Cancer by Stage depth of invasion that should be considered microinvasive (stage Ia). This led to considerable confusion and controversy in the literature. Over the years, as many as 18 different definitions were used to describe microinvasion. In 1974, the Society of Gynecologic Oncologists recommended a definition that is accepted by FIGO: A microinvasive lesion is one in which neoplastic epithelium invades the stroma to a depth of less than 3 mm beneath the basement membrane and in which lymphatic or blood vascular involvement is not demonstrated. The purpose of defining microinvasion is to identify a group of patients who are not at risk for lymph node metastases or recurrence and who therefore may be treated with less than radical therapy.
Diagnosis must be determined on the basis of a cone biopsy of the cervix. The treatment decision rests with the gynecologist and should based on a review of the conization specimen with the pathologist. It is important that the pathologic condition be described in terms of (i) depth of invasion, (ii) width and breadth of the invasive area, (iii) presence or absence of lymph–vascular space invasion, and (iv) margin status. These variables are used to determine the degree of radicality of the operation and whether the regional lymph nodes should be treated (12).
Stage IA1 ≤3 mm Invasion Lesions with invasion less than or equal to 3 mm have less than 1% incidence of pelvic node metastases. Within this group, it appears that the patients most at risk for nodal metastases or central pelvic recurrence are those with definitive evidence of tumor emboli in lymph vascular spaces (74,155). Therefore, patients with less than 3 mm invasion and no lymph–vascular space invasion may be treated with extrafascial hysterectomy without lymphadenectomy. Therapeutic conization appears to be adequate therapy for these patients if preservation of childbearing capability is desired. Surgical margins and postconization endocervical curettage must be free of disease. If there is lymph–vascular space invasion, a type I (extrafascial) or II (modified radical) hysterectomy with pelvic lymphadenectomy should be considered.
Treatment of microinvasive cervical adenocarcinoma is complicated by a lack of agreement on approaches. Recent reports show that patients with stage Ia1 cervical adenocarcinoma may be treated in a fashion similar to patients with this stage and a squamous lesion (103–105). Some experts disagree with this interpretation because of the difficulty in establishing a pathologic diagnosis of microinvasion from a frankly invasive adenocarcinoma. Patients diagnosed with microinvasive cervical adenocarcinoma should have expert pathologic assessment before considering treatment with extrafascial hysterectomy or conization.
Stage IA2 >3–5 mm Invasion Lesions with invasion of greater than 3 to 5 mm have a 3% to 8% incidence of pelvic node metastases; thus, pelvic lymphadenectomy is necessary for these lesions (155,156). The primary tumor may be treated with a modified radical hysterectomy (type II) or a radical trachelectomy if preservation of fertility is desired. If intermediate-or high-risk pathologic factors are identified in the surgical specimen, adjuvant radiation or chemoradiation therapy is recommended.
Stages IB1, IB2, and IIA1 Invasive Cancer Stage Ib lesions are subdivided into stage IB1, which denotes lesions that are 4 cm or smaller in maximum diameter, and stage IB2, which denotes lesions that are greater than 4 cm. Stage IIA1 disease involves the upper two-thirds of the vagina, but total lesion size is 4 cm or less. These patients may be managed with either radical trachelectomy or a type III radical hysterectomy, with pelvic lymphadenectomy.