Tuesday, December 30, 2008

Vulvar Cancer - GOG 37 and GOG 88

In re to conference this AM, there were some questions and confusion between the GOG 37 and 88 trials. Here are my notes on these two important trials -

Pelvic Nodal Control: GOG 37 (Homesley et al. OB Gyn 1986;68:733 PMID:3785783)

Resectable vulvar SCC

s/p radical vulvectomy & bil superficial and deep inguinal dissection found to have + inguinal LNs

114 pts randomized to:

Pelvic node dissection - PLND (15/53 patients had + pelvic LNs)

RT (45-50 Gy to inguinal nodes and pelvic nodes BUT NOT vulvar region)

50% of patients were cN0 (PE not sensitive for groin node mets)

Groin recurrence PLND 13/55 vs RT 3/59 (p=0.02)

OS (2) PLND 54% vs RT 68% (p=0.03)

Subgroup analysis showed benefit primarily to RT when >1 node was invovled, which has become standard for many gyn-oncs, however, this was a subgroup and should be interpreted with all of the standard caveats.

Inguinal Nodal Control: GOG 88(Stehman et al. IJROBP 1992;24:389)

Resectable vulvar SCC; Excluded T1 lesions unless LVI or >5mm invasion; s/p radical vulvectomy

58 pts randomized to

Bilateral groin dissection, RT if positive

Bilateral groin irradiation

50 Gy/ 25fx, with 50% of dose given with 12-13 MeV electrons; Rx'd to 3 cm

5/25 patients had + nodes in Arm A

OS and DFS were better in the dissected + selective RT arm, with a large portion of local failures in the RT arm in the groin.

However- the standard critique of this study is that RT was Rx'd to 3cm, which is clearly insufficient in many cases. See Koh IJROBP 1993;27:969-974 for a good discussion of this.

So there you go. GOG 37 is about pelvic nodes and GOG 88 is about inguinal.

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