Vulvar cancer possibly tied to bacteria not known in such cancers
Lymph nodes carrying rare malignancy 'heavily infected' with F. necrophorum
The first recorded case of vulvar cancer that occurred alongside an infection with the Fusobacterium necrophorum bacteria was described in a recent case report from the U.S.
F. necrophorum previously has been linked to other cancers, but exactly how it might contribute to tumor development is not known.
“This case highlights the intersection of gynecology-oncology and infectious disease, with a never-before-documented bacterial infection in the context of vulvar cancer,” the scientists wrote. “Further ingestion is needed to understand the role of this pathogen in the development of vulvar cancer.”
The report, “Intersecting Pathologies: Vulvar Cancer Complicated by a Fusobacterium necrophorum Infection,” was published in Cureus.
Human papillomavirus is among known risk factors for vulvar cancer
Vulvar cancer is a rare gynecological cancer affecting the vulva, a collective term for the external parts of the female genitalia. Its exact cause is not known, but risk factors include smoking, conditions that compromise the immune system, and infection with human papillomavirus (HPV), a common sexually transmitted infection.
The 49-year-old woman came to a rural hospital in North Carolina with complaints of a painful groin mass, fever, and chills for the previous three days.
She indicated that she had a palpable vaginal mass and had experienced bleeding after sex for the last five years.
Over the previous nine months, she also had a rash on her torso and legs that had been treated as scabies, a rash caused by mites burrowing into the skin. In the past, she had undergone a hysterectomy — a surgery to remove the uterus — for reasons unrelated to cancer.
Hospital lab work showed high levels of white blood cells, or immune cells, in her blood and urine. Imaging scans of the abdomen and pelvis showed a mass in the groin with surrounding inflammation.
A gynecology team, examining the mass while the woman was under anesthesia, determined that it started in the labia majora, a part of the vulva, and extended into the vagina.
Doctors took out lymph nodes in the groin area that looked abnormal and sent them, along with nearby fluids, to be tested in the lab. Findings showed cancer in the lymph nodes, which were also heavily infected with F. necrophorum.
Tissue analyses from the vaginal mass revealed that the woman had a type of cancer called high-grade squamous cell carcinoma. Ultimately, she was diagnosed with stage 3B vulvar cancer, with the tumor on the vulva having spread into the vagina and nearby lymph nodes.
Lab tests also found that the woman had latent syphilis, a sexually transmitted infection (commonly called an STI). She was treated with antibiotics for two weeks.
Because of its extent, surgery to remove the vulvar cancer was not feasible. Instead, the patient was given radiation daily to the pelvic region for six weeks and treated with the chemotherapy agent cisplatin weekly for two months.
A post-treatment imaging scan showed signs of cancer remaining in a lymph node of the groin, and another round of chemotherapy was planned for the following months.
F. necrophorum infection has been tied to colorectal cancer, particularly
F. necrophorum is a microbe that’s normally found in the mouth and gut, but its excessive growth is associated with various types of infections, including tonsillitis and those in gynecological tissues.
Some studies point to a link between F. necrophorum and the development of certain cancers, particularly colorectal cancer. But no studies to date have connected the pathogen to gynecological cancers, the scientists noted.
“The mechanism of the interaction between the pathogen and cancer is not completely understood at this time,” they wrote, adding that research suggests it could be related to interactions between the bacteria and a person’s immune system, acting to weaken immune responses that fight cancer growth.
An STI history also has been linked to invasive vulvar cancer, so the woman’s syphilis infection could have played a role. It “adds another layer of complexity,” according to the scientists.
“These results highlight the importance of the clinician’s role in primary prevention and education,” the team concluded, adding that its findings should encourage doctors to recommend HPV vaccination to young women and education about safe sex practices to reduce their cancer risk.
The HPV vaccine protects against gynecological cancers and genital warts tied to human papillomavirus infection.
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