However, cancers typically grow very slowly, and while every effort will be made to keep waiting times to a minimum, a few weeks usually doesn't affect the chances of treatment success. If you are concerned about either yourself or a friend or relative waiting too long, here's what you need to know.
In the UK from 2013-2014, 95.3 per cent of patients urgently referred for suspected cancer by their GP were seen by a specialist within 14 days. However, following a cancer diagnosis, it is essential that your doctors have as much information about the disease - what stage it is at and whether it has spread - in order to decide upon the best course of treatment. That often means undergoing a number of tests such as CT, MRI or liver scans.
Once any necessary tests have been conducted, a radiology specialist will examine the scans, and send a report through to your consultant, who will then speak to you about your options. Should the test results be deemed urgent by the doctor, it will be noted on the scan request form, and it is likely the results will come back earlier, but in general it takes a couple of weeks. It is perfectly understandable that you will be anxious, and your consultant will be happy to advise on how long it may be before the results are through - if you haven't heard within that timeframe, it is worth ringing to check.
How long you have to wait for treatment to start will depend on the type of cancer you have, whether further tests are necessary, and what type of treatment your doctor has recommended, and rest assured that if the situation is considered urgent, treatment will begin as soon as possible.
The Government has set waiting time targets for the treatment of cancer patients in England and Wales - no more than two months between an urgent GP referral and the start of treatment, and no more than 31 days from the decision about what course of action to take and treatment beginning.
NHS statistics show that these targets were being met in the majority of cases last year, with 86 per cent starting treatment within 62 days of their GP referral (94.7 per cent if referred by an NHS cancer screening service), and 98.3 per cent receiving their first treatment within 31 days of diagnosis.
That timeframe will undoubtedly seem frightening to most of those who have been diagnosed, and if you are worried about waiting times, speak to your doctor. In most cases they will be able to reassure you that that worrying few weeks will not affect the success of your treatment.
Have you had to wait for diagnosis or treatment of cancer? What advice would you give to others in the same position? Leave your comments below...