MED2042 WEEK 3 - Complimentary Medicine & cancer
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- A review of all the evidence regarding the effects of chemotherapy for the 22 major adult malignancies suggests that the 5-year survival benefit is:
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2%
As the 5-year relative survival rate for cancer is now over 60%, it iw very clear that cytotoxic chemotherapy only makes a minor contribution to cancer survival. To justify the continued funding and availability of drugs used in cytotoxic chemotherapy, a rigorous evaluation of the cost-effectiveness and impact on the quality of life is urgently required. - What are the statistics for drug company funded research?
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- 2.6 times more likely to report positive findings
- 10-20 times less likely to report negative findings
- implications: research, evidence, ethics, funding, clinical decisions, medico-legal
- there is more to EBM than evidence
- Not surprising that many people beginning to mistrust OM - In a 19-year old woman with BRCA 1/2 breast cancer genes, a chest x-ray will:
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Increase HR of breast cancer to 4.64.
Any reported exposure to chest x-rays was associated with an increased risk of Breast Cancer (hazard ratio [HR] = 1.54; P = .007). This risk was increased in carrier women aged 40 years and younger (HR = 1.97; P < .001)... particularly those exposed only before the age of 20 years (HR = 4.64; P < .001) - Describe the link between herceptin and the survival of women with breast cancer.
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Herceptin
- reduces recurrence but doubtful improvement in survival
- cost: $75-85 000 per year
- side effects: 8% have major problems (e.g. heart failure, cardiac events) - Describe the link between physical exercise and the survival of women with breast cancer.
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- Clearly shown that physical activity decreases the incidence of breast cancer
- Does physical activity among women with breast cancer decrease their risk of death from breast cancer compared with more sedentary women?
> prospective observational study based on 2987 females diagnosed with stage I-III breast cancer
> outcome: breast cancer mortality risk according to physical activity category
- physical activity after a breast cancer diagnosis may reduce the risk of death from this disease
- benefit of physical activity particularly apparent among women with hormone-responsive tumours
- greatest benefit in women who performed the equivalent of walking 3 to 5 hours a week on average - Describe the link between fruits, vegetables and cancer.
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- Women in the higest quartile of plasma total cartenoid concentration had significantly reduced risk for a new breast cancer event (HR 0.57)
- plasma carotenoids are a biologic marker of intake of vegetables and fruit, so this observation supports findings from previous studies that have linked increased vegetable and fruit intake with greater likelihood of recurrence-free survival in women who have been diagnosed with early-stage breast cancer. - Describe the link between green tea and cancer.
- Green tea extracts contain a unique set of catechins that possess biologic activity in antioxidant, antiangiogenesis and antiproliferative assays that are potentially relevant to the prevention and treatment of various forms of cancer.
- Describe the link between green tea and breast cancer.
- Green tea decreases levels of estrogen receptor-alpha (ER) in tumours both in vitro and in vivo. We also observed that green tea blocked ER-dependent transcription, as well as estradiol-induced phosphorylation and nuclear localization of mitogen activated protein kinase (MAPK). ... The combination of green tea and tamoxifen is more potent than either agent alone in suppressing breast cancer growth.
- Describe the link between social support and breast cancer.
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- Women with metastatic breast cancer were divided into two groups
> one had support group (communication, relaxation, dealing with difficult emotions) plus usual care
> control group had usual care alone
- Results 1 year later - support group had better adjustment, coping, dealing with pain QoL, mood, relaxation
- 10 years later
> average doubling of survival time in support group (18vs36 months)
> 3 long term survivors in support group and non in control group - Describe the link between shark cartilage and cancer.
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Data on total of 83 evaluable patients were analyzed. There was no difference in overall survival between (breast and colorectal cancer) patients receiving standard care plus a shark cartilage product versus standard care plus placebo. Likewise, there was no suggestion of improvement in quality of life for patients receiving the shark cartilage compared with those receiving placebo.
- A range of possible benefits for cancer therapy
> shark cartilage has proven to have inhibitory effects on angiogenesis
> highly augment delayed-type hypersensitivity response in mice
> decrease the cytotoxic activity of NK cells
> Intraperitoneal injection to tumor-bearing mice increase T-cell infiltration into the tumor, and decrease the tumor lesion size
> has strong inhibitory effect on HBMEC proliferation and migration in fibrin matrix
- According to these results, we supposer that this fraction is a good candidate for further studies in cancer therapy. - Why do doctors need to know about CM?
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People are using it
- interactions with conventional medicine
- need to know what our patients are up to
- need to have open lines of communication
Offers potential new treatments
- need to be up to date with evidence
- ineffective, symptomatic relief, potential cure..?
Need to help patients make informed and safe decisions
- patients do not always consult quality sources of information
- concerns if patient forgo effective medical therapies - What can "there is no evidence" mean?
