Cancer Screening Guidelines: Mammography to Colonoscopy

Cancer screening guidelines differ by organ, and so do the red flags that should prompt referral. Dr. Shubham Jain recommends mammography every one to two years from 50 to 74, annual low-dose CT of the chest for heavy smokers aged 50 to 80, a Pap smear or HPV test between 25 and 65, and colonoscopy from 45, alongside age thresholds for six common presenting symptoms.

This article sets out, cancer by cancer, the screening strategy Dr. Shubham Jain, Senior Director Surgical Oncology, Fortis Cancer Institute, Defence Colony, New Delhi, India, recommends and the symptom thresholds that should prompt evaluation. The referral pathway itself, including the minimum workup before sending a patient onwards, is in the complete guide to when to refer suspected cancer.

Breast cancer: triple assessment and mammography screening

Every breast lump must undergo triple assessment, whether it is painful or painless. Triple assessment is the combination of three tests that, read together, explain why the problem is happening and how it is likely to behave:

1. Clinical examination, after a careful history.
2. Imaging: mammography, ultrasound or MRI, depending on the resources available and the clinical setting.
3. Pathology: a biopsy or fine needle aspiration cytology (FNAC).

Red flags for breast cancer

The findings that should alert a clinician, in Dr. Jain's teaching, are:

• any change in the skin of the breast;
• an unexplained lump in the breast or armpit in a woman over 30;
• one-sided symptoms, such as nipple discharge or nipple retraction, in a woman over 50.

Breast cancer screening guidelines

Digital mammography or digital breast tomosynthesis (a three-dimensional form of mammography) is strongly recommended every one to two years for women aged 50 to 74. Dr. Jain adds that clinical breast examination, done properly every two years alongside breast cancer awareness, saves lives lost to breast cancer, as clinical trials conducted in India have shown. Breast MRI may be recommended for women with a strong family history or certain genetic mutations. In younger women, breast ultrasound (sonography) gives better results than mammography, which is an X-ray of the breast.

How to prepare a patient for a mammogram

Dr. Jain gives referring doctors four practical instructions to pass on to patients:

1. Avoid the week before a period and the days of menstruation, when the breasts are swollen and tender.
2. Wear no deodorant, powder or perfume on the day, because these can show up as artefacts on the image.
3. Wear a top with a skirt or trousers rather than a dress, so that it is easy to undress from the waist up.
4. After a recent vaccination in the arm, tell the radiographer, because it can briefly enlarge the lymph nodes in the armpit; screening need not be delayed.

Hoarseness and the mouth: head and neck cancer red flags

A persistent, unexplained change in the voice calls for caution, particularly when the patient:

• has a history of tobacco use;
• is over 45;
• has recently noticed loosening of the teeth;
• has an unexplained lump in the neck, or a lump in the lip or mouth;
• has an unexplained ulcer in the mouth, or red or white patches inside it.

Hoarseness lasting more than two weeks, without an acute infection to explain it, should be evaluated, especially in patients who use tobacco or alcohol. The cause is not always in the throat. The recurrent laryngeal nerve, which supplies the vocal cords, runs through the chest, so an advanced lung or oesophageal cancer can also present with a hoarse voice.

Oral self-examination for high-risk patients

For head and neck cancers, the screening tool Dr. Jain emphasises is the patient's own eyes. People at high risk of oral cancer should inspect the different areas of their mouth themselves at regular intervals, perhaps every month or two, so that any new ulcer or patch is brought to medical attention promptly.

Persistent cough and lung cancer: low-dose CT screening

A doctor should think of lung cancer when a persistent cough, with or without unexplained haemoptysis (blood staining the sputum), occurs in a patient who:

• is over 40;
• has a history of tobacco use;
• has an abnormal finding on a chest X-ray; or
• has been exposed to asbestos.

His closing rule is direct: any smoker over 40 with unexplained haemoptysis or an abnormal chest X-ray must be evaluated.

Who should have low-dose CT lung cancer screening

The screening strategy is an annual low-dose CT scan of the chest, indicated for heavy smokers: people aged 50 to 80, in otherwise good health, with a smoking history of more than 20 pack-years. It is called low-dose because the radiation is small enough to make it safe as a screening test. Dr. Jain puts the dose at roughly one tenth of the exposure from a CT scan of the abdomen.

What does 20 pack-years mean?

A pack-year measures cumulative smoking: the number of packs smoked per day multiplied by the number of years of smoking. It does not mean 20 packs a day. As Dr. Jain explained in answer to a question during the session, each of these smoking histories adds up to 20 pack-years:

• two packs a day for 10 years;
• one pack a day for 20 years;
• half a pack a day for 40 years.

