Interesting Lung Cancer Facts

Dr Ou of the UCI Medical Center

Dr Ou of the UCI Medical Center

Last night I attended a meeting near the UCI Medical Center. The speaker, Doctor Ou, is an Associate Clinical Professor at the school. He brought up some interesting facts.

 

• There are more deaths among women from lung cancer (70,490) than from breast cancer, ovarian cancer, cervical cancer, uterine cancer, vulva cancer, and vaginal cancer combined (68,290).

• There are tests for early detection of many forms of cancer (i.e. mamograms for breast cancer and PAP smears for cervical cancer), but there is no test for early detection of lung cancer.

• Because of the difficulty in detecting lung cancer at an early stage, it generally takes 25 years to manifest itself. Almost half of all new patients diagnosed are in the late stage (IIIB and IV) of the disease, making treatment unlikely to be successful.

• Those who smoke but quit at the age of 30 have more than double the chance of dying from lung cancer than those who have never smoked. Those who quit at age 50 have more than a six-fold lung cancer mortality rate.

• Women who never smoke are much more likely than men who have never smoked to develop lung cancer. This is more pronounced in the Asian countries than in Europe and the US, although it holds true in all geographic areas studied.

• Radon gas is the second leading cause of lung cancer. Produced by decaying uranium-238 in the soil, it is estimated that 8 million homes in the US have elevated levels of radon, primarily in Northern states.

• As with most diseases, genetic mutations have been identified as being involved with the development of lung cancer. Epidermal growth factor receptor (EGFR), when mutated, can cause the uncontrolled cell division known as cancer.

• A drug under study, Gefitinib, shows great promise in stopping some forms of lung cancer, but while it works extremely well in some patients, it does not work at all in others. Its effectiveness depends on the specific mutations in the EFGR gene. I will write more about Gefitinib in a future post.


Advanced Lung Cancer Treatment

Cancer research toolsEarly detection and treatment has provided the US with the best cancer survival rate in the world, including other Western nations.  This survival rate may soon be getting even better.

For non-small cell lung cancer, specific genetic factors have been determined to be the cause in about 5% of cases.  Recent advances in genetic research, combined with a new treatment, may turn a virtual death sentence into a manageable condition for those with this genetic characteristic.

A gene called Anaplastic Lymphoma kinase, more commonly known as the ALK gene, can combine with another gene or form a duplicate copy of itself.  When this happens, a relatively rare type of tumor can appear.

Presence of the ALK gene is determined by FISH testing which is also sometimes used to detect copies of the HER2 gene in breast cancer patients.

By administering a new oral drug called an “ALK inhibitor”, this type of lung cancer is not only stopped from growing, but appears to melt away.  The drug does not rid the body of the gene, so tumors can reappear, requiring additional future treatments… but the disease becomes manageable.

Five cancer centers worldwide participated in the first two trials of the drug, including the University of Colorado Cancer Center, one of the few places where the related FISH test can be performed.

23 people were treated in the initial studies and almost all of them had dramatic responses within short periods of time.

Ila Hegland, diagnosed nine years ago with stage 4 non-small cell lung cancer, was told she only had two years to live. After six weeks of treatment with the ALK inhibiting drug, no signs of the cancer could be found.

Third stage trials are now being performed and it is hoped that the treatment will be generally available in the near future.

Other forms of cancer are also tied to the ALK gene, including 10 to 15 percent of childhood non-hodgekin lymphomas and myofibroblastic tumors (sarcoma).  With further studies, perhaps the drug can be applied to these types of conditions as well.


Height Related To Cancer Risk

A tall person

A tall person

Several studies have shown a relationship between a person’s height and the risk of developing various forms of cancer.

A study from Seoul National University in Korea following 788,789 people between the ages of 40 and 64 determined that for every 5 centimeters in additional height, men’s cancer risk increased by 5% and women’s cancer risk increased by 7%.

The study was adjusted for relevant factors such as age and socioeconomic status. A positive association was found for colon, breast, thyroid, ovarian, and prostate cancer.

A review study of literature done at John Hopkins University , which also found links between height and cancer, found the most consistent associations were for breast cancer. While the links found were relatively weak, they were still conclusive.

Several of the studies have suggested that increased levels of an insulin-like growth factor known as IGF-1 may be involved. Cancer and natural growth have factors in common – namely, division and increases in cells. More IGF-1 causes more growth, often leading to greater height.

IGF-1 protects new cells from being attacked by the body, a necessary function when growing. But raised levels of IGF-1 may also diminish the ability of the body to rid itself of abnormal cells such as cancer.

