Cancer / 22 May, 2020

Screening for cancer in women – what tests do I need?

Dr Lau Pik Onn

Cancer cases have been rising over the years in Singapore. However, with early detection and treatment, women can have a better outcome. This is why regular screening is so important to detect early diseases, even before any signs and symptoms appear. Health screening must always come with a proper and detailed medical and family history, physical examination and relevant investigations. At Icon Health Screening, we are proud to offer comprehensive health screening options for women of every age.

Cancer in Singapore

The four most common cancers in Singaporean women are:1

  1. Breast cancer
  2. Colorectal cancer
  3. Lung cancer
  4. Uterine cancer

Breast cancer

Breast cancer is the most common cancer among Singaporean women. Breast cancer develops when malignant (cancer) cells spread within breast tissue. In Singapore, the incidence of breast cancer has almost tripled over the last four decades.

All women are at risk of developing breast cancer and the risk increases with age. However, the chances of surviving breast cancer increase with early detection.


Risk factors

The causes of breast cancer are unknown but there are many known risk factors which include:

  • Family history of breast cancer
  • Early onset of menstruation
  • Late menopause
  • Never having children
  • Late childbearing
  • Being on hormone replacement therapy for a long time
  • Excessive weight gain, especially after menopause
  • Excessive alcohol intake over a long time

However, many women who have breast cancer have none of the above risk factors. This is why screening is so important to ensure early detection.


Signs and symptoms

Early breast cancer usually does not have any symptoms. However, signs to look out for include:

  • A lump or thickening in breast
  • A change in size and shape of breast
  • A change in colour or feel of skin of the breast, areolar or nipple
  • Bleeding or unusual discharge from nipple
  • Persistent rash on nipple or areolar
  • Recently retracted or inverted nipple

If you have any of the above signs or symptoms, it is important you consult your doctor immediately.


Screening guidelines

Most breast cancers are sporadic, which is why screening is very important for early detection.

If 39-years-old and below
  • Practice monthly breast self-examination to check for lumps or any breast changes
If between 40 and 49-years-old
  • Practice monthly breast self-examination to check for lumps or any breast changes
  • Undergo clinical breast examination yearly
  • Do a mammogram* annually
If above 50-years-old
  • Practice monthly breast self–examination to check for lumps or breast changes
  • Undergo clinical breast examination yearly
  • Do a mammogram* every two years

 

*Mammogram is the primary screening test for breast cancer. There are minimal side effects. The discomfort experienced during the procedure differs from person to person and also depends on factors such as timing of the examination in relation to your menstrual cycle. Radiation exposure is low and the benefits outweigh the risk.

Mammogram is not fail proof and a small number of breast cancer cases may be hidden, especially in very dense breasts.

Other tests that can be done are:

Breast ultrasound

  • This uses high frequency sound waves to produce an image of the breast tissue. There is no radiation involved.
  • Ultrasound of the breasts can also be carried out at the same time when you come for your mammogram.
  • An ultrasound can determine if a lump is filled with fluid (a cyst) or solid.
  • It also adds information to other tests such as a mammogram or breast MRI.
  • However, it does not replace a mammogram as it is not useful for detecting microcalcifications in early breast cancer.

MRI of the breast

  • This is a special screening procedure that takes images of the breast using strong magnetic fields and radio waves. It is not a replacement for a mammogram.
  • A MRI is used as a supplemental tool to mammograms, usually when there is an abnormality on the mammogram that cannot be conclusively determined as a cancerous lump.

These are guidelines for normal risk women without any symptoms. However, if you have any symptoms or are at higher risk, the screening schedule will be different and you will need to consult your doctor for advice.

Colorectal cancer

Colorectal cancer is now the most common cancer in Singapore, as it affects both males and females.

Your risk of colorectal cancer increases after the age of 50, but up to 20% of cases seen by doctors today are young adults. Colorectal cancer is the second most common cancer in women after breast cancer. It is a cancer that can be prevented or treated successfully if discovered early.


Signs and symptoms

Symptoms of colorectal cancer include:

  • Change in bowel habits
  • Changes in stool colour of shape
  • Presence of blood in the stools
  • Persistent abdominal discomfort or lump felt in abdomen
  • Unexplained weight loss
  • Unexplained anaemia

Risk factors

You are also at higher risk if you:

  • Have a family history of colorectal cancer (higher risk if family member had the cancer before age 45)
  • Are above the age of 50
  • Have a previous history of polyps
  • Have a history of ulcerative colitis or Crohn’s disease
  • Are a smoker (which has been shown to increase polyp formation)
  • Have a diet high in fats and red meats
  • Have a diet low in fruits and vegetables

Screening

Survival rates for colorectal cancer can be as high as 90% if detected early. This is why regular screening is crucial. Methods for screening for women who do not have any symptoms or are at low risk of colorectal cancer include:

Faecal immunological stool test (FIT) or faecal occult blood test (FOBT)

  • This is a simple test where a stool sample is collected and sent to the lab to detect the presence of blood in stool that cannot be seen by the naked eye
  • If the results are positive, a colonoscopy will be required

Colonoscopy

  • This is the ‘gold standard’ for colorectal cancer screening
  • Colonoscopy detects both precancerous lesions (such as polyps) as well as cancerous lesions and tumours
  • This is recommended for women who are at average risk of colorectal cancer, do not have any symptoms and are aged 50 and above
  • May be conducted earlier for anyone with higher risk or symptoms

These are general screening tests. For women who are at higher risk or have symptoms, please consult your doctor for advice.

Lung cancer

Lung cancer is the third most common cancer in women in Singapore.

