RELATIVE TOTAL DOSE INTENSITY OF TREATMENT WITH R-CHOP IN OBESE VERSUS NON OBESE LYMPHOMA PATIENTS DOSED ON ACTUAL BODY WEIGHT: A SINGLE CENTRE EXPERIENCE
(Abstract release date: 05/19/16)
EHA Library. Preston A. 06/09/16; 134626; PB1726
Mrs. Andrea Preston
Contributions
Contributions
Abstract
Abstract: PB1726
Type: Publication Only
Background
The number of obese patients in the UK is growing to epidemic proportions and due to an aging population the incidence of cancer is also increasing. To ensure good patient outcomes it is imperative that we optimally treat obese patients, particularly in the curative setting for diseases such as diffuse large B-cell lymphoma (DLBCL). In 2012 the American Society of Clinical Oncology (ASCO) released a Clinical Practice Guideline recommending that obese patients should be dosed on their full body weight. It is recognised however that clinicians in the UK continue to dose adjust (or ‘cap’ doses) in fear of excess toxicity.
Aims
This study aims to assess whether dosing on actual body weight in obese patients with R-CHOP chemotherapy for DLBCL affects relative total dose intensity of treatment (RTDI).
Methods
A retrospective analysis was performed of 77 consecutive patients who had received treatment with R-CHOP chemotherapy for DLBCL from 2006 to 2010. After exclusions for insufficient individual patient data or modifications to the regime e.g. addition of etoposide (R-CHOEP), the remaining number of patients for analysis was 66 (obese patients dosed on full body weight; n= 18 and non-obese; n = 48).Baseline characteristics were recorded. Weight and height measurements within 1 month of treatment initiation were used to calculate body surface area (BSA) and body mass index (BMI). Patients were defined as obese if BMI ≥ 30kg/m2 as per WHO classification. IBW was calculated for obese patients using the BJ Devine formula. RTDI was calculated using previously published methods. It is the ratio of Actual Total Dose Intensity (ATDI) and Planned Total Dose Intensity (PTDI) expressed as a percentage i.e. RTDI (%)= ATDI/ PTDI x 100. PTDI is the planned dose intensity over the entire treatment duration, averaged across the chemotherapy agents used. For permanent treatment discontinuation for a reason other than disease progression, relapse or death, the remaining cycles are calculated with planned length and zero dose. In cases of disease progression, relapse or death PTDI is calculated based on number of cycles completed. ATDI is the actual average dose intensity over the real treatment duration i.e. actual total dose (mg) / duration of therapy (weeks). RTDI therefore takes into account the effects of treatment delays as well as dose reductions, and premature cessation of therapy due to reasons other than disease progression or death. It is a surrogate marker of survival and multiple studies have demonstrated that achieving an average RTDI > 90% is associated with improved long term outcomes. The chi squared test for trend was used to test for a trend in the number of patients being dose reduced at baseline between the two groups. Univariate analysis was performed for age, gender, performance status (PS), baseline characteristics including renal function, hepatic function, full blood count, line of treatment, and GCSF usage using chi-squared tests, t-tests and Mann-Whitney tests. Multivariable linear regression was performed to adjust for confounding factors.
Results
Before adjusting for confounding factors, there was a non-significant difference in average RTDI for R-CHOP between obese and non-obese patients of 7.22%. After adjusting for age, gender, performance status, and whether patients were dose modified in the 1st cycle, a multivariable linear regression showed a reduction in this difference to 5.67% . There was no evidence to suggest a difference in RTDI between the two groups.
Conclusion
These findings, although of limited value due to small patient numbers, would reassure clinicians and pharmacists that full weight based dosing in obese patients should not lead to excess toxicity. In conjunction with the broader published literature and ASCO’s Clinical Practice Guideline they support dosing on actual body weight for R-CHOP for obese patients with DLBCL.
Session topic: E-poster
Keyword(s): Chemotherapy, Chemotherapy toxicity, Diffuse large B cell lymphoma, Obesity
Type: Publication Only
Background
The number of obese patients in the UK is growing to epidemic proportions and due to an aging population the incidence of cancer is also increasing. To ensure good patient outcomes it is imperative that we optimally treat obese patients, particularly in the curative setting for diseases such as diffuse large B-cell lymphoma (DLBCL). In 2012 the American Society of Clinical Oncology (ASCO) released a Clinical Practice Guideline recommending that obese patients should be dosed on their full body weight. It is recognised however that clinicians in the UK continue to dose adjust (or ‘cap’ doses) in fear of excess toxicity.
Aims
This study aims to assess whether dosing on actual body weight in obese patients with R-CHOP chemotherapy for DLBCL affects relative total dose intensity of treatment (RTDI).
