Wednesday, January 2, 2008

Gestational Trophoblastic Disease and Choriocarcinoma Staging

Hydatidiform mole
Hydatidiform mole (molar pregnancy) is disease limited to the uterine cavity.
Invasive mole (chorioadenoma destruens) is a locally invasive, rarely metastatic lesion.
The FIGO staging system is as follows:
• Stage I: Disease confined to the uterus
o Stage IA: Disease confined to the uterus with no risk factors.
o Stage IB: Disease confined to the uterus with one risk factor.
o Stage IC: Disease confined to the uterus with two risk factors.
• Stage II: Gestational trophoblastic tumor (GTT) extends outside of the uterus but is limited to the genital structures (ovary, tube, vagina, and broad ligament)
o Stage IIA: GTT involving genital structures without risk factors.
o Stage IIB: GTT extends outside of the uterus but is limited to genital structures with one risk factor.
o Stage IIC: GTT extends outside of the uterus but is limited to the genital structures with two risk factors.
• Stage III: GTT extends to the lungs, with or without known genital tract involvement
o Stage IIIA: GTT extends to the lungs, with or without genital tract involvement and with no risk factors.
o Stage IIIB: GTT extends to the lungs, with or without genital tract involvement and with one risk factor.
o Stage IIIC: GTT extends to the lungs, with or without genital tract involvement and with two risk factors.
• Stage IV: All other metastatic sites
o Stage IVA: All other metastatic sites, without risk factors.
o Stage IVB: All other metastatic sites, with one risk factor.
o Stage IVC: All other metastatic sites, with two risk factors.

The American Joint Committee on Cancer (AJCC) has designated staging by TNM classification.

TNM definitions
Primary tumor (T)
• TX: Primary tumor cannot be assessed
• T0: No evidence of primary tumor
• T1: Disease limited to uterus
• T2: Disease outside of uterus but is limited to genital structures (ovary, tube, vagina, and broad ligaments)
Distant metastasis (M)
• M0: No clinical metastasis
• M1a: Lung metastasis
• M1b: All other distant metastasis
Risk factors affecting staging include the following:
1. Human chorionic gonadotropin (hCG) >100,000 IU/24-hour urine.
2. The detection of disease more than 6 months from termination of the antecedent pregnancy.

AJCC stage groupings
Stage IA
• T1, M0, no risk factors
Stage IB
• T1, M0, one risk factor
Stage IC
• T1, M0, two risk factors
Stage IIA
• T2, M0, no risk factors
Stage IIB
• T2, M0, one risk factor
Stage IIC
• T2, M0, two risk factors
Stage IIIA
• Any T, M1a, no risk factors
Stage IIIB
• Any T, M1a, one risk factor
Stage IIIC
• Any T, M1a, two risk factors
Stage IVA
• Any T, M1b, no risk factors
Stage IVB
• Any T, M1b, one risk factor
Stage IVC
• Any T, M1b, two risk factors