The epidemiology of gestational throphoblastic disease

1
The epidemiology of gestational throphoblastic
disease

• Fabio Parazzini

2
Summary

• Frequency
• Geographical differencies
• Time trends
• Risk factors

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Incidence of HM/100000 pregnancies selected
studies
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CHM vs PHM

• Few data are available from epidemiological
  studies
• In a study in Danmark the rate of CHM was
  80/100000 and of PHM 39/100000
• In the French registry 2 out of 3 HM were CHM
  (Golfier et al, AJOG, 2007)
• In the French study PHM were reclassified in the
  25 of cases.

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Incidence of choriocarcinoma/100000 pregnancies
selected studies
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Age standardized incidence rates of
choriocarcinoma/100000 donne
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Methodological problems

• Cases identified through hospital pathology
  records
• Selection
• Confoundings are not taken into account

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Time trends
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Trends in migrants

• In a study conducted in the New Mexico the rate
  of GTD decreased of about 40 in white and 62 in
  other races (not black) (Smith et al, 2006)
• No data are available from European countries

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Risk factors

• Parental age
• History
• Reproductive factors
• Oral contraceptives use
• Miscellanea

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Maternal age OR (reference category 20-35)
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Paternal age
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History of GTD and reproductive factors

• In women with previous GTD the risk of recurrent
  GTD is about 20-40 times higher (Di Cintio et al,
  1997, BerMac Gregor et al, 1969)
• Previous term births are associated with a
  decreased risk OR 0.4-0.8(Di Cintio et al, 1997,
  La Vecchia et al, 1985 Parazzini et al, 1991)
• Previous spontaneous abortions are associated
  with an increased risk OR 1.2-1.4 (Di Cintio et
  al, 1997, La Vecchia et al, 1985 Parazzini et
  al, 1991)

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Oral contraceptives

• Some studies have suggested an increased risk of
  PTD/choriocarcinoma after the evacuation of a HM,
  but the data are not consistent (Bagshawe and
  Lawler, 1982,Mallon and Modan , 1972)
• Ever OC use has been related with the risk of HM
  (Altieri et al, 2007)

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OC and risk of GTD
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Blood groups

• Women with blood groups A and AB have an
  higher risk(OR about 1.5-2.0) than women with
  group O and B

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ABO blood groups
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Other factors

• Infection
• a role of infection has been suggested , but
  epidemiological data are controversial
• Smoking
• possible risk factor OR about 1.5-2.0
• (La Vecchia et al, 1985, Di Cintio et al,
  1997)
• Diet/Social class
• the highest rates of GTD in women of lower
  social class in less developed countries may be
  explained by low protein intake.

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Molar pregnancy and childhood cancer
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Conclusions frequency

• In North America and Euope the rates are about
  10/100000 pregnancies
• PM are about 1 out of 3 molar pregancies
• Choriocarcinomas are about 1 out of 20-30 molar
  pregnancies
• Higher rates are observed in some areas of Asia
  and Middle East
• Chorioarcinoma shows similar geographical
  differencies
• The differencies seem to lower during time

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Conclusions risk factors

• Age is the main determinant in particular for CHM
• A previous history is another strong risk factor
• Other factors include repoductive history
  maternal blood groups, OC use, diet and infection
• The relation between mole and childohood cancers
  needs further studies