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