ročník 11,2003 č.4

The attitude to ovarian carcinoma: from staging to surgical cytoreduction

P. Bartoš, P. Popelka

Department of Operative and Minimally invasive Gynaecological Surgery
Na Homolce Hospital,

Thorough surgical staging is the hallmark of treatment for early-stage ovarian cancers. Comprehensive staging determines surgical stage and is important in guiding adjuvant chemotherapy for patients with ovarian cancer. Comprehensive staging is critical in early-stage ovarian cancer, since certain patients may not require further therapy following surgery.
The standard procedure for surgical staging in early-stage ovarian carcinoma includes an adequate midline vertical incision, peritoneal washings, thorough exploration of the abdominal and pelvic cavities, biopsy of any suspicious lesions, random peritoneal biopsies, bilateral diaphragm sampling, total abdominal hysterectomy, bilateral salpingooophorectomy, bilateral pelvic and paraaortic lymph node dissection, and infracolic omentectomy. Lymphatic drainage pattern of the ovary follows that of the ovarian vein, which empties into the vena cava on the right and the renal vein on the left. Thus, these high aortic nodes should be removed in order to determine the extent of disease accurately and often a generous incision is required. If a tumor of mucinous histology is suspected or noted on frozen section, an appendectomy should also be performed.
The surgical staging of gynecologic malignancies relies heavily on the evaluation of the pelvic and paraaortic lymph nodes.The concept of decreasing the morbidity associated with the surgical staging procedure has given rise to the use of minimally invasive techniques for the surgical staging of gynecologic malignancies.
In 1989, Dargent and Salvat reported on the use of laparoscopy to evaluate pelvic lymph nodes. This concept was soon applied to the staging of gynecologic malignancies.
The use of minimally invasive surgery for the management of gynecologic malignancies seems ideal for surgical staging. Avoiding the morbidity associated with traditional laparotomy in the early-stage patient is the primary goal of the laparoscopic staging procedure. Yet, this must be performed without the loss of accuracy. The comparable precision of the two approaches to staging has been demonstrated in terms of lymph node counts in both humans and porcine models. Additional benefits of the laparoscopis approach include decreased length of stay, overall costs and postoperative adhesions.
Laparoscopic staging procedure includes a thorough survey of the abdomen and pelvis, bilateral pelvic and paraaortic lymph node dissections, an infracolic omentectomy, pelvic and peritoneal washings, random biopsies, a hysterectomy, and bilateral salpingo-oophorectomy.
A number of reports in the peer-reviewed literature suggest a therapeutic advantage to performing a complete lymphadenectomy in patients with early-stage disease.
From the surgical cytoreduction viewpoint is should realized that ovarian cancer is the fifth most common malignancy in women and the second most common gynecologic malignancy, but it is the leading cause of death of all gynecologic malignancies in the USA. It is estimated that there will be 25,400 new cases of ovarian cancer in 2003 and an estimated 14,300 deaths in the USA. Early-stage ovarian cancer has a high cure rate with surgery and chemotherapy. Unfortunately, 75% of patients will present with disease that is no longer confined to the ovary (FIGO Stage II-IV), in which long-term survival is worse. Ovarian cancer can be thought of as a "chronic" disease in sense that many patients develop multiple recurrences that can often be induced into remission with further surgery and/or chemotherapy. Also, complications such as bowel obstruction are often a result of advanced, persistent, or recurrent ovarian cancer. Surgery is an essential modality in the treatment of ovarian cancer and is most often performed prior to the initiation of chemotherapy. The goal of surgery in this setting should be to achieve a complete gross resection (complete cytoreduction) of all visible disease. Griffiths first reported the value of surgical cytoreduction in 1975. Many retrospective studies and reviews since have confirmed that the amount of residual tumor strongly correlates with survival.
Cytoreduction to less than 2 cm has been shown to provide a significant survival advantage. Some authors have reported that cytoreduction to no visible disease offers an even greater benefit.Cytoreductive surgery offers no benefit, except possibly for palliation of symptoms, if the tumor cannot be reduced to less than 2cm. Based on more recent analyses, the Gynecologic Oncology Group (GOG) currently defines optimal cytoreduction as that in which the maximum diameter of residual tumor is less than 1cm. The benefit of optimal cytoreduction has also been reported for patients with Stage IV disease (i.e. parenchymal liver metastases, distant metastases, and/or malignant pleural effusions).
Currently , there are no accurate or validated methods of preoperatively predicting optimal cytoreduction.
The rate of optimal cytoreduction varies between institutions, and to some degree depends on specialty training, philosophy and surgical aggressiveness. The surgical morbidities must always be considered. Aggressive attempts at tumor resection may require radical hysterectomy, omentectomy, resection of either small or large intestine, splenectomy, diaphragmatic stripping, hepatic resection, or other related procedures. Splenectomy, diaphragmatic stripping, and hepatectomy, as well as elimination of peritoneal implants, can be safely performed in carefully selected patients with upper abdominal disease.
Ovarian cancer rarely progresses below the pelvic peritoneal reflection and therefore it is possible to safely perform low colorectal anastomoses in the majority of cases.
Patients who develop recurrent disease, or those with desease noted at the time of surgical reassessment procedures, will also benefit from cytoreduction.
Successful surgical cytoreduction requires thorough knowledge of pelvic and abdominal anatomy as normal anatomical structures and relations are often distorted in advanced ovarian cancer.