Caloric intake during early years may also be related to the height versus cancer risk. A study done in Norway comparing historic periods where food was less abundant, suggested that reduced nutrition leading to reduced adult height could be linked to fewer cases of breast cancer.

With regard to prostate cancer, it has been found that the more aggressive the cancer, the better the correlation to height. This was noted in an article in Cancer Epidemiology Biomarkers & Prevention

We tall people sometimes seem to be at an advantage, but where cancer is involved, it might be better to be short.


Migraines And Breast Cancer

Researchers from the Fred Hutchinson Cancer Research Center at the University of Washington Public Health Sciences Program have shown that women with histories of migraines are less likely to develop breast cancer.

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The relationship between migraines and breast cancer had previously only been looked at in a single relatively small study that was unable to assess the effect of migraine triggers, such as alcohol consumption and hormone therapy, which are also well-established breast cancer risk factors.

The more recent study compared data from 4568 women with breast cancer and 4678 healthy women using in-person interviews.  Women with histories of migraines were found to have a 26% lower risk of breast cancer, taking other factors into account such as migraine triggers, menopause, and prescription drugs.

Estrogen may be a key factor as low levels of the hormone seem to increase the severity and frequency of migraines and higher levels are known to raise breast cancer risk.

The results of the study were published in Cancer Epidemiology, Biomarkers & Prevention, a publication of the American Association for Cancer Research.


Charred Meat and Pancreatic Cancer

Kristen Anderson, Ph.D.

Kristen Anderson, Ph.D.

Kristen Anderson, Ph.D., an associate professor at the University of Minnesota School of Public Health, led a study linking charred meat with pancreatic cancer.

Her group had previously studied the effects of compounds that form on red meat during high heat cooking.

208 cases of pancreatic cancer were observed in this later 9 year study, based on 62,581 people’s actual diets.   The survey data were taken as a part of the PLCO (Prostate, Lung, Colorectal and Ovarian) Multi-center Screening Trial.

The people in the study were divided into 5 groups depending on their preferences of how their meat was cooked.  Almost all of the cases of pancreatic cancer occurred in the two groups who preferred their meat well done.  Comparing the groups with the highest consumption of well cooked meat versus the lowest showed a 70% increase in pancreatic cancer incidence.

Frying, grilling, or barbecuing produces heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons.  These mutagens and carcinogens are formed in time- and temperature-dependent manners.

Baking, stewing or microwaving and pouring off juices before grilling reduce the precursors of these carcinogenic chemicals.  Cooking longer over a lower heat also kills bacteria without forming carcinogens.  Burned sections of meat should always be trimmed off.

With summer coming on, be aware that those barbecued steaks on the grill, as delicious as they may be, might result in pancreatic cancer.


Fosamax and Esophageal Cancer Risk

On Wednesday, Diane Wysowski of the Food and Drug Administration’s division of drug risk assessment said there are potential links between bisphosphonate drugs prescribed for osteoporosis, and esophageal cancer.

Reports of cancer incidence have been received from the US, Europe, and Japan.  Typically, tumors appeared two years after starting therapy with the drugs.

Such drugs include Merck’s Fosamax, Proctor & Gamble’s Actonel or risedronate and Didronel or etidronate, and Roche’s Boniva or ibandronate.

The drugs were developed to increase bone mass in an effort to treat osteoporosis, a condition which weakens bones.

Other side effects of the drugs have been reported, but the FDA stated in November that the clinical trials showed no overall risk of heart rhythm problems.  Conflicting reports may call for further investigation.

What is known is that the drugs can cause esophagitis, an inflammation of the esophagus.  Now, with the possible link to esophageal cancer, there is added cause for concern with bisphosphonate drugs.


Inorganic Phosphates and Lung Cancer

A diet high in inorganic phosphates, commonly added to processed foods such as Lungsmeats, cheeses, bakery products and beverages may contribute to the development of lung cancer in individuals predisposed to disease.

Lung cancer is a disease of uncontrolled cell proliferation in lung tissue and the most lethal of all cancers, being the number one cause of cancer death in the world.

In a study conducted at Seoul National University and led by Dr. Myung-Haing Cho, lung cancer mice were given  a four week diet of either .5 or 1.0 percent phosphate, simulating modern human diets.  When the two levels of dietary phosphates were analyzed, the diet higher in phosphates caused an increase in the size and growth rate of the tumors.

While phosphate is an essential nutrient to living organisms, in high doses it may alter the signaling pathways by which normal cell growth is maintained.  A small alteration in these signaling pathways can cause a normal cell to become malignant.

Rapidly increasing use of phosphates in an increasing number of processed foods may be leading to an increased consumption by as much as 1000mg per day since the 1990s, a three-fold increase.

