Mother and son fight breast cancer together

May 17, 2010 by  
Filed under CANCER

What are the chances that cancer strikes twice in a family? Rather high, I would say, since genetics is a risk factor in many types of cancer. However, the case of breast cancer striking a mother and son duo is rather uncommon as in the case of Lynda and Cedric Skillom.

Whereas breast cancer is commonly thought to be a woman’s disease, men do get the cancer even though breast cancer in men is relatively rare. Whereas the lifetime risk of developing breast cancer is 12% in women, the figure in men is about 1 in 1000. The American Cancer Society estimated that about 1,910 new cases of invasive breast cancer were diagnosed in men in 2009 and that about 440 men would die of the disease.

A large fraction of breast cancer is due to mutations in the BRCA1 or BRCA2. These two genes are tumor suppressors and mutations lead to uncontrolled cell growth and cancer. Although the BRCA gene mutations are closely linked to breast cancer, these mutations also increases the risk for other cancers such as cervical, colon, pancreatic, uterine, bile duct, gallbladder, pancreatic, and stomach cancers, and melanoma. The latest development in genetic testing has enabled testing for these mutations

Lynda Skillom was diagnosed with breast cancer and underwent treatment at the Loyola University Health System. She tested positive for BRCA2 mutation. Her 29-year old son Cedric also underwent genetic testing and tested positive for the same mutation. In men, inheriting the BRCA2 mutation means higher risk than inheriting BRCA1 mutation. About 10% of breast cancer in men is due to the BRCA2 mutation.

A precancerous lump found in Cedric’s breast warranted the performance of a double mastectomy, which according to oncologist and hematologist Dr. Patricia Robinson at Loyola: “A double mastectomy is often the best option for long-term prognosis for these patients.

The American Cancer Society estimated that about 1,910 new cases of invasive breast cancer were diagnosed in men in 2009 and that about 440 men would die of the disease. Breast cancer screening is routine among women but not in men. In many cases, breast cancer in men is detected at a later stage than in women, thus with poorer prognosis. Thus, the breast cancer diagnosis and genetic testing of Lynn Skillom led to early screening and detection of breast cancer in her son that might have saved his life.

Lynda and her son Cedric celebrated Mother’s Day cancer-free.

Insulin production and food anticipation

April 8, 2010 by  
Filed under DIABETES

Anticipation is sometimes more fun than the actual event itself. This was shown in the case of vacations –  as well as in eating. And in the case of the latter, looking forward to a meal can actually have some physiological consequences, e.g. on the blood sugar level, for example. In a study on lab animals, researchers at Duke University observed that anticipation of a meal, either by sight or by smell, activates the parasympathetic nervous system to perform biological processes such as saliva production and increased insulin production. Increased salivation is expected to aid in the mastication and digestion of food whereas increased insulin production is in preparation of the event that glucose will be entering the bloodstream. In other words, our body anticipates what we need and prepares for it in advance. The parasympathetic nervous system therefore plays an important role in sugar metabolism.

Disruption of insulin secretion creates havoc with glucose levels in the blood and for those suffering from diabetes, can have some serious consequences. Researchers found that a certain genetic mutation can lead to ankyrin-B deficiency that impairs the parasympathetic production of insulin.

According to lead researcher Dr. Vann Bennett, professor in the departments of cell biology, biochemistry, and neurobiology at Duke University:

“We think this parasympathetic response is potentially important in type 2 diabetes. Our study showed there is a novel mutation in the gene encoding ankyrin-B, which increases the risk of type 2 diabetes. This happens through an impairment of the insulin secretion that is added by the parasympathetic nervous system.”

To confirm that this problem also occurs in humans, the researchers looked at genetic specimens of the American Diabetes Association’s GENNID collection from families with type 2 diabetes. They performed genotyping on 524 people with diabetes and 498 people without diabetes for comparison. They found that one of these mutations of ankyrin-B (R1788W) was associated with type 2 diabetes in about 1% of Caucasian and Hispanic individuals. You would think this is a very low percentage. However, according to Dr. Bennet

“Genomewide studies have failed to identify more than a small fraction of the genetic heritability in diabetes as well as in other complex diseases. There are estimates that only 6 percent of the heritability of type 2 diabetes has been detected, by multiple genomewide studies.”

There are still a lot of diabetes-associated genes out there that need to be identified. The gene mutation for ankyrin B deficiency seems to be relevant in 1% of patients with type 2 diabetes.

Tick tock goes the male biological clock

February 18, 2010 by  

Tick tock tick tock. As soon we women reach the age of 30, we hear the biological ticking away as we try to hold on to our fertility just for another while. But what about men? Don’t they have a biological clock to listen to?

