Introduction
Primary tumors of the vagina are relatively rare, they account for 1-2% of gynecological malignancies [2]. However their incidence is increasing due to the spread of HPV infections.
Vaginal cancer occurs most often in women around 60 to 65 years old, but due to diverse factors, more young women are diagnosed with this disease nowadays. A cancer of the vagina can be diagnosed after a medical examination, following the occurrence of certain symptoms, or during a routine check, at a general practitioner or a gynecologist [1].
In the vast majority of cases, the histological type is a squamous cell carcinoma. Adenocarcinomas, more rare, develop from the glands of the Mullerian canals. These were more common in the 1970s among 15-20-year-old girls exposed in utero to diethylstilbestrol (DES) [1].
As with all cancers, the earlier the diagnosis is made, the better the treatment will be. This highlights the importance of medical consultations, especially for women above 60.
Anatomy of the vagina:
The vagina is a muscular and elastic tube measuring 7.5 to 9 cm long [3]. It is located in the pelvis, between the bladder and the rectum. The vagina extends from the cervix to the vulva (external part of the female genitals).
The vaginal wall has 3 layers:
- The inner layer, called the mucosa, is composed of squamous cells. It is also called epithelium.
- The middle layer, called muscularis, is formed of muscle tissue.
- The outer layer, is made of connective tissue.
The vagina contains many nerves, blood vessels and lymphatic vessels. Glands located in the cervix and near the vaginal opening secrete mucus that keeps the mucous membrane moist.
A cancerous (malignant) tumor is a mass of cells that can invade and destroy surrounding tissues. It can also spread (metastasize) to other parts of the body.
Incidence and risk factors
The incidence of primary vaginal cancer is estimated at 1/100 000.
A risk factor is something, such as a behavior, substance or condition that increases the risk of developing cancer [1]. Most cancers are due to risk factors, but vaginal cancer may occur in women who have none of the risk factors described below.
The risk factors retained are essentially infectious and mechanical [2]:
- Defective hygiene seems to favor the appearance of vaginal cancer, but it is proved that HPV (human Papilloma Virus) infection is the dominant element. In cancers of the vagina, we find the same oncogenic HPVs as in cervical cancers.
The most commonly involved type of virus involved is the HPV 16.
- A neglected third degree prolapse is found in 4 to 20% of cases. In this case, the lesion takes on the appearance of circular infiltration.
- Radiotherapy has also been implicated in some studies.
- The risk of getting cancer of the vagina increases with age. Vaginal cancer mainly affects women aged 60 and over.
- History of cancer of the cervix, vulva or anus: Women diagnosed with cancer of the cervix, vulva or anus are more likely to develop cancer of the vagina. This may be due to the fact that these cancers have similar risk factors, such as HPV infection.
- A weakened immune system: Women whose immune system is weakened (immunodepressed) are more likely to have vaginal cancer. These include women with human immunodeficiency virus (HIV) infection and those who have received organ transplants and who need to take drugs to inhibit their immune system. In immunodepressed women, HPV infections are more persistent, and precancerous lesion have a greater risk to degenerate into cancer.
- Certain substances such as diethylstilbestrol (DES) are also incriminated in the appearance of cancer of the vagina.
- Vaginal intraepithelial neoplasia (VAIN) is a precancerous condition of the vagina. It’s not cancer, but it can sometimes turn into cancer of the vagina if left untreated. Some of the risk factors for vaginal cancer can also cause NAV.
Hysterectomy has long been wrongly considered as a risk factor [1]. Vaginal cancer after hysterectomy is common when hysterectomy has been performed for a precancerous cervical lesion. After hysterectomy for non-cervical lesion, vaginal cancer is exceptional. It should be noted that smoking, race and parity seem to have no influence.
Types of vaginal cancer
Squamous cell carcinomas account for 75 to 95% of vaginal tumors and adenocarcinomas 5 to 10%, the other histological forms (often melanomas) represent 1 to 3% of cancers. Sarcomas are also very rare [2].
