Therefore, sentinel node dissection may be useful when performed by a surgeon experienced in the procedure, and it may avoid the need for full groin node dissection or radiation in patients with clinically nonsuspicious lymph nodes. (Refer to the Role of Radiation Therapy section of this summary for more information.)
Role of Radiation Therapy
Groin lymph node metastases are present in approximately 20% to 35% of patients with tumors clinically confined to the vulva and with clinically negative nodes.[7,8] Lymph node dissection is traditionally part of the primary surgical therapy in all but the smallest tumors. However, a major cause of morbidity after surgery is groin node dissection, which is associated with high rates of wound breakdown, lymphocele formation, and chronic lymphedema. Some investigators recommend radiation therapy as a means to avoid the morbidity of lymph node dissection, but it is not clear whether radiation therapy can achieve the same local control rates or survival rates as lymph node dissection in early stage disease.
A randomized trial to address the radiation therapy issue in patients with clinically localized vulvar cancer has been reported.[8,9] In that study, women with disease clinically confined to the vulva, who did not have groin lymph nodes clinically suspicious for metastases, underwent radical vulvectomy followed by either groin radiation (50 Gy in 2 Gy fractions) or groin dissection (plus groin radiation if nodes were pathologically involved).
Although the planned accrual was 300 patients, the study was stopped after 58 women were randomly assigned to it because of worse outcomes in the radiation therapy arm. Five (18.5%) of 27 women in the radiation therapy arm and 0 of 25 women in the surgery arm had a groin recurrence, but this difference was not statistically significant (relative risk [RR], 10.21; 95% CI, 0.59–175.78). There were ten deaths in the radiation therapy arm versus three deaths in the groin dissection study arm (RR, 4.31; 95% CI, 1.03–18.15). Disease-specific mortality was not statistically significantly different between the two arms; however, there were eight versus two vulvar cancer-related deaths (including one related to groin dissection), in the radiation therapy arm and groin dissection arm, respectively (RR, 3.70; 95% CI, 0.87–15.80).[8,9][Level of evidence 1iiA] There were fewer cases of lymphedema in the radiation therapy arm (0 vs. 7) and shorter hospital stays. The dose penetration of the radiation (3 cm for full dose) has been criticized as inadequate. In summary, the trial was stopped prematurely, and little can be said about the relative efficacy of the two treatment approaches.
Pelvic radiation has been compared to pelvic node dissection in the setting of documented groin node-positive disease. Patients with clinical stage I to stage IV primary squamous cell carcinoma of the vulva in whom groin nodal metastases were found at radical vulvectomy and bilateral groin node dissection were randomly assigned during the surgical procedure to receive either ipsilateral pelvic node resection or pelvic radiation (45 Gy–50 Gy at 1.8 Gy–2.0 Gy per fraction). Because of a perceived emerging benefit of radiation, the planned accrual of 152 was stopped after 114 patients were randomly assigned. However, the apparent benefit of radiation was subsequently attenuated with further follow-up.