Combined radiotherapy and chemotherapy
Michael C. Joiner, Albert J. van der Kogel in Basic Clinical Radiobiology, 2018
Classically, cytotoxic anti-neoplastic drugs are divided into different classes based on their mechanisms of action, i.e. anti-metabolites, alkylating agents, topoisomerase inhibitors, anti-microtubule agents and antibiotics. Compared to radiotherapy or surgery, chemotherapy is a systemic treatment administered mainly intravenously or orally. Chemotherapy agents are used alone (monochemotherapy) or in combination (polychemotherapy). Typically, chemotherapeutic agents are biologically active by killing dividing cells, thus exerting both their efficacy and their toxicity (Table 19.2). The main side effects typically observed with chemotherapy, but with important variations in intensity from one drug to another, include nausea, vomiting, alopecia, mucositis, fatigue, anaemia, thrombopenia and neutropenia. In addition, some specific toxicities can be observed with specific agents (e.g. cardiac dysfunction with anthracyclines, bladder toxicity with ifosfamide). Table 19.2 describes the main cytotoxic agents with their biological activity and specific toxicities.
Nanomaterials for Theranostics: Recent Advances and Future Challenges *
Valerio Voliani in Nanomaterials and Neoplasms, 2021
Despite the widespread clinical application of chemotherapy, its validity has been frequently questioned [37, 38, 396]. It appears that the usefulness of chemotherapy is limited to small subgroups of patients, e.g., old patients and patients with less common malignancies, such as esophagus, stomach, rectum, and brain cancer [397–402]. Furthermore, chemotherapeutic agents are not specific to cancer cells, which causes significant damage to rapidly proliferating normal cells, including skin, hair, gastrointestinal, and bone marrow cells. In general, chemotherapeutic drugs exhibit poor solubility in blood and therefore require usage of organic solvents for dosing, which further increases their toxicity. A number of new chemotherapeutic drugs have been hailed by cancer patients and medical staff in past decades, but their impact on curing cancer has continuously failed to meet expectations [171]. In order to solve the problems encountered in the application of chemotherapeutic drugs, gene therapies are being developed as alternative treatment modalities for cancer and hereditary diseases, which are linked to the presence of defective genes due to mutations.
Oncology
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss in Understanding Medical Terms, 2020
Surgical treatment options for excision of breast cancer include mastectomy (radical, extensive radical, modified radical, simple [total], or subcutaneous), and lumpectomy (tylectomy). Oophorectomy (removal of the ovaries) is another surgical procedure sometimes used to reduce the level of endogenous ovarian hormones and temporarily regress hormone-dependent tumors. Adrenalectomy and hypophysectomy (excision of the adrenal and pituitary glands, respectively) are also utilized to decrease hormone secretions. Radiation therapy has been used for all types of breast cancer as primary, adjuvant, and palliative treatment. A number of chemotherapeutic agents are used successfully in treatment, particularly in multidrug regimens. Hormonal manipulation has also been a significant addition to treatment options. Use is determined by the presence of estrogen receptor protein (ERP) in the tumor tissue.
Construction of novel procoagulant protein targeting neuropilin-1 on tumour vasculature for tumour embolization therapy
Published in Journal of Drug Targeting, 2019
Mingyuan Zou, Malik Samiullah, Peilan Xu, Shengyu Wang, Jie He, Ting Wu, Fanghong Luo, Jianghua Yan
Tumour embolisation therapy is highly efficient. Because each vessel provides the nutrition for and facilitates removal of waste products of metabolism from, many thousands of tumour cells. Blockage or destruction of the tumour-supplying vessel may then result in thousands of downstream cells death [29–31]. Besides, in order to successfully control cancer, chemotherapeutic agents have to reach every cancer cell and lead them to be eradicated or prevented from dividing. This is difficult to achieve because even in very small tumour deposits of 1 cm3 may require to contact with up to 109 of cells. While tumour vascular targeted therapy can directly contact vascular endothelial cells. Since all solid tumours depend upon the presence of vascular supply, tumour vascular targeted therapy has a broader spectrum of treatment [32]. Most importantly, highly selective tumour vascular targeted therapy has fewer toxic side effects than traditional tumour therapy [33].
Carbohydrates based stimulus responsive nanocarriers for cancer-targeted chemotherapy: a review of current practices
Published in Expert Opinion on Drug Delivery, 2022
Cheng-Wu Zhang, Jun-Gang Zhang, Xue Yang, Wen-Lin Du, Zi-Lin Yu, Zhen-Ye Lv, Xiao-Zhou Mou
Chemotherapeutic agents, either alone or in combination with other treatment modalities, are currently widely used for the treatment of various types of cancers. However, anticancer drugs are highly non-specific for cancerous cells. The therapeutic concentration in the tumor microenvironment for anticancer drugs is achieved at the expense of extensive contamination of the rest of the body, thus leading to diverse off-target side effects. Therefore, nanocarriers are explored as an alternative and efficient strategy for targeted and site-specific delivery of anticancer drugs. Stimulus-responsive nanocarriers are designed in a way that they respond to exterior stimuli like ultrasonic, light, heat, and magnetic fields, along with various internal stimuli including pH, hypoxia, enzyme, redox potential, thus releasing their loaded anticancer agents specifically in the micro-environment of the tumors. This in turn leads to the increased concentration of the drugs in the proximity of the tumor while avoiding the non-specific distribution of the drugs in other healthy tissues. Thus, stimulus-responsive nanocarriers achieved higher therapeutic efficacy for the anticancer drugs with minimum off-target side effects.
An update: emerging drugs to treat squamous cell carcinomas of the head and neck
Published in Expert Opinion on Emerging Drugs, 2018
Yoon Se Lee, Daniel E. Johnson, Jennifer R. Grandis
Combination chemotherapy regimens and postoperative concurrent chemoradiation therapy (CCRT) have not consistently resulted in notable improvements in the survival rate of HNSCC patients [18,19]. Moreover, the combination of chemotherapeutic agents may increase the rate of adverse events, including myelosuppression, mucositis, hair loss, and general weakness. The development and application of molecular targeting agents is aimed at minimizing off-target effects and adverse toxicities. Cumulative evidence supports EGFR as a therapeutic target in HNSCC leading to the 2006 FDA approval of the monoclonal antibody cetuximab. EGFR is a transmembrane tyrosine kinase receptor that activates the Ras and PI3K pathways and induces cellular proliferation, angiogenesis, invasion, and metastasis [20]. Treatment with cetuximab resulted in improved response rates, relative to conventional treatment, in patients with platinum-refractory metastatic or recurrent HNSCC [21]. However, despite widespread EGFR expression in HNSCC tumors, only a subset of HNSCC patients benefit from cetuximab therapy and studies to date have failed to identify predictive biomarkers to guide treatment selection.
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