In the month of March we celebrate Colon Cancer Awareness.

Colon cancer is one of the few cancers we can prevent successfully with colonoscopy, better than breast cancer or any other cancer with the exception of cervical cancer.

It takes usually about 5-10 years to develop colon cancer, which gives us a great window of opportunity to screen. We know that usually we see polyps first, which can develop into cancer, but that normally takes years. With screening we can see polyps and remove them before they develop into cancer.

Because of this prolonged development, the recommendation have been a baseline colonoscopy at age 50 and then every 5-10 years, but if any polyps are seen repeat colonoscopy in a year except if the polyps are hyperplastic.

Yes, we can prevent colon cancer. There is no discussion that we can.

The dilemma we have is that we still see many patients in their twenties, thirties, and forties with metastatic disease who have some symptoms but are told by their physician it is upset stomach and it can’t be colon cancer because they are too young.

We need to take these symptoms seriously! Any ongoing abdominal discomfort which is not explained should include a colonoscopy as a diagnostic tool even in a young patient.

It is also critical to know that any family history, ANY, will increase your risk and particularly if the family member was diagnosed at a young age. Screening should start about 10 years younger than the family member with cancer.

It is also important to know if there is a genetic predisposition, that colonoscopies need to be done yearly, because in these patients colon cancer can develop much faster and it is possible to see cancer within a year. This syndrome is called HNPCC, hereditary non- polyposis colon cancer. As you probably noticed these patients usually have no polyps but flat lesions which are much more difficult to see on colonoscopy. It is critical to have an experienced gastroenterologist who takes his time to evaluate the colon. It has been shown that up to 20% of the lesions in the right side of the colon (the furthest away from the anus) are easily overseen if you rush in and out.

It is also important that the location of the tumor also is important for symptoms. When the tumor is on the right side, patients have some change in bowel movement habits, some abdominal discomfort, and a feeling like an upset stomach. If the tumor is on the left side, symptoms are more typical including like diarrhea, blood in the stool, and pain with bowel movements.

Please make sure you talk to your family and friends about doing a colonoscopy.

Yes we can prevent this disease.

Recent studies from Swedish investigators suggest that blueberries may prevent colon cancer development. They suggest that blueberries should be eaten with probiotic yoghurt to further improve the benefit.

We have known for many years that antioxidants may have protective effects, but no prospective studies have validated these findings. There is a lot of data showing that colored fruits and vegetables affect cancer development, but so far we have not seen trials proving their effect.

However we know that ongoing oxidative stress is a major part of developing colon cancer. Antioxidants can help the normal cells to defend against oxidative stress. We had big hopes for selenium however it did not show the benefit we all hoped for. However we have learned in recent years that the environment in the colon may be very important.

The presence of good bacteria (probiotics) not only help with your bowel movements and regularity (ACTIVA), but these bacteria may influence the way cancer develops. The interaction of the colon mucosa (linings), bacteria, and potential agents which can cause cancer are very important.

We have started to recommend probiotic yoghurt to all our patients because of this impact on the gastrointestinal tract. How the antioxidants and bacteria interact is unclear but these data suggest that we can change the environment with bacteria and supplements and reduce the risk of colon cancer.

We are a long way to better understanding of how to further reduce colon cancer risk successfully. The exciting new data also suggest that these good bacteria may also impact how cancer behaves if it develops.

EAT your yoghurt with blueberries.

Recent data suggest that a compound in coffee has been found to possibly protect against colon cancer.

We have known for a long time that estrogen can protect against colon cancer and that women who take hormone replacement can also prevent polyps and cancer development. We also have recently seen that women do better than men when younger than 45 years old.

How estrogen can protect is still unclear, However we know that estrogen receptors are expressed in the colon which may be responsible for the estrogen effect. This compound identified in coffee has shown to be estrogenic. These studies are done by Texas AgriLife Research scientists.

We don’t have any data on how much coffee we need to drink to have this effect, but the scientists say the compound, called trigonelline or “trig,” may be a factor in estrogen-dependent breast cancer but beneficial against colon cancer development. These data were published in the Journal of Nutrition.

Dr. Clinton Allred’s lab studies dietary compounds that can mimic the hormone estradiol – the primary hormone in women. His main focus has been to look at how estrogen protects against the development of colon cancer. Estradiol is one of three estrogen hormones.

We have seen data in recent years that modulation of estrogen with soy, which is able to decrease estrogen levels, has an effect on breast cancer and colon cancer, but in opposite ways. Soy can increase breast cancer risk but not the risk of colon cancer, because estrogen can protect against colon cancer.

