Info Blog – Beating Bowel Cancer

BBCTodays info blog is provided by Paula Madden, Senior Nurse Advisor at Beating Bowel Cancer.

We have seen an increase in the number of women diagnosed with bowel cancer over the last few months, many of whose symptoms were mistaken for part of their pregnancy or post birth body changes, only to then be diagnosed much later.

As Vicky’s story will illustrate later today, women know their bodies and should be listened to.

Bowel Cancer and pregnancy

The data on the incidence of bowel cancer in pregnancy is scarce. An American paper estimates it to be around 1:50,000 pregnancies (1). Although extremely rare its effect is devastating for both mother and foetus. It also presents clinical challenges with ethical, religious, moral and huge emotional impact.

Patients may delay reporting symptoms because some of the symptoms of bowel cancer can be similar to the normal effects of pregnancy. Doctors may delay diagnostic tests because of potential foetal risks and because of lack of attention to the potential significance of symptoms owing to the relative rarity of bowel cancer in this young age group. This can lead to cancers being missed, being diagnosed at more advanced stage and with a poorer prognosis. In addition, because of the amount of hormones produced during pregnancy, there is potential to affect the speed of which bowel cancer could grow.

Symptom commonalities between normal pregnancy and bowel cancer can include abdominal pain, nausea, vomiting and altered bowel movements. Also a frequent pregnancy condition is haemorrhoids (piles) which are enlarged swollen veins around the anal area which, because of hormonal changes, can cause veins to relax and be prone to piles, causing rectal bleeding. Also anaemia can be a sign of bowel cancer but can indicate a food deficiency in pregnancy, sometimes associated with cravings to eat non-food substances (pica).

The challenge for clinicians is to know when it is appropriate and safe to go ahead and investigate symptoms during a pregnancy, and if cancer is found, how to treat it to ensure the best for both mother and baby.

Bowel cancer is rare in the child-bearing age group. This age group is getting older as more women are postponing pregnancy until later in life. This could mean the risk of bowel cancer occurring during pregnancy may increase. The latest figures state 95% of bowel cancer cases occur in people aged 50 and over (2).

Investigations for bowel symptoms and cancer during pregnancy:

With regard to the bowel cancer itself there are no reports of adverse foetal outcomes due to the malignancy, even in widespread metastatic disease (3). It is more the investigation and treatment decisions that can pose significant risk.

If bowel symptoms are thought to need investigation during pregnancy colonoscopy is considered to be safer during the second trimester provided that a consultation with an obstetrician and close monitoring takes place. With this type of investigation the bowel needs to be clear for good visualisation and this requires bowel cleansing medication. There is a lack of data in the medical literature about the safest product, so decisions are not easy to make.

Contrary to the general population, 86% of bowel tumours found during pregnancy occur in the left lower bowel and rectum. (4) These tumours are detectable by flexible sigmoidoscopy (which most often does not require sedation). Those undergoing colonoscopy would be more likely to require sedation, although it can be done without. Sedation could pose a risk for the foetus and radiation exposure could cause risk (if investigated with CT Colonography (CTC)). It is therefore thought that flexible sigmoidoscopy may be a safer and more appropriate alternative to colonoscopy or CTC, unless there are any signs or symptoms of right sided bowel cancer eg anaemia or right sided abdominal pain and/or palpable mass.

If a bowel cancer diagnosis is made there needs to be a staging Computerised Tomography (CT) scan done to detect the extent of the tumour and if there are any metastases. Abdominal & pelvic CT scan is generally contraindicated during pregnancy, particularly the first trimester, because of radiation exposure. Magnetic resonance imaging is an appropriate substitute for computed tomography in staging when needed and are considered safe during pregnancy because they don’t use ionizing radiation (5).

Management and treatment of bowel cancer in pregnancy

Generally in pregnancy, what benefits the mother benefits the foetus because of foetal dependence on the mother. This general principle fails, however, in bowel cancer treatment. Surgery for bowel cancer during early pregnancy is beneficial to the mother but may be detrimental to the foetus. Chemotherapy for bowel cancer with lymph node involvement is beneficial to the mother but detrimental to the foetus, particularly during the first trimester. Radiotherapy for locally advanced rectal cancer during pregnancy is beneficial to the mother but highly detrimental to the foetus.

Bowel cancer treatment has to be modified during pregnancy to avoid radiation toxicity and to minimize foetal risks from cancer surgery and adjuvant chemotherapy. The type of treatment chosen depends on many factors, including the stage of the pregnancy, the type, location, size, and stage of the cancer; and the wishes of the expectant mother and her family. Because some cancer treatments can harm the foetus, especially during the first three months of pregnancy, treatment may be delayed until the second or third trimesters. When cancer is diagnosed later in pregnancy, doctors may wait to start treatment until after the baby is born, or they may consider inducing labor early. In some cases doctors may wait to treat the cancer until after the baby is delivered.

