New England Journal of Medicine: Prostate cancer is predominantly a disease of older men, occurring most frequently in the seventh decade of life. In most cases, prostate cancers grow relatively slowly over time. The ideal treatment for prostate cancer continues to be vigorously debated by the experts, with no broad consensus available at this time. Current treatment options include surgical removal of the prostate gland, radiation to the prostate gland, cryotherapy (freezing the prostate gland to kill tumors cells), and medications that block the synthesis of testosterone (and other so-called androgen hormones), as well as combinations of these options. The use of androgen-blocking drugs has become a popular method of treating prostate cancer over the past 10 years, as it allows many patients to at least initially avoid surgery, radiation, or other invasive treatments. However, a known side effect of androgen blockade is the gradual but sustained loss of bone mineral content which can, in turn, lead to osteoporosis.

A new study has evaluated 50,613 men who were diagnosed with prostate cancer between 1992 and 1997. Among the men in this group who survived at least 5 years following diagnosis, 19.4 percent of those who received androgen blockade therapy experienced at least one bone fracture, as compared with a 12.6 percent incidence of fractures in men receiving other forms of prostate cancer therapy. Moreover, the number of doses of androgen-blocking medications given within the first 12 months following the diagnosis of prostate cancer was significantly associated with the risk of fractures in these men.

While this study did not analyze the overall health impact of fractures associated with androgen blockade therapy, it does, at least, provide physicians and their patients with some quantitative data regarding the increased risk of osteoporosis and bone fractures associated with such treatment. What is needed now is new research that will incorporate this new risk data into studies of the overall risk-to-benefit equation for androgen blockade therapy, as well as the impact of treating patients receiving androgen blockade therapy with drugs that preserve or increase the mineral content of bone.

ALCOHOL & CANCER GROWTH:

Cancer: Excessive consumption of alcohol has previously been linked to an increased risk of several cancers, including esophageal cancer, and cancers of the mouth, larynx (voice box), liver, breast, colon, rectum, pancreas and stomach. The incidence of these cancers, moreover, is especially increased by concomitant heavy alcohol intake and smoking. A number of possible mechanisms whereby alcohol might cause cancer have been proposed. However, there is not a great deal of scientific data to support many of these hypotheses. A new study, therefore, looks at the effects of alcohol on human cancer cells implanted within chick embryos. In this study, the daily application of “physiologic doses” of alcohol to chick embryos with implanted tumors was compared to other tumor-implanted embryos that received only saline solution. The study found that, after 9 days, the alcohol-treated embryos had tumors that were more than twice as large as those growing in the embryos that received only saline solution. Exposure to alcohol was also found to significantly increase the tumor levels of chemicals known to be important for tumor growth and metastasis (spread to other sites in the body). Thus, this intriguing study suggests that chronic exposure to alcohol may switch on genes in tumor cells that stimulate the tumor cells to grow and divide more rapidly, and that facilitate the spread of tumor cells throughout the body. Furthermore, these adverse effects were directly proportional to the amount of alcohol that the chick embryos were exposed to. Once again, this study suggests that if you are going to consume alcohol, then you should do so in moderation. Another very important question that this study indirectly raises—but does not answer—is the clinical significance (if any) of increased alcohol consumption by patients who have cancer. Additional clinical research studies should, therefore, be undertaken to evaluate the effects of mild and moderate alcohol consumption on the survival rates of patients with various types of cancer.

OCCULT BREAST CANCER CELLS: THE ENEMY WITHIN

Clinical Cancer Research: We know that among breast cancer patients without clinical or radiographic evidence of cancer spread to the lymph nodes, as many as 30 percent will experience a later recurrence of their breast cancer somewhere within their bodies. Research performed in my laboratory, and in other labs, has shown that nearly undetectable numbers of breast cancer cells within the blood, the bone marrow or the lymph nodes may be associated with later cancer recurrence, even when there are no traces of remaining tumor cells that can be detected by standard hospital blood tests and x-ray studies. (Using sophisticated “molecular assays,” scientists are now able to identify a single cancer cell floating in the midst of a million or more normal cells.)

A new multi-institutional study followed 36 patients with a prior history of breast cancer, and compared them to 26 age-matched patients without a history of breast cancer. The researchers found evidence of viable circulating cancer cells in the blood of 13 of the 36 (36 percent) women who had previously undergone mastectomy (7 to 22 years earlier) for breast cancer. At the time of this study, none of these long-term breast cancer survivors had any clinical or x-ray evidence of residual or recurrent breast cancer. Among the 13 women in the control group, one patient had an abnormal blood test that suggested the presence of breast cancer cells in the blood. However, stringent evaluation of the abnormal cells in this one patient revealed the lack of characteristic genetic abnormalities that are often seen in breast cancer cells.

The researchers studied the circulating cancer cells detected in the blood of the long-term breast cancer survivors, and found that half of these malignant cells died off within 1 to 2.4 hours. This suggests that, even 22 years following diagnosis and treatment for breast cancer, occult sites of breast cancer are still growing in perhaps as many as a third of patients who currently meet all clinical criteria for being considered “cured” of their breast cancer. These results also help to explain the unfortunately not infrequent observation that some women will present with a recurrence of their breast cancer one or more decades after all of their disease was thought to have been eradicated. Clearly, we need better tests that will help us to detect and localize microscopic tumors hidden within the body, as well as more effective treatments to fully eradicate these hidden nests of tumor cells that may continue to slowly grow and spread over a period of years, or even decades.