The predominant localization of cancers of the vagina is at the upper 1/3 and on the posterior wall. The extension can reach laterally the paracolpos, the parameters and possibly the pelvic walls, the vesico-vaginal partitions forward and recto-vaginal backwards.
Visceral metastases are rare in epidermoid (squamous cell) forms, a little more common in adenocarcinoma. The epidermoid forms have a rather favorable prognosis because of their good response to treatment, whereas melanocarcinomas have a catastrophic prognosis [2].
Clinical symptomatology
For many studies [1], the signs present at the first consultation are:
- Spontaneous or provoked metrorrhagia (vaginal bleeding) in 80% of cases.
- Leucorrhea in 20% of cases
- Pelvic pain in 10% of cases.
- Sometimes metastatic inguinal
- Rarely a hematuria.
- Exceptionally a vaginal mass.
- In the case of an advanced vaginal tumor, dysuria, rectal signs, pelvic thrombosis, edema of the lower limb or recto-vaginal or vesico-vaginal fistula may occur.
Clinical examination
It is the speculum examination that can sometimes highlight a budding tumor, or more often a bleeding ulcer on contact. The biopsy will make the diagnosis. Sometimes the tumor is very bulky, prolapsed, protruding out of the vulva.
To affirm a primary cancer of the vagina, it is necessary that the tumor localization is exclusively vaginal and that the cervix and the vulva do not present tumor infiltration.
During the examination, the search for ganglionic extension in the form of adenopathies is systematic. Loco-regional extension especially is better appreciated by the rectal examination.
Paraclinical examinations
- Colposcopy:
Colposcopy is a procedure in which a colposcope (an instrument with a lens and a light source) is used to examine the vulva, vagina and cervix.
Colposcopy is performed when an HPV test is positive or there is clinical suspicion of a gynecological tumor, as these results may indicate the presence of a precancerous condition or cancer of the vagina.
Description: The doctor inserts a speculum into the vagina. This plastic or metal instrument separates the walls of the vagina so that the doctor can clearly see the cervix and vagina. The doctor could apply a solution that helps to better visualize the abnormal regions. He then uses a colposcope to carefully examine the inner surface of the cervix and vagina. The colposcope is placed outside the vaginal opening rather than inside the vagina [4]. If the doctor detects an abnormal region in the vagina, he could practice a biopsy during colposcopy.
- Biopsy:
The diagnosis is, of course, histological, the primitive character being, remembered, retained after eliminating another associated cancer (especially the cervix).
The biopsy is an essential to diagnose this pathology; it also helps to determine the prognosis by specifying the histological type and the grade of cellular aggressiveness [3].
- Ultrasound:
Abdominal ultrasound allows examination of tumors of the upper of the vagina when they are bulky. It also allows an assessment of extension by the search for liver metastases.
Endovaginal ultrasound offers a better view of tumor images [4]. Finally, endorectal ultrasound is the reference examination for vaginal study, both for the entire tumor process and for its loco-regional extension.
- CT and MRI:
These seem to offer very few advantages over ultrasound, except for the possibility of obtaining sagital and frontal sectional plans, and for MRI, a better evaluation of tumor volume. They allow visualizing the iliac and latero-aortic lymphadenopathies [4].
- Endoscopy:
Endoscopy allows the doctor to observe the inside of the body cavities using a flexible tube at the end of which are fixed a light source and a lens. In case of a large vaginal tumor, endoscopy is done to determine if the cancer has spread to the bladder (by a cystoscopy) or to the rectum (rectoscopy). It can also be used to help establish the stadification the cancer or to guide biopsies.
Other investigations may be required, such as intravenous ultrasound, to evaluate a possible renal repercussion of tumor extension, or pulmonary radiography for pulmonary metastases.
