Borderline tumors of the ovary: a separate entity

Borderline tumors of the ovary: a separate entity Authors Key words A.Ph. Makar Excellent prognosis, conservative surgery, adjuvant therapy Summary Borderline ovarian tumors (BOT) account for 10% to 20% of all epithelial ovarian tumors. BOT represent a separate entity with pathologic features and biologic behaviour intermediate between distinctly benign and frankly malignant. The misunderstanding of such entity results in over-treatment of BOT both surgically and pharmaceutically. BOT present in the majority of cases as FIGO stage I and are associated with an excellent prognosis. Treatment is mainly surgical and adjuvant therapy is not beneficial. (BJMO 2009;Vol 3;1:28-xx) Introduction Epithelial ovarian tumors with histopathologic features and biologic behaviour intermediate between clearly benign and frankly malignant have been identified as a separate group. In 1971, this group of tumors was classified by the International Federation of Gynaecology and Obstetrics (FIGO) as carcinoma of low malignant potential, and in 1973 by the World Health Organization (WHO) as BOT. 1,2 The histologic diagnosis of BOT is based on the following criteria as established by Hart and Norris and detailed by Scully: epithelial cellular proliferation (stratification of the epithelial lining of the papillae, multi-layering of the epithelium, mitotic activity and nuclear atypia) without stromal invasion. As opposed to women with invasive carcinoma, those with BOT tend to present at an earlier stage and at a younger age. 4,5 Women with BOT have a better prognosis than those with invasive carcinoma, and the 5-year survival for stage I disease exceeds 95%. 1-5 Incidence BOT account for 10% to 20% of all epithelial ovarian tumors. The median age at presentation is 45 years which is 10 years younger than the median age seen with invasive tumors. 2,3 About 27% will present during the reproductive age. In over 80% of cases, the tumor is limited to one or both ovaries. Intra-abdominal spread occurs in less than 10%. 1-3 This is the opposite as the situation seen in invasive tumors which present with advanced stage in more than 75% of the cases. Etiology Unlike invasive tumors of the ovary there is no genetic predisposition seen with BOT. 2 The use of oral contraceptives seems to have a protective effect. 1,2 Histologic subtypes Serous BOT account for approximately 55% of all BOT cases. 1-3 They present as a cystic mass with intra-and extra-cystic vegetations (Figure 1). Bilaterality exists in about 40% of the cases. Unlike invasive counterparts, the presence of extracystic vegetations or bilaterality does not imply bad prognosis. The outcome of serous BOT correlates with the FIGO stage. Stage I has a 15-year survival of 99%. In stage III, however, the 15-year mortality rate varies from 0% to 50%. 1-5 The survival rate depends on the extent of extra-ovarian spread. Peritoneal implants at the time of diagnosis have been reported in 35% of the cases. It is a matter of discus- 28

Figure 1. Bilateral serous BOT showing external vegetations. Figure 2. Mucious BOT with smooth capsule. sion whether these implants are true implantation metastases or rather manifestations of multifocal in situ lesions of the peritoneum. Some of these implants will progress to infiltrating cancer, while the majority will remain either stationary or regress after removal of the main ovarian tumor. The survival would only be affected by true conversion to invasive disease. 5 Invasive implants must be differentiated from foci of endosalpingiosis and noninvasive implants that arise from benign glandular elements of the peritoneal serosa (potential for Müllerian differentiation). Mucinous BOT account for 40% of all BOT cases. They present as uni-or multilocular cystic mass with smooth capsule (Figure 2). Mucinous BOT cannot be macroscopically distinguished from benign cystadenomas or cystadenocarcinomas. 5 Mucinous BOT present in 85% of the cases as stage I and are associated with excellent 15-year survival (97%). In Stage III, the reported mortality rate was 64%. 2-5 Extra-ovarian spread at the time of diagnosis is rare. However 10-15% of the cases are associated with pseudomyxoma peritonei. The impact of pseudomyxoma on survival is controversial. The mucinous BOT can be separated into the endocervical (Müllerian) and intestinal types. Pseudomyxoma is only present in the intestinal type. Mucinous tumors of the appendix coexist in 8% of these cases. It is controversial whether a patient with a mucinous BOT in the ovary and in the appendix has two primaries or has a primary appendiceal lesion and a metastatic ovarian lesion. 5 About 5% of the BOT cases are non-serous, mucinous tumors (endometrioid 2%, mixed 2%, clear cell < 1%, and Brenner < 1%). The clear cell type has the worst prognosis. 5 DNA ploidy state Different studies showed that tumor ploidy state is the most powerful indicator for risk of relapse and for survival. 3 Hormonal receptor state Unlike invasive tumors, the majority of BOT contain positive hormonal receptors both for oestrogen and progesterone. 2 Staging and re-tagging Staging is pathological according to the FIGO classification of 1988. Surgical staging for BOT follows the same guidelines as those for invasive tumors. However, the prognostic significance of external vegetations or capsular rupture is not so evident in BOT as it is in invasive tumors. Diagnosis of BOT in young women often occurs postoperatively on pathological examination following removal of a presumed benign cyst. Different studies stressed on the significance of re-staging in such cases especially in case of serous BOT. Stage upgrading has been reported in up to 15% and suboptimal staging is associated with worse survival. Omentectomy is recommended especially with serous BOT as it is the potential site for disease recurrence in about 50% of the relapses. Appendectomy is recommended for mucinous tumors. 1,5,6 Lymph node metastases are rare in case of mucinous BOT but occur in 10-15% of serous BOT cases, especially when they are associated with invasive implants. Lymph node metastases need to be differentiated from endosalpingosis. 1,5,6 Surgical cytoreduction to 0 cm implies excellent 29

