Vaginal Cancer: Causes, Symptoms, and Treatment — Overview, Diagnosis & Treatment Options | MyMedicPlus

Vaginal cancer is a rare gynaecological malignancy accounting for approximately 1-2% of gynaecological cancers, with approximately 6,000 new cases diagnosed per year in the United States. The rarity of primary vaginal cancer is partly explained by the strict definitional requirement that the tumour must originate from the vaginal wall without involvement of the cervix (which would classify it as cervical cancer) or the vulva (which would classify it as vulvar cancer). Squamous cell carcinoma of the vagina accounts for approximately 80-90% of primary vaginal cancers, predominantly affecting postmenopausal women with a median diagnosis age of 60-65 years and most commonly arising in the upper third of the posterior vaginal wall — the area with the greatest glandular tissue and HPV susceptibility. Adenocarcinoma accounts for approximately 4-9%, including clear cell adenocarcinoma — significantly associated with intrauterine diethylstilbestrol (DES) exposure — and arising characteristically in young women aged 17-21 years. Rare histological types include primary vaginal melanoma, sarcoma botryoides (embryonal rhabdomyosarcoma in infants), and small cell carcinoma. Vaginal intraepithelial neoplasia (VAIN) — graded VAIN 1, 2, and 3 — is the recognised precursor lesion for invasive SCC. Due to the rarity of vaginal cancer, robust randomised controlled trial evidence guiding treatment is very limited; management is largely extrapolated from cervical cancer data.

The majority of vaginal SCC share a common aetiological pathway with cervical cancer, driven by persistent high-risk HPV infection. HPV infection — particularly HPV-16, which accounts for over 50% of HPV-positive vaginal cancers — is implicated in approximately 60-70% of vaginal SCCs through integration of viral oncoproteins E6 (degrading TP53) and E7 (degrading pRb) that disrupt cell cycle control and drive epithelial dysplasia to invasive carcinoma. The stepwise progression from HPV infection through VAIN 1, VAIN 2, VAIN 3, to invasive carcinoma mirrors the cervical carcinogenesis pathway; the latency period from VAIN to invasive cancer is estimated at 2-10 years, providing a window for surveillance-based intervention. Additional risk factors for vaginal SCC include prior cervical cancer or cervical intraepithelial neoplasia (CIN) — reflecting the 'field effect' of high-risk HPV infection throughout the lower genital tract — prior pelvic radiotherapy (which may cause radiation-induced secondary vaginal malignancy years after treatment of cervical or rectal cancer), tobacco smoking (which impairs local immune surveillance and HPV clearance), and immunosuppression from HIV, solid organ transplantation, or other immunocompromising conditions. Vaginal adenosis — columnar epithelium replacing normal vaginal squamous mucosa — which is a direct consequence of in utero DES exposure, provides the adenomatous substrate from which clear cell adenocarcinoma develops. Chronic irritation from a vaginal pessary ring used for pelvic organ prolapse has been associated with rare reports of vaginal cancer and warrants vigilance.

Vaginal cancer frequently presents with symptoms that may be attributed to more common benign conditions, contributing to diagnostic delays. Postmenopausal vaginal bleeding — any bleeding occurring more than 12 months after the last natural menstrual period — is the most common presenting symptom and requires gynaecological evaluation without delay. Postcoital bleeding (bleeding following sexual intercourse) occurring in a premenopausal or postmenopausal woman should always prompt colposcopic assessment of the cervix and vagina. Abnormal vaginal discharge — blood-tinged, watery, or malodorous — is a common but non-specific symptom. Pelvic discomfort, dyspareunia (pain during intercourse), and perineal pain reflect local tumour invasion or ulceration. Urinary symptoms — frequency, urgency, haematuria, and difficulty voiding — indicate anterior invasion into the urethra, bladder trigone, or periurethral tissues. Constipation and change in bowel habit may reflect posterior invasion of the rectovaginal septum. A palpable vaginal lump or firmness may be detected by the patient or during vaginal examination; unfortunately, many women delay gynaecological examination, particularly postmenopausal women no longer undergoing routine cervical cancer screening. In many cases, vaginal cancer is detected incidentally during colposcopy or vaginal vault cytology surveillance following prior treatment for cervical cancer or CIN. DES-associated clear cell adenocarcinoma in young women may present with vaginal discharge and abnormal bleeding in their late teens or early twenties.

Gynaecological examination under adequate illumination — including speculum examination, bimanual palpation, and rectal examination — is the first step, enabling direct visualisation of the vaginal mucosa and palpation of tumour extent. Colposcopy with the application of acetic acid (3-5%) and Lugol's iodine (Schiller's test) enables identification of VAIN and early invasive carcinoma; directed punch biopsy or excisional biopsy of any acetowhite or iodine-negative lesion establishes histological diagnosis. The staging classification for vaginal cancer is the FIGO clinical staging system (I-IVB), based on physical examination and selected imaging, and modified by the AJCC TNM system. MRI of the pelvis is the optimal imaging modality to delineate local tumour extent — specifically invasion depth, longitudinal extent, involvement of the bladder trigone, rectovaginal septum, and pelvic sidewall — which are critical for planning external beam radiotherapy field design and brachytherapy applicator selection. PET/CT with 18F-FDG provides highly sensitive detection of pelvic, inguinal, and para-aortic lymph node metastases and distant disease; PET/CT-based staging frequently upstages patients compared to CT alone. HPV genotyping by PCR guides prognostication. Prior cervical cancer or CIN and primary cervical involvement must be thoroughly excluded by sampling the cervical transformation zone and carefully mapping lesion distribution before confirming a primary vaginal cancer diagnosis.