Methods
A retrospective analysis was performed of 77 consecutive patients who had received treatment with R-CHOP chemotherapy for DLBCL from 2006 to 2010. After exclusions for insufficient individual patient data or modifications to the regime e.g. addition of etoposide (R-CHOEP), the remaining number of patients for analysis was 66 (obese patients dosed on full body weight; n= 18 and non-obese; n = 48).Baseline characteristics were recorded. Weight and height measurements within 1 month of treatment initiation were used to calculate body surface area (BSA) and body mass index (BMI). Patients were defined as obese if BMI ≥ 30kg/m2 as per WHO classification. IBW was calculated for obese patients using the BJ Devine formula. RTDI was calculated using previously published methods. It is the ratio of Actual Total Dose Intensity (ATDI) and Planned Total Dose Intensity (PTDI) expressed as a percentage i.e. RTDI (%)= ATDI/ PTDI x 100. PTDI is the planned dose intensity over the entire treatment duration, averaged across the chemotherapy agents used. For permanent treatment discontinuation for a reason other than disease progression, relapse or death, the remaining cycles are calculated with planned length and zero dose. In cases of disease progression, relapse or death PTDI is calculated based on number of cycles completed. ATDI is the actual average dose intensity over the real treatment duration i.e. actual total dose (mg) / duration of therapy (weeks). RTDI therefore takes into account the effects of treatment delays as well as dose reductions, and premature cessation of therapy due to reasons other than disease progression or death. It is a surrogate marker of survival and multiple studies have demonstrated that achieving an average RTDI > 90% is associated with improved long term outcomes. The chi squared test for trend was used to test for a trend in the number of patients being dose reduced at baseline between the two groups. Univariate analysis was performed for age, gender, performance status (PS), baseline characteristics including renal function, hepatic function, full blood count, line of treatment, and GCSF usage using chi-squared tests, t-tests and Mann-Whitney tests. Multivariable linear regression was performed to adjust for confounding factors.
Results
| Obese N=18 | Control (non-obese) N=48 | P-value | |
| Average RTDI Mean (sd%) | 94.05 (7.13) | 86.83 (16.05) | 0.071 (t-test) |
Conclusion
These findings, although of limited value due to small patient numbers, would reassure clinicians and pharmacists that full weight based dosing in obese patients should not lead to excess toxicity. In conjunction with the broader published literature and ASCO’s Clinical Practice Guideline they support dosing on actual body weight for R-CHOP for obese patients with DLBCL.
Session topic: E-poster
Keyword(s): Chemotherapy, Chemotherapy toxicity, Diffuse large B cell lymphoma, Obesity
Abstract: PB1726
Type: Publication Only
Background
The number of obese patients in the UK is growing to epidemic proportions and due to an aging population the incidence of cancer is also increasing. To ensure good patient outcomes it is imperative that we optimally treat obese patients, particularly in the curative setting for diseases such as diffuse large B-cell lymphoma (DLBCL). In 2012 the American Society of Clinical Oncology (ASCO) released a Clinical Practice Guideline recommending that obese patients should be dosed on their full body weight. It is recognised however that clinicians in the UK continue to dose adjust (or ‘cap’ doses) in fear of excess toxicity.
Aims
This study aims to assess whether dosing on actual body weight in obese patients with R-CHOP chemotherapy for DLBCL affects relative total dose intensity of treatment (RTDI).
Methods
A retrospective analysis was performed of 77 consecutive patients who had received treatment with R-CHOP chemotherapy for DLBCL from 2006 to 2010. After exclusions for insufficient individual patient data or modifications to the regime e.g. addition of etoposide (R-CHOEP), the remaining number of patients for analysis was 66 (obese patients dosed on full body weight; n= 18 and non-obese; n = 48).Baseline characteristics were recorded. Weight and height measurements within 1 month of treatment initiation were used to calculate body surface area (BSA) and body mass index (BMI). Patients were defined as obese if BMI ≥ 30kg/m2 as per WHO classification. IBW was calculated for obese patients using the BJ Devine formula. RTDI was calculated using previously published methods. It is the ratio of Actual Total Dose Intensity (ATDI) and Planned Total Dose Intensity (PTDI) expressed as a percentage i.e. RTDI (%)= ATDI/ PTDI x 100. PTDI is the planned dose intensity over the entire treatment duration, averaged across the chemotherapy agents used. For permanent treatment discontinuation for a reason other than disease progression, relapse or death, the remaining cycles are calculated with planned length and zero dose. In cases of disease progression, relapse or death PTDI is calculated based on number of cycles completed. ATDI is the actual average dose intensity over the real treatment duration i.e. actual total dose (mg) / duration of therapy (weeks). RTDI therefore takes into account the effects of treatment delays as well as dose reductions, and premature cessation of therapy due to reasons other than disease progression or death. It is a surrogate marker of survival and multiple studies have demonstrated that achieving an average RTDI > 90% is associated with improved long term outcomes. The chi squared test for trend was used to test for a trend in the number of patients being dose reduced at baseline between the two groups. Univariate analysis was performed for age, gender, performance status (PS), baseline characteristics including renal function, hepatic function, full blood count, line of treatment, and GCSF usage using chi-squared tests, t-tests and Mann-Whitney tests. Multivariable linear regression was performed to adjust for confounding factors.
