The results are “intriguing,” said Eric Jacobs, the American Cancer Society’s Strategic Director of Pharmacoepidemiology in Reuters Health. However, Jacobs cautioned, a recent large United Kingdom study showed no link between bisphosphonates and colon cancer, but a higher risk of esophageal (throat) cancer. Bone-density drugs are taken by millions of people for osteoporosis and there have been rare but severe side effects including jaw-bone deterioration. Effects of long-term use are not yet known.

Using an Israeli population, the researchers found 933 postmenopausal women diagnosed with colorectal cancer. They matched these patients with 933 “controls”—women of the same age, ethnicity, and clinic location. Of these women, 97 who developed colorectal cancer had taken alendronate (Fosamax), compared to 138 “controls” who had taken the medicine and did not develop cancer. The associated lower risk persisted even after adjusting for known colorectal cancer risk facts such as physical activity and diet.

The study’s authors did caution that their study should only serve to “generate a hypothesis” for further investigation. For example, the bone-density drugs work on the same biologic pathways as cholesterol-lowering statin drugs, which also have shown some association with lower rates of colorectal cancer.

Patient take-away:

• If you’re taking a bone-density drug for osteoporosis, you still need to keep up with screening for colorectal cancer, and pay attention to possible symptoms. The only proven way to prevent or cure colorectal cancer is by early detection through colonoscopy.
• No matter who you are, your mother is still right: Eat your vegetables and get exercise! This and other studies continue to show strong evidence that regular physical activity and a diet high in vegetables and low in red meat are clearly linked to lower colorectal cancer risk.

SOURCES: Journal of Clinical Oncology, online on Feb. 14, 2011; Reuters Health; and HealthNewsReview.org

Older men with prostate cancer who received treatment that reduced androgen had a 30 to 40 percent higher risk of getting colorectal cancer than men who didn’t have the therapy. The longer they received the treatment, the greater their risk.

Androgen deprivation therapy (ADT) is approved for treatment for men with advanced prostate cancer, but its use is controversial in older men with earlier, low-risk cancer although it is widely used in those men.

The link of ADT to colorectal cancer may help lower-risk men make a decision about therapy for their prostate cancer.

The men received ADT either through a drug that blocked gonadotropin-releasing hormone (GnRH agonist) or by having their testicles removed (orchiectomy).

Increased Risk of Colorectal Cancer

• Men who didn’t receive ADT:  3.7 cases of colorectal cancer per 1,000 person years.
• Men who received GnRH agonist therapy: 4.4 cases per 1,000 person years
• Men who had orchiectomy: 6.3 cases per 1,000 person years.

Colorectal tumors in men who had orchiectomy were more frequently poorly differentiated or undifferentiated.

Statistics

The study reviewed information in the SEER (Surveillance, Epidemiology, and End Results) and Medicare database and found  107,859 men who were 67 or older at diagnosis, diagnosed from 1993 through 2002, and had follow-up information through 2004.  About half (55,901 ) had ADT during that time — most (50,097 ) treated with GnRH blockers, but 5,804 had orchiectomy.

Since radiation therapy for prostate cancer increases risk for rectal cancer, the research team looked at men who got radiation treatment and found that the increased risk with ADT was unchanged.

Conclusions

Silke Gillessen, MD, and the team at the University of Michigan in Ann Arbor, wrote in an early online edition of the Journal of the National Cancer Institute,

Long-term androgen deprivation therapy for prostate cancer is associated with an increased risk of colorectal cancer.

In an accompanying editorial in JNCI, Jennifer H. Lin and Edward Giovannucci discuss the impact of the study on our understanding of how sex hormones affect the development of colorectal cancer.  They point out that decisions about ADT need to be made in light of potential impact on colorectal cancer and that men who are being treated with androgen deprivation therapy need careful screening for colorectal cancer as well as lifestyle practices like physical activity that reduce its risk.

Although some subgroups of prostate cancer patients will benefit overall from androgen deprivation therapies, the medical side effects and effects on quality of life are important considerations. The findings of Gillessen et al. suggest that an elevated risk of colorectal cancer may be an additional consideration to weigh in the risk vs benefit profile. Their findings also reinforce the need for routine screening for colorectal cancer and the adoption of lifestyle practices such as physical activity that may help to counter some of the drawbacks of anti-androgen therapies.

A study reported two years ago in the Journal of the American Medical Association found no difference in overall survival between men with locally limited prostate cancer who got primary androgen deprivation therapy (PADT) did no better than men who had no treatment at all.

