Conization as Definitive Treatment for Microinvasive Squamous Carcinoma of the C
Conization as Definitive Treatment for Microinvasive Squamous Carcinoma of the Cervix
By David Gershenson, MD
The definition and management of early invasive carcinoma of the cervix remains an area of controversy. In 1985, the International Federation of Gynecology and Obstetrics (FIGO) redefined microinvasive squamous carcinoma of the cervix to include lesions that invade to a depth of not more than 5 mm as measured from the basement membrane and do not exceed 7 mm of horizontal spread. Those lesions that have minimal microscopically evident stromal invasion are assigned to FIGO stage IA1. Lesions that are large enough to be measured are assigned FIGO IA2. This classification scheme has been criticized since it allows lesions with a depth of invasion greater than 3 mm and those with lymph vascular space invasion to be included in the category of microinvasive disease. Several investigators have shown a small but worrisome incidence of metastatic disease in those patients. Because of a diversity of opinion, FIGO changed its definition of stage IA in 1995. Stage IA1 is now measured invasion of stroma no greater than 3 mm in depth and no wider than 7 mm; stage IA2 is measured invasion of stroma greater than 3 mm, no greater than 5 mm, and no wider than 7 mm. The functional definition of microinvasive disease was outlined by consensus opinion of the Society of Gynecologic Oncologists (SGO) in 1974 as having no more than 3 mm of stromal invasion and no lymph vascular space involvement. Using this definition, many gynecologic oncologists have advocated hysterectomy as definitive therapy for microinvasive lesions.1,2 Since there are anecdotal reports of lymph node metastasis in microinvasive disease, even using the SGO criteria, some continue to advocate a more radical approach to stage IA2 cervical carcinoma.3 The literature on this issue is confusing since authors use a variety of definitions of microinvasive cancer and compare dissimilar patient groups.
Few can argue that a less radical approach is preferred if we can be assured of a favorable therapeutic outcome. Radical hysterectomy is a procedure with little mortality, but the added morbidity, cost, patient discomfort, and time lost from work are significant. The possibility of bladder and sexual dysfunction must also be considered with the more radical approach.
Several investigators have documented the safety and efficacy of extrafascial hysterectomy as definitive treatment for microinvasive cervical cancer as defined by SGO.4,5 If we accept extrafascial hysterectomy as complete therapy in this group of patients, can we safely take the next step to conization alone for treatment of microinvasive lesions? By accepting hysterectomy as complete therapy, we must believe that the parametria, pelvic lymph nodes, and upper vagina have little or no chance of harboring metastatic disease. Can we make the same argument for the residual cervix and uterine corpus when treating patients with conization as definitive therapy? Unfortunately, the literature provides little information regarding residual tumor following conization for microinvasive cancer with negative margins.6 There are several reports in the literature that describe conization as definitive therapy for early cervical cancer.7 In no case is the SGO definition exclusively used, and it is often difficult to draw any conclusions. A recently published report does shed some light on this topic.8 In this study, 87 women who underwent conization that contained microinvasive squamous carcinoma, followed by either repeat conization or hysterectomy, were studied. Significant predictors of residual invasion included status of the internal margin (residual invasion present in 22% of women with an involved margin vs 3% with a negative margin) and the combined status of the internal margin and post-conization ECC (residual invasion in 4% of patients if both negative, 13% if one positive, and 33% if both positive). Depth of invasion and number of invasive foci in the conization specimen were not significant.
Consideration of conization for the definitive treatment of microinvasive cervical cancer requires careful patient selection and pathologic evaluation.9 Patients should desire fertility and be fully counseled regarding this treatment approach. The surgeon should expect compliance with the follow-up regimen and provide proper surveillance for persistent disease. The cancer should be of the squamous cell histologic type and have no lymph vascular space involvement. Those lesions with extensive lateral spread (> 7 mm) or multifocal lesions may be best treated by hysterectomy. The margins of the cone specimen should be negative for invasive cancer. Pathologic sectioning should be performed in a consistent manner with full evaluation of the margins. When the margins are inevaluable or if disease is close to a margin, a second cone biopsy or hysterectomy should be considered.
Following conization, patients are followed with Pap smears, endocervical curettage, and colposcopy at frequent intervals. Such a surveillance strategy should minimize the advancement of persistent disease prior to detection.
References
1. van Nagell JR, Jr., et al. Am J Obstet Gynecol 1983;145:981-991.
2. Copeland LJ, et al. Gynecol Oncol 1992;45:307-310.
3. Maiman MA, et al. Obstet Gynecol 1988;72:399-403.
4. Lohe KJ, et al. Gynecol Oncol 1978;6:31-50.
5. Kolstad P. Gynecol Oncol 1989;33:265-272.
6. Greer BE, et al. Am J Obstet Gynecol 1990;162: 1406-1411.
7. Burghardt E, et al. Cancer 1991;67:1037-1045.
8. Roman LD, et al. Obstet Gynecol 1997;90:759-764.
9. Morris M, et al. Gynecol Oncol 1993;51:193-196.
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