Results
Before adjusting for confounding factors, there was a non-significant difference in average RTDI for R-CHOP between obese and non-obese patients of 7.22%. After adjusting for age, gender, performance status, and whether patients were dose modified in the 1st cycle, a multivariable linear regression showed a reduction in this difference to 5.67% . There was no evidence to suggest a difference in RTDI between the two groups.
Conclusion
These findings, although of limited value due to small patient numbers, would reassure clinicians and pharmacists that full weight based dosing in obese patients should not lead to excess toxicity. In conjunction with the broader published literature and ASCO’s Clinical Practice Guideline they support dosing on actual body weight for R-CHOP for obese patients with DLBCL.
Session topic: E-poster
Keyword(s): Chemotherapy, Chemotherapy toxicity, Diffuse large B cell lymphoma, Obesity
Type: Publication Only
Background
The number of obese patients in the UK is growing to epidemic proportions and due to an aging population the incidence of cancer is also increasing. To ensure good patient outcomes it is imperative that we optimally treat obese patients, particularly in the curative setting for diseases such as diffuse large B-cell lymphoma (DLBCL). In 2012 the American Society of Clinical Oncology (ASCO) released a Clinical Practice Guideline recommending that obese patients should be dosed on their full body weight. It is recognised however that clinicians in the UK continue to dose adjust (or ‘cap’ doses) in fear of excess toxicity.
Aims
This study aims to assess whether dosing on actual body weight in obese patients with R-CHOP chemotherapy for DLBCL affects relative total dose intensity of treatment (RTDI).
Methods
A retrospective analysis was performed of 77 consecutive patients who had received treatment with R-CHOP chemotherapy for DLBCL from 2006 to 2010. After exclusions for insufficient individual patient data or modifications to the regime e.g. addition of etoposide (R-CHOEP), the remaining number of patients for analysis was 66 (obese patients dosed on full body weight; n= 18 and non-obese; n = 48).Baseline characteristics were recorded. Weight and height measurements within 1 month of treatment initiation were used to calculate body surface area (BSA) and body mass index (BMI). Patients were defined as obese if BMI ≥ 30kg/m2 as per WHO classification. IBW was calculated for obese patients using the BJ Devine formula. RTDI was calculated using previously published methods. It is the ratio of Actual Total Dose Intensity (ATDI) and Planned Total Dose Intensity (PTDI) expressed as a percentage i.e. RTDI (%)= ATDI/ PTDI x 100. PTDI is the planned dose intensity over the entire treatment duration, averaged across the chemotherapy agents used. For permanent treatment discontinuation for a reason other than disease progression, relapse or death, the remaining cycles are calculated with planned length and zero dose. In cases of disease progression, relapse or death PTDI is calculated based on number of cycles completed. ATDI is the actual average dose intensity over the real treatment duration i.e. actual total dose (mg) / duration of therapy (weeks). RTDI therefore takes into account the effects of treatment delays as well as dose reductions, and premature cessation of therapy due to reasons other than disease progression or death. It is a surrogate marker of survival and multiple studies have demonstrated that achieving an average RTDI > 90% is associated with improved long term outcomes. The chi squared test for trend was used to test for a trend in the number of patients being dose reduced at baseline between the two groups. Univariate analysis was performed for age, gender, performance status (PS), baseline characteristics including renal function, hepatic function, full blood count, line of treatment, and GCSF usage using chi-squared tests, t-tests and Mann-Whitney tests. Multivariable linear regression was performed to adjust for confounding factors.
Results
| Obese N=18 | Control (non-obese) N=48 | P-value | |
| Average RTDI Mean (sd%) | 94.05 (7.13) | 86.83 (16.05) | 0.071 (t-test) |
Conclusion
These findings, although of limited value due to small patient numbers, would reassure clinicians and pharmacists that full weight based dosing in obese patients should not lead to excess toxicity. In conjunction with the broader published literature and ASCO’s Clinical Practice Guideline they support dosing on actual body weight for R-CHOP for obese patients with DLBCL.
Session topic: E-poster
Keyword(s): Chemotherapy, Chemotherapy toxicity, Diffuse large B cell lymphoma, Obesity
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