treatment of cancer during pregnancy
Post on 21-Jan-2018
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Treatment of cancer during pregnancy
incidence
The diagnosis of cancer during pregnancy is uncommon
1 in every 1000 pregnant women
cancers are those most commonly diagnosed during pregnancy:
Breast, melanoma and cervical cancers
diagnosis and biological features
Symptoms indicative of cancer:
- breast lump, atypical vaginal discharge, changing mole , enlarging
lymph node
pathological examination are usually comparable with age- and stage-
matched non-pregnant
After the diagnosis of cancer during pregnancy
- the patient should be referred to an institution with expertise
in dealing with such cases.
Staging and risk assessment
Imaging procedures
- Ultrasound: is the preferred imaging modality for breast, abdomen
and pelvis
- Chest X-ray and mammography: with abdominal shielding can be
safely
- MRI: without gadolinium
- CT and PET scans: should be avoided throughout the course of
pregnancy
Review : the effects of ionizing radiation
The potential biological effects of radiation exposure to a developing fetus in utero
- prenatal death
- intrauterine growth restriction
- small head size
- mental retardation
- organ malformation
- childhood cancer
Review:the effects of ionizing radiation
o The risk of each effect depends on:
- gestational age at the time of exposure
- fetal cellular repair mechanisms
- absorbed radiation dose level
o Fetal doses below 100 mGy should not be considered a reason
for terminating a pregnancy
o exposure to less than 5 rad [50 mGy] has not been associated
with an increase in fetal anomalies or pregnancy loss
Incidence of prenatal & neonatal death and
abnormalities
Biological effects of ionizing radiation
Staging and risk assessment
Imaging procedures
- Ultrasound: is the preferred imaging modality for
breast, abdomen and pelvis
- Chest X-ray and mammography: with abdominal
shielding can be safely
- MRI: without gadolinium
- CT and PET scans: should be avoided throughout the
course of pregnancy
Staging and risk assessment
evaluating serum tumor markers
CA125 and CA15.3 :they should not be considered in the
management of pregnant cancer patients
treatments
local treatments
- Surgery
- Radiotherapy
systemic treatments
-Chemotherapy
Surgery
Surgery can be safely carried out at any time during the course
of the pregnancy
- mastectomy or breast conservative surgery
- Radical hysterectomy:pregnancy termination and fetal death
Major abdominal and pelvic surgery might be associated with
increased morbidity
slightly higher risk of miscarriage has been reported during the
first trimester
careful monitoring particularly after the 25th week of gestation
Radiotherapy
Several fetal adverse effects have been described after gestational radiotherapy
- risk of childhood cancer
- intrauterine growth restriction
- mental retardation
- fetal death
critical factors
- fetal dosage
- radiation field extension
- gestational age
Radiotherapy
increased risk of fetal malformation and mental retardation occurs
radiation doses >100–200 mGy
fetal doses in excess of 100mGy can result in some reduction of IQ
this dose is generally not reached with curative radiotherapy
- tumors are located sufficiently far from the uterus
- uterus adequate shielding
lower dosages might be causal in the development of childhood
cancer or sterility
Radiotherapy
radiation is during the first or second trimesters; fetus dose should be
low and below the threshold for deterministic effects
adjuvant radiotherapy is never an urgent procedure postponement of
radiotherapy until delivery could result in delay of radiotherapy for
>6 months, which could increase the risk of local recurrence
Careful planning of the local management strategy should be made in
breast cancer patients diagnosed during the first trimester
Radiotherapy
Heavy ion radiotherapy during pregnancy
o Carbon therapy
The difference of dose distribution by one port between carbon ion
beams and X-ray and proton
Carbon therapy
Characteristics of carbon ions
- Higher biological effect; cause double-strand DNA break by one hit
- high-LET;Carbon ion beams deliver a larger mean energy per unit
length
- carbon ion beams allowing a highly localized deposition of energy
- fall-off around the target is steeper with carbon ion beams than proton
beams
Carbon therapy
Characteristics of carbon ions:
- Treatment is feasible over a short period of time
- achieving precise dose localization in the target lesion
while causing minimal damage to surrounding normal
tissues
- Energy deposition of carbon ion beams increases with
penetration depth up to the sharp maximum
Characteristics of carbon ions
shielding and dosimetry uterus region
Chemotherapy
should not be administered during the first trimester of gestation
starting in the second trimester do not experience significant long-
term complications
If pregnancy occurs during Chemotherapy , the patients should be
informed of the possible increased risk of fetal malformations
secondary to the first trimester exposure(while on tamoxifen)
Other alternative methods of treatment
monoclonal antibodies
- trastuzumab & rituximab:did not show fetal malformations
secondary to brief first trimester exposure
Tyrosine kinase inhibitors
- imatinib for patients with CML:suggest a high risk of fetal
malformation and miscarriage following first trimester exposure
pregnancy in cancer survivors
pregnancy rates are 40% lower among female cancer survivors
compared with the general population
This observation is highly dependent on the cancer type,
- in which women diagnosed with melanoma or thyroid cancer have
pregnancy rates highly comparable with the general population
women with breast cancer have the lowest chance of subsequent
pregnancy, which is nearly 70% lower compared to the general
population
Thank you for your attention
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