Cervical cancer in young girls

Some of you have asked me about the new pap smear guideline where the starting age is now 21 years old.  There are concerns of cervical cancer may be missed in young girls.  A study published in November 2012 evaluated this question by reviewing combined data from US cancer registries and SEER program covering 92% of US population.  The study found that for women younger than age 40 years, only 1% of cancer is found in women younger than 20 years old.  Since we have about 12,000 new cervical cancers each year in the US, the new pap smear guideline will miss about 120 cervical cancer in young girls.

Various organizations (NCCN, American Cancer Society, USPFTF, ACOG, etc) recommend starting pap smear at age 21 (for "average risk" women) knowing that there will be these a few girls missing their cancer diagnosis.  Their reasoning is earlier age pap smear may cause more harm and cost with follow up procedures than the benefit of diagnosing these girls of cervical cancer.   I have to admit that I have a mixed feeling about this...   Intellectually, I understand the concept but emotionally I have difficulty since I have cared for young girls with cervical cancer.

Reference:
- Benard VB, et al.  Cervical carcinoma rates among young females in the United States.  Obstet Gynecol.  2012; 120:117-23.
- US preventive services task forces. 2012
- Saslow D, et al. CA Cancer J Clin. 2012;127:516-42

Shark cartilage and cancer

Shark cartilage has been promoted to cure cancer since around 1950.  It started with surgeon John Prudden claimed that shark cartilage reduced tumor almost by half the size.  Laboratory studies suggested that it may have anti angiogenesis (reducing cancer blood vessels).  Unfortunately, clinical studies showed no prove of its effectiveness in cancer patients.   Most recently, a purified shark cartilage extract (Neovastat) failed to help survival of patients with non-small cell lung cancer.  The Federal Trade Commission has prevented several companies from promoting this cartilage for cancer treatments.

My opinion is to leave the shark cartilage alone.  Sharks should be allowed to live too....

Reference:
-Loprinzi CI, et al.  Evaluation of shark cartilage in patients with advanced cancer.  Cancer. 2005; 104:176-82
- Lu C, et al. Chemoradiotherapy with or without AE-941 in stage III non small cell lung cancer: a randomized trial.  J Natl cancer Inst.  2010; 102:859065
- Federal Trade Commission.  "operation cure all" nets shark cartilage promoters. http://ftc.gov/opa/2000/06/lanelabs.shtm

Malnutrition and cancer

Malnutrition and weight loss are common in patients with cancer for 3 reasons.  First, experimentally, cancer has preferentially gotten our calorie then the left over is distributed to our healthy cells. Secondly, cancer treatments such as chemo and radiation decrease our appetite.  Finally, depression is common after diagnosis of cancer and may affect our mood and appetite.

It is logical to conclude that our nutritional technology could help cancer patient patients.  Some of my patients have asked about having nutrition given to them using intravenous way (TPN-total parenteral nutrition).   TPN is a solution mixture of sugar, fat and protein and infused usually in the hospital or sometimes at home.   The American Gastroenterological Association (AGA) reviewed 26 randomized trials of parenteral nutritional support in cancer patients, including 19 in those receiving chemotherapy, three in patients being treated with radiation therapy (RT), and four in those undergoing stem cell transplantation.  AGA concluded that TPN in cancer patients have no effect in mortality, 40% increase in overall complication rates (16% increase in infection), and 7% reduction in tumor response to treatment.

TPN may play role for a short period in very malnourished patients undergoing surgery.   If you are not malnourished, TPN seems to increase complications.   In the Veterans Affairs Cooperative Study, 395 malnourished patients who underwent abdominal/chest surgeries (65 percent of whom had cancer) were randomly assigned to TPN for seven days before surgery and three days after surgery or no TPN. Overall, patients receiving TPN had a higher rate of infectious complications (14 versus 6 percent) and a nonsignificant reduction in 30 day mortality (7.3 versus 4.9 percent). However, in the severely malnourished subgroup (n = 24), those treated with TPN had significantly fewer noninfectious complications than controls (43 versus 5 percent)

 So, what should we do if we have cancer and losing weight.  I recommend to eat 5-6 small meals a day, instead of 3 large meals.   Do eat more thick creamy soups, dairy (milk, milk shakes, cheese, yogurt, ice cream) and peanut butters.  Nutritional supplement such as Ensure and Boost also are useful but more expensive than milk (Milk has about the same amount of protein).  Your doctors could also prescribe appetite stimulants (Progestin and Marinol).   However, they have some potential side effects such as depression, blood clot and hallucination.  If you ended up in the hospital, some studies suggest that giving you food thru feeding tube is healthier than using TPN.  However, there are some circumstances that TPN would still be suitable.  Do discuss with you doctor.


