Chapter 10: Vaginal Cancer

INTRODUCTION

Primary vaginal cancer is an uncommon gynecologic malignancy and constitutes only 1% to 2% of gynecologic malignancies. Because of its rarity, there are specific guidelines for the diagnosis of primary vaginal cancer. A malignancy located in the vagina and not involving any adjacent pelvic organs is considered to be a primary vaginal cancer. If the malignancy extends to the cervix or vulva, it is considered a primary lesion of the nonvaginal site. Based on the observation that 95% of patients with recurrent cervical cancer will experience relapse within 5 years, all squamous cell carcinomas identified in the vagina within this period are defined as recurrences. Only those squamous cell carcinomas found more than 5 years after the diagnosis of cervical cancer are defined as primary vaginal cancers.¹ If there is a history of endometrial cancer, a diagnosis of adenocarcinoma in the vagina is usually considered a recurrence regardless of the time from primary treatment.

Primary vaginal malignancies are most commonly located in the upper third of the vagina and on the posterior wall (Figure 10-1). The most common histologic type is squamous cell carcinoma, which accounts for approximately 80% of all primary vaginal malignancies. Less commonly encountered are adenocarcinomas (10%), melanomas (3%), sarcomas (3%), and other rare tumors. Eighty-four percent of malignancies identified in the vagina are secondary, most commonly originating from the cervix (32%) and endometrium (18%); less common primary sites include the vulva, gastrointestinal tract, and ovary, as well as gestational trophoblastic disease.²

Prior to the mid-20th century, vaginal cancer was generally considered to be an incurable disease. Advances in radiation therapy and surgical techniques have been associated with significant improvement in cure rates, even in women with advanced disease.

EPIDEMIOLOGY

Key Points

1. Risk factors for vaginal cancer include human papillomavirus infection, smoking, in utero diethylstilbestrol exposure, and a prior history of cervical cancer.

2. Vaginal intraepithelial neoplasia (VAIN) is a potential precursor lesion to invasive squamous cell carcinoma of the vagina.

3. A history of pelvic radiation is a risk factor for vaginal sarcoma.

Primary vaginal cancer is a rare entity and constitutes only 1% to 2% of gynecologic malignancies. It has an incidence of approximately 1 in 100,000 women per year. The American Cancer Society estimates that there will be 2300 new vaginal cancers diagnosed in 2010 with approximately 780 deaths.³

The peak incidence of vaginal cancer is in the sixth and seventh decades. Risk factors for the disease closely mirror those for cervical cancer and include an increased number of lifetime ...