Towards Earlier Cancer Diagnosis

Hamish Whitaker GP Tutor Guildford

Context

• 25% deaths in developed world from cancer

• Most present to primary care with symptoms, even if a screening test exists

• Early symptoms shared with benign disease

• Average full time UK GP will have a new cancer diagnosed in one of their patients each month

Context

• UK cancer mortality record poor compared to other countries

• Current estimate 7500-10000 lives lost annually due to late diagnosis

• Two week rule and easier access to investigations has made little difference

Why the delay?

• Patient delay – eg only 41% patients report rectal bleeding to GP

• Positive predictive value of colorectal cancer with bleeding is 0.1%- but 2-3% by the time presented to GP (and 5-7% by time get to 2ary care)

• Do UK GPs have too high a threshold for selecting patients for referral?

• Pressure from PCT and 2ary care not to refer, criticism of inappropriate use of guidelines

Breast cancer

• 75% breast cancers identified following presentation of symptoms

• Screening much less impact• Little evidence to guide referral exists• Breast pain and lumps commonest

symptoms• 8% women with breast lump reported to

primary care are cancer- but depends on age (0.5% if < 25 yrs)

Breast cancer

• Breast pain cancer risk 0.9% overall

• Younger women higher risk of inflammatory breast cancer

• Present with swelling redness and warmth, may appear rapidly and therefore be mistaken for infection

• Poor prognosis

Lung cancer

• Prognosis generally poor – does early diagnosis make a difference?

• Usually spread by the time symptoms presented

• Only 20% UK patients eligible for surgical resection

• Screening little impact – current study on annual cytology and CT in COPD smokers, and spiral CT

Lung cancer

• Italian spiral CT trial- can detect nodules of 0.5cm (CXR smallest 3cm)

• High false positive rate

• Encouraging symptom awareness

• Study in Doncaster to encourage reporting cough and early CXR increased rate of cancers diagnosed in stage 1 or 2 from 11% to 19% after campaign

Lung cancer

• 25% lung cancers have normal CXR• But CXR cheap and easy to obtain• Estimate if CXR all smokers over 60 with

cough would speed the time to diagnosis by 9 months in 25% of cancer cases

• Haemoptysis is relatively uncommon in lung cancer- only 40% report it

• Haemoptysis risk is 2.4-7.5% depending on age

Lung cancer

• Cough , dyspnoea , weight loss, fatigue , chest pain, loss of appetite commoner symptoms than haemoptysis

• But even more common in benign conditions- positive predictive value 1%

• UK delay in diagnosis 51 days; Sweden 26 days

• Low threshold for CXR good strategy

Colorectal cancer

• Current UK guidelines 6 weeks of bleeding or bleeding with diarrhoea for TWR

• Over 60 risk of cancer > 2% for any bleeding so are current guidelines correct?

• Iron deficient anaemia- men <11 women <10 – risk of cancer 7.7% and 13.3% respectively

• Abdominal pain , constipation and diarrhoea much lower predictive value (<1%)

• Problem is colonoscopy more expensive , some risk, uncomfortable

Colorectal cancer

• CT colonography misses 1 in 10 lesions larger than 1cm – which colonoscopy picks up

• Biomarkers may help in future- matrix metalloproteinase-9, free DNA in rectum possibilities for future

• Risk scores – CAPER and SELVA- but both lead to too many false positives and excessive interventional investigation

Colorectal cancer

• GPs often do get it right• “change in bowel habit” means diarrhoea

or constipation and reasonable chance of bowel cancer

• Has 4% predictive value for cancer in 80yr old , whereas constipation or diarrhoea has 0.7% and 1.2%

• Unclear what these soft features are that GP uses to label as change in bowel habit

Prostate cancer

• Debate re importance of early diagnosis• Screening trials show little benefit to

mortality• Treating small cancers gives small mortality

gain , but possible complications ; incontinence/ impotence

• Treatment of larger cancers or spread less controversial- and these usually cause symptoms

Prostate cancer

• Suggests definitely appropriate to search for cancer if LUTS

• But positive predictive value only 3% for cancer

• Impotence can be an early symptom of cancer – rare

• Remember PSA in back pain in men

Ovarian cancer

• Symptoms are common and early- and often missed

• Fatigue, bloating, abdominal pain, urinary frequency

• Combination of Ca125 and TV ultrasound probably best initial investigation

Other cancers

• Oesophageal cancer 5.7% risk in men with dysphagia

• Urinary tract cancer 7.4% risk in men with haematuria (women 3.4%)

• <2% lymphadenopathy presented in 1ary care malignant

• Brain tumour risk with headache 0.1%

Tumour markers

• Over 50% tumour markers requested in primary and secondary care inappropriate – and requests for PSA in women and CA125 in men not unusual!

• Key points 1/measuring more than one not helpful (except germ cell HCG and AFP)

• 2/ not helpful in non specific symptoms – often raised in benign disease also

Tumour markers

• Main uses in monitoring cancers- response to treatment or detecting recurrence

• Not helpful in screening asymptomatic individuals

• Except AFP for hepatocellular ca in cirrhosis from Hep B or C

• Ca125 for ovarian cancer (with TVUS) and PSA debatable

Tumour markers

• PSA - prostate ; also elevated in BPH , prostatitis , UTI , cycling! PR doesnt raise . Finasteride reduces PSA

• C125- ovary . Also raised in endometriosis, menstruation, colitis, laparoscopy, SLE. In conjunction with TVUS. Can be negative despite cancer – refer if suspicious

Tumour markers

• CEA colon cancer – only useful for monitoring

• CA153 breast cancer – monitoring

• CA19-9 pancreatic cancer – can aid diagnosis

• HCG and AFP germ cell tumours – can aid diagnosis and AFP in hepatocellular ca

Tumour markers

• Calcitonin ; medullary thyroid cancer- can aid diagnosis

• Thyroglobulin ; follicular /papillary thyroid cancer -can aid diagnosis

• Paraproteins eg Bence Jones – myeloma; useful in diagnosis

• Ref BMJ 2009 ; 339:b3527

Conclusions

• GPs may have too high a threshold for investigation

• Gatekeeper role may inhibit early diagnosis, and financial pressures may be increasing this

• Two week rule does not appear to have made a significant impact on speeding cancer diagnosis