Therapeutic means
- Surgery:
The type of surgery will depend on the patient’s age, tumor location and degree of invasion. It will be adapted case by case; the surgery can range from a simple expanded local excision to a pelvic exenterating with lymph node dissection [5].
- Radiotherapy:
External and intracavitary (brachytherapy) radiotherapy can be used. The results of this treatment are excellent but it causes many and unpleasant adverse effects.
- Chemotherapy:
The results of chemotherapy are not convincing. Its only indication is the melanoma of the vagina.
Prognosis and survival for vaginal cancer
As in any other cancer, the prognosis is the main question that the patient asks when the diagnosis is made. Prognosis is the act by which the doctor best assesses how cancer will affect a person and how they will respond to treatment.
Prognosis and survival depend on many factors. Only a doctor who is familiar with your medical history, the type, stage, and characteristics of the cancer you have, the treatments you choose, and the response to treatment can look at all of this data in conjunction with survival statistics to arrive at a prognosis [5].
The following are the main prognostic factors of vaginal cancer:
- Tumor size, tumor volume, and local extent:
The size of the tumor corresponds to the widest diameter of the tumor (at its largest dimension). The tumor volume refers to the 3 dimensions of the tumor: its height, width and thickness. Existing data indicate that the prognosis is more favorable if the size and volume are small than if they are large [2].
Local extent refers to the depth to which the tumor has invaded the lining of the vagina and the surrounding tissues. The more it has developed in depth, the less favorable the prognosis.
- Stadification:
There are two main stadifications in vaginal tumors: the TNM and the FIGO classifications. Both are based on the size of the tumor, the lymphatic extensions and the existence of a distant metastasis [1].
The stadification is the most important prognostic factor for vaginal cancer.
- Type of tumor:
The type of vaginal tumor is an important prognostic factor. Squamous cell carcinoma has a better prognosis than other types of tumors [2], such as vaginal melanoma. It appears that carcinoma that occurs in women whose mothers took diethylstilbestrol (DES) during pregnancy, is associated with a more favorable prognosis than other types of adenocarcinomas.
- Histological grading:
Low-grade tumors, which evolve slowly and are less likely to spread, have a more favorable prognosis than high-grade tumors [3].
- Age and general health:
The prognosis of young women with good general health is generally better than that of women aged 60 or older. It should be noted that age is often associated to comorbidities, which might contra-indicate some types of treatment like a radical surgery or radiotherapy [2].
Prevention
If the risk of vaginal cancer can never be nullified, some measures can help to prevent its mortality in the majority of the cases:
- Have regular pelvic exams and Pap tests. The percentage of early discovery of vaginal cancer can be increased by performing regular pelvic exams and Pap tests. When discovered in its early stages, vaginal cancer is more likely to be cured. These examinations can also detect precancerous lesions that can eventually transform (if not treated) into cancer [1].
- The HPV (human Papilloma Virus) vaccine: Receiving a vaccination to prevent HPV infection can reduce the risk of vaginal cancer and other HPV-related cancers like anal, cervix and vulva cancer. This procedure is encouraged by the World health Organization and consists of two or three injections [3].
To conclude, primary cancers of the vagina are rare and represent less than 1% of gynecological cancers. They are characterized by a clinical polymorphism that can often be related to other nearby cancers such as cancer of the cervix or the anus. However, awareness of this condition is essential to reduce risk factors and to promote an early detection that would significantly improve the prognosis.
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Sources
- The World Health Organization official website: who.int/
- The National Center for Biotechnology Information website: ncbi.nlm.nih.gov
- DAW E. Primary carcinoma of the vagina. Obstetrics & gynecology 1971.78:853.
- Mc CARTHY S., TAYLOR K. J. W. – Sonography of vaginal masses, Am. Journal of Gynecology, 1983 ; 140.
- RUTLEGE F. – Cancer of the vagina. Am. J. Obstet. Gynecol., 1967 ;97-123; :635-655