CARNIVORES & COLON CANCER…

Journal of the American Medical Association: The consumption of red meat has been associated with a variety of ills, including cancer of the colon and rectum. However, the results from previous epidemiological studies have been somewhat contradictory in their findings. A new study has attempted to overcome the weaknesses of previous studies by evaluating the impact of long-term red meat intake on the risk of developing cancer of the colon and rectum. Almost 150,000 adults, aged 50 to 74 years, were enrolled in the Cancer Prevention Study II between 1982 and 2001. These volunteers provided extensive dietary information in 1982, and again in 1992/1993, and were followed until August 2001. A total of 1,667 colorectal cancers were identified in this very large group of study volunteers during the course of the research study.

This huge study found that the quantity of long-term red meat intake was proportional to the risk of developing cancer of the lower colon and rectum. Volunteers with the highest levels of red meat intake, and the intake of highly-processed meats in particular, were 50 percent more likely to develop cancers of the lower colon and rectum when compared to people who ate the least amount of such meats. The higher the ratio between red meat intake and the intake of poultry and fish, the higher the risk was of lower colon and rectal cancers, as well. Conversely, long-term increased consumption of poultry and fish in the diet was associated with a lower rate of colon and rectal cancers.

This is not the first study to link high intakes of red meat and processed meats with an increased risk of colorectal cancers. However, this study combines a huge number of study volunteers with a very long period of follow-up, which yields statistically powerful results. As with many similar—if smaller—studies, this study strongly suggests that heavy red meat or processed meat intake is associated with a significantly greater risk of developing colorectal cancer.

TO SLEEP, PERCHANCE TO EAT…

Archives of Internal Medicine: By now, everyone knows that we face an unprecedented epidemic of obesity in our society, with nearly 65 percent of the population meeting the criteria for being overweight or obese. Convenience devices and calorie-dense processed foods make it difficult for most of us to burn enough calories each day to fully offset those that we consume. At the same time, most of us are working more hours each week, and sleeping less, than did our forefathers. Some have, therefore, wondered whether or not there might be a link between sleep deprivation and excess calorie intake, as well. A new study strongly suggests that inadequate sleep and excessive eating may indeed be linked with each other.

This prospective study evaluated nearly 1,000 patients, ages 18 to 91 years. Each patient volunteer completed an extensive questionnaire that covered demographics, medical history, sleep habits, and any history of sleep disorders. Body mass index (BMI) values, a measure of obesity that takes height and weight into consideration, was calculated for all study volunteers, and this information was then analyzed with respect to self-reported sleep habits.

The average BMI of this group of volunteers was 30 (a normal BMI is less than 25), which was somewhat higher than the current average BMI of 26 to 27 in the US. Another interesting finding was that, on average, women slept more hours each night than men. More importantly, however, was the finding that overweight (BMI = 25 to 29.9) and obese (BMI = 30 to 39.9) volunteers slept significantly fewer hours per night than volunteers with a normal BMI of less than 25. Ironically, the super-obese (BMI equal to or greater than 40) appeared to spend more time sleeping than normal-weight volunteers.

These findings represent an interesting correlation between obesity and sleep habits, and suggest that overweight and obese people tend to spend less time sleeping than their normal-weight counterparts. However, this study does not identify any “cause-and-effect” relationships between obesity and sleep habits. Therefore, based upon the results of this study, it is possible that people who sleep less tend to eat more (or/and burn fewer calories throughout the day) when compared to people with normal BMIs. However, it may also be the case that being obese people spend less time sleeping due to one or more obesity-related factors. While it is an interesting hypothesis that chronic sleep deprivation may lead to increased eating or/and decreased physical activity and, hence, to a greater risk of obesity, this study cannot confirm such a hypothesis. However, the correlation between obesity and sleep habits is intriguing, and further research should be done to between understand the reasons for this correlation.

WARNING: THE HOLIDAY SEASON MAY BE BAD FOR YOUR HEART!

Circulation: Now that the Christmas and New Year holidays are safely behind us for another year, boasting about “surviving another holiday season” may be more than just a figurative observation, based upon a new research study that has just been published. There is, in fact, considerable epidemiological research that confirms what many of us already suspect: the major holiday seasons are times of both great joy and great stress for many folks (and, for a lot of unfortunate people, a time of great despair and great stress, and without much joy), and the stresses associated with life during these holidays claims its share of victims from heart attacks, strokes, accidents and, sadly, suicides. However, from a scientific perspective, it has not been entirely clear as to exactly why deaths from cardiac causes peak during December and January each year. (Some prior studies suggest that weather or other environmental stresses that occur during the winter months might be responsible, such as the “snow shoveler’s heart attack.”

A thorough analysis of mortality statistics was performed, and statistically analyzed. The researchers then found that there were 5 percent “extra” noncardiac deaths and 4.65 percent more cardiac deaths that occurred during the Christmas-New Year holiday period when compared to year-round trends, and after correcting for climactic and other seasonal variables. Although the exact cause—or causes—of this spike in both cardiac and noncardiac deaths was not determined by this study, there are clearly risk factors associated with the winter holiday season in the US, and these risk factors result in an increased risk of death. Moreover, based upon epidemiological data, the number of “excess deaths” recorded during each successive Christmas-New Year holiday period seems to be growing larger each year. Whether it is the effects of increased stress, increased alcohol intake, decreased physical activity, bad eating, delays in seeking medical care, or some combination of these or other factors, the likelihood is that at least some of the holiday-associated health risk factors are likely to be modifiable. The next important step in understanding holiday-associated increases in mortality is to identify the pertinent causes, so that we can modify our behavior in such a way as to minimize any added risks.