Women with vulval cancer who have a negative sentinel node biopsy have a low risk of recurrence and good disease-specific survival outcomes, investigators report.
One of two current standard treatment approaches for early-stage vulval cancer is radical excision of the tumor and inguinofemoral lymph node dissection, wrote Ligita P. Froeding, MD, of Copenhagen University Hospital Rigshospitalet, and coauthors. Their report is in Gynecologic Oncology. However, this procedure is associated with the disabling complication of leg lymphedema, which can significantly affect a woman’s quality of life.
Radical excision with sentinel biopsy is also an option, but the authors said large, population-based studies on the safety of this procedure when performed outside multicenter clinical trials were lacking.
In a prospective, nationwide cohort study, researchers analyzed data from 190 patients with vulval cancer who underwent the sentinel node procedure and had a negative biopsy. Of these, 73 patients had a unilateral procedure and 117 had a bilateral biopsy.
Over a median follow-up of 30 months’ follow-up, 32 patients (16.8%) died – 12 (37.5%) of vulval cancer and 20 (62.5%) from other causes. The 3-year overall survival rate was 84% and disease-specific survival was 93%.
The overall rate of recurrence in these sentinel node–negative women was 12.1% during the follow-up period. Fourteen patients (7.4%) experienced an isolated local vulval recurrence at a median time of 16 months after their primary treatment, and eight of these patients subsequently underwent inguinofemoral lymph node dissection following treatment of the recurrence. Three patients in this group died from vulval cancer, so the 3-year overall survival rate for patients with recurrent disease was 58%.
Four patients developed an isolated groin recurrence at a median of 12 months, and were treated with a combination of inguinofemoral lymph node dissection and chemoradiation. Two then developed a second recurrence.
Histopathological revision of original sentinel node specimens from the four women who experienced groin recurrences revealed that two patients actually had metastases at the time of the sentinel node procedure. In one case there were scattered tumor cells measuring less than 0.1 mm, while in the other there was a metastasis measuring 0.9 mm that was seen in six consecutive slides.
The authors noted that the failure to detect these metastases occurred despite strict adherence to histopathological procedure protocols. They suggested the first misdiagnosis may have been the result of the pathologist’s reluctance to make a histological diagnosis with so few tumor cells present. The second slide was originally screened microscopically by a specially trained medical laboratory technician, before being signed out by a pathologist, which “potentially decreases the pathologist’s diagnostic awareness,” they suggested.
“In conclusion, our study showed that the SN procedure is safe in selected VC patients when the current guidelines are strictly followed, and the procedure is performed in specialized gynecological oncology centers with a high volume of patients.”
No conflicts of interest were declared.
SOURCE: Froeding L et al. Gynecol Oncol 2019 Nov 8. doi: 10.1016/j.ygyno.2019.10.024.