Grace L. Lu-Yao and her team wrote,

In conclusion, our analyses suggest that PADT is not associated with improved survival among the majority of elderly men with T1-T2 prostate cancer. The significant adverse effects and costs associated with PADT, along with our finding of a lack of overall survival benefit, suggest that clinicians should carefully consider the rationale for initiating PADT in elderly patients with T1-T2 prostate cancer.

SOURCES:  Gillessen et al, Journal of the National Cancer Institute, Advance Access, November 10, 2010.

Lin and Giovannucci, Journal of the National Cancer Institute, Advance Access, November 10, 2010.

Lu-Yao et al., Journal of the American Medical Association, Volume 300, Number 2, July 9, 2008.

Yet, when more than 60,000 Finns were followed for more than 18 years, there was no difference in colon or rectal cancer between those who drank more than 10 cups a day and those who didn’t drink coffee at all.

Researchers tracked 60,041 Finnish men and women, aged 26 to 74 at enrollment, for an average of 18 years.  None had cancer when they began the study.  During that time there were 538 cases of colon cancer and 234 cases of rectal cancer.

Comparing the group who drank more than 10 cups of coffee a day and those who didn’t drink coffee at all, there was no differencel  in risk for colon or rectal cancer for men, women, or men and women together.

Dr.Siamak Bidel and his team concluded,

In this study, we found no association between coffee consumption and the risk of colorectal, colon and rectal cancer.

SOURCE:  Bidel et al., European Journal of Clinical Nutrition, Volume 64, Number 9, September 2010.

Several studies have found a connection between eating red and processed meat and colorectal cancer.  But the reason for that connection hasn’t been clear.

To answer the question, researchers collected detailed information about the type of meat eaten by a large group of over 300,000 men and women and how the meat was  cooked.

Linking that information to data on meat iron content, chemicals used in processing meat, and chemicals produced when meat is cooked at high temperatures, they were able to  find that heme iron, nitrates and nitrites, and heterocyclic amines (HCAs) from high-temperature cooking increase risk for colon and rectal cancer.

Among 300,948 patients enrolled in a large, prospective trial,  2,719 developed colorectal cancer.  When researchers ranked diets from those who ate the least red and processed meat to those who ate the most, they found:

• Heme iron was associated with a 13 percent increase in risk.
• Nitrates from processed meats increased risk by 16 percent.
• HCAs produced during high temperature cooking raised risk by 19 percent.

Generally, risks were higher for rectal cancer than for colon cancer, with the exception HCA proteins, which only increased colon cancer risk.

• Heme iron is available in the diet from meat, poultry and fish.  Nonheme iron comes from plants, including lentils and beans.  It is also added to enriched cereals, flour, and grain.
• Nitrates and nitrites are used to process meat into bacon, hot dogs, and sausage.
• HCAs are produced during high temperature cooking like grilling.

Amanda J. Cross and her associates concluded,

In conclusion, we found a positive association for red and processed meat intake and colorectal cancer; heme iron, nitrate/nitrite, and heterocyclic amines from meat may explain these associations.

SOURCE: Cross et al.,Cancer Research, Volume 70, Number 6, March 15,2010.

Advanced adenomas were also reduced significantly.

Scientists at the German Cancer Research Center in Heidelberg compared a group of 553 people who had a negative screening colonoscopy to another group of 2701 who didn’t receive a colonoscopy.

After an average of 11.9 years, there were no colorectal cancers diagnosed in people with a negative colonoscopy compared to 8.4 in the group that weren’t screened.

Advanced adenomas — polyps most likely to become cancerous — were more than 52 percent lower 11 to 15 years later.  Even after 16 years, risk of finding an advanced adenoma was reduced by more than  47 percent.

Statutory health insurance in Germany has offered free screening colonoscopies to people over 55 since 2002.  Since that time over 1.8 million colonoscopy screenings have been done reaching about 40 percent of German women and 30 percent of men.

Hermann Brenner, MD, MPH and his colleagues concluded:

The low risk of CRC and advanced adenomas after a negative colonoscopy supports suggestions that screening intervals be extended to ≥10 years.

SOURCE: Brenner et al., Gastroenterology, Volume 138, Issue 3, Pages 870-876, March 2010.

Over 110,000 Ontario residents had complete negative colonoscopies between 1992 and 1997, almost all done in a hospital (86 percent).  In the 15 year follow-up time through 2006, 1,596 patients developed colorectal cancer.

Although the number of colonoscopies performed by an individual doctor didn’t make a difference in the risk of getting colon or rectal cancer, the physician’s specialization did.  Exams performed by gastroenterologists led to significantly fewer diagnoses of colorectal cancer during the follow-up period than tests done by other doctors, including general surgeons, internist, or family physicians.

