Minimally invasive surgery in ovarian cancer
Laparoscopy has dramatically altered management of many gynecologic malignancies, but its utility in ovarian cancer has been limited—until now.
IN THIS ARTICLE
she wants laparoscopy. yes or no?
Maria is a 57-year-old mother of 4 who presents to a gynecologic oncologist with pelvic pain and ultrasonographic evidence of a 7-cm complex mass at the right adnexa. She has an enlarged fibroid uterus (12-week size), a preoperative CA125 level of 21 U/mL, and she says she wants laparoscopic management.
Is minimally invasive surgery an acceptable choice?
This large, complex mass is possibly malignant. Until now, laparoscopy has played only a small role in the management of ovarian cancer, although it has greatly changed treatment of other gynecologic malignancies. Since women with ovarian cancer tend to be older and have coexisting diseases, laparoscopy could confer many benefits, provided surgical staging is comprehensive, and timely diagnosis and patient outcomes are not compromised.1
The utility of laparoscopy in ovarian borderline tumors and cancer is increasing. This article surveys current applications and concerns, including
- when to refer,
- predicting malignancy,
- effects of carbon dioxide (CO2) peritoneum,
- risk of port-site recurrences,
- hand-assisted laparoscopy,
- comprehensive staging, and
- assessing resectability.
Conventional staging by laparotomy with a vertical incision from above the umbilicus to the symphysis pubis is still the gold standard; however, laparoscopy can be used in the management of selected cases of ovarian cancer:
- to manage and stage apparent early-stage ovarian cancer,
- to determine the extent of advanced disease and potential resectability,
- to resect disease via hand-assisted laparoscopy in selected women with advanced disease, and
- to obtain a “second look,” or reassess the patient for disease recurrence and placement of intraperitoneal catheters.
Benefits of laparoscopy for benign masses
The benefits of laparoscopy over laparotomy in the management of benign adnexal masses are well defined:2
- less postoperative morbidity,
- less postoperative pain,
- less analgesia required,
- shorter hospitalizations, and
- shorter recovery time.
When to refer. Referral of at-risk patients to a gynecologic oncologist should be based on personal and family history, physical, imaging, and tumor markers.
When to get a consult: ASAP. General gynecologists may encounter malignancy unexpectedly. When they do, it is of paramount importance to obtain gynecologic oncology consultation intraoperatively, if possible, or as soon as possible postoperatively.
How common is cancer in laparoscopically managed masses?
Consider a complex ovarian mass potentially malignant until proven otherwise. Why? Because it remains difficult to rule out malignancy preoperatively, even with strict patient selection.
For example, a study involving 292 laparoscopically managed women found a 3.8% malignancy rate.3 These women had undergone preoperative vaginal ultrasound, CA125 measurement, and pelvic examination, but malignancy was not detected until surgery.
The incidence of malignancy at laparoscopy for a pelvic mass varies widely due to different guidelines for patient selection. In 1 series of 757 patients,4 the rate of unanticipated malignancy was 2.5%. This included 7 invasive cancers and 12 borderline tumors. Preoperative evaluation entailed routine clinical and ultrasound examinations. At laparoscopy, peritoneal cytology was obtained, the ovaries and peritoneum were inspected, and any cysts were punctured so their contents could be examined. If a malignant mass was encountered or suspected, the woman in question was treated by immediate laparotomy using a vertical midline incision.4
History of nongynecologic cancer heightens risk of malignancy
For example, of 31 women with stage IV breast cancer and a new adnexal mass, 3 (10%) were found to have primary ovarian cancer, and 21 (68%) had metastatic breast cancer.5
In a study at our institution,6 51 of 264 patients (19%) with a history of nongynecologic cancer and a new adnexal mass were found to have a malignancy. Of these women, 22 (43%) had primary ovarian cancer; the rest had metastatic disease. Most patients had laparoscopy even when malignancy was encountered.
Utility of frozen section
Frozen-section analysis speeds diagnosis of the adnexal mass, allowing the necessary surgery to be performed immediately.The overall accuracy of frozen-section analysis is high, reported at 92.7% in 1 study.7 It is less accurate in borderline tumors because of the extensive sampling required.
Intraoperative frozen section has high accuracy in women with metastases to the adnexae. In 36 patients with a history of breast or colorectal carcinoma who developed adnexal metastases, intraoperative frozen section correctly diagnosed carcinoma in 35 patients (97%). In more than 80% of these women, the carcinoma was accurately diagnosed as metastatic.8
Laparoscopy for Suspicious Masses?
Is laparoscopy appropriate for pelvic masses that appear suspicious for cancer at the time of preoperative evaluation? And if malignancy is confirmed, is conversion to laparotomy warranted?
For example, Dottino et al10 managed all pelvic masses referred to their oncology unit laparoscopically unless there was evidence of gross metastatic disease (ie, omental cake) or the mass extended above the umbilicus. Immediate frozen-section analysis was performed in all cases. Although most of the masses were suspicious for malignancy preoperatively, 87% were in fact benign, and 88% were successfully managed by laparoscopy. If conversion to laparotomy was necessary for successful debulking, it was performed. However, laparoscopic surgery often was adequate.
Canis and colleagues9 support diagnostic laparoscopy regardless of the ultrasonographic appearance of the pelvic mass, although they recommend immediate conversion to laparotomy for staging if malignancy is found.
Does CO2 Sspread Cancer?
