Many discussions had concerned stage IC disease because results in the seven series reported different outcomes for patients treated conservatively for stage IC disease, and not all the authors suggested FSS in this case. Probably the key to the discussion in order to explain such potential differences is the heterogeneity of patients having stage IC according to the 1988 FIGO classification [12]: patients are classified as having stage IC disease in case of uni- or bilateral tumour with (a) spread of the tumour on the surface of the ovary (excrescences) and/or (b) ascites containing malignant cells or positive cytology after positive washing and/or (c) capsular rupture. So, patients included as having a stage IC disease were not probably “similar” in terms of criteria used to classify disease as stage IC in those patients. Furthermore, the histological subtype is perhaps somewhat different in those seven series concerning this substage of disease. Such fine difference could explain the absence of homogeneity in the literature until the new 2014 FIGO staging system [1]. Nevertheless, summarising the seven series, conservative management could be probably accorded in stage IC grade 1 disease (9 % of recurrence) but should not be performed in grade 2 or 3 disease, respectively, 14 % and 23 % of recurrence (Table 7.1).

Kajiyama et al. [13] explored recently recurrence predicting prognostic factors after FSS in patients with EOC. In a multicentre study, they included 94 patients on stage I EOC treated conservatively. In accord to the new FIGO classification [1], IC substage was defined: intraoperative spillage (IC1), preoperative capsule rupture or surface invasion (IC2) and positive cytology (IC3). They found 14 recurrences (14.9 %) and the overall recurrence-free survival (RFS) was 84.3 %. There was no significant difference in RFS between patients with stage IC1 and those with stage IA disease. In contrast this significant difference was found between IC2/3 and stage IA. Moreover they showed a significant poorer RFS of patients with grade 1 than grade 2–3 disease. FSS is not recommended for patients with preoperative capsule rupture or surface invasion (IC2), positive cytology (IC3) and grade 2 and 3 disease.

In a recent study about 18 patients [14] only on stage IC (14 grade 1 and 4 unknown), the authors find 5 recurrences (28 %) after FSS, and tumour histology did not exert a statistically significant effect. In terms of fertility outcome, of 10 patients who attempted to conceive, 7 singleton pregnancies were recorded for 5 women. The authors, based on their favourable fertility outcomes in spite of an elevated recurrence rate, suggest that FSS could be considered for EOC patients other than just those with FIGO stage IA grade 1 disease.

The analysis of the SEER (Surveillance, Epidemiology and End Results) database reports the absence of impact on the survival of preservation of the ovary in stage IA or IC disease [15]. Nevertheless, as stated by the authors, “to detect a 20 % difference in survival for pts with stage IC disease, a cohort of 1282 pts with 52 deaths is required”. So, as none of the series published involved such a large number of patients, it is not possible to conclude definitively about the safety of conservative management in this situation.

The recommendations of the Fertility Task Force of the European Society of Gynecologic Oncology (ESGO) [2] indicated a safe FSS in EOC for stage IA and IC grade 1, stage IA grade 2 and “conventional histological subtypes”. FSS is discussed in stage IC grade 2 and in stage IA clear cell subtype. FSS is contraindicated for grade 3 tumour, stage > I, histologically aggressive tumour.

The large recent Italian series, including 240 patients treated conservatively for EOC, support these recommendations; in particular regarding grade of disease, the authors find that grade 3 disease is an independent worst prognostic factor for RFS and OS compared with grade 1 and grade 2 disease [11].

In the same direction goes the result of the recent retrospective study of Ditto et al. [16]. The authors compared 70 patients treated conservatively for EOC versus 237 treated radically for EOC. In the FSS group 38 (54.3 %) and 32 (45.7 %) patients were at low risk (FIGO stage IA grade 1–2) and high risk (FIGO stage IA grade 3 or more), respectively. On multivariable analysis only stage of disease correlated with DFS: patients affected by FIGO stage IC or more advanced stage experienced a 4.7-fold increased risk of developing recurrences in comparison to patients affected by FIGO stage IA–IB. The FIGO grade 3 is associated with worse OS in multivariable analysis.

It appears obviously that for disease extending beyond the ovaries, FSS is avoided because of the major risk of recurrences [7, 8]. Nevertheless there are in literature some cases reported that have been analysed in the recent review of Petrillo et al. [17]. The authors identified 21 patients with stage II–III disease receiving FSS. Recurrent disease was observed in 9 patients (42.8 %) and 23.8 % of the 21 patients died of disease. Radical surgery remains the standard for advanced EOC.

Histological type plays a great role in inclusion criteria: only serous, mucinous and endometrioid EOC should be considered for conservative management.

The data of the seven series (Table 7.1) showed a lower recurrence rate for mucinous subtype (9 %), 12 % of recurrence for endometrioid subtype and 16 % and 17 % for serous and clear cell disease, respectively.

In a recent retrospective series, Lee et al. [18] investigated the outcome of 90 patients treated for a mucinous epithelial ovarian cancer confined to the ovaries: 35 conservatively and 55 radically. There was no statistical difference between the two groups in DFS suggesting that FSS is safe in this histological subtype that occurs commonly in younger women.

Kajiyama et al. [19] compared two groups of patients with stage I clear cell carcinoma: 16 were treated with conservative surgery and 205 with radical surgery. The OS and DFS were not statistically different between the two groups, and furthermore patients with clear cell carcinoma who underwent FSS did not show a poorer OS and DFS than patients with other histological subtypes. In spite of the small number of patients included, the authors suggested that such management could be proposed in clear cell tumour. The evolution of clear cell disease is different between Asia and Europe and this is probably the reason for such good results. Nevertheless, waiting furthers studies concerning such histological subtype considered as a high-grade disease, patients with clear cell (at least in Europe) and anaplastic EOC must not be considered for conservative treatment, because of the high risk of relapse on the remaining ovary.

The literature review (Table 7.2) of overall recurrences after FSS in patients with EOC showed a large range between 5 and 29 %, in relation with the heterogeneity of patients included in the different series. The median 5-year OS of all the series is good (94 %) as we expected for an early-stage disease, but it will be interesting to know the 10-year OS probably most influenced by recurrence, but the limited follow-up of these studies not allowed these data.