The data from Dr. Allred show that “trig” is in coffee beans, though in different amounts depending on the variety of coffee bean.

Dr. Allred said,

The more you roast a coffee bean, the less there is. But the most critical aspect is that when you do a water extract of ground coffee, which is basically how you make a cup of coffee. It does in fact come out in the water, so we know it is in a cup of coffee.

We need much more data to better understand what this substance is able to do and what the mechanisms of actions are before we run to Starbucks and order a double latte.

Dr. Lenz

I wanted to come up with some recommendations on diet over this Thanksgiving holiday. Searching the web and looking for advice to give you,  I came across a wonderful website  — TOP TEN FOOD tips by the National Foundation for Cancer Research — I wanted to share with you.

Here’s what they said.

• Skin the turkey – By removing the skin from the turkey (or chicken) after you cook it, you reduce the amount of fat and actually make the traditional centerpiece of the holiday meal better for you.

• Add more fiber to your stuffing – Try adding brown rice, celery, chopped apples, apricots, or nuts to your stuffing this year. These ingredients are all rich in fiber which is essential in a diet to deter cancer.

• Fruit not fudge – Rather than reaching for the tray of fudge and cookies this year for dessert, try Southern Ambrosia, a mixture of oranges, apples, bananas, pineapples, and coconut. Click here for the recipe!

• Use healthier cooking methods – Try broiling, grilling, roasting, or baking your holiday meals instead of frying and sautéing them. This reduces the amount of fat and allows the true taste of the food to come through.

• Cook with lower-fat dairy products – By using low-fat dairy products, you decrease the intake of fat that is later stored and used by cancer cells to grow. In most cases, you and your guests will not notice the difference in taste.

• Include fish in your holiday tradition – The Omega-3 oils in tuna, salmon, and mackerel appear to be protective of cell linings in fighting off cancer growth. Avoid tuna packed in vegetable oil, however.

• Eat plenty of fruits and vegetables – Research indicates that people who eat five to nine servings of fruits and vegetables each day can cut their cancer risk in half compared to those who eat only one serving per day.

• Make a spinach salad – Spinach contains one of the top cancer-fighting enzymes, sulforaphane, where traditional iceberg lettuce is a nutritional weakling. Don’t drench the salad with too much dressing which adds fat and calories. Even low-fat dressing may be loaded with too much sugar.

• Use tomato and pasta sauce – Research has proven that processed tomato products have a higher concentration of lycopene, the most powerful antioxidant carotenoid, than unprocessed tomato products. This includes tomato sauce, pasta sauce, stewed tomatoes, and other tomato products.

• Drink tea – Soda contains nothing more than empty calories and some juice drinks can be loaded with sugar. Green tea is one of the best drinks because it contains no calories and has well-documented cancer-fighting properties.

To all of you Happy Thanksgiving.

Recent publications have questioned the safety and adequacy of cancer screening procedures particular mammograms, but today I am reviewing the risks of colonoscopies.

There is no doubt that colonoscopies can prevent colon cancer almost 100%.

We have learned over the last couple of years that the experience of the gastroenterologist is critical in identifying suspicious lesions. We have learned that lesions which are on the right side of the colon (farthest away from the anus) can be missed, particularly if they are not growths like polyps but flat lesions.

The key of the success of colonoscopies is how clean the colon is, since any remaining stool can mask small lesions.

Overall, colonoscopy is a very safe procedure, but as with any medical procedure, complications can occur. Studies have estimated the overall risk of complications for routine colonoscopy to be extremely low, at approximately 0.35 percent.

During colonoscopies where a polyp is removed (a polypectomy), the risk of complications is higher, although still very uncommon, at about 2.3 percent. In contrast, the lifetime risk for developing colon cancer is about 6 percent.

Complications during a colonoscopy can include perforation, bleeding, postpolypectomy syndrome, reaction to anesthetic, and infection. Complications during the prep for a colonoscopy are uncommon, but can occur, particularly in elderly patients, or in those with congestive heart failure.

We are particular worried about perforation, which is a tear or a hole in the gut.  The risk of perforation is very low. A perforation can be caused by taking a biopsy from a thin point in the colon wall or when air introduced into the colon during the test to evaluate the intestinal lining better. We have seen that patients who have diverticula or diverticulitis may be at higher risk.