Among patients who had their colonoscopies done in private offices, specialization didn’t make a difference in colorectal cancer development after a negative test.

Linda Rabeneck, MD, MPH, of the University of Toronto who led the study said,

The overall incidence of colorectal cancer is reduced for at least 10 years following a negative colonoscopy, compared with the general population. However, colorectal cancers do occur in individuals following a negative colonoscopy. For this reason, having extensive formal training matters, especially when procedures are more challenging to perform. We found that among those physicians who perform colonoscopy in the hospital setting, gastroenterologists are more proficient at colonoscopy than other physicians, including general surgeons. This may reflect the considerable formal training in endoscopy that forms part of gastroenterology core training requirements in the U.S. and Canada.

SOURCE:  Rabeneck et al., Clinical Gastroenterology and Hepatology, online November 2, 2009.

A number of studies have found that red meat and processed meats — the hamburgers, steaks, and hotdogs of summer backyard barbeques — increase risk for colon and rectal cancer.  Grilling those meats at high temperatures makes the risk even higher.

Eating more fruits and vegetables can reduce the chances of getting cancer, and grilling them is safe.

Grilling is an interesting new way to get the additional fruits and vegetables into your diet.  Brush them lightly with olive or canola oil to prevent sticking.

Registered dietician Vicki Piper from M.D. Anderson Cancer Center in Houston offers more ideas for healthy grilling.

Among her tips for reducing cancer risk are,

• Grill fish and skinless chicken breasts rather than red or processed meat.
• If you do grill meat, choose lean cuts.  Cuts with “loin” in their name, such as tenderloin or loin chops are the leanest along with round steaks.
• Keep meat portions small by cutting them into chunks, such a kabobs.
• Serve any meat as an accent to a meal of plant-based foods, not as the main attraction.
• Precook or marinate meat and grill at low temperatures.
• Flip meats often during cooking to reduce the chemicals produced by high heat that cause cancer.

Image courtesy of M.D. Anderson Cancer Center.

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.

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.

Verna Cox with Sen. Bob Casey in Washington

C3 Advocate Verna Cox was featured in the Philadelphia Daily News yesterday, and there’s a link to her story as well as links to the winning entries in the Get Screened Video Contest.

This week, we also report research showing that the elderly benefit from irinotecan chemotherapy treatments, a potential vaccine for travelers diarrhea, and no link between coffee drinking and colorectal cancer.

Research Reports

• In a large randomized trial comparing various combinations of irinotecan, 5-FU, or Xeloda (capecitabine), elderly colorectal cancer patients treated with irinotecan-based chemotherapy had no more serious side effects than younger patients.  Patients over 70 also benefitted equally from treatment with  similar rates of tumor shrinkage, time until cancer got worse, and overall survival time. Nadine A. Jackson, MD, MPH, from Dana-Farber Cancer Institute in Boston published the results of her team’s analysis in Cancer online April 20, 2009.
• A vaccine against traveler’s diarrhea (Campylobacter jejuni) may be possible based on research in mice and monkeys.  Vaccinated against C. jejuni, mice developed strong immune responses and had significantly fewer symptoms when exposed to the bacteria.  Monkeys who were also exposed were completely protected from developing diarrhea.  Besides traveler’s diarrhea, C. jejuni can cause irritable bowel syndrome. Dr. Patricia Guerry, from the Naval Medical Research Center in Maryland, says that a vaccine for humans is “very feasible.”  Her colleagues’ research was published in the March, 2009 issue of Infection and Immunity.
• Reviewing 12 studies prospective studies that followed almost 647,000 people, researchers found no connection between drinking coffee and colorectal cancer.  There was a small decrease in risk for women and colon cancer, particularly for Japanese women.  Youjin Je and colleagues at the Harvard School of Public Health report their analysis in the April 1, 2009 International Journal of Cancer.

Other Headlines

• Winning videos from the Get Screened Video Contest sponsored by EndColonCancerNow.Org at the Fred Hutchinson Cancer Research Center are now online.  Zach Smith of Spokane, WA was the grand-prize winner, awarded $2,500 for Your Choice.  Watch Zack’s video and  those from the four runner-ups. You can also see entries from the 15 finalists.
• C3 advocate Verna Cox’s story was featured in the Philadelphia Daily News and on Philly.com on  April 23, 2009.  Verna discusses her diagnosis and treatment very frankly and what pushed her to become an advocate to prevent others from getting colorectal cancer.  She says, “My strategy is — and it’s spiritual — if I can help somebody as I travel on, then my living will not be in vain.”  Her story is part of the ongoing Beating Cancer section in the Philadelphia newspapers.