To advise, guide, and treat properly the pregnant patient facing these emotionally charged, difficult, complex, and delicate decisions regarding treatment requires a Multidisciplinary Team (MDT) including a gastroenterologist, colorectal surgeon, obstetrician, oncologist, anesthesiologist midwife and specialist nurse.

Surgery for bowel cancer

Surgery is the removal of the tumor and surrounding tissue during an operation. It poses little risk to the developing baby and is considered the safest cancer treatment option during pregnancy. Surgery could be performed safely before 20 weeks of gestation when appropriate (6). After this gestational age it is recommended that surgery be delayed to have a reasonable maturation of the foetus (around 32 weeks). It has been proposed that bowel cancer surgery can be done right after an uncomplicated caesarean section (7).


Chemotherapy is the use of drugs to destroy cancer cells, usually by stopping the cancer cells’ ability to grow and divide. Chemotherapy can harm the foetus, particularly if it is given during the first trimester of pregnancy when the foetus’ organs are still developing and may cause birth defects or even the loss of the pregnancy (miscarriage) (8).

Chemotherapy is safer during the second and third trimester of pregnancy and some types of chemotherapy may be given without necessarily harming the fetus. The placenta acts as a barrier between the mother and the baby, and some drugs cannot pass through this barrier, or they pass through in very small amounts. However there may be an increase in the incidence of intrauterine growth retardation and prematurity (9). Although a few cancer chemotherapy studies have failed to show adverse effects in treatment in the third trimester, the possible neurocognitive effect of chemotherapy cannot be totally excluded because brain development is not completed during pregnancy or even early in life (10).

Chemotherapy can cause side effects like malnutrition and anemia (a low red blood cell count) in the mother that may cause indirect harm. In addition, chemotherapy sometimes causes early labour and low birth weight, both of which may lead to further health concerns for the mother and the baby. The baby may struggle to gain weight and fight infections, and the mother may have trouble breastfeeding. Chemotherapy drugs may be transferred to the infant through breast milk so breast feeding is best avoided.


Radiation therapy is the use of high-energy x-rays or other particles to destroy cancer cells, and is used mainly in rectal cancer treatment. Because radiation therapy can harm the foetus, particularly during the first trimester, doctors generally avoid using this treatment. Even in the second and third trimesters, the use of radiation therapy is uncommon, and the risks to the developing baby depend on the dose of radiation and the area of the body being treated. Foetal radiation exposure should be measured by a medical physicist in any radiation during pregnancy (11). Pelvic radiation after delivery can be considered, but should be discussed with the patient, as it might end in infertility (12).

Pregnancy post cancer treatment

Becoming pregnant after cancer treatment is considered safe for both the mother and the baby, and pregnancy does not appear to raise the risk of cancer recurring. Some doctors recommend that women not get pregnant within the first six months after finishing chemotherapy because any eggs that may have been damaged by treatment are thought to leave the body within this time period.

Other doctors recommend waiting at least two to five years because that is the window of time in which a cancer is most likely to recur and/or the time needed to receive optimal treatment.

There are no set guidelines for how long men should wait to try having a child after finishing cancer treatment. However, doctors typically recommend waiting at least two to five years before trying to have a child. Doctors have estimated that any sperm damaged by chemotherapy or radiation therapy should be repaired within two years. Although there isn’t any scientific evidence that children conceived sooner after treatment is finished have a greater risk of developing serious health problems, doctors often advise men to continue using contraception for about a year after treatment.

Key messages:

1) Bowel cancer is rare under 45 years old. 95% of bowel cancers occur in people over 50, however it can happen in younger people.

2) The three main symptoms of bowel cancer are blood in the stools (faeces), changes in bowel habit (such as to more frequent, looser stools) and abdominal pain. However, it is important to note most people with these symptoms do not have bowel cancer.

3) Most people who are diagnosed with bowel cancer usually have one of the following symptom combinations:

  • a persistent change in bowel habit causing a need to go to the toilet more often passing looser stools, usually together with blood on or in stools
  • a persistent change in bowel habit without blood in their stools, but with abdominal pain
  • blood in the stools without other haemorrhoid (piles) symptoms such as soreness, discomfort, anal pain, itching or a lump hanging down outside the back passage
  • abdominal pain, discomfort or bloating always provoked by eating, sometimes resulting in a reduction in the amount of food eaten with appetite and weight loss

4) Bowel symptoms are more significant when they persist despite trying simple treatments. It is important to discuss this with your GP, obstetrician or midwife, as you know your bowel function better than anyone else.