Bloating and ovarian cancer: ultrasound and CA 125

Women in particular may present with a feeling of generalised abdominal distension. On examination, there may be ascites (free fluid in the abdomen) or a nodular or fixed mass that the clinician can feel.

When such a patient is over 50 and also has pelvic or abdominal pain, vague urinary symptoms such as urgency or frequency, or unexplained weight loss, Dr. Jain's advice is to arrange an ultrasound of the abdomen and a CA 125 blood test (a tumour marker raised in many ovarian cancers) to rule out malignancy. A fixed or nodular pelvic mass with a raised CA 125, or with ascites, should never be ignored.

Not every distended abdomen is ovarian cancer. Some patients have pseudomyxoma peritonei, the "jelly belly" in which a mucinous material fills the abdomen; how it is treated is described in the article on diagnosis and treatment after referral.

Abnormal vaginal bleeding: endometrial and cervical cancer

Any bleeding after menopause, and unscheduled bleeding in women over 55, needs to be evaluated for endometrial cancer. It is a definite cause for concern when it comes with vaginal discharge, haematuria (blood in the urine) or anaemia.

The test Dr. Jain recommends for the endometrium is a transvaginal ultrasound, which can detect abnormal thickening of the endometrium (the lining of the womb). Women with abnormal vaginal bleeding, or with a family history suggestive of inherited cancers, should start this evaluation early.

HPV vaccination prevents cervical cancer

Cervical cancer is common in African countries, and it is largely preventable through timely vaccination against human papillomavirus (HPV), the virus that causes it. Dr. Jain gives the schedule as:

• girls aged 9 to 14: two doses;
• girls and young women aged 15 to 26: three doses.

Vaccination on this schedule significantly reduces the risk of cervical cancer and other HPV-related cancers.

Pap smear and HPV testing

Screening is by a Pap smear or an HPV test, primarily between the ages of 25 and 65. HPV DNA testing can also be combined with the Pap smear (co-testing). Screening intervals are three to five years, depending on the test used. A Pap test should not be scheduled while the patient is having her period, or within two days of intercourse.

Bowel habit, rectal bleeding and upper gastrointestinal symptoms

Changes in eating or bowel habits and rectal bleeding are common presenting symptoms of gastrointestinal cancers. Dr. Jain separates the upper and lower tract.

Upper gastrointestinal warning signs

• dysphagia (difficulty swallowing);
• haematemesis (vomiting blood) or melaena (black, tarry stools);
• an upper abdominal mass;
• involuntary, unexplained weight loss;
• anaemia, particularly with upper abdominal pain;
• persistent reflux that is not relieved by medication and antacids;
• upper abdominal symptoms with jaundice.

Colorectal warning signs after the age of 40

Alarm features in patients over 40 include:

• bleeding that persists after successful local treatment of haemorrhoids;
• a change in bowel habit, whether constipation or diarrhoea;
• progressive abdominal pain or unexplained weight loss;
• an abdominal mass;
• anaemia severe enough to need a blood transfusion;
• a significant family history.

Colonoscopy screening guidelines

Colonoscopy screening should be recommended from 45 to 75, or for as long as life expectancy is more than ten years. High-risk individuals can start before 45, and their screening interval is shortened: typically every five years when a first-degree relative has had colorectal cancer, and every one to two years in Lynch syndrome. Patients who are unwilling to have a colonoscopy can be offered stool-based tests or a visual examination such as flexible sigmoidoscopy. In the discussion that followed, Dr. Jain described the routine options as a colonoscopy every ten years, or a sigmoidoscopy combined with a faecal occult blood test (which detects hidden blood in the stool).

Cancer screening guidelines: which tests a referring doctor can order

Age, family history and smoking status decide which screening tests are appropriate. Asked which tests referring doctors can use for early detection, Dr. Jain began with the patient rather than the test. Tumour markers have a role, but at a basic level the radiological tests do most of the work:

The frequency of each test varies, but used this way, in his view, they can identify the majority of these cancers early. The questions doctors asked on screening and referral are recorded in the masterclass Live Discussion.

Other perspectives on early cancer detection

Other masterclass series in oncology cover overlapping ground from a different angle: Dr. Nithin S.G. groups the warning signs of cancer by type, Dr. Niti Raizada pairs each diagnostic red flag with the test that confirms it, and Dr. Rajesh Kumar Jain sets out organ-by-organ red flags for general practitioners.