In recent years patients who are being treated for colon cancer with Avastin may be also at higher risk. Therefore, we are particularly careful in patients who receive Avastin. Usually we wait until treatment is completed or wait at least six weeks after the last Avastin dose or in patients with diverticulitis.

We also know that bleeding can occur after colonoscopies  in about 1 out of every 1,000 colonoscopy procedures. The bleeding may be treated during the test, but in most instances, bleeding will resolve on its own. When a polyp is removed, there is a 30 to 50% chance that bleeding will occur anywhere from two to seven days after the colonoscopy. This type of bleeding may also resolve on its own, but may require treatment if it is severe.

If you experience any unusual pain after the procedure or you have ongoing bleeding please contact your physician.

A recent study by Dr. Rubin from the University of Chicago evaluated over 180,000 patients with urological cancers such as renal pelvis and ureteral cancers and over 350,000 with colorectal cancer.

It is known that families with a genetic predisposition to colon cancer known as HNPCC (hereditary colorectal cancers) are at higher risk to develop additional cancers such as upper gastrointestinal cancers, ovarian and endometrium cancers but also renal cancers. This is one of the first and largest studies to connect colorectal and urological cancers.

The numbers are quite impressive. For example, for patients with colorectal cancer the risk for urological cancers was increased by 24%. For patients with ureteral cancers, an 80% increase risk of subsequent colorectal cancers were seen. Patients with renal pelvis cancer had a 44% increased risk of colorectal cancers. Patients with bladder cancers also had a small increase.

These data have implications for how patients with colorectal and urological cancers are followed up. We need to make sure that patients with either disease are screened for their increased risk of the other cancers (including getting colonoscopies).

These data were published in the May issue of Archives of Internal Medicine. In Dr. Rubin’s data set patients with multiple primary colon cancers had significantly increased risk for renal pelvis cancer.

It is difficult to understand why questions like how does smoking, family history, screening bias lead to these data. I also find it interesting that the patients diagnosed between 50 and 60 had increased the risk for the other cancers.

We have learned that we can prevent colon cancer by taking aspirin. However because of the significant side effects such as gastric ulcer, bleeding complications and kidney problems, aspirin is not recommended for the public to prevent colon cancer.

In an effort to prevent colon cancer but avoid the side effects of aspirin, COX-2 inhibitors such as Celebrex® (celecoxib) was developed and tested to see if they could prevent colon cancer without the side effects of aspirin. Unfortunately, we have witnessed that high doses of Celebrex can cause heart attacks which put a significant hold on the development of these drugs as chemopreventative agents.

The studies of Celebrex have been disappointing so far, and we may know why. A recent study let by Dr. Sanford Markowitz (PNAS this week) was able to show that individuals with low levels of 15-PGDH did not benefit from Celebrex therapy.  This is an important finding because it may allow selection of patients for chemoprevention (a FIRST) but also to develop novel chemoprevention strategies for individuals who have low 15-PGDH levels. There is now significant efforts to study the molecular mechanisms of 15-PGDH and resistance to Celebrex in mouse models.

How does 15-PDGH levels relate to colon cancer development? Investigators from the Dana Farber Cancer Center (Monica M. Bertagnolli) examined colon biopsies from human patients who had participated in the APC trial of Celecoxib. They found that among these individuals colon 15-PGDH levels varied by 12-fold from lowest to highest. Most importantly, they found that the patients who were resistant to Celecoxib and had developed new colon tumors were all individuals who had low levels of colonic 15-PGDH. Thus in both mice and humans, Celecoxib works to prevent colon tumors only if levels of colonic 15-PGDH are high, while low levels of 15-PGDH leads to Celecoxib resistance.

Both investigators Markowitz and Bertagnolli point out that these findings require additional studies with larger numbers of patients. In the future we need to become much more sophisticated to prevent colon cancer. We are moving away from one size fits all to a tailored strategy in chemoprevention.

I’ve been reading about why red meat is associated with higher colon cancer risk. Initially it was thought it was because of the fat in the meat, but this has changed. It may due to protein.

Worldwide, red meat consumption in countries matches colon cancer incidence perfectly. Countries where people eat a lot of red meat such as US, Europe, and South America have the highest incidence. Countries like Japan, China, and the Far East, which have increased their intake of red meat with the westernization of diet, have the highest increase of colon cancer incidence. Japan, a country which used to have the lowest incidence of colon cancer, has now a higher incidence than the USA.  Japan has a dramatic shortage of oncologists to deal with the increasing number of cases.