Reference:
- Koretz RL, et al.   AGA technical review on parenteral nutrition. Gastroenterology. 2001;121(4):970
- Perioperative total parenteral nutrition in surgical patients. The Veterans Affairs Total Parenteral Nutrition Cooperative Study Group.  N Engl J Med. 1991;325(8):525.
- Bozzetti F, et al. Postoperative enteral versus parenteral nutrition in malnourished patients with gastrointestinal cancer: a randomised multicentre trial.  Lancet. 2001;358(9292):1487.

Can you get cancer from obesity?

Indeed several cancers such as postmenopausal breast, endometrial, renal, colon and esophageal cancer have been associated with obesity.   Fat contains enzyme called Aromatase which produces excess estrogen.  This constant production of estrogen is postulated to lead to development of breast and endometrial (uterine -womb) cancers.  In colon cancer, obesity is thought to increase the risk thru insulin and inflammatory pathways.

In my practice, I see many patients with uterine cancer related to excess weight.  We have about 40,000 new uterine cancers in the United States but see it very little in Africa or China where obesity is not yet a problem. Thus, reducing risk of cancers is another reason to lose weight.

Reference:

- Wolin KY, eta l. Physical activity and colon cancer prevention: a meta-analysis. Br J Cancer. 2009;100(4):611

 - Wolin KY, et al. Obesity and cancer. Oncologist. 2010;15(6):556.

Vitamin B12 injection for energy

A few patients had asked me for Vit B12 injection to boost their energy.   I was not aware of this and thus ended up reviewing the history and literature of vit B12 supplementation.

Vit B12 was discovered when malnourished dogs were found to be anemic (low blood volume).  This anemia seemed to be resolved by feeding the dogs food containing liver.   After much experimentation, Vit B12 was purified from liver juice.  Indeed, Vitamin B12 which plays role in folate (Vit B9) generation.  Lacking folate could contribute to pernicious anemia.

Since Vit B12 mostly contained in animal product but little in vegetables, complete vegans are at risk for poor vitamin B12 intake. Vegans who still take dairy products are usually not at risk for Vit B12 deficiency. Similarly,  alcoholics, and people with little dietary variation (such as some older adults) may be vit B12 deficient.   Vitamin B12 supplementation in healthy adults and in those with vitamin B12 deficiency is well-tolerated without significant adverse effects.

To test for vit B12 deficiency is very simple.  Your doctor could order CBC (complete blood count) including a subtest called MCV (measure the size of red cells).  If the red blood cells are larger than normal and your hemoglobin (red blood cell) level is low, then you may have a type of anemia that may benefit from vit B12 and folate supplementation.  There are blood tests that could also test vit B12 directly.

My recommendation is to have large variety of diet as recommended by USDA.  Following this diet recommendation, you risk of vitamin deficiency is minimal.

Reference:
Uptodate. Vitamin supplementation. November 2012.

Numbness and pain on fingers/toes with chemo

Some chemo agents are responsible for neuropathic pain.   This pain on your nerves is defined as numbness, tingling and/or pain on feet and/or fingers associated commonly with chemo Taxol (Paclitaxel) and cisplatin.   The pain is increasing as you receive more of these chemo agents.  Severe nerve pain occurs in 20 to 35 percent of patients receiving 250 mg/m² of Taxol every three weeks compared to 5 to 12 percent in large series using doses ≤200 mg/m² every three weeks (1). 

Prevention is usually better than treatment.   Thus, when you start to have these sensations, please let you oncologist knows who then can reduce the dose or change the chemo.

There are medications you may receive for neuropathic pain such as Gabapentin (Neurontin).  Recently, an early study of a randomized placebo-controlled trials have shown a benefit for Duloxetine (Cymbalta),  an antidepressant of the serotonin norepinephrine reuptake inhibitor (SNRI) category, in patients with diabetic neuropathy, and the drug is approved for this use in the United States. In a preliminary report reported at the 2012 meeting of ASCO, duloxetine reduced pain and improved quality of life in patients with painful chemotherapy-induced peripheral neuropathy following chemotherapy (2)

Reference:
1.Lee JJ, et al. J Clin Oncol. 2006;24(10):1633
2.Lavoie Smith EM, et al.  CALGB 170601: A phase III double blind trial of duloxetine to treat painful chemotehrapy-induced peripheral neuropathy. J Clin Oncol 30, 2012

New pap smear guideline 2012

The American College of Ob.gyn just came out in November with the new guideline for cervical cancer screening (pap smear) for women.  It recommends:
- To start getting pap smear: age 21 years old
- age 21 to 29 years old: pap smear every 3 years
- age 30 to 65 years old: pap smear with HPV testing (both tests combined called "cotesting") every 5 years
- Older than age 65 years old: no pap needed

Do remember that these are just guidelines.  Your doctor may modify them depends on your clinical situation.  Also, you may get pap more frequently if you have had abnormal pap smear, cervical cancer or other conditions.  do talk to your doctor. 

Reference:
ACOG practice bulletin, no 131.  November 2012