Palliative Therapy Palliative therapy for patients with incurable disease consists of radiation or chemotherapy or both. Palliative radiation therapy is intended to relieve symptoms of pain or bleeding associated with advanced disease and may be administered as either external beam therapy (teletherapy) or brachytherapy. Special care should be given to previously irradiated sites because additional radiation therapy may be associated with unacceptable morbidity. Single or multiagent palliative chemotherapy may be used with variable response rates. Symptomatic recurrent disease within previously irradiated fields may not respond well to palliative chemotherapy.
Primary vaginal cancer is a relatively uncommon tumor, representing only 2% to 3% of malignant neoplasms of the female genital tract. In the United States it is estimated that there were 2,160 new cases in 2009, and 770 deaths from the disease (1). Squamous histology accounts for 80% (202). Primary vaginal cancer should be differentiated from cancers metastatic to the vagina, which constitute the majority of cancers found in the vagina (84%) (203).
Staging The FIGO staging of vaginal cancer dictates that a tumor extending to the vagina from the cervix be regarded as a cancer of the cervix, whereas a tumor involving both the vulva and the vagina should be classified as a cancer of the vulva.
Table 36.6 FIGO Staging of Vaginal Cancer
FIGO, International Federation of Gynecology and Obstetrics. From FIGO Annual Report. Int J Gynecol Obstet 2006;95:S29 and Int J Gynecol Obstet 2009;105:3–4.
The FIGO staging for vaginal carcinoma is shown in Table 36.6. Staging is performed by clinical examination and, if indicated, cystoscopy, proctoscopy, and chest and skeletal radiography. Information derived from lymphangiography, CT, MRI, or PET cannot be used to change the FIGO stage; however, it can be used for planning treatment. Less than 30% of vaginal cancers present at stage I (204–206).
Surgical staging and resection of enlarged lymph nodes may be indicated in selected patients. FIGO staging does not include a category for microinvasive disease. Because vaginal cancer is rare and treatment is by radiotherapy, there is very little information concerning the spread of disease in relation to depth of invasion, lymph–vascular space invasion, and size of the lesion.
Etiology The association of cervical cancer with HPV suggests that vaginal cancer may have a similar association (207). A study of 341 cases revealed that in younger patients the disease seemed to be related to HPV infection, while in older patients there was no association (206). In addition, as many as 30% of women with vaginal cancer have a history of cervical cancer treated within the previous 5 years (208–210). As with cervical cancer, there appears to be a premalignant phase called vaginal intraepithelial neoplasia (VAIN) (see Chapter 19). The exact incidence of progression to invasive vaginal cancer from VAIN is not known; however, there are documented cases of invasive disease occurring despite adequate treatment of VAIN (211,212).
By convention, any new vaginal carcinoma developing at least 5 years after cervical cancer is considered a new primary lesion. There are three possible mechanisms for the occurrence of vaginal cancer after cervical neoplasia: 1.
Residual disease in the vaginal epithelium after treatment of the cervical neoplasia 2.
New primary disease arising in a patient with increased susceptibility to lower genital tract carcinogenesis (the role of HPV in this setting is suspected) 3.