Should We Abandon All Conservative Treatments for Uterine Fibroids?

The Problem With Leiomyosarcomas

Funlayo Odejinmi; Nilesh Agarwal; Kate Maclaran; Reeba Oliver

Disclosures

Women's Health. 2015;11(2):151-159. 

In This Article

Abstract and Introduction

Abstract

Fibroids are the most common tumor in women and many medical and surgical options exist for their management. The incidence of uterine sarcoma in women undergoing treatment for fibroids has previously been thought to be extremely rare, however there has been recent controversy as to whether this risk has been underestimated. This article reviews the literature investigating the incidence of leiomyosarcoma and explores how different treatment modalities may affect risk from occult malignancy. We aim to provide a tool for counseling women who are considering options for the management of their fibroids.

Introduction

Uterine fibroids are the commonest tumor in women. By the age of 50, 80% of Afro-Caribbean and 70% of Caucasian women will have at least one fibroid.[1] It is one of the commonest clinical conditions dealt with by gynecologists.

Advances in minimally invasive surgery over recent decades have allowed the traditional surgical treatments of myomectomy or hysterectomy to be performed laparoscopically or vaginally, with their well-documented advantages over open surgery.[2] Central to the success of these minimally invasive routes is the technique of tissue morcellation, which divides the specimen into fragments enabling removal through small incisions. Although originally carried out manually, the development of electromechanical morcellation significantly improved the ease and efficiency of specimen removal. In turn this has increased the size of fibroids that can be treated using minimally invasive routes.

Leiomyosarcomas (LMS) are the most common of the uterine sarcomas and are notorious for their aggressive nature and poor prognosis. The problem of leiomyosarcoma has been brought to the forefront by the unfortunate experience of a patient in the USA who underwent a laparoscopic myomectomy for a presumed benign fibroid which unfortunately turned out to be malignant, as highlighted in the Wall Street Journal,[3] leading to the US FDA statement advising on the use of power morcellators for the management of uterine fibroids.[4] Subsequently there have been many opinion articles looking at the incidence of leiomyosarcomas and the possible association with poor outcome in women who have had morcellation of their specimen.[5,6] Many medical societies have produced statements on the interim way forward, and the need to exercise caution when using the morcellators to extract specimen from the abdominal cavity,[7,8] and subsequently Ethicon, a major supplier of power morcellators, have withdrawn from the market.

The power morcellators were first introduced in 1993 and have revolutionized laparoscopic surgery for the management of uterine fibroids. It however has not been without its negative implications. Since its introduction there have been 55 reported complications with 6 deaths with most of these due to the inexperience of the surgeon using the instrument.[9] There has also been the issue of morcellomas due to the dissemination of benign fibroid tissue, which implants on the peritoneal surface of the abdominal cavity.[10]

Traditionally hysterectomy has been the main modality of treatment of uterine fibroids, modern treatments of these tumors have diversified to include modalities that promote uterine preservation and include medical, conservative or interventional surgical procedures. These treatment modalities, due to the lack of histological specimens can lead to delay in diagnosis of malignancy and treatment and may compromise patient survival. Thus gynecologists evaluating women presenting with fibroids are faced not only with the choice of whether to offer treatment, but also the type of treatment to offer. They have the clinical challenge of deciding which patient, although rare, might have a sarcoma. Of additional concern are procedures, which disrupt and disseminate tumor cells as with morcellation. The clinician has to equally balance the need to avoid unnecessary extensive surgery, and possible complications for the purposes of avoiding a rare condition and evaluate the known benefits of minimally invasive procedures for the patient. Most of the articles published on this issue to date have looked at the effect of the morcellator on leiomyosarcoma; this article reviews the effect of conservative management of fibroids and how this affects leiomyosarcoma diagnosis, and to provide a tool for counseling women who are considering options for the management of their fibroids. Relevant articles were identified by a computerized search of the Pubmed database. The search included the following key words: 'uterine sarcoma', 'leiomyosarcoma', 'morcellation', 'morcellator', 'leiomyoma AND conservative management'. The search period covered January 1990 to July 2014.

Epidemiology of Leiomyosarcoma

Uterine fibroids are one of the most commonly encountered benign gynecological conditions, affecting 40–80% of women depending on ethnicity.[1,11,12] Although the majority of fibroids remain asymptomatic, symptoms such as dysmenorrhea, menorrhagia, pelvic pain and subfertility occur in approximately 30–50% of women with fibroids.

Uterine sarcoma is rare (3–7 per 100,000 in the US population) with a poor prognosis.[13] Leiomyosarcomas are the most common of the uterine sarcomas. Brooks et al. reported on the surveillance, epidemiology and end results analysis of 2677 cases of uterine sarcoma between1989–1999. Racial differences in the incidence of uterine sarcoma existed for leiomyosarcoma (1.51/105 for Afro-Caribbean vs 0.91/105 for Caucasians, and 0.89 for women of other races, p < 0.01).[13] The median age at presentation is 55 years, but Afro-Caribbean women have a bimodal distribution with an initial peak at 35 years of age.[14]

The risk of cancer has never been an indication for prophylactic removal of fibroids as the risk of a sarcoma of the uterus is estimated at 17 in a 1,000,000 and only 1 in 1000 women treated for uterine fibroids is found to have a sarcoma. It is contentious whether the quoted incidence is accurate and also whether the incidence in women treated for uterine fibroids is accurate. Studies incorporating large series of patients have shown the incidence to be between 0.1–0.5%. Parker et al. found that the total incidence of uterine sarcoma (leiomyosarcoma, endometrial stromal sarcoma and mixed mesodermal tumor) among patients operated on for uterine leiomyoma is low at 0.23%.[15] An incidence of 0.1% was found by Kamikabeya et al., 0.4% by Takamizawa et al. and 0.49% by Leibsohn et al..[16–18]

A recent report by the FDA reviewed all published data reporting the incidence of LMS. The primary analysis included nine studies ranging in size from 104 to 1429 patients. The prevalence of both uterine sarcoma and leiomyosarcoma ranged from 0 to 4.9 per 1000 persons.[4] They estimated the prevalence of occult uterine sarcoma in women undergoing hysterectomy or myomectomy for presumed benign leiomyomas as 1 in 354 and of leiomyosarcoma specifically as 1 in 498. However, this estimate is not without limitations and needs to be interpreted with caution. All studies involved in the recent analysis were retrospective and the overall number of sarcomas detected was low. There is potential for population bias as centers were predominantly single-center tertiary referral centers, covering a heterogeneous population and some included women of postreproductive in whom a diagnosis of benign fibroids may have been less likely.

A recent commentary highlights the difficulty in estimating risk based on the analysis of data from pooled studies as the CI of 0.07–0.3% spans a fivefold difference in incidence estimation.[19]

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