Cancer Prevention through your GP
Every 20 minutes in Queensland someone is given a new diagnosis of cancer. Your GP thinks about it as often.
National Cancer screening programmes for breast and bowel cancer will contact you on set birthdays. This is a very convenient service. The problem is that the forms or pots can easily lie on the shelf for weeks, or get lost! The GP will be on the lookout for any age-related tests that you may have missed and can arrange these directly.
Your GP will also be mindful of your risk of cancer during a health checkup and may arrange additional tests. For example:
- PSA testing (prostate cancer test). There are pros and cons to the test. The decision is for the individual to take but the test is far less accurate (ie. sensitive and specific) than most people think. So have the test, yes, with your eyes open.
- Breast screening for younger women not at increased risk of breast cancer. Ultrasound and/or mammogram may be considered. Gene testing for women with a strong family history is generally arranged by your GP through a referral to Genetic health Queensland.
The culture of healthcare in South East Queensland is very much geared towards regular colonoscopies.
We all know that family history is a risk factor for bowel cancer. However, most people over-estimate their risk of bowel cancer. The NHMRC regard the following people to be at ‘near average risk’ of bowel cancer :
- One parent, sibling or child (‘first-degree relative’) with bowl cancer diagnosed at the age of 55 years or older, or
- One parent, sibling or child (‘first-degree relative) and One second-degree relative with bowel cancer diagnosed at age 55 years or older, or
- No first-degree or second-degree relative with bowel cancer.
Less than 2% of the population have a moderate to high risk of bowel cancer. The typical scenario of ‘moderately increased risk’ would be a parent with bowel cancer diagnosed under the age of 55. Even a person whose father, for example, was diagnosed with bowel cancer at the age of 60 (and without any other family history of bowel cancer) is regarded at ‘near average risk.’
What is the role for colonoscopy?
Look at the following bowel cancer screening infographic.
Of 100,000 people tested with the free ‘poo in the pot’ test (FOBT), there are 115 deaths (114 from bowel cancer, and 1 from a perforated bowel caused by the colonoscopy). Of 100,000 people tested with colonoscopy there are 103 deaths (95 from bowel cancer, and 8 from a perforated bowel caused by colonoscopy).
In other words, of 100,000 people tested with colonoscopy instead of the poo test, 12 are alive who would not otherwise be alive. That’s 10,000 colonoscopies to save one life. There are lots of good reasons to do colonoscopies, but if you are asking for one because everyone else seems to have had one then do just ask your GP for advice before asking for the referral letter!
OK, so you’ve had your tests and they are all-clear. What next?
Cancer reduction is a hugely important health issue and can broadly be separated out:
- Lifestyle risk factors – weight, exercise, alcohol, smoking
- Preventative Medication
Bowel cancer risk may be reduced with low dose aspirin.
Breast cancer risk in high risk women may be reduced by a number of different medications. Tamoxifen reduces the chance of breast cancer significantly in high risk women. However Tamoxifen may cause side effects including (rarely) blood clots or the development of cancer of the uterus. Anastrazole and letrozole are alternative medications for women who have had breast cancer.
A skin check been shown to improve rates of diagnosis of skin cancers such as melanoma, particularly when dermoscopy is used in a systematic way such as that used in the Menzies method or Chaos & Clues Algorithm or pattern analysis.
Controversial cancer sreening tests
- Whole Body CT or MRI Scans. Sounds good? A randomised trial in the USA found that 64% of participants had abnormalities on the scans but no cancers were found. Such abnormalities are called “incidentalomas” – generally they lead to worry without any benefit to the patient.
- The term “tumour marker” (eg. CEA, CA125, CA19-9) is a bit of a misnomer! Whilst these tests may have a useful role in the investigation of some symptoms, or monitoring after a diagnosis of cancer, the tests are generally not recommended in a low risk situation.
- Whole Body PET Scans. Radiologists ‘don’t like to do these’ for otherwise healthy people because of the large dose of radiation required for a whole body PET scan.
When a cost-effective test is proven to save lives, then the test becomes freely