Health Briefs

September 13, 2002

Update on Prostate Cancer

Prostate cancer is, in many ways, analogous to breast cancer in women.  Like breast cancer, sex hormones are thought to play a stimulatory role in the majority of cases.  It is estimated that there will be 189,000 new cases of prostate cancer diagnosed in the United States in 2002, and that just over 30,000 men will die of the disease during the same timeframe.  Two important prostate cancer research studies are reported in the current issue of the New England Journal of Medicine (NEJM).  The first study looked at differences in survival among patients undergoing aggressive surgery versus observation.  Unlike many other cancers, prostate cancer tends to be rather slow-growing, and patients often live for many years, even after the disease has spread outside of the prostate gland.  A total of 695 men with prostate cancer were included in this study, with 348 patients randomized to the “watchful waiting” group and 347 patients randomized to the radical prostatectomy group.  All patients were followed for a median of 6.2 years.  The death rate, from all causes, between the two groups of patients did not statistically differ from each other.  However, the death rate specifically due to prostate cancer was significantly higher in the “watchful waiting” group.  In the group that underwent radical prostatectomy, 4.6 percent of the patients died of prostate cancer during the study, while 8.9 percent of the patients in the “watchful waiting” group succumbed to prostate cancer.  Moreover, the men who were treated with radical surgery experienced a 37 percent reduction in the risk of developing spread of prostate cancer outside of the prostate (metastasis).  As prostate cancer occurs most commonly in older men, it is not surprising that the death rate, from all causes, between the two groups of patients was similar.  This study, however, suggests that radical surgery for prostate cancer significantly reduces the risk of metastatic cancer, as well as the risk of dying due to prostate cancer.  These findings appear to confirm the benefit of radical surgery for early stage prostate cancer.  At the same time, radiation therapy is an accepted treatment alternative to surgery.  As a corollary to this study, a new study comparing radiation therapy versus “watchful waiting” would be a logical next step in prostate cancer research.

A second prostate cancer study in this week’s NEJM looked at the quality of life associated with radical prostatectomy versus “watchful waiting.”  A total of 326 prostate cancer patients who had undergone either radical prostatectomy or “watchful waiting” participated in this Swedish study.  Sexual dysfunction was, not surprisingly, more common in the patients who had undergone prostatectomy than among the patients who were managed without surgery (90 percent vs. 45 percent, respectively), as was the incidence of urinary incontinence (49 percent vs. 21 percent).  Obstruction of the urinary bladder, however, was far more common among the men who did not receive surgical therapy when compared to the prostatectomy patients (44 percent vs. 28 percent, respectively).  When the men were asked to rate their overall quality of life, though, the two groups of patients rated themselves equally in terms of levels of anxiety and depression, a sense of well-being, and overall quality of life.  Thus, the complications and symptoms associated with either surgical or nonsurgical management of prostate cancer, while different within each group of patients, resulted in a generally equivalent quality of life based upon patient self-assessment. 

These two studies, when taken together, add considerable insight into the optimal management of prostate cancer.  Of course, other health factors must be taken into consideration for each individual patient when deciding whether to recommend surgery, radiation therapy or “watchful waiting” for patients with newly diagnosed prostate cancer.

A Nutty Approach to Heart Disease Prevention

The current issue of the journal Circulation features a fascinating study on the effect of almonds in the diet with respect to known coronary artery disease risk factors.  Classically, nuts have been considered to be relatively unhealthy for heart disease patients, as they have a rather high fat content.  Recently, however, it has been learned that most nuts contain a high concentration of monounsaturated fats which may actually reduce levels of LDL (the “bad cholesterol”).  In this study, 27 patients with high LDL cholesterol levels were placed on a diet containing whole almonds as snacks for one month.  Blood cholesterol levels were measured just prior to beginning the study, at two weeks, and again at four weeks.  All patients were then switched to a half-dose of almonds and whole wheat muffins for one month, followed by whole wheat muffins, alone, as snacks for one month.  The same laboratory tests were again performed during each of these two month-long segments of the study.  During the “muffin-only phase” of the study, there was no change in the LDL levels.  During the “almond (with and without muffins) phase” of the study, however, LDL levels significantly declined over time.  The actual decrease in LDL levels was found to be proportional to the amount of almonds in the diet among the research volunteers.  This is an interesting study that, indirectly at least, suggests a beneficial role for nuts in the diet in terms of heart health.  In order to fully evaluate this interesting correlation, however, the actual incidence of heart disease as a function of long-term nut content in the diet will need to be evaluated.

