Malignant diseases of the vagina account for about 1% of gynecologic cancers. Approximately 95% of vaginal malignancies are squamous cell carcinomas. A variety of neoplasms have, however, been noted as arising in the vagina, and these are listed in Table 1. Like squamous cancer of the vulva, this disease occurs predominately in a geriatric population but occasionally is seen in premenopausal women.
Screening
Opinion is divided about cytologic screening. A case may be made that such a procedure is not “cost-effective” in view of the rarity of primary vaginal cancer. The principal justification for cytologic screening is the observation that outcome results are vastly better for those few patients who can be diagnosed prior to onset of symptoms. Inspection of all vaginal walls should be part of a careful gynecologic examination, especially during colposcopy. Small lesions can be easily overlooked without it.
Women with a history of prior hysterectomy for dysplasia/carcinoma in situ (CIS) are at greater risk for vaginal intraepithelial neoplasia (VAIN)/dysplasia and probably need annual cytologic screening. Another small but special subset of patients at risk would be young women growing to adulthood with vaginal adenosis secondary to intrauterine exposure to diethylstilbestrol(Drug information on diethylstilbestrol) (DES). These patients are at increased risk for vaginal clear cell carcinoma and possibly vaginal and cervical intraepithelial neoplasia.
Diagnosis
Colposcopy and directed biopsies may be used to establish the extent and diagnosis of an occult lesion. Cervical, vulvar, and endometrial cancers can extend directly to involve the vagina. The vagina is also a common site for metastatic cancer, and for this reason critical assessment of histology and complete evaluation of the patient is required.
Staging
The International Federation of Gynecology and Obstetrics (FIGO) staging system for vaginal cancer is shown in Table 2. The staging rules established by FIGO allocate cancers involving both the vagina and the cervix to primary cervical cancer; cancers involving the vagina and vulva are allocated to primary vulvar cancer. These rigid rules are followed even though the bulk of the cancer may be in the vagina, and it may seem quite apparent to the clinician that one is dealing with a bulky vaginal cancer that encroaches upon the cervix or extends to the vulva.
Treatment
Radiation therapy is the primary therapeutic choice for vaginal cancer. Brachytherapy alone for stage I disease, the use of a reduced field of external-beam therapy to a bulky portion of the neoplasm, and interstitial volume implants rather than conventional in-tracavitary brachytherapy are acceptable treatment modalities. Continued selective use of the surgical approach, however, is also associated with excellent results, particularly in low-stage disease. A small but identifiable salvage rate exists for advanced-stage disease when exenterative surgery is selectively applied.
The sexual health of the patient afflicted with vaginal cancer is often a major casualty, notwithstanding possible loss of life. High-dose radiation therapy often produces fibrosis, rigidity, and concentric lumen constriction. Radical surgery in the past precluded vaginal function, but this situation has been improved significantly by the use of split-thickness grafts, substitution of intestinal segments, and myocutaneous flap reconstruction.
The following discussion refers to the decision tree (Table 3) and related treatment options (Table 4).
Carcinoma in Situ and Vaginal Intraepithelial Neoplasia—The degree of the VAIN, the extent of the process and the age and general health of the patient are important. The process appears to evolve very slowly, and there seems to be little urgency in either early or aggressive treatment.
Laser therapy is a valuable alternative to vaginectomy. Half-strength Lugol solution and the use of colposcopy will help define the extent of the process.
Intravaginal fluorouracil(Drug information on fluorouracil) (5-FU) cream has a role when used selectively. Principal drawbacks include secondary, poorly healing ulcerations and pain, a relatively high relapse rate, and, occasionally an unanticipated degree of vaginal stricture. Radiation therapy is used only in patients too ill for standard treatment.
Stage I, Upper Third—The primary radical hysterectomy with pelvic lymphadenectomy or primary irradiation therapy may be used, as with carcinoma of the cervix.
Stage I, Middle Third—The treatment of choice most commonly is irradiation therapy with brachytherapy, with or without external-beam therapy. If the lesion is very small, a wide local excision may be considered.
Stage I, Lower Third—These cancers can be treated with irradiation or surgery. Radiation options would include brachytherapy, with or without external-beam therapy, and/or interstitial implants. The surgical approach would be extended to include some of the vulvar structures.
Stage II, Upper Third—A primary surgical approach might be applied selectively if the extension to stage II is minimal; however, the most common approach to therapy is radiation therapy.
Stage II, Middle Third—These tumors are treated by irradiation therapy. Special techniques for delivery will occasionally be required, such as interstitial implant cylinders.
Stage II, Lower Third—Radiation therapy would most commonly be used; the occasional patient will be suited for a radical surgical approach.
Stage III and Stage IV—Irradiation therapy is the primary modality for management of stage III and IV vaginal cancer. Exenterative procedures may be selectively employed. A reasonable case may be made for CT scan search for bulky nodes and resection before radiation therapy for cases of stage III and IVA disease, as well as bulky stage II cases.
Special Considerations
Sarcoma Botryoides (Embryonal Rhabdomyosarcoma) and Endodermal Sinus Tumors
These neoplasms are found in infants and children.
Screening—There is no screening technique for these tumors
Diagnosis—Evaluation of discharge or bleeding in the infant or the visualization of a soft-tissue mass at the introitus.
Staging—The FIGO staging system for vaginal cancer may be employed.
Treatment—The combination of multiagent chemotherapy, wide local excision of the tumor bed, and selective radiotherapy is the treatment of choice. Exenterative surgery is no longer used in primary therapy.
Vaginal Melanoma
Primary vaginal melanoma is an extremely rare condition found primarily in middle-aged women. This diagnosis carries a dismal prognosis associated with a high rate of local failure and only rare long-term survivorship. The process is thought to arise in vaginal epidermal melanocytes found in a very small percentage of adult women.
Biopsy of a lesion or excision of an area of pigmentation may yield the diagnosis of melanoma. If melanocytic hyperplasia or melanosis is found, further therapeutic options should be employed.
Treatment—When possible, the entire lesion should be surgically excised. Because this tumor does not respond well to irradiation or chemotherapy, cure of advanced lesions is rare. Such tumors frequently have systemic metastases at the time of diagnosis. However, brachytherapy as an adjuvant to local excision may have a role in selected localized cases. Wide excision of a smaller lesion may also be followed by high-fraction external-beam radiation protocols in selected instances.
Vaginal Adenocarcinoma
A biopsy diagnosis of adenocarcinoma in the vagina obligates the clinician to exclude a primary site elsewhere. The most common primary vaginal adenocarcinoma in contemporary literature is the clear cell adenocarcinoma (mesonephric) arising in young women with a history of intrauterine exposure to DES. Other adenocarcinomas may arise in women of any age from residual glands. Adenocarcinoma can also occur within endometriosis.
Young women known or suspected to be at risk for intrauterine exposure to DES should undergo regular clinical and cytologic evaluation. New lesions in the vagina (visible or palpable) require biopsy.
Treatment—Therapy is the same as that for carcinoma of the vagina.
Treatment of Recurrence
Recurrent cancer confined to the pelvis may be treated by various exenterative procedures, viz anterior, posterior, or total exenteration with or without vulvectomy. More advanced disease may be treated with chemotherapy or selective irradiation for palliation.
A 70-year-old man with a history of localized prostate cancer treated with whole-pelvis radiation therapy with a boost to the prostate, in conjunction with androgen deprivation therapy 7 years prior, presented with lower back pain. A bone scan revealed an area of activity in the sacrum. What is the most likely diagnosis?
