The main strategy for conventional medical cure cancer is excision of all malignant cells by surgical intervention. In the past, this involved the excision of all affected tissue and the maximum number of potentially affected tissues, including the surrounding tissues and lymph nodes. For some tumors, especially breast cancer, it is not necessary as ablative surgery (mastectomy) in most cases.
Improvements in surgical techniques, knowledge on physiology, anesthesia and the availability of potent antibiotics and blood products, have led to more limited surgery, with fewer sequels and more speedy recovery.
However, many cancers are too widespread at the time of diagnosis for curative surgery is possible. If the local extent of tumor affects surrounding tissues that can not be resected, or if there are distant metastases, surgery is not curative treatment.
However, it may be beneficial for symptomatic relief of certain situations such as obstruction, or may have in order to reduce the tumor mass to allow better response to chemotherapy or radiotherapy thereafter.