P站视频

Ancient physicians and surgeons knew that cancer would usually come back after it was surgically removed. The Roman physician Celsus wrote, “After excision, even when a scar has formed, none the less the disease has returned.”

Galen was a 2nd-century Greek doctor whose books were preserved for centuries. He was thought to be the highest medical authority for over a thousand years. Galen viewed cancer much as Hippocrates had, and considered the patient incurable after a diagnosis of cancer had been made. His views set the pattern for cancer management for centuries.

Even though medicine progressed and flourished in some ancient civilizations, there was little progress in cancer treatment. The approach to cancer was Hippocratic (or Galenic) for the most part. To some extent the belief that cancer cannot be cured has persisted even into the 21st century. This has served to fuel the fear people have of the disease. Some people, even today, consider all cancer incurable and put off seeing a doctor until it’s too late for optimal treatment.

Cancer treatment has gone through a slow process of development. The ancients recognized that there was no curative treatment once a cancer had spread, and that intervention might be more harmful than no treatment at all. Galen did write about surgical cures for breast cancer if the tumor could be completely removed at an early stage. Surgery then was very primitive with many complications, including blood loss. It wasn’t until the 19th and early 20th centuries that major advances were made in general surgery and cancer surgery.

There were great surgeons before the discovery of anesthesia. John Hunter, Astley Cooper, and John Warren achieved lasting acclaim for their swift and precise surgery. But when anesthesia became available in 1846, the work advanced so rapidly that the next hundred years became known as “the century of the surgeon.”

Three surgeons stand out because of their contributions to the art and science of cancer surgery: Bilroth in Germany, Handley in London, and Halsted in Baltimore. Their work led to “cancer operations” designed to remove the entire tumor along with the lymph nodes in the region where the tumor was located.

William Stewart Halsted, professor of surgery at Johns Hopkins University, developed the radical mastectomy during the last decade of the 19th century. His work was based in part on that of W. Sampson Handley, the London surgeon who believed that cancer spread outward by invasion from the original growth. (The general concept of the radical mastectomy can be traced all the way back to Lorenz Heister, a German who wrote about his ideas for mastectomy and lumpectomy in his book, Chirurgie, published in 1719.)

Halsted did not believe that cancers usually spread through the bloodstream: “Although it undoubtedly occurs, I am not sure that I have observed from breast cancer, metastasis which seemed definitely to have been conveyed by way of the blood vessels.” He believed that adequate local removal of the cancer would cure it – if the cancer later appeared elsewhere, it was a new process. That belief led him to develop the radical mastectomy for breast cancer. This became the basis of cancer surgery for almost a century. Then, in the 1970s, modern clinical trials demonstrated that less extensive surgery is equally effective for most women with breast cancer. Today, a radical mastectomy is almost never done and the “modified radical mastectomy” is performed less frequently than before. Most women with breast cancer now have the primary tumor removed (lumpectomy), and then have radiation therapy.

At the same time Halsted and Handley were developing their radical operations, another surgeon was asking, “What is it that decides which organs shall suffer in a case of disseminated cancer?” Stephen Paget, an English surgeon, concluded that cancer cells spread by way of the bloodstream to all organs in the body but were able to grow only in a few organs. In a brilliant leap of logic he drew an analogy between cancer metastasis and seeds that “are carried in all directions, but they can only live and grow if they fall on congenial soil.”

Paget’s conclusion that cells from a primary tumor spread through the bloodstream but could grow only in certain, and not all, organs was an accurate and highly sophisticated hypothesis that was confirmed by the techniques of modern cellular and molecular biology almost a hundred years later. This understanding of metastasis became a key element in recognizing the limitations of cancer surgery. It eventually allowed doctors to develop systemic treatments used after surgery to destroy cells that had spread throughout the body so that they could use less mutilating operations in treating many types of cancer. Today these systemic treatments may also be used before surgery.

During the final decades of the 20th century, surgeons developed greater technical expertise in minimizing the amounts of normal tissue removed during cancer operations. Like the trend from radical mastectomy to lumpectomy, progress was also made in removing bone and soft tissue tumors of the arms and legs without the need for amputation in most cases, and in avoiding a colostomy for most patients with rectal cancer. This progress depended not only on understanding cancer better as a disease and on better surgical instruments, but also on combining surgery with chemotherapy and/or radiation.

Until near the end of the 20th century, diagnosing cancer often required “exploratory surgery” to open the abdomen (belly) or chest so the surgeon could take tissue samples to be tested for cancer. Starting in the 1970s, progress in imaging tests such as ultrasound (sonography), computed tomography (CT scans), magnetic resonance imaging (MRI scans), and positron emission tomography (PET scans) have replaced many exploratory operations. CT scans and ultrasound can also be used to guide biopsy needles into tumors.

Today, doctors use instruments with fiberoptic technology and miniature video cameras to look inside the body. Surgeons can operate using special surgical instruments through narrow tubes put into small cuts in the skin. These instruments can be used to look and work inside the abdomen (laparoscopic surgery) or chest (thorascopic surgery). A similar instrument, the endoscope, can be used to remove some tumors in the colon, esophagus, or bladder by entering through natural body openings such as the mouth or anus.

Less invasive ways of destroying tumors without removing them are being studied and/or used. Cryosurgery (also called cryotherapy or cryoablation) uses liquid nitrogen spray or a very cold probe to freeze and kill abnormal cells. Lasers can be used to cut through tissue (instead of using a scalpel) or to vaporize (burn and destroy) cancers of the cervix, larynx (voice box), liver, rectum, skin, and other organs. Radiofrequency ablation transmits radio waves to a small antenna placed in the tumor to kill cancer cells by heating them.

The future of cancer surgery

Robotic surgery

This term refers to manipulation of surgical instruments remotely by robot arms and other devices controlled by a surgeon. Robotic systems have been used for several types of cancer surgery; radical prostatectomy is among the most common uses in surgical oncology. As mechanical and computer technology improve, some researchers expect future systems will be able to remove tumors more completely and with less surgical trauma.