Therapies that suppress the immune system do not increase the risk of vulvar or vaginal cancer in women with inflammatory bowel disease (IBD), a new study has found.
The study, “Vulvar and vaginal neoplasia in women with inflammatory bowel disease,” was published in the journal Digestive and Liver Disease.
Medications that limit the activity of the immune system are the cornerstone of IBD treatment. While these therapies aim to limit disease-associated immune activity, they also can lessen the normal activity of the immune system and increase the risk of certain types of cancer, including skin cancer and lymphoma. Lymphoma is a cancer that starts in cells that are part of the body’s immune system.
However, whether these therapies also increase the risk of cancers in the female genital tract, such as vulvar and vaginal cancer, is still unknown.
To address this question, a team of Dutch researchers analyzed data from a nationwide network and registry of histopathology and cytopathology reports in the Netherlands, called PALGA. The team identified 55 women with IBD — 37 with Crohn’s disease and 18 with ulcerative colitis — who developed vulvar or vaginal cancer from 1991 to 2015.
After combining these data with other nationally collected information, the researchers determined the age-adjusted rate for these cancers among women with IBD was at 4.8 cases per 100,000 people. That is very similar to the rate seen in the general population.
Further, among people with IBD, the use of immunosuppressive therapies did not significantly change the incidence —the occurrence of new cases — of these cancers, nor the risk and time to disease recurrence (cancer return).
However, the investigators found that women with IBD who were treated with immunosuppressive therapies were much younger at the time they received their cancer diagnosis compared with those who did not receive these therapies (median age of 49 versus 60 years).
“A high percentage of HPV [human papillomavirus]-related tumors might explain the younger age at diagnosis,” Maxine D. Rouvroye, MD, a PhD candidate at Universiteit Amsterdam and study co-author, said in a press release.
“HPV is strongly associated with higher rates of vaginal cancer in the general population, and other research suggests that IBD patients are at an increased risk for other cancers including cervical cancer,” Royvroye said. “Unfortunately, our data on HPV status are incomplete, as HPV status was analyzed in very few cases.”
Despite the lack of data, the researchers were convinced most of the cases were related to HPV. In addition to the lack of data on HPV status, a study limitation was a shortage of information available on both the duration and dosage of the immunosuppressive therapies patients were receiving. The researchers pointed to missing and incomplete patient records for the lack of information.
Among the immunosuppressive therapy users, however, there were three cases of vulvovaginal lymphoma, the researchers noted. This type of cancer rarely occurs in the genital tract. Since it is difficult to draw conclusions from such a small sample size, more research into this may be warranted, the team said.
“Overall, although IBD patients are at higher risk of HPV-related cancers, our data do not support intensified screening for vulvar or vaginal malignancies in female IBD patients [beyond what is typically done for the general population],” the researchers said.