Discussion:
Ovarian cancer is the leading cause of death from gynecological cancer
[1]. Early-stage ovarian carcinoma seldom produces symptoms, and
consequently more than half of all ovarian carcinomas are at an advanced
stage[2]. 70% of patients are diagnosed at an advanced stage
[1]. Although serous adenocarcinoma is the most common histological
subtype [1], an exceptional complication has been described.
According to a recent literature review by a Japanese team [2],
regarding colo-adnexal fistula, only a case was noted with serous
carcinoma. Fistulae usually occur after previous surgery and
chemotherapy, in the setting of relapsed disease rather than as an
initial presentation [3], spontaneous fistulization of ovarian
cancer into digestive tract with a fistula tract is a different and rare
phenomenon [4]. Direct invasion of ovarian cancer to the walls of
the colon, rectum, and other organs is not unusual, the extension of
ovarian cancer to invade the colon and rectum with resultant fistulas is
extremely unusual [2]. Enterogenital fistulas occupy the dominant
cause of gynecological fistulas, according to a retrospective national
cohort study of women treated for gynecological fistula, whereas
urogenital fistulas are the prerogative of post-hysterectomy women
[5]. Formation of a fistula to the recto-sigmoid colon, is the most
common site [2], accounting for 40% of all involved organs as
described in KIZAKI and al. review [6]. This complication affects
the prognosis. Indeed, the fistulous communication in the digestive
lumen leads to the overflow of it microbial deposit. The tumor therefore
becomes superinfected and may result in pelvic peritonitis in case of
secondary rupture. Surgical treatment therefore becomes unavoidable. On
the other hand, the patient is deprived of the benefit of undergoing
neoadjuvant chemotherapy, which will decrease the chances of a complete
macroscopic cytoreduction. In addition, the operative procedure becomes
more laborious: the patient will require segmental colonic resection
during the same narcosis. Trimming then suturing the fistula orifice by
the colonic side seems to us inadequate because it is necessary to
perform a monobloc resection of the entire conglomerate mass in order to
comply with the carcinological constraints. Moreover, the disconnection
of the fistula may induce a spillover of tumor clones into the large
peritoneal cavity which will inevitably evolve into a peritoneal
miliary. The other issue is the potential to leak stercoral and bowel
flora contents into the peritoneal cavity. A primary anastomosis is
required in clement conditions. In case of uncompensated hemodynamic
state or peritoneal pyo-stercoral diffusion, transformation into a
terminal stoma is the rule. Spontaneous resolution can be awaited with
bowel discharge of pus as reported by KAZUOIMAMURA and al. [7], the
patient reconsulted only after 46 years after a recrudescence of her
symptoms. We cannot count on this eventuality while risking the
expansion of suppuration and peritoneal neoplastic graft, without taking
into account the overestimation of hospital costs dilapidated in the
control. The case reported by SHAI et al. [8] demonstrates that a
conservative treatment could be undertaken in order to avoid an
extensive resecting surgery and to permit a neoadjuvant treatment but
this eventuality will be validated only if the fistulous track has
closed spontaneously thus requiring a simple separation of the two
abutting viscera. But evidence of fistulous communication may be
difficult to obtain with the usual imaging methods. Rectal contrast is
not recommended during the period of acuitization, as it can
repermeabilize or enlarge the visceral communication. Thus, it seems
that this attitude could bring more risk than it offers safety. It is
true that fistulization does not always imply a tumor invasion, the
chronic inflammation inflicted by the iterative twisting attacks or
chronic pressure causes this fistulous communication as it was described
by [2]. This is explained by the fact that the dermoid cyst, which
for a long time was proclaimed to be at risk of torsion because of its
large size [9] occupies the first rank of the histological type
involved in oophoro-sigmoid fistula. But, considering the high
probability of cancerous invasion causing fistulization, reaching up to
38% according to the review of KIZAKI and al. [6], en-bloc
resection is imperative in order not to leave a residual neoplastic
niche. Finally, considering that concomitant colo-rectal resection
doesn’t worsen the prognosis, an optimal resection is the mainstray of
available therapeutic tools. This is supported by the review by FOURNIER
[10] who recommend extensive resection which has little influence on
post-operative morbidity but significantly improves survival.