Fill up the blanks with the most appropriate choice, from any of the words given below the passage.
For a long time, cancer has been treated with open surgery, which is a ___1___ style, thereby ___2___ pain for the patients who ___3___ surgery. However, technology has developed tremendously ___4___ the past two decades and this has mitigated the pain of the patients to ___5___.
The surgeries for cancer-related ___6___ is an area, where there are continuous efforts to ___7___ the treatment pattern. Cancer affects the cells of the human body, causing massive ___8___ of its cells. This expands and ___9___ to the other parts of the body, thereby causing a threat to life. Surgery is a significant course of treatment and ___10___ tumours are eliminated, which will prevent ___11___ permanent damage to the organs.
In an open surgery, the surgeon manually makes a single ___12___ , through which the surrounding tissues and nodes are removed. Open ___13___ help patients greatly, but have their own ___14___ problems. Loss of blood, long recovery span and hazard of infection still ___15___ as major threats in this system.