This review shows that a significant proportion of patients in curative-intent clinical trials experience toxicities that result in dose modifications-dose reduction , dose delays or missed doses-despite strict selection criteria and intense monitoring .
Toxicities of systemic cancer therapies are often less frequently observed in clinical trials than in clinical practice , due to the careful selection of patients with fewer comorbidities .
Although guidelines exist for the estimation of chemotherapy dose , clinical factors like age , comorbid illness and extremes of body habitus are not considered in the method of dose calculation , which can result in significant toxicity .
Effect of age and comorbidity in postmenopausal breast cancer patients aged 55 years and older.
CONTEXT Postmenopausal women aged 55 years and older have 66 % of incident breast tumors and experience 77 % of breast cancer mortality , but other age-related health problems may affect tumor prognosis and treatment decisions . OBJECTIVE To document the comorbidity burden of postmenopausal breast cancer patients and evaluate its relationship with age on disease stage , treatment , and early mortality . DESIGN AND SETTING Data were collected on breast cancer patients ' comorbidities by retrospective hospital medical records review and merged with information on patients ' tumor characteristics collected from 6 regional National Cancer Institute Surveillance , Epidemiology , and End Results cancer registries . Patients were followed up until death or for 30 months from breast cancer diagnosis . PARTICIPANTS Population -based r and om sample of 1800 postmenopausal breast cancer patients diagnosed in 1992 stratified by 3 age groups : 55 to 64 years , 65 to 74 years , and 75 years and older . MAIN OUTCOME MEASURES Extent of disease , therapy received , comorbidity , cause of death , and survival . RESULTS Seventy-three percent ( 1312 of 1800 ) of the sample was diagnosed with stage I and II breast cancer , 10 % ( n = 188 ) with stage III and IV breast cancer , and 17 % ( n = 300 ) did not have a stage assignment . Of the 1017 patients with stage I and stage II node-negative breast cancer , 95 % received therapy in agreement with the National Institutes of Health consensus statement recommendation for early-stage breast cancer . Patients in older age groups were less likely to receive therapy consistent with the consensus statement ( P<.001 ) , and women aged 70 years and older were significantly less likely to receive axillary lymph node dissection as determined by logistic regression analysis ( P<.01 ) . Diabetes , renal failure , stroke , liver disease , a previous malignant tumor , and smoking were significant in predicting early mortality in a statistical model that included age and disease stage . Breast cancer was the underlying cause of death for 135 decedents ( 51.3 % ) . Heart disease ( n = 45 , 17.1 % ) and previous cancers ( n = 22 , 8.4 % ) were the next major underlying causes . In the 30-month follow-up period , 263 patients ( 15 % ) died . CONCLUSION Patient care decisions occur in the context of breast cancer and other age-related conditions . Comorbidity in older patients may limit the ability to obtain prognostic information ( ie , axillary lymph node dissection ) , tends to minimize treatment options ( eg , breast-conserving therapy ) , and increases the risk of death from causes other than breast cancer
This review shows that a significant proportion of patients in curative-intent clinical trials experience toxicities that result in dose modifications-dose reduction , dose delays or missed doses-despite strict selection criteria and intense monitoring .
Toxicities of systemic cancer therapies are often less frequently observed in clinical trials than in clinical practice , due to the careful selection of patients with fewer comorbidities .
Although guidelines exist for the estimation of chemotherapy dose , clinical factors like age , comorbid illness and extremes of body habitus are not considered in the method of dose calculation , which can result in significant toxicity .