Whether CO2 contributes to cancer spread and growth is of particular concern in ovarian cancer, since it is predominantly a peritoneal disease. In a rat ovarian cancer model, tumor dissemination increased throughout the peritoneal cavity with laparoscopy, compared with laparotomy, without increased tumor growth.11
However, a separate study12 in women with persistent metastatic intraabdominal peritoneal or ovarian cancer at the time of second-look surgery found no difference in overall survival between patients who had undergone laparoscopy versus laparotomy
Fear of Port-Site Recurrence
Fear of tumor implantation at the trocar site is commonly cited as a reason to avoid laparoscopy in ovarian cancer. One metaanalysis found a port-site recurrence rate of 1.1% to 13.5%, but many of the studies included were small series or case reports.13 In ovarian cancer, most reports of port-site recurrences have been associated with advanced-stage disease with peritoneal seeding and the presence of ascites.13,14
The term “port-site recurrence” (previously it was thought to be a metastasis) describes cancer occurring in the subcutis in the absence of carcinomatosis.15 Now that the definition has been refined, the rate of port-site recurrences may be substantially lower.
A large retrospective study at our institution found 4 (0.64%) subcutaneous tumor implantations at or near a trocar site after 625 laparoscopic procedures in 584 women with ovarian/tubal cancer. Most of these implantations were discovered after positive second-look operations, and all were associated with synchronous carcinomatosis or other sites of metastatic disease.16
In a separate study14 involving 102 women with primary or recurrent advanced-stage ovarian cancer, large-volume ascites and a longer interval between chemotherapy and cytoreductive surgery were associated with more port-site recurrences. In addition, full-layer closure of the abdominal wall reduced port-site recurrences from 58% to 2%, emphasizing the importance of trocar-site closure in cases of malignancy. There was no survival disadvantage in women with portsite recurrences.
What causes port-site recurrences?
Possible factors include:
- trauma to the site,
- frequent removal of instruments through the port,
- removing the specimen through the port, and
- continued leakage of ascites.13
Avoiding cyst spillage and routinely using laparoscopic bags for cyst removal may decrease the incidence of these recurrences (FIGURE 1). Partial cyst excision and morcellation of a solid mass are always contraindicated.
Irrigation of port sites may decrease tumor cell implantation and should be considered at the end of the procedure.13 To further reduce risk, experts recommend closing all layers at the time of laparoscopy and resecting laparoscopic ports in their full thickness at the time of the staging laparotomy.14
FIGURE 1 Cyst removal using an endoscopic bag
Avoid spillage and routinely use laparoscopic bags for cyst removal to decrease the incidence of port-site recurrences.
This hybrid procedure combines the advantages of minimally invasive surgery with the tactile sensation of laparotomy. It has gained favor among urologists and general surgeons. (The first nephrectomy using this method was performed in 1996.17)
Technological advances now enable the surgeon to insert and remove the nondominant hand into the peritoneal cavity without losing pneumoperitoneum and to insert instruments through the same port if needed (FIGURE 2).
Advantages over traditional laparoscopy include the ability to palpate tissue, assist with tissue retraction, perform blunt dissection, and rapidly control hemostasis. This approach has been described in management and staging of early-stage ovarian cancer and in debulking advanced disease.18
FIGURE 2 Hand-assisted laparoscopy
The nondominant hand and surgical instruments can be inserted and removed through the special port without affecting pneumoperitoneum.
resection and analysis of ovary
Maria underwent laparoscopy via the open technique. The surgeon found a cystic right ovarian mass, a fibroid uterus, and small diaphragmatic nodules, which were biopsied and found to be benign.
Pelvic washings were obtained, and after the right infundibular pelvic ligament and right utero-ovarian ligament were clamped and cut, the intact ovary was placed in a laparoscopic bag. The bag was pulled through the 12-mm suprapubic trocar, the cyst wall was perforated, and the cyst was drained within the laparoscopic bag, producing brown fluid. The bag was removed from the peritoneal cavity through this port, and the cyst was sent to pathology.
There was no contamination to the peritoneal cavity or abdominal wall, and the bag remained intact. Surgical gloves were then changed, and instruments used to drain the cyst were removed from the operating field.
When frozen-section analysis revealed a borderline serous ovarian tumor, Maria underwent BSO, infracolic omentectomy, laparoscopic pelvic and paraaortic lymphadenectomy, and laparoscopically assisted vaginal hysterectomy. There were no intraoperative complications, the total time in the operating room was 330 minutes, and there was blood loss of approximately 150 mL.
When an ovarian malignancy is discovered, immediate staging is indicated, and should include:
- peritoneal biopsies,
- pelvic and para-aortic lymph node sampling,
- infracolic omentectomy, and
- bilateral salpingo-oophorectomy (BSO) and hysterectomy.1
Since changes in staging affect prognosis and treatment, complete staging should include the retroperitoneal nodes.
When the patient wants to preserve fertility
In selected younger women who have not yet completed childbearing, conservative treatment with retention of the uterus and contralateral ovary is an option—though we lack outcomes data on patients treated this way.
This option should be restricted to women with proven stage I disease after comprehensive staging.1
Can staging be done laparoscopically?
Complete staging—consisting of a detailed peritoneal assessment (with BSO and vaginal hysterectomy), omentectomy, and pelvic and para-aortic node dissection—can safely be done laparoscopically.19-21 Studies show low morbidity, with accurate findings and adequate node counts.21,22
A comparison of laparoscopic and conventional (laparotomy) staging in women with apparent stage I adnexal cancers found no differences in omental specimen size or the number of lymph nodes removed, and none of the patients required conversion to laparotomy.22
When definitive staging is delayed
Several studies have found poorer outcomes with delayed staging. However, the tumor ruptured in some of these studies, with considerable delay from the initial laparoscopy until definitive staging and treatment.