Size of sentinel-node metastasis and chances of non-sentinel-node involvement and survival in early stage vulvar cancer: results from GROINSS-V, a multicentre observational study.
BACKGROUND
Currently, all patients with vulvar cancer with a positive sentinel node undergo inguinofemoral lymphadenectomy, irrespective of the size of sentinel-node metastases. Our study aimed to assess the association between size of sentinel-node metastasis and risk of metastases in non-sentinel nodes, and risk of disease-specific survival in early stage vulvar cancer.


METHODS
In the GROningen INternational Study on Sentinel nodes in Vulvar cancer (GROINSS-V), sentinel-node detection was done in patients with T1-T2 (<4 cm) squamous-cell vulvar cancer, followed by inguinofemoral lymphadenectomy if metastatic disease was identified in the sentinel node, either by routine examination or pathological ultrastaging. For the present study, sentinel nodes were independently reviewed by two pathologists.


RESULTS
Metastatic disease was identified in one or more sentinel nodes in 135 (33%) of 403 patients, and 115 (85%) of these patients had inguinofemoral lymphadenectomy. The risk of non-sentinel-node metastases was higher when the sentinel node was found to be positive with routine pathology than with ultrastaging (23 of 85 groins vs three of 56 groins, p=0.001). For this study, 723 sentinel nodes in 260 patients (2.8 sentinel nodes per patient) were reviewed. The proportion of patients with non-sentinel-node metastases increased with size of sentinel-node metastasis: one of 24 patients with individual tumour cells had a non-sentinel-node metastasis; two of 19 with metastases 2 mm or smaller; two of 15 with metastases larger than 2 mm to 5 mm; and ten of 21 with metastases larger than 5 mm. Disease-specific survival for patients with sentinel-node metastases larger than 2 mm was lower than for those with sentinel-node metastases 2 mm or smaller (69.5%vs 94.4%, p=0.001).


CONCLUSIONS
Our data show that the risk of non-sentinel-node metastases increases with size of sentinel-node metastasis. No size cutoff seems to exist below which chances of non-sentinel-node metastases are close to zero. Therefore, all patients with sentinel-node metastases should have additional groin treatment. The prognosis for patients with sentinel-node metastasis larger than 2 mm is poor, and novel treatment regimens should be explored for these patients.
Oonk
Maaike H
MH
University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
van Hemel
Bettien M
BM
Hollema
Harry
H
de Hullu
Joanne A
JA
Ansink
Anca C
AC
Vergote
Ignace
I
Verheijen
René H
RH
Maggioni
Angelo
A
Gaarenstroom
Katja N
KN
Baldwin
Peter J
PJ
van Dorst
Eleonora B
EB
van der Velden
Jacobus
J
Hermans
Ralph H
RH
van der Putten
Hans W
HW
Drouin
Pierre
P
Runnebaum
Ingo B
IB
Sluiter
Wim J
WJ
van der Zee
Ate G
AG
D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006119:Groin; D006801:Humans; D008207:Lymphatic Metastasis; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D011379:Prognosis; D016016:Proportional Hazards Models; D055502:Secondary Prevention; D021701:Sentinel Lymph Node Biopsy; D016019:Survival Analysis; D014846:Vulvar Neoplasms / Q000473:pathology* / Q000601:surgery