Dr. Eunyoung Cho from Harvard published an interesting paper in 2007 showing that choline, which is found in red meat, promotes the growth of polyps. He studied over 39,000 female US nurses enrolled in the Nurses Health Study. He found that women with the highest intake of choline had 45% higher risk of developing a polyp. Choline is a nutrient found in red meat, but also in eggs, poultry, and wheat germ.

We need to be cautious because this study does not prove that choline causes polyps or that avoiding it prevents them, but it warrants further study to better understand the relationship of choline and colon polyps.

There is still ongoing discussion about what red meat is (versus processed meat). Pepperoni is a red meat. Would that mean that lots of pepperoni pizza means a high intake of red meat in studies? In another study on diet and colon cancer, a 21% increase in colorectal cancer risk for each 1.7 ounces of processed (smoked, salted, cured, chemical preservatives) meat was found. We know that nitrates, present in most preserved meats you find in the grocery, have been found to be associated with colon cancer risk.

However there are interesting questions about whether it makes a difference if you eat quality grass-fed meats, fatty or not. In addition, the preparation of meat has an impact on colorectal cancer and polyp risk. Cooking “low and slow” is the safest way, along with avoiding chemically-preserved meats.

There are interesting data, for example, that Argentina, known for its beef, has lower incidence of colorectal cancer than the United States, and that groups such as Mormons, who love meat, have lower incidence than vegetarians groups. This raises the question of how important alcohol and smoking are.

There is still to learn a lot about the role of red meat.

Only about five years ago, every patient of mine who finished chemotherapy was given a vitamin cocktail to further reduce colon cancer risk. It was calcium, selenium, vitamin E and folic acid.

Over the last three years, folic acid has been shown to increase growth of polyps, and in patients with metastatic disease  it may shorten life. The protective value of vitamin E has been questioned, and there was evidence that it might increase prostate cancer risk. Selenium did not show benefit.

So we are down to calcium. This supplement has been shown repeatedly to benefit patients by reducing cancer risk for a variety of solid tumors including colon cancer. A recent publication by Dr. Yikyung Park from the National Cancer Institute showed that supplementation of 1200 mg calcium in women and men over the age of 50 decreased cancer risk by 17% for men and 23% for women (Archives of Internal Medicine, February 23, 2009). These were cancers of the gastrointestinal tract mainly colon cancers.

The usual source for calcium in our diet is milk products (yogurt, cheese, etc) as well as meat. The calcium pathway is very interesting because it requires activity of vitamin D. Without vitamin D it is difficult to absorb calcium and put it into the organs where we need it, but to make sure we have sufficient vitamin D we need some sun exposure (vitamin D is activated in the skin) and we need a functional kidney.

When vitamin D was tested in patients with colon cancer it was found by Dr. Charles Fuchs in the Journal of Clinical Oncology published in June last year that the patients with the highest vitamin D levels lived longer suggesting that low levels may be associated with shorter survival. Since there are very rare side effects from either vitamin D or calcium supplementation, I recommend all my patients take 1500 mg of calcium and 1000-3000 units of vitamin D daily.

I have one funny story from one of my patients giving him the spiel of calcium supplementation which he loved and started right away. About three months later he was admitted with kidney stones. He had inflammatory bowel disease which has higher risk of kidney stones which was further aggravated by calcium supplementation. Therefore if you have a history of kidney stones or inflammatory bowel disease please check with your doctor first before starting calcium supplements.

We had a couple of patients in our clinics which developed ice craving. They loved to crush and chew on ice chips all the time. When they saw their physician for another reason, blood tests showed low level of hemoglobin, known as anemia.

It turned out that these patients had iron deficiency coming from blood loss from colon cancer. These iron deficiencies can lead to a craving to chew or eat ice chips. Iron deficiencies can affect the mucosa in the gut and mouth, and ice chips may relief some of the discomfort caused by iron deficiencies.

My patients diagnosed with anemia underwent colonoscopies and were found to have colon cancer, which in both cases resulted in a curative removal by surgery and successful adjuvant chemotherapy.

Usually iron deficiencies develop over a long period of time. When diagnosed it takes months to replace iron in the storage in the body. Iron is critical for red blood cell production. We usually use Slow Fe because it is better tolerated than other preparations which can cause stomach upset.

You need to know if you take iron supplements your stool may look black, similar to patients who have bleeding from their stomach. When there is bleeding in the stomach the stool is black because of its interaction with stomach acid. When bleeding  is in the colon, the stool is red.

If you are abnormally craving ice chips, make sure you are checked for iron deficiency.