HOLLYWOOD, Florida — The National Comprehensive Cancer Network (NCCN) put vulvar cancer in the spotlight here at its 21st Annual Conference.
Vulvar cancer is extremely rare. it is estimated that this year in the United States, there will be 6000 cases and 1000 deaths from this disease.
This makes it difficult to do solid randomized controlled trials, said Wui-Jin Koh, MD, professor of radiation oncology at the University of Washington and medical director of radiation oncology at the Fred Hutchinson Cancer Research Center/Seattle Cancer Care Alliance.
"It's not for lack of trying. For example, there have been two or three randomized trials that have looked specifically at whether radiation or chemoradiation might improve outcome, but those studies have all failed for lack of accrual. It's not as though there aren't any questions that need to be answered, but there is now a general recognition that the best we may be able to do for now are phase 2 observational studies, as opposed to randomized trials," Dr Koh, who is cochair of the NCCN cervical/uterine cancers panel, told Medscape Medical News.
According to the 2016 NCCN guidelines, vulvar cancers can be divided into two categories: early-stage disease, which is often cured by resection alone; and late-stage disease, which requires more extensive treatment with radiation with or without chemotherapy.
A big change that has occurred in the past decade is the reduction in the scope of surgery, Dr Koh said.
"There has been an evolution from the Halstedian approach to more limited, tailored surgery. Our aim is for more function-preserving surgery, not these ultraradical surgeries," he said.Dutch studies and the GOG [Gynecologic Oncology Group] 173 trial [Intraoperative Lymphatic Mapping and Sentinel Node Identification in Patients With Squamous Cell Carcinoma of the Vulva], it is becoming increasingly established that sentinel lymph node biopsy is the acceptable standard of care," Dr Koh said.
Until those studies were conducted, women underwent bilateral full-groin (inguinal-femoral) dissection.
"This would be like doing a full axillary node dissection for women with breast cancer. Now we realize that many women can get good outcomes and functional preservation with sentinel lymph node dissection. We've learned from the breast cancer experience, we've learned from the melanoma experience, that you don't have to take out 20 nodes," he said.
Another highlight of the 2016 NCCN guidelines for vulvar cancer is the selection of appropriate patients for adjuvant treatment.
"Again, the focus is on the nodes," Dr Koh said.
"If you find positive nodes, even if the disease seems clinically early stage, what do you do then? The standard of care has been to use radiation after surgery, especially if there are two or more positive lymph nodes or if there is a single big node. However, this is undergoing refinement. I mean, what is a big node?"
The consensus now is that a node larger than 2 mm should be considered a big node, he said.
"You may not think of 2 mm as a big node, but it now appears that that size may be a better cutoff. It appears that 2 mm drives a poorer biology," Dr Koh said.
The third highlight of the guidelines is the integratation of chemotherapy and radiation not only as adjuvant treatment, but in unresectable disease.
"We borrowed from cervical cancer, anal cancer, and GOG 101 and GOG 205, which were two prospective phase 2 studies. Those trials clearly show an increasing ability to shrink big tumors. As a result, now, the standard is to give cisplatin and radiation, which will shrink the tumor, and 50% of women will actually have no cancer remaining after such treatment," he said.
"As we move ahead and push radiation and chemotherapy judiciously, we may even improve that rate to 75% disease clearance. This is what we are hoping for," Dr Koh said.
Vulvar cancer is often fatal because it is not caught early enough. It is also a serious cancer in the sense that there is a great deal of morbidity associated with it. Women develop abscesses, infections, and fistulas, and suffer a great deal of pain, he reported.
"Historically, there has been a delay in diagnosis because the average age for women to develop vulvar cancers is in the range of 60 to 70 years. One of the early signs is itching or some bleeding, and postmenopausal women may just say it's a postmenopausal symptom of maturity. We have to educate women and physicians to not simply blame symptoms on menopause. If a patient comes in complaining of itching, some bleeding, or painful intercourse, don't assume this is just a menopausal effect," Dr Koh said.
He also stressed that the guidelines have a particularly important role to play in vulvar cancer, especially because there is evidence from randomized clinical trials for the disease.
"One thing that the guidelines help with is in stating what we should do and in quantifying the areas that we have questions about. Everybody sees a few of these, and people might argue about what is to be done, what the correct steps are to take. The guidelines represent a consensus of NCCN institutions from people who have the most experience and, interestingly enough, despite the lack of concrete evidence compared with many other cancers, there is actually a lot of consensus. We argue more about uterine cancer than we do about vulvar cancer. But by quantifying these pathways, it becomes easier to see where we need another study, even if it is not randomized, to tell us what we should do. The guidelines provide a framework, not just for clinical care, but for research to help us decide the areas that we still need to improve," he said.
Robert J. Morgan Jr., MD, codirector of the gynecological cancers program at City of Hope in Duarte, California, agrees that vulvar cancer is a relatively rare cancer that, unfortunately, because of its location, might not be diagnosed or treated until it is advanced.
"These guidelines provide an outline of the optimal treatment of this cancer, which will allow optimal treatment in addition to a better quality of life for these patients," Dr Morgan told Medscape Medical News.
"It would be best if people were more aware of changes in their skin, as vulvar cancer may be considered a form of skin cancer that occurs in an area of the body that may not be routinely scrutinized. This could allow them to be treated with less disfiguring and uncomfortable surgeries and avoid the need for radiation or chemotherapy altogether," he said.
Dr Koh and Dr Morgan have disclosed no relevant financial relationships.
National Comprehensive Cancer Network (NCCN) 21st Annual Conference. Presented April 1, 2016.