage therapy for relapsed follicular or low-grade lymphomas now includes monoclonal antibody therapy. The combination of chemotherapy and monoclonal antibody therapy may improve outcomes for patients with advanced-stage aggressive non-Hodgkin's lymphomas. Confirmatory randomized trials are now in progress. Therapy for Hodgkin's disease continues to evolve toward the most efficacious programs, which also minimize the long-term probability of toxicity. The combination of high-dose chemotherapy and stem cell transplantation is probably the most effective therapy for patients with relapsed or refractory Hodgkin's disease.

Is post-operative radiation for renal cell carcinoma justified?

PURPOSE

To identify the pattern of failure in patients with resected renal cell carcinoma (RCC).

MATERIALS AND METHODS

The records of 116 patients with unilateral, non-hematogenous metastatic RCC who were treated with definitive surgery and referred to the Ottawa Regional Cancer Centre between 1977 and 1988 were reviewed. Distribution by stage included T1 (3 patients), T2 (42 patients) and T3 (71 patients). The median follow-up was 44 months, with a range of 4-267 months.

RESULTS

Local regional failure (LRF) developed in 8 patients. Nine patients developed local or regional recurrence, plus distant failure. Fifty-eight patients had distant metastases (DM) only. The 7-year actuarial rate for LRF and DM were 12%, and 67%, respectively. The overall 7-year actuarial survival rate was 35%, and cause-specific survival was 42%.

CONCLUSIONS

LRF alone is rare following nephrectomy. DM is the main pattern of failure. This data does not support the role of adjuvant radiation therapy in this disease.

Radiotherapy for localized prostate carcinoma. The correlation of pretreatment prostate specific antigen and nadir prostate specific antigen with outcome as assessed by systematic biopsy and serum prostate specific antigen

BACKGROUND

The objective of this study was to correlate the failure pattern of localized prostate carcinoma after radiotherapy (RT) with pretreatment (preTx) PSA and post-RT nadir PSA, using systematic biopsies and serum PSA in the assessment of outcome.

METHODS

From January 1990 to February 1994, 207 patients treated with external beam RT were followed prospectively with systematic transrectal ultrasound-guided biopsies and measurements of serum PSA levels. Three hundred forty-three biopsies were performed, with 4-7 samples taken per session. The distribution of T classification was as follows: 19 patients had T1b, 15 had T1c, 34 had T2a, 79 had T2b/c, 53 had T3, and 7 had T4. Median follow-up was 36 months (range, 12-70 months). Failures were categorized as biochemical (chemF) (PSA > 2.0 ng/mL and > 1 ng/ mL over nadir), local (LF) (positive biopsy and PSA > 2), and distant (DF). The Cox proportional hazards model was used for multivariate analysis (MVA).

RESULTS

Overall, failures were seen in 68 of 207 patients: 20 LF, 24 DF, 7 LF + DF, and 17 chemF. In univariate analysis, failures correlated significantly with preTx PSA, post-RT nadir PSA, T classification, and Gleason's score (GS). The total failure rate was 12% for T1b, T1c, and T2a; 39% for T2b and T2c; and 60% for T3 and T4 (P < 0.0001). By evaluation with preTx PSA, at 36 months the total failure rate was 3% for preTx PSA < or = 5 ng/mL 16% for 5.1-10 ng/mL, 32% for 10.1-15 ng/mL, 42% for 15.1-20 ng/mL, 63% for 20.1-50 ng/mL, and 88% for > 50 ng/mL (P < 0.0001). By evaluation with post-RT nadir PSA, at 36 months the total failure rate was 4% for nadir PSA < or = 0.5 ng/ mL, 26% for 0.6-1 ng/mL, 33% for 1.1-2 ng/mL, and 92% for > 2 ng/mL (P < 0.0001). In MVA, nadir PSA (P < 0.0001) and T classification (P < 0.0005) were independent predictors for any failure. LF occurred in 13% of patients (27 of 207). For these 27 patients, the categorization of T classification was: T1b/T1c/T2a, 7%; T2b/T2c, 16%; and T3/T4, 15% (P = not significant). In MVA, only nadir PSA (P = 0.0004) predicted for LF. DF occurred in 15% of patients (31 of 207). In MVA, nadir PSA (P < 0.0001) and T classification (P < 0.0001) predicted for DF, with pretreatment PSA of borderline significance (P < 0.05). To assess preTx predictors of outcome, post-RT nadir PSA was removed from the model. PreTx PSA then became the dominant variable to predict any failure (P < 0.0001), LF (P = 0.05), chemF (P = 0.0001), and DF (P < 0.003), while T classification also predicted for any failure (P = 0.03), chemF (P = 0.05), and DF (P < 0.0001).

CONCLUSIONS

Systematic prostate biopsies, performed as part of the rigorous followup of prostate carcinoma after RT, define the patterns of failure and confirm the prognostic value of preTx PSA, post-RT nadir PSA, and T classification. Prior to treatment, preTx PSA is the overwhelming independent predictor of failure, but it is surpassed by post-RT nadir PSA when this is added to the model.

Hematopoietic growth factors

Over the past ten years, the availability of pharmacologic quantities of hematopoietic growth factors has opened many avenues of study in basic science and clinical investigation. Numerous studies performed to date have demonstrated significant benefits from the use of these cytokines. The side effect profiles, particularly for "later acting" growth factors, indicate that they are generally well tolerated by most patients. The table summarizes the potential indications for hematopoietic growth factor use as discussed in this article, as justified by current evidence of benefit, harm, and cost effectiveness resulting from their use in various clinical settings. It has been clearly demonstrated in standard-dose chemotherapy regimens that these agents shorten the duration of myelosuppression, reduce the incidence of significant infection, can shorten hospital stay, and reduce antibiotic use for most patients, although the cost/benefit ratio for growth factors such as G-CSF makes this a cost-effective approach only for regimens with a high (40 percent or more) incidence of febrile neutropenia. Limited indirect evidence supports the use of growth factors in patients with a prior episode of fever and neutropenia. The suppressive approach to growth factor use could potentially benefit patients with documented infection or clinical deterioration, but it has not otherwise been shown to be a particularly effective or cost-effective approach. Administration of hematopoietic growth factors has been instrumental in facilitating both autologous and allogeneic peripheral progenitor cell mobilization and techniques such as ex vivo expansion. There is an increasing body of data supporting the use of high-dose chemotherapy regimens with progenitor cell rescue for a number of malignancies and limited data supporting the benefits of maintaining dose-intensity for certain malignancies in standard-dose settings. Although of continuing concern, clinically significant evidence of disease stimulation and recurrence has not been unequivocally demonstrated in studies to date. A comprehensive set of evidence-based guidelines has recently been published by the American Society of Clinical Oncology. As often is the case, current studies have perhaps generated more questions than answers. Future investigation will undoubtedly focus on use of hematopoietic growth factors in conjunction with other techniques, such as outpatient-based treatment of febrile neutropenia, CD34-positive stem cell selection in autologous transplantation, selective manipulation of T-cell subsets (to decrease the incidence of severe graft-versus-host disease) in allogeneic transplantation, and high-dose therapy with stem cell transplantation.