Due to some smokers higher propensity for developing lung cancer, further studies may be done to correlate the intake of phosphates in these individuals.

The study appeared in the first January issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.  It concludes that careful regulation of dietary inorganic phosphate may be critical for lung cancer prevention as well as treatment.


Saturated Fats And Cancer Of The Small Intestine

In a study led by Dr Amanda Cross of the National Cancer Institute, it was found that saturated fat intake is positively associated with the development of carcinoid tumors in the small intestines.

Dr. Cross’ research interests have been in meat and meat-mutagens as risk factors for cancers of the colorectum, prostate and pancreas.

Most cancer studies of the digestive tract have been done on the large intestine as that is where most of the cancers occur.  Relatively few cancers occur in the small intestine, but the incidence is increasing.

While consumption of red meat or processed meat has been linked to colon cancer, there was no significant statistical link between red meat and cancer of the small intestine.

However, those with a high saturated fat intake had over three times the risk of developing carcinoid tumors than those with a low saturated fat intake.

The results were found from an 8 year study which asked about meat and fat consumption in a sample of half a million men and women.


Breast Cancer And Omega-6

Heterocyclic amines (HAs), formed when meat and fish are cooked at high temperatures, have been linked to mammary gland cancer in rats, and some studies indicate increased breast cancer risk by consumption of well-done meat.

The evidence linking HAs to breast cancer is sparse, especially from prospective studies. Moreover, high-fat diets rich in omega-6 polyunsaturated fatty acids (PUFAs) have produced higher frequencies of HA-induced mammary gland tumors in rats compared to those fed low-fat diets.

The aim of a study led by Dr. Emily Sonestedt of The Department of Clinical Studies at Lund University, Malmo was to evaluate prospectively if intake of HAs is associated with breast cancer incidence, and if the association is independent of omega-6 PUFA intakes.

Among women 50 years or older, from the population-based prospective, 430 women were diagnosed with incident invasive breast cancer during a follow-up of 10.4 years. Information on dietary habits was collected by a modified diet history method.

Other facors taken into account, a 95% confidence interval was developed comparing breast cancer with energy-adjusted intakes of HAs and omega-6 PUFA.  Various levels of intakes of HAs were not associated with breast cancer incidence.

However, in individuals with low HA intakes, a significant increased risk was observed among those with high intakes of omega-6 PUFAs.

In conclusion, intakes of HAs are not associated with breast cancer incidence in this Swedish study, but dietary patterns very high in omega-6 PUFA may promote breast cancer development.


Low LDL Cholesterol May Cause Cancer

This blog deals with cancer and would not normally discuss cardiovascular disease, but today’s entry has to touch on both as the reduction of LDL cholesterol, one of the goals of many physicians for preventing cardiovascular disease, causes increased cancer risk.

Most people, including many physicians, do not understand the mechanics of heart disease.  A study of the works of Linus Pauling and Louis Ignarro, both Nobel prize winners for their research on cardiovascular disease, gives a glimpse into how cardiovascular disease occurs.

Linus Pauling

Linus Pauling found that the triple helix of collagen, which supports all of the blood vessels in the body giving them their elasticity and their strength, breaks down, allowing the vessels, particularly near the heart where the pressure is greatest, to begin to shred and form cracks.

Cholesterol in the blood senses there is a break in the vessel wall and patches it, much in the same way blood forms a scab on a wound.

As this cholesterol builds up on the break in the vessel wall, it causes turbulence which, in turn, creates blood clots.  These cause strokes and heart attacks.

Louis Ignarro

More recently, Louis Ignarro of the UCLA Department of Pharmacology, discovered that nitric oxide produced by the vessels walls is the key to keeping the vessels open and flexible.   As we age the vessels lose this ability to produce nitric oxide.

Nitric oxide cannot be added externally as it only exists for a very short period of time.  It can only be produced in the body by the blood vessel walls themselves.

Supplementing the diet with L-Arginine and L-Citrulline causes an increase in nitric oxide.  This not only keeps the blood vessels healthy, but actually reduces plaque which is a build up of cholesterol and other components in the blood.

What has this to do with cancer?

In a study led by Dr. Richard Karas of the Tufts Medical Center in Boston to determine if statin drugs, which are used to reduce LDL cholesterol in the blood, cause cancer, it was found that those persons with the lowest LDL cholesterol had a four-fold increase in the incidence of cancer over those with the highest LDL cholesterol.

It would appear that the medical and pharmaceutical community, by urging patients to lower their cholesterol with statin drugs rather than increasing the production of nitric oxide by taking l-Arginine and L-Citrulline are actually causing cancer!