Bowel cancer in pregnancy is distinct from bowel cancer in the general population.
Pregnancy-associated cancer refers to the instance when the initial diagnosis of cancer is made during pregnancy or within 12 months of delivery.
Cancer is a leading cause of death in women in childbearing ages, and bowel cancer is among the eight most common malignancies in pregnancy.
Pregnant patients typically present with advanced bowel cancer, which is usually due to delayed diagnosis.
Patients frequently delay self-referral. Common presenting symptoms of bowel cancer include abdominal pain, constipation, vomiting, anaemia, and rectal bleeding; most of these symptoms might be attributed to pregnancy itself and are therefore overlooked. Rectal bleeding can also be attributed to haemorrhoids, which are common in pregnant women.
Specialists may delay diagnostic tests because of inattention to the potential significance of symptoms owing to the relative rarity of bowel cancer in this young population, and potential foetal risks.
For these reasons, most cases of bowel cancer are diagnosed later in pregnancy when more widespread metastasis has occurred.
Arguably, pregnancy should provide an opportunity to diagnose bowel cancer earlier than usual in the general population because of frequent routine doctor visits by the pregnant patient to the specialist. However, this often is sadly not the case.
As the presenting features of bowel cancer can overlap with those of pregnancy itself, there is a risk of development of advanced disease, with poorer prognosis at diagnosis.
You are never too young to have bowel cancer, and bowel cancer is being diagnosed in women while pregnant or shortly afterwards.
No one knows your body better than you, so regardless of whether you are pregnant or not, if something isn’t right and you are experiencing any possible bowel cancer symptoms, discuss your concerns with your doctor as soon as possible.
If caught in time, 90 per cent of bowel cancer cases can be successfully treated.
It is important not to miss critical diagnoses that might put both mother and baby at serious health risk.
Bowel cancer diagnosis and treatment during pregnancy
Pregnancy affects the clinical presentation, evaluation, therapy, and prognosis of bowel cancer.
When diagnosis of bowel cancer is made during pregnancy, multidisciplinary involvement of the obstetrician, perinatologist, colorectal surgeon, and radiation and medical oncologists is essential to achieving the goal of early delivery that allows for the earliest treatment of the patient’s cancer.
In situations in which therapeutic intervention is necessary at patient diagnosis, the stage of the pregnancy can have an impact on the types of procedures (e.g. radiologic and endoscopic intervention) and medications used (e.g. sedatives). However, once diagnosed, the evaluation of pregnant patients with bowel cancer is similar to the evaluation of nonpregnant patients.
Treatment and prognosis by cancer stage are not different from those in the general population. However, there are several factors to consider when planning management of the cancer treatment, the types of treatments used and when they are administered, including the location of the cancer, gestational age, elective versus emergency presentation, the stage of the tumour, complications of tumour or pregnancy, and the patient’s decision.
There are still lots of unanswered questions
The exact reasons for why bowel cancer is often diagnosed in more advanced stages during pregnancy is still associated with lots of unanswered questions.
A possible association between neoplastic cell growth and proliferation and gestation may have a role in the pathogenesis of bowel cancer in pregnancy. Maybe the increased levels of estrogen and progesterone during pregnancy stimulate the growth of tumoral cells with such receptors. Similarly, the enzyme cyclocoxygenase-2 (Cox-2), and tumour suppressor protein p53 have been implicated in the carcinogenesis of bowel cancer in pregnancy. However, further research is required.
Research indicates that most diagnosed cases of bowel cancer in pregnancy are rectal carcinomas, below the peritoneal reflection. However, this may reflect a detection bias due to rectal exams performed during routine antenatal care.
Cases of familial adenomatous polyposis have also been reported to be first diagnosed during pregnancies.
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Bowel Cancer Australia Helpline
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