A hydatidiform mole is an
abnormal growth within the uterus at the beginning of pregnancy. The
tissues, which should have normally developed into the placenta (the tissue
which attaches the fetus to the uterus and provides nutrition to the fetus),
grow abnormally and forms a mass.
Hydatidiform mole often
affects women less than 16 years or more than 45 years of age. Symptoms include vaginal bleeding in the
first three months of pregnancy. Blood
or urine tests reveal a very high level of human chorionic gonadotropin (hCG). (hCG is the same hormone whose levels are
detected during a pregnancy test). The
mole is treated with a surgical procedure called dilatation and curettage, in
which the uterus is evacuated of its contents.
The abnormal tissues can then be directly examined and the diagnosis
The tissue remaining in the
uterus following the evacuation procedure normally regresses. In some cases, however, this tissue may
undergo cancerous changes and result in a cancer called choriocarcinoma. Cancerous
changes are detected by a rise in hCG level, thus hCG levels are regularly
monitored after removal of hydatidiform mole. Suspected cases of cancer are treated with the chemotherapy with
methotrexate or dactinomycin.
It has been suggested that women with high hCG levels beyond 6 months
post evacuation of hydatidiform mole should be treated with chemotherapy drugs,
even if the hCG levels are falling. The reason
behind this is, if chemotherapy is delayed beyond a certain point, it becomes
more and more difficult to treat the cancer.
But is this really necessary?
Some researchers conducted a study to answer this question.
Patient data was collected
from a hospital database between January 1993 and May 2008. Patient records with persistently high hCG
levels 6 months after hydatidiform mole evacuation were identified. Some of these women underwent continued
surveillance, whereas others were treated with chemotherapy.
In the women undergoing
surveillance, blood and urine testing was carried out every 2 weeks till the
hCG levels came back to normal. Testing
was then carried out monthly for the next 6 months.
In women who underwent
chemotherapy, blood testing was done twice a week till the levels came down to
normal. Testing was then done once a
week till 6 weeks following the end of chemotherapy. At this point, the patients underwent Doppler ultrasound. Frequency of testing was further reduced,
till only urine testing every 6 months was necessary.
A total of 76 patients who
had high hCG values 6 months following evacuation of hydatidiform mole were
included in the study. Among these, 66 patients underwent only continued
surveillance. hCG values became normal in 44 patients within 8 months of evacuation,
15 patients within 1 year, and 5 patients within 18 months. One patient who had 3 consecutive rises in
hCG level was lost to follow-up, but her levels subsequently normalized without
chemotherapy and she had a normal pregnancy.
Only 1 patient continued to have persistently high levels, but she also
suffered from kidney failure - the high hCG levels were due to the kidney
failure and not due to cancerous changes.
Thus, despite not receiving chemotherapy at 6 months post-evacuation,
none of the patients under surveillance developed cancer or had a relapse.
Ten patients with persistent hCG levels 6 months after evacuation were
given chemotherapy with methotrexate and folinic acid. (Methotrexate is curative for cancers due to hydatidiform
mole. Folinic acid is given along with
methotrexate to prevent some of its side effects). Six of these patients responded completely to treatment with a
normalization of hCG levels. In 2
patients, hCG levels came to normal after treatment was stopped, within 1 week
and 1 month. In the last 2 patients,
hCG levels continued to be slightly high for 3 and 15 years. Both these patients did well and had successful
Thus, in patients of hydatidiform mole with declining hCG levels at 6
months, chemotherapy may not be required.
Instead, continued surveillance in these patients may be more than
enough. This approach could especially be followed in
patients not at a high risk for developing cancer. The patient can thus avoid the
side effects of chemotherapy. This
approach could also enable patients to plan their next pregnancy earlier.
To decide which patients should undergo chemotherapy and which should
not, a cut-off value could be marked below which chemotherapy may not be
necessary. Chemotherapy should be
considered in patients with high hCG levels, with imaging tests indicating
cancer or when hCG levels are consistently plateaued or rising.
Further large-scale studies
are necessary to establish the findings of this study.
Chemotherapy and human chorionic gonadotropin concentrations 6 months
after uterine evacuation of molar pregnancy: a retrospective cohort study;
Roshan Agarwal et al; The Lancet, Early Online Publication, 29 Nov 2011.