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- Studies suggest that the evidence is negative (not helpful or possibly harmful)
- studies suggest that the evidence is inconclusive
- studies suggest that evidence is positive but the doctor is unaware of the evidence
- there is evidence but only empirical or from studies using a different paradigm
- not studied yet - What are the mechanisms and outcomes of CM and OM?
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In OM and CM often outcomes do not meet expectations although a lot may be known about mechanisms.
Often outcomes achieved although little known about mechanisms. - Describe the three kinds of ecidence.
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Circumstantial evidence - a number of studies suggesting a possible role or plausible mechanism.
Provisional evidence - some effects on tumor size, prognostic factors or less rigorous trials
Definitive evidence - quality and reproducible outcome studies (relatively few yet) - What are some potential new treatments?
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Pomegranate juice for cancer (and cardiac function)?
Resveratrol for cancer
Mistletoe extract and cancer - What has been found to be useful for symtpom control in women with breast cancer?
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Acupuncture for nausea
Relaxation for stress reduction
Group support for anxiety
Self-hypnosis for pain reduction - What are CM options for pain control?
- Acupuncture, transcutaneous electrical nerve stimulation, supportive group therapy, self-hypnosis, massage, relaxation/imagery
- What are CM options for dyspnoea?
- Acupuncture, acupressure, and muscle relaxation with breathing retraining
- What are CM options for Depression?
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Best evidence - St John's wort, physical exercise, self help guides (e.g. CBT, bibliotherapy) and light therapy (winter depression)
Promising evidence - folate, vitamin E, vitamin B6, vitamin D, SAMe, phenyalanine, acupuncture, light therapy (non-seasonal depression), massage therapy, negative air ionisation (winter depression), relaxation therapy, yoga, dance, and reducing or avoiding alcohol, sugar and caffeine avoidance and possibly music therapy
Little or no evidence - aromatherapy, homeopathy, fish oil, lemon balm, ginseng, selenium, prayer, color therapy, progesterone cream, pets and chocolate - What is the Ornish lifestyle intervention?
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Vegan diet
- fruits, vegetables, whole grains, legumes and soy
- 10% calories from fat
- supplemented by soy (tofu), fish oil (3gm daily), vitamin E (400IU daily), selenium (200mcg daily), vitamin C (2gm daily)
Exercise
- walking 30min 6 times weekly
Stress management
- gentle yoga, meditation, breathing and PMR
Support group 1 hour weekly - What are the relationships between psychosocial factors, biology and cancer?
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1. The HPA axis, cortisol and other stress hormones
2. Genetic mutation and expression
3. Stress causing suppression of the immune cells (NK cells) leading to reduced host defences
4. Induction of protective 'anti-cancer' hormones such as melatonin
5. Angiogenesis i.e. the ability of cancers to make their own blood supply
6. Better compliance with treatment
7. Healthier lifestyle
8. others? - List the A-K of cancer prevention.
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Alcohol consumption > 3 units a day
- most squamous cancers, especially bladder and oesophagus
Body mass index >25 and certainly >30
- all solid cancers
Cigarette smoking at any level (even passive smoking)
- Bladder, lung, head and neck, oesophagus, and oropharyngeal cancers
Diet, especially one that is high in fat
- all solid cancers
Exercising <30 minutes a day
- all solid cancers
Family history of cancer (in at least one first degree relative and at least three people in two or more generations)
- inherited cancer syndromes, including breast, colorectal, diffuse gastric, ovarian, prostate, and uterine cancers
Genital and sexual health (sexuallly transmitted infections)
- cervical cancer
Health promoting drugs that may decrease global cancer risks (but need a careful risk benefit analysis)
- colonic adenomas can be treated with low dose aspirin but can have serious side effects; HRT is linked with breast cancer
Intense sunburn
- Melanoma
Job related factors
- lung cancer (exposure to asbestos and particulates), skin cancer (contact with arsenic)
Known disease associateions
- colorectal cancer has predisposing mucosal pathology - adenomas, coeliac disease, ulcerative colitis - What are some important points about CM?
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CM is generally:
- not an alternative to OM
- low but not no risk
- reliant on patient participation
- costs patient more out of pocket
- 'natural' and 'holistic' in approach
- orthdox medicine can be holistic and CM may not always be
Be careful about extreme claims
- If it sounds too good to be true then it generally is
Modern doctors need to be informed and open-minded. - What are some concerns about the use of CM?
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- False hope
- Monetary exploitation
- Delayed use of effective OM
- Little scientific evidence for some therapies
- Potential dangers and side-effects
- Poor training and regulation of some practitioners - issues are also relevant to OM
- heightened concerns for cancer patients - What does the modern trainee doctor need to know?
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- How to engage with patients
- How to respect choices and help patients to make informed and safe choices
- How to support healthy lifestyle change
- To have basic knowledge about CM or at least where to find information