Table 1. Guidelines for fertility conserving surgery Laparotomy through vertical incision Cytologic examination of peritoneal washing Careful evaluation of abdominal cavity and biopsy of all suspicious areas Avoid capsular rupture Unilateral ovariectomy or cystectomy in case of bilateral tumors Omentectomy Appendectomy with mucinous tumors Resection of all peritoneal implants The presence of pseudomyxoma is not a contraindication for conservative approach Lymphadenectomy only with serous tumors associated with invasive implants Endometrial curettage in case of BOT of the endometrioid type prognosis in patients with advanced stage. Some reports suggested that laparoscopic surgery is less safe as it is associated with more peritoneal recurrences. 1,7 Fertility conserving surgery About one third of BOT will present during the reproductive age. In over 80% of the cases, the tumor is limited to one or both ovaries (FIGO stage I). Fertility conserving approach must therefore be an option (Table 1). A thorough surgical staging is mandatory and is preferably performed by a gynaecologic oncologist. Definitive surgery should be recommended after family planning. 5-8 About 40% of serous BOT are bilateral and partial ovariectomy (cystectomy) can be performed. Positive resection margins after cystectomy are associated with a recurrence rate up to 15%. Generous sampling of the resection margins of ovarian cysts is therefore very important. Blind wedge biopsies of a macroscopically normal contralateral ovary are still controversial even in case of serous BOT. 1,5,8 Fertility conserving surgery does not worsen the obstetrical or the prenatal outcomes. Also, the use of fertility inducing drugs (if necessary), does not seem to be associated with increased risk of disease relapse. The recurrence rate for conservatively operated stage IA patients is 0% to 30%. Survival is not affected if the patients are re-operated at recurrence. The corresponding recurrence rate is below 5% for serous BOT who have received relapse treatment. 5 Conservatively treated patients need close follow-up and definitive surgery must be recommended after family planning. 1,5,8 Follow-up must include vaginal sonography. In contrast to invasive tumors, CA125 is only elevated in less than 25% of the relapses. 9 Adjuvant therapy There is no evidence that adjuvant chemo- or radiotherapy improves survival in early stage BOT. On the contrary, a review of randomized trials showed that adjuvant therapy was even associated with high morbidity without therapeutic benefits. 2-4 In patients with extra-ovarian spread, adjuvant platinum based chemotherapy is especially used with the presence of invasive peritoneal implants. However, there is no therapeutic evidence for this. Non invasive implants have been reported to regress spontaneously following removal of the primary tumor. 1,5 Disease recurrence BOT has an excellent prognosis with a 10 years survival over 95%, both for serous and mucinous types. The risk of local recurrence is high in case of suboptimal staging and with the presence of invasive peritoneal implants, especially when surgical cytoreduction is not completed. Local recurrence in case of fertility conserving surgery is also high after cystectomy with positive resection margins. 1,5,8 Unlike invasive tumors, serum CA125 is not elevated in the majority of BOT recurrences, this is especially the case in the non-invasive ones. 9 Surgical resection is the preferred treatment for recurrent disease. Almost all recurrences are inside the abdominal cavity and distant spread is an exception. 30