I mean, look at the following oldies celebrity dads who fathered kids beyond their 60th birthday:

  • David Letterman, at age 61
  • Donald Trump, 62
  • Sylvester Stallone, 62
  • Rod Stewart, 63
  • Michael Douglas, 64
  • Mick Jagger, 65
  • Hugh Hefner, 65
  • Paul McCartney, 66
  • Clint Eastwood 66.
  • Sir Michael John Gambon, 68
  • Woody Allen, 73
  • Charlie Chaplin, 73
  • Larry King, 75
  • Anthony Quinn, 81

Surely for men, age doesn’t matter for fertility.

However, there is increasing evidence that this is not the case, and that men too, should listen to the ticking clock starting at midlife. Researchers report that the sperm quality of men decreases with age, and that fertility starts to wane when they reach the 30s, and plummets when they reach their 40s. During the time, the overall chance of fathering a child drastically decreases. And if a pregnancy is ever achieved, the likelihood of miscarriage is increased. In addition, the resulting offspring would have a higher likelihood to suffer from genetically related disorders such as autism, schizophrenia, autism and low IQ. This is according to a study by researchers at the Eylau Centre for Assisted Reproduction in Paris, France who looked at more than 1,200 couples.

So what’s reason behind the male biological clock?

Researchers think it is due to some kind of “sperm decay” which is characterized by DNA damage and abnormalities. Men start producing sperms at puberty at a rate of 100 million new sperms per day. During the process, DNA is copied and duplication from one sperm to another. During the countless sperm-copying processes, mistakes occur and DNA mutations happen. These errors accumulate with age, leading to decreasing sperm quality.

According to fertility specialist Dr. Carl Herbert

“These subtle copying defects cause a long list of diseases in the children of older fathers. Lesch Nyhan syndrome, polycystic kidney disease and hemophilia A are among the most well known. For fathers over age 40, the risk of having a child with a disease-causing mutation is similar to the risk the mother has for a child with Down syndrome.”

Aside from age, other health factors, including body weight and diabetes, can also adversely affect sperm quality.

According to Dr. Harry Fisch, urologist at Columbia University, and author of the book The Male Biological Clock

“…couples are waiting longer to have children, and advances in reproductive technology are allowing older men and women to consider having children. The lack of appreciation among both medical professionals and the lay public for the reality of a male biological clock makes these trends worrisome.”

He further advises older dads to “have a thorough history and physical examination focused on their sexual and reproductive capacity. Such examination should entail disclosure of any sexual dysfunction and the use of medications, drugs, or lifestyle factors that might impair fertility or sexual response.”

Dad’s testicular tumors and baby’s genetic disorder

October 29, 2009 by  
Filed under CANCER

DNA2It is well-known that maternal age is a big factor in the health outcomes of the baby. It has been shown that children born to older women are more likely to suffer from chromosomal aberrations. What is less known is that the age of the father also matters and contributes to the development of certain diseases in the offsprings.

According to a study by researchers at the University of Oxford and Copenhagen University Hospital, there is a link between severe genetic disorders in children and a rare form of testicular tumors that occur among older men.

The rare childhood genetic disorders referred to by the study report include:

  • Achondroplasia
  • Aper Syndrome
  • Noonan Syndrome
  • Costello Syndrome

Some of these conditions are so serious that they can result in retarded growth and development or even result in stillbirth.

According to study leader Professor Andrew Wilkie from the University of Oxford:

“We think most men develop these tiny clumps of mutant cells in their testicles as they age. They are rather like moles in the skin, usually harmless in themselves. But by being located in the testicle, they also make sperm – causing children to be born with a variety of serious conditions. We call them ‘selfish’ because the mutations benefit the germ cell but are harmful to offspring.”

Sperms develop from germ cells. Mutations in these cells cause tiny tumors in the testicles. These tumors are normally harmless. However, these genetic aberrations tend to affect the ability to produce healthy sperms. These mutations and the resulting tumors accumulate as a man ages. Thus, an older Dad is most likely to pass on mutant sperms to the next generation, causing the abovementioned genetic disorders than a younger father.

More common diseases linked to paternal age are breast cancer, autism and schizophrenia but the mechanisms behind the link are not known. The researchers hypothesize that similar but milder mutation as reported above maybe responsible.

Dr. Wilkie continues to explain:

“What we have seen so far may just be the tip of a large iceberg of mildly harmful mutations being introduced into our genome. These mutations would be too weak and too rare to be picked up by our current technology, but their sheer number would have a cumulative effect, leading to disease.”

With recent developments in reproductive medicine, it is now possible for women to get pregnant, even at the postmenopausal age. However, there have been questions about whether there should be an age limit to motherhood. But nobody says anything about an age limit to fatherhood. The current study suggests that maybe there should be.

Related Posts with Thumbnails

NOTE: The contents in this blog are for informational purposes only, and should not be construed as medical advice, diagnosis, treatment or a substitute for professional care. Always seek the advice of your physician or other qualified health professional before making changes to any existing treatment or program. Some of the information presented in this blog may already be out of date.