Efficacy of Nonprescription Smoking Cessation Aids

In the summer of 1996, the FDA authorized the sale of nicotine gum and patches without a prescription.  Previous research had revealed that the maximum effectiveness of these smoking cessation aids required both the use of the nicotine replacement medication and ongoing counseling.  Thus, many addiction specialists predicted that easy access to nicotine replacement medications, and without a physician’s involvement, would further reduce the already modest effectiveness of these drugs in aiding smokers to quit tobacco.  In this week’s Journal of the American Medical Association is a study that looked at the impact of over-the-counter nicotine replacement medications on the smoking cessation rate of California smokers.  The authors looked at smokers who had completed state-sponsored smoking surveys in 1992 (5,247 people), 1996 (9,725 people) and 1999 (6,412 people).    Not surprisingly, in 1996 and 1999, only 1 in 5 smokers attended the recommended one-on-one or group therapy sessions while taking a nicotine supplement (some patients also used an antidepressant, bupropion, that has been commonly prescribed to treat nicotine addiction).  Most importantly, the study determined that the long-term smoking cessation success rate associated with the use of nicotine replacement medications was modest but significant in 1992, but essentially disappeared in 1996 and 1999.  The authors conclude that the widespread availability of smoking cessation drugs without a physician’s prescription (and, hence, without an extrinsic source of motivation to attend counseling sessions) has all but eliminated any of these medications’ effectiveness as smoking cessation tools.  Indeed, my own observation, as a clinician, is that smokers now routinely use these nicotine supplements as a replacement for the nicotine that they crave when they are unable to smoke.  Although the FDA’s original intention in releasing these drugs from prescription constraints was to increase smokers’ access to smoking cessation aids, the end result has been the loss of even the previously marginal success rate that these medications enjoyed when combined with ongoing professional addiction counseling….

Dairy Products, Calcium, Vitamin D & the Risk of Breast Cancer

Recent research has suggested that high levels of calcium in the diet might reduce the risk of breast cancer.  In the current issue of the Journal of the National Cancer Institute, this hypothesis was formally studied.  Nearly 90,000 women who were previously enrolled in the Nurses’ Health Study were assessed for dietary calcium intake through dietary surveys taken in 1980, 1984, 1986, 1990 and 1994.  Among these 90,000 study volunteers, 3,482 women developed breast cancer during the course of the study.  Among postmenopausal women, no significant reduction in the risk of breast cancer was found among study volunteers reporting the highest levels of calcium and vitamin D in their diet.  However, among the premenopausal women, an increased consumption of low-fat dairy foods, and especially skim milk, was associated with a significantly reduced risk of breast cancer.  When comparing premenopausal women with the lowest calcium intake levels and premenopausal women with the highest calcium intake, the women in the latter group experienced a 32 percent reduction in the risk of developing breast cancer.  Increased levels of dietary vitamin D, which enhances calcium absorption from the GI tract, was also associated with comparable reductions in the risk of developing breast cancer among premenopausal women.  It is unclear why postmenopausal women did not appear to enjoy the same protective effects of calcium and vitamin D with respect to their risk of breast cancer in this study.  However, this study provides further scientific evidence to support an inverse relationship between long-term intake of calcium (and vitamin D) and breast cancer.  Calcium-rich diets have been recently been linked to a possible reduction in the risk of colorectal cancer as well.  As always, mom knew what she was talking about when she implored us to drink our milk in order to remain healthy!

Dr. Robert A. Wascher