Women may be treated with chemo and/or radiation during pregnancy. But much depends on the type of cancer, required agents for optimal treatment, period of gestation and goal of treatment.
It is rare, though.
Please remember that cancer is not One disease with one uniform treatment. It is a name with several hundred smaller disorders under it, most of which are treated differently...even different patients with same disease may get a different treatment based on their condition.
There are many different drugs that comprise "chemotherapy" - some are relatively benign, and others quite hazardous. This is true of all drugs. Ativan is quite dangerous to pregnant patients, though many are not aware, as is gangcyclovir. There are are also now "targetted" therapies - that pinpoint cancer cells and limit damage to other cells.
There are chemo drugs that are never used in pregnancy, but there are some agents that can be used at certain points in gestation with a certain degree of safety and relative lack of danger to the baby.
Radiation is a bit more of a problem. If it is required, the abdomen is shielded, and it is done on a limited basis or at certain points in gestation. This is usually done to slow cancer growth/prevent pain to the mother. As cancer cells can "hide" in shielded areas - this will not work all that well as a curative measure, though could slow disease until the mother delivers and more extensive rad can be done. Early (if safe) delivery is induced/csected sometimes.
As far as abortion, the patient is presented with the diagnosis, extent of disease, treatment options and prognosis. If the patient opts for abortion, and it is legal in the locale and within an acceptable trimester, that is her option. This procedure has never been done on any onco floor that I have worked, though there are Gyn Onco floors that might deal with it.
Chemo and/or rad are given to pregnant patients - usually in a specialty/teaching facility, as these are considered high risk patients. They require intensive treatment and much teamwork among several different disciplines. It tends to be leukemics and breast cancer patients, mostly that I have seen. As far as ethical issues, the MD gives all the information previously mentioned, discusses what options are available, those that they will consider and those offered by other facilities. If the patient insists on a treatment that the MD considers incompatible with medical ethics , the patient may go elsewhere. If the MD insists on treatments that go against ethical consideration, the patient may decline them. As a general rule, within certain choices, the medical team must provide the safest , most responsible and healthiest options. Most uses of chemo in pregnant patients require an extensive informed consent form be signed, spelling
out clearly the risks.
I have never seen Oncos give anything to a pregnant patient that had high risks of defects or hazards to the fetus, in the trimester in which it was given, and the dose level that was given. Most would refuse exposing the fetus to unduly hazardous meds, as it would go against their ethics. Modification to protocols were made to limit possible dire effects. Most that handle these type of patients have access to ethics committees, especially since the patient crosses through several modalities.
It is generally (not always) safer to treat later in pregnancy than earlier, for all modalities.
Nonpregnant female patients of childbearing age are often (unless contraindicated) placed on hormonal birth control. Reason one, you really don't want them getting pregnant on chemo/rad. Reason two: especially for leukemics - There may be excessive blood loss, so we want to stop the periods if possible.
Male patients are asked to use birth control during treatment as sperm condition/quality will not be optimal during chemo. It is preferable for patients of either gender to not attempt conception for at least 6 monthes after treatment ends, preferably a year or longer.
There are some drugs such as Thalidomide that regs mandate NO ONE is to receive the drug unless they have proof that they are sterile or on two forms of reliable birth control. Frequent pregnancy tests are required. For a while thalidomide required the recipient to watch a video showing the birth defects associated with the drug, and sign an extensive informed consent. The capsules actually came with a picture of a pregnant woman with a crosshatch across them.
I know of the most amazing patient - a hemo cancer - that was dxd late pregnancy, underwent initial treatment and then after birth, went to BMT. The patient later had more children. This is remarkable, since the drugs used for hemo cancers and the conditioning tx for BMT can cause premature menopause/or infertility.