Pregnancy and cancer

It is always a joy to see a newborn baby but this 2.9kg boy was really special.

I remember the first time I saw his mother – she was 31 weeks pregnant and about to go bald from the ravages of chemotherapy. She was just 36 years old.

This patient had already undergone surgery for her breast cancer.

It had spread to the lymph nodes in her armpit. Because of the high number of lymph nodes affected by the cancer, she needed dose-dense chemotherapy.

This type of treatment is administered every two weeks instead of every three weeks. By shortening the intervals between treatments, the programme becomes more intense.

Studies have shown that dose-dense chemotherapy improves the cure rate of patients with breast cancer. However, because of the shorter rest period, the side effects are worse.

The diagnosis of breast cancer in a pregnant woman poses special considerations.

The standard approach for any breast cancer patient is to undergo a complete evaluation to assess if the cancer has spread to other sites, such as the lungs, liver or bones.

However, in a pregnant woman, a chest X-ray and a bone scan cannot be carried out because of the risks of radiation exposure to the unborn baby. Staging is restricted to ultrasound scans of the breasts, abdomen and pelvis.

Decisions on how to proceed depend on the stage of the pregnancy, the age of the patient, and whether the couple want to preserve the pregnancy.

In the earliest stages of conception, the general recommendation is to abort the baby. However, either out of personal choice or for religious reasons, this may not be acceptable to the patient.

In the second and third trimesters, abortion is often not an option.

When breast cancer is confirmed, the patient has two key concerns. First, should she remove the whole breast or just part of it? Second, will the cancer pass on to her baby?

On the first question, the patient has a choice of whether to have the entire breast removed or to have breast conservation surgery.

The latter would mean that the patient would need six to seven weeks of radiation, some time after the delivery of the baby. This often discourages most pregnant women from choosing breast conservation surgery.

In some situations, there is no surgery. This happens if the cancer is locally advanced or if it has spread to other organs. It is not uncommon to discover breast cancer in its advanced stages during pregnancy.

The reason for this is that breasts do undergo significant changes during pregnancy and cancerous breast lumps can often be mistaken for breast engorgement or infection.

I remember a pregnant doctor who was wrongly diagnosed with mastitis (infection of the breast) when, in fact, she had breast cancer.

After the surgery, many pregnant women would require chemotherapy. This is because breast cancer tends to be more aggressive when it occurs in younger pregnant women.

Chemotherapy, however, can be safely administered to pregnant women in their second and third trimesters. This was the case with the mother of the 2.9kg baby.

Often, as she sat in my clinic, her tummy wonderfully round and her head bare, patients would come in and whisper to me: ‘You mean it is safe for her baby?’

Yes, it is safe and she managed to complete three cycles of chemotherapy before she delivered her baby after 36 weeks of pregnancy. The baby turned out fine.

On the second question, there is always concern among pregnant mothers with cancer about cancer cells crossing the placenta and affecting the unborn baby.

Studies have shown that this generally does not occur. However, there have been a few reported cases of maternal-foetal transmission of blood cancer like leukaemia or lymphoma.

Barely one week after a normal vaginal delivery, my patient underwent computed tomography (CT) scan of her chest and liver as well as a bone scan. Thankfully, there was no evidence of cancer spread.

She resumed her chemotherapy once the investigations were completed.

The journey ahead is long – she will need a total of eight chemotherapy cycles, followed by six weeks of radiation.

Hopefully, the joy of a healthy baby, the relief of finding that her cancer had not spread to other organs despite being fairly advanced, and the love and support from her husband will make the journey less daunting.

This article first appeared in "Mind Your Body", a Straits Times Supplement.