Clinical Trials Paving the Way for Improved Vulvar Cancer Treatment

Cancers of the vulva – the external portion of the female genitals – are diagnosed in approximately 4,700 women in the United States each year. While many patients can be cured by a combination of surgery, chemotherapy, and radiation therapy, others – particularly those whose cancer has metastasized to other parts of the body – often don’t fare as well.

As one of the rarer forms of gynecologic cancer, vulvar cancer hasn’t attracted as much research funding as other forms. Still, several efforts are under way to make treatment options more effective, according to Neil Horowitz, MD, a vulvar cancer expert at the Susan F. Smith Center for Women’s Cancers at Dana-Farber.

Neil Horowitz, MD
Neil Horowitz, MD

One clinical trial is studying the effectiveness of chemotherapy administered at the same time as radiation therapy for women with extensive tumors confined to the vulva. The size of such tumors and proximity to the urethra (the tube that carries urine from the bladder), clitoris, or anus often means that surgeons would have to remove these important structures to remove the cancer. The new treatment seeks to shrink the tumor prior to surgery, reducing the long-term consequences of surgery or perhaps avoiding surgery altogether. Patients are treated with the chemotherapy agents cisplatin and gemcitabine, along with intensity-modified radiation therapy (IMRT), which uses computer-generated 3-D images to show the size and shape of the tumor. Previous trials have shown the effectiveness of cisplatin and traditional radiation therapy; the new trial is exploring whether the addition of gemcitabine and the use of IMRT offers even better results.

Another trial is confirming the safety and effectiveness of omitting a full lymph node evaluation after using a less-invasive method of determining whether vulvar cancer has metastasized, or spread. The conventional approach is to remove many of the lymph nodes near the diseased vulva and examine them for the presence of vulvar cancer cells – a procedure that can lead to a painful buildup of lymph fluid and swelling of the lower extremities. The trial is analyzing whether removing only the main, or “sentinel,” lymph nodes can be just as effective for detecting metastasis while producing less swelling. Additionally, the trial seeks to determine if radiation therapy rather than a complete lymph node removal can be used if a positive sentinel lymph node is discovered.

Horowtiz and his Dana-Farber colleague Ursula Matulonis, MD, medical director of Gynecologic Oncology at the Susan F. Smith Center, recently completed a clinical trial that found that the drug Tarceva temporarily stalled or reversed the growth of squamous cell vulvar cancers in some women. The trial marked the first time a “targeted” therapy, which aims at a specific abnormal protein in cancer cells, has been tested in patients with vulvar cancer.