Surgery for Ovarian Cancer
The successful treatment of ovarian cancer requires the involvement and coordination of several different treatment approaches, including surgery, chemotherapy and, in rare cases, radiation therapy. Nearly all women with ovarian cancer will undergo surgery and chemotherapy. The role of surgery in the initial management of ovarian cancer is to obtain a specimen for determining an accurate diagnosis, provide local treatment of the cancer in the pelvis and abdomen, and obtain other prognostic information to determine the stage of cancer and what additional treatment may be necessary.
Despite surgical removal of the tumor, many patients with ovarian cancer will already have microscopic cancer cells, called micrometastases, that have spread away from the ovary to other locations in the abdomen and distant parts of the body. These micrometastases often cannot be detected by currently available tests. Surgery is a local therapy and cannot treat micrometastatic cancer. Therefore, additional systemic treatment using chemotherapy is required to treat micrometastatic cancer. Information obtained during surgery and from other tests determines whether additional treatment with chemotherapy is necessary. Because most patients with ovarian cancer have advanced disease at diagnosis, the majority of patients will receive chemotherapy as part of the overall treatment plan.
Often, patients with ovarian cancer are initially treated with surgery aimed at debulking (decreasing the size of) the tumor. This type of surgery, in which the goal is to remove the greatest volume of cancer cells possible, is also called “cytoreductive” surgery. After completion of the surgery, most patients are placed on a chemotherapy regimen.
Over the past several years, there has been increasing interest in administering chemotherapy both before and after surgery. Chemotherapy given before surgery is referred to as neoadjuvant chemotherapy, and the surgery that follows is referred to as “interval” cytoreductive surgery. By administering chemotherapy first, micrometastatic cancer cells may be more easily destroyed and chemotherapy may reduce the amount of cancer, thereby allowing for more complete surgical removal of the cancer. The use of neoadjuvant chemotherapy remains controversial, but it may be considered for selected patients with advanced disease who do not appear to be candidates for initial surgery.1
Laparotomy (Initial Cytoreductive Surgery)
For patients diagnosed with ovarian cancer during surgery, the first phase of treatment is surgical laparotomy or exploration of the abdomen. During a laparotomy, the surgeon makes an incision down the middle of the abdomen and attempts to remove as much of the cancer within the abdomen and pelvis as possible. The goal of laparotomy is to accurately diagnose and stage the cancer and gain prognostic information that can determine whether additional therapy is necessary.
Typical debulking during the laparotomy includes a total hysterectomy (removal of the uterus), bilateral salpingo-oophorectomy (removal of the ovaries and fallopian tubes), omentectomy (removal of a flap of fatty tissue covering the bowel in the abdomen), and the removal of any visible cancer within the abdomen. If the cancer appears to be limited to the ovaries or the pelvis, the surgeon will also cut small pieces of tissue (biopsy) from the upper abdomen, The surgeon will collect abdominal fluid samples and remove lymph nodes so that they can be examined under a microscope to determine whether they contain cancer. These extensive and time-consuming surgeries are best performed by a gynecologic oncologist, who is a surgeon specialized in the treatment of female pelvic cancers.
For patients with metastatic ovarian cancer (cancer detected outside the abdomen), surgery may be beneficial for relief of symptoms and to improve duration of survival. Surgery to remove cancer in the abdomen may help relieve pain, prevent obstruction or blockage of the bowel, and improve a patient’s nutritional status.
The typical surgery for ovarian cancer prevents women from future childbearing because the reproductive organs (ovaries and uterus) are removed. Occasionally, ovarian cancer will occur in a younger woman who wishes to maintain fertility. If the cancer involves only one ovary and the surgery shows no cancer beyond a single ovary, a unilateral salpingo-oophorectomy (removal of one ovary and fallopian tube) can be performed. This allows the patient to bear children and still provides adequate treatment for the cancer. After childbearing is complete, the remaining ovary and the uterus are often removed in an effort to prevent a recurrence.
Despite surgical removal of the cancer, the majority of patients with stage II-IV ovarian cancer will experience a recurrence. This is because patients have micrometastases, which are undetectable microscopic cancer cells that have spread from the original site of cancer to distant locations in the body. In other cases, patients have visible spread of cancer cells outside the ovary into the abdomen, pelvis, or lymph nodes that cannot be completely removed by surgery. When the cancer is removed with surgery so that no remaining cancer is larger than 1 cm (about three-quarters of an inch), the cancer referred to as “optimally debulked” or “optimally cytoreduced.” When cancer larger than 1 cm remains after the surgery, the cancer is referred to as “suboptimally debulked” or “suboptimally cytoreduced.” Patients with optimally cytoreduced cancer are more likely to live longer and less likely to experience cancer recurrence following chemotherapy than patients who are suboptimally cytoreduced.
Patients who undergo laparotomy for ovarian cancer may experience lower abdominal pain after the operation. Complications related to surgery may include bleeding, infection, slow recovery of bowel function, temporary difficulty with emptying the bladder or other less common conditions. Your surgeon should explain the risk of side effects associated with treatment.
After completion of chemotherapy, patients undergo a physical examination, a CA-125 blood test and radiologic studies to evaluate the effectiveness of treatment. When all of these tests are negative for cancer, a patient is said to be in a complete clinical remission. Many patients in complete remission still have microscopic cancer that was not detected with the available tests. Some doctors recommend additional surgical evaluation after completion of chemotherapy in order to further evaluate the response to treatment. This operation is called a “second-look laparotomy.” A second-look laparotomy is the most accurate method of detecting persistent cancer cells when CA-125 levels are normal.
Second-look laparotomy will detect evidence of cancer in at least half of patients thought to be in clinical remission. Even when the second-look laparotomy does not detect any cancer cells, cancer still recurs in approximately 30-50% of patients.
Routine second-look laparotomy is no longer recommended as standard treatment. Many doctors recommend that it only be used as part of a clinical trial. This is because a second-look laparotomy only has value to a patient if the information gained during the laparotomy can change a patient’s outcome or subsequent treatment options. This is important for patients to understand because undergoing a second or unnecessary surgery is associated with additional risks and emotional discomfort. These risks include bowel obstruction, adhesions and pain.
Strategies to Improve Treatment
The following are surgical treatment strategies currently being evaluated in clinical studies. Given the poor outcomes of treatment for ovarian cancer, the greatest benefit to patients wishing to pursue aggressive or potentially curative treatments may be participation in clinical studies.
Neoadjuvant Chemotherapy: Although most patients with ovarian cancer receive chemotherapy after surgery, some researchers are exploring the effects of chemotherapy given both before and after surgery. Chemotherapy that is given before surgery is referred to as neoadjuvant chemotherapy. Some doctors believe that neoadjuvant chemotherapy can reduce the size of the cancer, thereby allowing easier surgical removal and more effective results from subsequent chemotherapy. The role of neoadjuvant chemotherapy, however, remains controversial.
1 Bristow RE, Eisenhauer EL, Santillan A, Chi DS. Delaying the primary surgical effort for advanced ovarian cancer: a systemic review of neoadjuvant chemotherapy and interval cytoreduction. Gynecologic Oncology. 2007;104:480-490.