The authors mention several risk factors, in particular infection with Papillomavirus (HPV), which could explain “ why women with a history of cervical cancer have an increased risk of developing squamous cell carcinoma of the vagina after hysterectomy “, and smoking:” it is well known that tobacco promotes the persistence of HPV infection. »
Why is this important?
This French study presents for the first time trends in the incidence of vaginal cancer over a long period (nearly 30 years), as well as the survival of women recently diagnosed. In France, it is too early to see the benefit of vaccination against Papillomavirus on this cancer, which mainly affects older women.
Methodology
The network of French cancer registries (FRANCIM) made it possible to access data from women who had been diagnosed with invasive vaginal cancer diagnosed between 1990 and 2015 and followed up until 2018. Thus, incidence trends could be analyzed. Net survival was assessed on the most recently diagnosed cases, i.e. between 2010 and 2015.
Principle results
In 2018, 162 new cases of invasive vaginal cancer were reportedly diagnosed. This cancer would therefore represent 0.9% of the incidence of cancers related to the genital sphere in women (i.e. 17,337 women). The median age at diagnosis was 75 years. Only 7.4% of women were under 50 at the time of diagnosis.
In 2018, the incidence of invasive vaginal cancer increased steadily from the age of 40 with a marked acceleration after 75 years to reach a peak incidence of 2.9/100,000 patient-years between 90-94 years of age. .
Between 1990 and 2018, the number of vaginal cancers decreased by 36% in the French population and the standardized incidence rate decreased by 3% per year. A similar decrease in the incidence rate was seen more recently between 2010 and 2018.
Overall survival (assessed on 227 cases diagnosed between 2010 and 2015) was 68% one year after diagnosis and 35% at five years. And the age-standardized net survival was 74% and 45% respectively.
Five years after diagnosis, there was little difference between overall survival and net survival (35% and 39% respectively).
Net survival decreased steadily with age, from 78% at 5 years in 40-year-old women to 27% in 80-year-old women. Excess mortality was higher immediately after diagnosis, especially when the diagnosis was made at an advanced age. This excess mortality was particularly clear in the year following the diagnosis, and it was 3 times higher at 80 years than at 40 years.
Principale limitation
Incidence and survival by specific histological types could not be analyzed due to the low number of cases.