Obesity and cancers

Some of my patients and family have asked me the effective way to reduce cancer.  As I searched extensive medical literature and the latest research, I found two most effective ways that we could control: stop smoking and achieves ideal body weight.   In addition to heart disease, joints problem, back pain, sleep apnea, diabetes, etc, obesity increases cancer risks in

• Esophagus
• Pancreas
• Colon and rectum
• Breast (after menopause)
• Endometrium (lining of the uterus)
• Kidney
• Thyroid
• Gallbladder

The mechanisms linking obesity and cancer are well described in the NCI websites:

• Fat tissue produces excess amounts of estrogen, high levels of which have been associated with the risk of breast, endometrial, and some other cancers.
• Obese people often have increased levels of insulin and insulin-like growth factor-1 (IGF-1) in their blood (a condition known as hyperinsulinemia or insulin resistance), which may promote the development of certain tumors.
• Fat cells produce hormones, called adipokines, that may stimulate or inhibit cell growth. For example, leptin, which is more abundant in obese people, seems to promote cell proliferation, whereas adiponectin, which is less abundant in obese people, may have antiproliferative effects.
• Fat cells may also have direct and indirect effects on other tumor growth regulators, including mammalian target of rapamycin (mTOR) and AMP-activated protein kinase.
• Obese people often have chronic low-level, or “subacute,” inflammation, which has been associated with increased cancer risk.

So, how do I lose weight.  Losing weight is hard but it is so worth it because you are worth it.   Please see my previous blog on weight loss.

Reference:

http://www.cancer.gov/cancertopics/factsheet/Risk/obesity

Blood thinner treatment in patients with blood clot and cancer

Patients with cancer are at higher risk to develop blood clot.  Blood clot in the leg is called deep venous trhormbosis and in the lung is called pulmonary emboli.  Clot is very serious and can be life threathening.  The treatment usually consists of giving patients blood thinner in the form of pills (Warfarin or coumadin) or injection (low molecular weight heparin such as dalteparin [Fragmin] or enoxaparin [lovenox]).

A multicenter, international, randomized clinical trial (CLOT trial) compared six months of treatment with either dalteparin or warfarin (target INR 2.0 to 3.0) in 672 patients with cancer and acute symptomatic blood clot. Dalteparin therapy was associated with a significant reduction in the cumulative rate of recurrent VTE at six months (9 versus 17 percent, hazard ratio 0.48, 95% CI 0.30-0.77). There were no significant differences in the rates of major bleeding (6 versus 4 percent), any bleeding (14 versus 19 percent), or overall mortality at six months (39 versus 41 percent) between the dalteparin and warfarin arms, respectively.  Dalterparin received approval to be used in patients with cancer and blood clot.  Please note that the patients who received coumarin in that study, only 46% were therapeutic coumarin leven, 30% were below and 24% were over the target coumarin level.

Another trial, the CANTHANOX trial compared three months of therapy with either warfarin or enoxaparin in cancer patients with bloot clot.  After 147 patients were accrued, the study concluded that warfarin was associated with a high bleeding and enoxaparin may be as effective as and safer than warfarin.

A 2008 Cochrane review of results in six randomized controlled trials in cancer patients receiving long-term treatment for VTE found no survival advantage for LMW heparin over warfarin and no difference in bleeding outcomes, but a significant reduction in VTE.

My experience show that not too many patients want to inject themselves for 3-6 months and prefer pill warfarin.   But you should discuss the pro and con with your oncologists of these 2 drugs if you have cancer and blood clot.

Reference

Lee AY, et al.  Randomized Comparison of Low-Molecular-Weight Heparin versus Oral Anticoagulant Therapy for the Prevention of Recurrent Venous Thromboembolism in Patients with Cancer (CLOT) Investigators. N Engl J Med. 2003;349(2):146.

Meyer G, et al. Comparison of low-molecular-weight heparin and warfarin for the secondary prevention of venous thromboembolism in patients with cancer: a randomized controlled study.  Arch Intern Med. 2002;162(15):1729.

Bauer KA.  Treatment of venous thromboembolism in patients with malignancy.  Uptodate.  Accessed 4-28-13

Akl EA, et al.  Anticoagulation for the long term treatment of venous thromboembolism in patients with cancer. Cochrane Database Syst Rev. 2008;

Doctors seem to differ in making medical recommendation for patient versus for themselves

Patients facing difficult medical decisions often ask physicians for recommendations. However, little is known regarding the ways that physicians' decisions are influenced by the act of making a recommendation. Many medical/treatment decisions are difficult to make since various factors are involved.   Having been a patient myself, I usually just told my own doctor to do what is best for me.    

A study in medical decision making seems to suggest that it is even more complicated than I thought.   In a study, 242 doctors were surveyed and questioned with 1 of 2 clinical scenarios (having colon cancer or suffers from avian influenza).  Both involved 2 treatment alternatives, 1 of which yielded a better chance of surviving a fatal illness but at the cost of potentially experiencing unpleasant adverse effects. The researchers randomized physicians to indicate which treatment they would choose if they were the patient or they were recommending a treatment to a patient.

Among those asked to consider a colon cancer scenario (n = 242), 37.8% chose the treatment with a higher death rate for themselves but only 24.5% recommended this treatment to a hypothetical patient (χ(2)(1) = 4.67, P = .03). Among those receiving an avian influenza scenario (n = 698), 62.9% chose the outcome with the higher death rate for themselves but only 48.5% recommended this for patients (χ(2)(1) = 14.56, P < .001).

The conclusion of the paper was physicians (at least in this study) making a different recommendation for patients and for themselves.  The study researchers commented on how physicians perhaps more careful in making decision for their patients and the need to be be publicly defensible than if they were to make decision for themselves.   The study did not conclude that physicians would be a better doctor for themselves.  I agree with this since I know that I am so biased about myself that I am afraid making diagnosis for my own symptoms.  But if you happen to be in the situation needing medical decision and unable to decide yourself,  you may ask your doctor what your doctor would do if he/she were you.  This may give you a different perspective.

Reference

Ubel PA, Angott AM, Zikmund-Fisher BJ.Physicians recommend different treatments for patients than they would choose for themselves. Arch Intern Med. 2011 Apr 11;171(7):630-4

 

Confirming your cancer diagnosis

As oncologists, we rely on making cancer diagnosis based on your tissue (usually obtained by biopsy or surgery).   For most cases, our pathologists are very reliable in making this cancer diagnosis.   However, there are some cases that your cancer may not be as common and the cancer diagnosis may not be as certain.

We published a paper a while ago that illustrated this situation.   We did 2nd review of the pathology report of 720 patients and found15 diagnosis were different than the original diagnosis (2% discrepancy rate).  After reviewing 15 major discrepancies, six surgeries were cancelled, two surgeries were modified, one adjuvant radiation treatment was added, one chemotherapy treatment was modified, and five adjuvant chemotherapy treatments were cancelled.

Doctors (pathologists included) are human and medicine is not an exact science.  Differing opinion occurs and may impact the patient's care.  Thus, if your oncologist seem a bit uncertain or if you have a rare cancer, you may request a second pathology review.   Most oncologists that I know will automatically do so without even letting you know.  But it does not hurt to ask.

Reference
Santoso JT, Coleman R, Voet R, Bernstein S, Lifshitz S.   Pathology slide review in gynecology oncology.   Obstetrics and Gynecology.  91 (5): 730-734, 1998