Treatment of vaginal cancer is largely based on stage, tumour location within the vagina, size, and patient fitness, with radiation-based treatment as the mainstay. For Stage I tumours of the upper vagina: small (less than 2 cm), superficially invasive lesions may be managed with wide local excision or partial vaginectomy with adequate margins; intracavitary brachytherapy alone (21-25 Gy prescribed to 5 mm depth) is highly effective for Stage I superficial tumours. Most Stage I-II tumours: definitive concurrent chemoradiation combining cisplatin-based chemotherapy (weekly cisplatin 40 mg/m²) plus external beam radiotherapy (EBRT, 45-50 Gy to the pelvis) followed by intracavitary or interstitial brachytherapy boost (to a total tumour dose of 80-85 Gy), mirroring the approach used in cervical cancer. Inguinal lymph node irradiation or dissection is included for tumours involving the lower third of the vagina (which drain to inguinal nodes rather than pelvic nodes). Surgery — radical vaginectomy with pelvic exenteration — is reserved for Stage I disease not suitable for radiation (particularly in patients with prior pelvic radiation) or for radiation failure and recurrence where further radiotherapy is contraindicated due to cumulative dose limits. Systemic therapy for metastatic or recurrent vaginal cancer: no prospective randomised data exist specifically for vaginal cancer; clinical practice extrapolates from cervical cancer data using platinum-based doublets (carboplatin-paclitaxel) plus bevacizumab and pembrolizumab or cemiplimab for checkpoint-eligible tumours.

Prevention of vaginal cancer is achievable through HPV vaccination, sustained cervical cancer screening programmes that detect and treat VAIN, and lifestyle risk factor modification. HPV vaccination with Gardasil 9 — targeting HPV types 16, 18, 31, 33, 45, 52, and 58, which account for approximately 90% of cervical and vaginal HPV-related cancers — is the most effective primary prevention strategy, reducing incident high-risk HPV infection that drives the HPV-related pathway of vaginal SCC. Vaccination is recommended at ages 9-26 years; catch-up vaccination up to age 45 years is endorsed by ACIP on a shared decision-making basis. Cervical cancer screening programmes — Pap smear cytology and HPV co-testing — detect VAIN in addition to CIN, particularly in women who have had colposcopic assessment of the full vaginal mucosa. VAIN 3 should be treated with CO2 laser ablation, topical 5-fluorouracil cream, or surgical excision to prevent progression to invasive cancer. Women who have been treated for cervical cancer or high-grade CIN require lifelong vaginal vault cytology surveillance, as field-change HPV infection makes them at significantly elevated risk of VAIN and vaginal SCC. Smoking cessation is recommended as tobacco impairs local immune surveillance against HPV infection. Avoidance of multiple sexual partners and use of condom protection reduce HPV transmission risk. Maintenance of immune health — including antiretroviral therapy in HIV-positive women — reduces HPV-related cancer risk.

Any postmenopausal vaginal bleeding — however light or brief — requires prompt gynaecological evaluation, as this symptom is the sentinel presentation of both endometrial and vaginal cancer; do not attribute postmenopausal bleeding to 'dryness' or atrophy without specialist exclusion of malignancy. Postcoital bleeding in any woman, regardless of age, warrants colposcopic assessment of the vagina and cervix within 2 weeks. Abnormal vaginal discharge — particularly if blood-tinged, watery, or persisting for more than 2-4 weeks without an infectious explanation — requires gynaecological examination. Women who have previously been treated for cervical cancer, high-grade CIN (CIN2 or CIN3), or VAIN must attend their scheduled vaginal vault surveillance appointments, as they are at significantly elevated risk of vaginal SCC. Young women (aged 15-30) with a history of maternal DES exposure during pregnancy who experience any vaginal bleeding or discharge should undergo thorough colposcopic examination of the entire vagina and cervix to exclude DES-associated clear cell adenocarcinoma. Pelvic pain, dyspareunia, or urinary symptoms in any woman that are persistent and unexplained by common benign causes should prompt clinical examination including a vaginal speculum assessment. HIV-positive women and immunosuppressed women (transplant recipients) should attend gynaecological surveillance annually, as their elevated HPV-related cancer risk requires proactive monitoring.

Stage I: 5-year OS approximately 70-80%. Stage II: approximately 45-55%. Stage III-IV: approximately 20-35%. Overall 5-year survival approximately 52%. HPV-positive tumours may respond better to chemoradiation. Outcomes are inferior to cervical cancer partly due to anatomical constraints on achieving adequate brachytherapy doses without rectal or bladder toxicity, and lack of dedicated randomised trial data for this rare cancer. The prognosis for Vaginal Cancer: Causes, Symptoms, and Treatment varies depending on severity at diagnosis, the patient's overall health, and how promptly treatment is initiated. With early diagnosis and appropriate management, many patients achieve good outcomes and maintain quality of life. Regular follow-up with healthcare providers is essential to monitor progress, adjust treatment as needed, and detect any complications early. Adherence to prescribed treatments and lifestyle modifications significantly improves long-term prognosis.