5) If symptoms don’t settle post-delivery (for example piles usually go away within weeks after the birth) it is advisable to go back to your GP to discuss this as you may need referring to the specialist at a colorectal clinic in hospital.

6) Risk factors for bowel cancer include:

  • age – 95% of bowel cancers occur in people over 50
  • diet – a diet high in red or processed meats and low in fibre can increase your risk
  • weight – bowel cancer is more common in people who are overweight or obese
  • exercise – being inactive increases the risk of getting bowel cancer
  • alcohol and smoking – a high alcohol intake and smoking may increase your chances of getting bowel cancer
  • family history – having a close relative (mother or father, brother or sister) who developed bowel cancer below 45 years of age puts you at a greater lifetime risk of developing the condition
  • Personal history of inflammatory bowel disease eg ulcerative colitis or Crohn’s disease

7) If a person feels they may be at increased risk it would be a good idea to discuss any concerns with a GP before planning a pregnancy.

8) Ask in your family about any cancer family history and if you have any close relatives diagnosed with bowel cancer especially if diagnosed under the age of 45 years. If there is ask your GP about referral to a family history clinic.

9) Eat a well-balanced diet and drink plenty of fluids during a pregnancy.

10) Bowel symptoms would be ideally investigated with a Flexible sigmoidoscopy with no sedation, within the second trimester if it was clinically thought an investigation could not wait until after the delivery.

11) If bowel cancer surgery is thought essential during pregnancy then it is thought better before 20 weeks or after 32 weeks gestation.

12) If a CT scan of abdomen and pelvis is thought necessary, MRI could be safely and appropriately undertaken as an alternative.

13) A full multidisciplinary approach is essential with at least the oncologist, obstetrician, and surgeon all involved, with a full open informed discussion with the mother and family as appropriate.

14) The prognosis (chance of recovery) for a pregnant woman with cancer is often the same as other women of the same age with the same type and stage of cancer. However, if a woman’s diagnosis or treatment is delayed during pregnancy, the extent of the cancer may be greater, resulting in potentially a worse overall prognosis.

15) It is important to recognise symptoms and not to put it all down to the pregnancy and not be afraid or embarrassed to ask and get help and advice.

16) It has been argued that a targeted program to improve the general population bowel cancer symptom knowledge and the establishment of a national consultant and screening program particularly for women with a planned pregnancy in the high risk group (as listed above) might be beneficial (13).


  • M. Girard, J. Lamarche, and R. Baillot, “Carcinoma of the colon associated with pregnancy: report of a case,” Diseases of the Colon and Rectum, vol. 24, no. 6, pp. 473–475, 1981.
  • Cancer Research UK
  • Heres P, Wiltink J, Cuesta MA, Burger CW, van Groeningen CJ, Meijer S. Colon carcinoma during pregnancy: a lethal coincidence.Eur J Obstet Gynecol Reprod Biol.1993;48(2):149–52.
  • Bernstein MA, Madoff RD, Caushai PF Colon and rectal cancer
  • Moran BJ, Yano H, Al Zahir N, Farquharson M. Conflicting priorities in surgical intervention for cancer in pregnancy.Lancet Oncol. 2007;8(6):536–44.
  • Cohen-Kerem R, Railton C, Oren D, Lishner M, Koren G. Pregnancy outcome following non-obstetric surgical intervention.Am J Surg. 2005;190(3):467–73.
  • Walsh C, Fazio VW. Cancer of the colon, rectum, and anus during pregnancy. The surgeon’s perspective.Gastroenterol Clin North Am. 1998; 27(1):257–67.
  • Pentheroudakis G, Pavlidis N, Castiglione M. ESMO Guidelines Working Group. Cancer, fertility and pregnancy: ESMO clinical recommendations for diagnosis, treatment and follow-up.Ann Oncol. 2008;19(Suppl 2):ii108–9.
  • Sommers GM, Kao MS. Using chemotherapeutic agents during pregnancy.Contemp Obstet Gynecol. 1987; 30:45–8.
  • Nulman I, Laslo D, Fried S, Uleryk E, Lishner M, Koren G. Neurodevelopment of children exposed in utero to treatment of maternal malignancy.Br J Cancer.2001; 85(11):1611–8.
  • Pereg D, Koren G, Lishner M. Cancer in pregnancy: gaps, challenges and solutions.Cancer Treat Rev .2008;34(4):302–12.Epub 2008 Mar 4.
  • Devita VT, Hellman S, Rosenberg SA. Principles and practice of oncology.3rd ed. Philadelphia, PA: JB Lippincott; 1989.
  • Sepideh Khodaverdi, Ali Kord Valeshabad, and Maryam Khodaverdi. A Case of Colorectal Cancer during Pregnancy: A Brief Review of the Literature. Case Reports in Obstetrics and Gynecology Volume 2013 (2013)
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