Table 2. Significant differences between BOT and invasive counterparts BOT is not associated with an increased genetic risk. About two thirds of BOT are diagnosed as FIGO stage I compared to only one fourth of invasive tumors. Mucinous tumors are more frequently observed with BOT. Median age at presentation is 45 years with BOT compared to less than 55 years in case of invasive tumors. Fertility conserving surgery is recommended in young women with BOT even in case of advanced stage. The prognostic significance of external vegetations or capsular rupture in early stage is not evident with BOT. Serum CA125 level is not trustable in follow-up of BOT independent on histologic subtype. Adjuvant chemotherapy does not improve survival in women with BOT. Disease recurrence can occur up to 10-15 years later and long follow-up is necessary in case of BOT. Surgery is the recommended treatment for BOT recurrences because chemotherapy has not been proven to prolong long-term survival. Platinum based chemotherapy in case of invasive recurrence was successfully used in retrospective series including limited number of patients. 2 The majority of BOT contain positive hormonal receptors and this deserves more attention in the clinical practice. Patients with pseudomyxoma peritonei recur more often, and may present with bowel obstructions. The treatment for this condition is surgery; even repeated laparotomies with removal of the mucus material are indicated. Chemotherapy does not seem to be effective, whether administered intravenously or as an intraperitoneal instillation. 5 Conclusions As opposed to invasive carcinoma, BOT tend to present at an earlier stage and at a younger age and fertility conserving surgery should be an option. BOT have very good prognosis and the 5-year survival for stage I exceeds 95%. Nevertheless, the 10-year survival figures show that some women may eventually die from their tumor. Biologic, epidemiologic, and pathologic aspects show distinct differences between BOT and invasive ovarian tumors (Table 2). References 1. Makar A, Declercq S. Epitheliale borderlinetumoren van het ovarium: een aparte entiteit.tijdschr voor Geneeskunde 2006;62(18):1291-1299. 2. Burger CW, Prinsen HM, Baak JPA, Wagenaar N, Kennemans P. The management of borderline epithelial tumors of the ovary. Int J Gynecol Cancer 2000:10;181-197. 3. Kaern J, Trope CG, Kristensen GB, Abeler VM, Pettersen EO. DNA ploidy: the most important prognostic factor in patients with BOT of the ovary. Int J Cancer 1993;6:349-358. 4. Trope G, Kaern J, Vergote IB, Kristensen G, Abeler V. Are BOT of the ovary overtreated both surgically and systemically? A review of four prospective randomized trials including 253 patients with BOT. Gynecol Oncol 1993;51:236-243. 5. Tropé CG, Kristensen G, Makar AP. Surgery for borderline tumor of the ovary. Seminars in Surgical Oncology 2000;19:69-75. Key messages for clinical practice 1. BOT present at an earlier stage and at a younger age than invasive carcinoma and fertility conserving surgery should be an option. 2. BOT have very good prognosis and the 5-year survival for stage I exceeds 95%. 3. However, 10-year survival figures show that some women may eventually die from their tumor. 4. Treatment is mainly surgical and adjuvant therapy is not beneficial. 31

6. Camtte S, Morice P, Thoury A. Impact of surgical staging in patients with macroscopic "stage I" ovarian borderline tumors: analysis of a continuous series of 101 cases. Eur J Cancer 2004:40;1842-1849. 7. Maneo A, Vignali M, Chiari S, Colombo A, Mangioni C, Landoni F. Are BOT of the ovary safely treated by laparoscopy? Gynecol Oncol 2004:94;387-392. 8. Morice P, Leblanc E, Rey A.Conservative treatment in epithelial ovarian cancer: results of a multicentre study of the GCCLCC (Groupe des Chirurgiens de Centre de Lutte Contre le Cancer) and SFOG (Societe Francaise d'oncologie Gynecologique). Hum Reprod 2005;20:1379-1385. 9. Makar AP, Kaern J, Kristensen GB, Vergote I, Bormer O, Tropé CG. Evaluation of serum CA 25 level as a tumor marker in borderline tumors of the ovary. Int J Gynecol Cancer 1993;3:299-303. C o r r e s p o n d e n c e a d d r e s s Author: A. Ph. Makar Department of Gynaecologic Oncology, University Hospital Ghent, Belgium Department of Gynaecologic Oncology, ZNA Middelheim, Antwerp, Belgium Please send all correspondence to: Prof. Dr. A. Ph. Makar De Pintelaan 185 B-9000 Ghent Belgium Tel: 0032 9 332 57 52 amin.makar@pandora.be amin.makar@zna.be Conflicts of interest: the author has nothing to disclose and indicates no potential conflicts of interest. Geen tijd om bij elke grote internationale bijeenkomst aanwezig te zijn? Toch behoefte om het nieuws van de recentste ontwikkelingen direct tot u te nemen? Meldt u dan nu aan voor onze digitale congresmailing Oncologie, een nieuwe service van het Nederlands Tijdschrift voor Oncologie. Digitale Congresmailing Oncologie U kunt zich aanmelden via http://congresmailing.ariezmp.nl Voor meer informatie kunt u zich wenden tot Ariez Medical Publishing, 0031-20-5612050 32