People who smoke have the greatest risk of lung cancer, as risk increases with each cigarette smoked as well as the number of years smoking has occurred. However, non-smokers may develop lung cancer as well due exposure to second hand smoke.

Asian women who never smoke are increasingly being diagnosed with late stage lung cancer and the number of new cases seen in Singapore is increasing. Statistics have shown that globally, Asian female non-smokers are more vulnerable to lung cancer than their western counterparts. This is an area of current research.


Risk factors

Risk factors for lung cancer include:

  • Exposure to second hand smoke at home or in the workplace
  • Environmental pollutants
  • Family history of lung cancer
  • Smoking

Signs and symptoms

Lung cancer, especially at early stages, often does not have any symptoms. As the condition worsens, some symptoms include:

  • Persistent cough
  • Presence of blood when coughing
  • Shortness of breath or wheezing
  • Hoarse voice
  • Chest pain
  • Loss of appetite
  • Unexplained weight loss
  • Tiredness or weakness

It is important to consult your doctor if you experience any of these symptoms.


Screening

Regular screening may help in early detection and treatment of lung cancer. This includes:

  • Chest x-ray
  • Sputum (phlegm) testing
  • CT scans (computed tomography)

Further tests will be needed if any abnormalities are detected or if you are at high risk of lung cancer.

Uterine cancer

Uterine cancer (also known as endometrial cancer) is the fourth most common cancer in Singaporean women. Uterine cancer arises from the uterus or womb, affecting women of any age. 70% of cases occur after the age of 50. If detected and treated early the cure rate is very good, with over 90% of ovarian cancers able to be successfully treated if detected in the early stage.


Risk factors

Some factors associated with uterine cancer include:

  • Early menstruation/menarche
  • Not ovulating regularly and often missing menses
  • Late menopause
  • Never being pregnant
  • Obesity
  • Polycystic ovarian syndrome
  • A previous history of ovarian cancer

In about 40% of uterine cancer cases, no risk factors are identified.


Signs and symptoms

Signs and symptoms of uterine cancer include:

  • Abnormal vaginal bleeding (post-menopausal, irregular bleeding, spotting or intermenstrual bleeding, bleeding after intercourse)
  • Abnormal vaginal discharge
  • Pain during intercourse
  • Pelvic pain
  • Unexplained weight loss

Most cases of uterine cancer present early with abnormal vaginal bleeding. Post-menopausal bleeding is often the most common symptom. Please see your doctor immediately if you experience any of these symptoms.


Screening

There is no simple way to screen for uterine cancer. However, an ultrasound of the pelvis is useful to demonstrate whether there is an abnormality (thickening) of the endometrium.

For diagnosis, the gynaecologist will have to do further tests like a biopsy or dilatation and curettage (D&C).

If you have any of the above symptoms or are at higher risk of uterine cancer, it is important you see a gynaecologist for further investigations.

Cervical cancer

Cervical cancer is the tenth most common cancer in Singaporean women and can be effectively treated if detected early. The incidence has decreased significantly over the years as a result of pap smear screening in Singapore and early treatment of pre-invasive cervical cancer.

The peak age groups affected by cervical cancer are women in their 40s and 50s according to the Singapore Cancer Society.

Cervical cancer arises from the cervix, which is the neck of the womb. The most common cause of cervical cancer is infection from the human papilloma virus (HPV) which is sexually transmitted. 70% of cervical cancer worldwide is caused by HPV types 16 and 18.


Risk factors

The risk of cervical cancer increases with the following:

  • Multiple sexual partners
  • Having unprotected sex from a young age
  • Weakened immune system

Signs and symptoms

Early cervical cancer may have no symptoms. In the later stages, one may have:

  • Abnormal vaginal bleeding (after intercourse or in between menses)
  • Abnormal vaginal discharge
  • Lower pelvic pain or pain during sexual intercourse
  • Painful or difficult urination and cloudy urine
  • Leaking of urine or faeces from the vagina

Please see your doctor immediately if you have any of the above symptoms.


Prevention and screening

Cervical cancer is highly preventable and curable when detected and treated early.

HPV vaccination

  • In Singapore, HPV vaccines are approved for use in females between 9 and 26 years of age. It is most effective if given before first sexual exposure.
  • However, women who are sexually active may still benefit from the vaccine as they may not have been exposed to the types of HPV covered by the vaccine.
  • If you are above 26 years of age, you should consult your doctor to find out if you are suitable for the vaccine.

Cervical cancer screening

  • The role of cervical cancer screening is to detect potentially pre-cancerous and cancerous cells in the cervix.
  • This involves a pap smear test/ HPV test. Cervical screening is recommended for anyone aged 25 and older who have had sexual intercourse. A pap smear can detect abnormal cells in the cervix.

The best time for your pap smear is two weeks after the start of your menstrual period, so that the cervical cells obtained are the clearest and cleanest sample. If you have reached menopause, you can schedule your pap smear anytime.

Take control of your health

As most cancers do not present with symptoms in the early stage, prevention and early detection of cancers are the most important strategies to reduce the impact of cancer in Singapore.

You can protect yourself by going for early health screening, which will include a detailed history, physical examination and proper advice on the necessary investigations.

It’s important to continue to keep healthy with maintaining a good diet and keeping fit with physical exercises. Knowledge is power and we must equip ourselves with it to ensure good health throughout our life.

References

For a full list of references, click here.
  1. Health Promotion Board. (2015). Singapore Cancer Registry Annual Registry Report 2015. Retrieved on 22 May 2020 from https://www.nrdo.gov.sg/docs/librariesprovider3/Publications-Cancer/cancer-registry-annual-report-2015_web.pdf?sfvrsn=10
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