ABSTRACT
Cancer is a genetic disease that is developed due to accumulated multiple genetic defects along human life span. The heterogenous natures of genetic and malignant phenotypes within each type of cancer create a great challenge for cancer diagnosis and treatment [1]. At present the time, a high percentage of cancer patients are incurable, especially for solid tumors in late stage [2]. So, the quality of life (QOL) is particularly important to patients with advanced cancer, because most of them are symptomatic when diagnosed [3,4]. In addition, repeated utilization of chemotherapy agent
nonspecifically kills proliferating cells, which leads to significantly toxic side effects and decreased patient QOL [5]. Such nonspecific therapeutic strategy induces chemo-resistance, which creates a situation of either further increasing chemotherapy dosage with more severe toxicity or making patients intolerable for treatment. Neither is a best therapeutic strategy for cancer patients. Therefore, when treating cancer patients at the intermediate or advanced stage, the evaluation of patient outcomes should not just focus on the elimination of tumor burden at the expense of cancer patient QOL.
