This phase II trial studies how well radiation therapy works when given with gemcitabine hydrochloride and cisplatin work in treating patients with squamous cell cancer of the vulva that has spread from where it started to nearby tissue or lymph nodes. Specialized radiation therapy that delivers a high dose of radiation directly to the tumor may kill more tumor cells and cause less damage to normal tissue. Drugs used in chemotherapy, such as gemcitabine hydrochloride and cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving radiation therapy together with gemcitabine hydrochloride and cisplatin may kill more tumor cells.

PRIMARY OBJECTIVES:

I. To determine the efficacy of cisplatin, gemcitabine (gemcitabine hydrochloride), and intensity-modulated radiation therapy (IMRT) in achieving a complete pathologic response when used for the primary treatment of locally-advanced squamous cell carcinoma of the vulva.

SECONDARY OBJECTIVES:

I. To determine the efficacy of cisplatin, gemcitabine, and IMRT in achieving a complete clinical response when used for the primary treatment of locally-advanced squamous cell carcinoma of the vulva.

II. To determine the vulvar progression-free survival and groin progression-free survival in women treated with cisplatin, gemcitabine and IMRT for locally advanced vulvar carcinoma.

III. To determine the toxicity and surgical morbidity of the combined modality approach of cisplatin, gemcitabine and IMRT followed by reduced-scope surgery for the treatment of locally-advanced vulvar carcinoma.

OUTLINE:

Patients undergo IMRT 5 days a week for 6 weeks. Patients also receive gemcitabine hydrochloride intravenously (IV) over 30 minutes and cisplatin IV over 60 minutes weekly for 6 weeks in the absence of disease progression or unacceptable toxicity. Within 6-8 weeks after completion of chemoradiation patients undergo local core biopsy to confirm response or surgical excision of gross residual disease in the vulva and/or inguinal-femoral lymph nodes.

After completion of study treatment, patients are followed up every 3 months for 2 years and then every 6 months for 3 years.

Inclusion Criteria:

• Patients with locally advanced, previously untreated squamous cell carcinoma of the vulva
• Patients with T2 or T3 primary tumors (N0-3, M0) not amenable to surgical resection by standard radical vulvectomy
• Absolute neutrophil count (ANC) >= 1,500/mcl
• Platelets >= 100,000/mcl
• Creatinine =< 1.5 times institutional upper limit of normal (ULN) OR calculated creatinine clearance >= 60 mL/min
• Bilirubin =< 1.5 x ULN
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =< 3.0 x ULN
• Alkaline phosphatase =< 3 x ULN
• Patients judged capable of tolerating a radical course of chemoradiation therapy
• Patients must not be eligible for a higher priority Gynecologic Oncology Group (GOG) protocol, if one exists; in general, this would refer to any active GOG Phase III protocol or Rare Tumor protocol for the same patient population
• Patients must have signed an approved informed consent and authorization permitting release of personal health information
• Patients with a GOG performance status of 0, 1, or 2

Exclusion Criteria:

• Patients with recurrent carcinoma of the vulva regardless of previous treatment
• Patients who have received prior pelvic radiation or cytotoxic chemotherapy
• Patients with vulvar melanomas or sarcomas
• Patients with circumstances that will not permit completion of the study or the required follow-up
• Patients with evidence of active septicemia, severe infection, gastrointestinal bleeding or severe gastrointestinal symptoms requiring medical or surgical therapy
• Patients with a history of other invasive malignancies, with the exception of non-melanoma skin cancer, are excluded if there is any evidence of other malignancy being present within the last five years; patients are also excluded if their previous cancer treatment contraindicates this protocol therapy