Diet & Hormone Levels in Adolescent Girls

It has been known, since the 1930s, that early onset of menstruation, or late passage through menopause, are linked to an increased risk of breast cancer over a woman’s lifetime.  It is thought that the risk of breast cancer is, in general, proportional to the cumulative lifetime exposure to estrogen and other female sex hormones.  Therefore, it follows that interventions that might reduce lifetime exposure to ovarian sex hormones might, at least in principle, reduce the risk of breast cancer.

In the current issue of the Journal of the National Cancer Institute is a study that looked at the effects of diet manipulation on female sex hormone levels in the blood of adolescent girls.  The study participants were adolescent girls who had previously participated in another research protocol.  The prior study looked at the impact of dietary modifications on cholesterol levels in prepubescent girls with elevated LDL (the “bad cholesterol”).  In the current study, 286 adolescent girls with elevated LDL levels were randomized into two groups.  One group received diet counseling to maintain a low fat diet, while the other group was permitted to eat whatever they liked.  Blood samples were collected from all of the girls at year-1, year-3, year-5 in the study, and at the final study follow-up appointment (the median duration of follow-up within this study was about 7 years).  Estradiol, estrone, and progesterone, the primary female sex hormones, were measured, and the results for each of the two groups were analyzed.

At the 5-year mark, the low fat diet group had, on average, 30% lower estradiol levels in the blood when compared to the non-diet group.  Estrone levels were about 29% lower in the diet group than in the non-diet group.  Progesterone levels were also reduced by about 53% in the diet group.  The study’s authors, therefore, concluded that even a relatively modest reduction in fat intake during puberty is associated with significant reductions in female sex hormone levels in the blood (at least among adolescent girls with elevated LDL and cholesterol levels).  Although the study did not follow the volunteers long enough to directly observe any actual reductions in breast cancer risk after dieting, this study at least demonstrated that it might be possible to lower lifetime sex hormone exposure by reducing fat content in the diet.  There is, in fact, pretty solid scientific evidence that significant obesity during adulthood is associated with an increase in the risk of breast cancer in women.  However, additional studies will be necessary, and with much longer clinical follow-up, to definitively show a reduction in breast cancer incidence among women who reduce the fat content in their diets.  At the same time, this particular study recruited girls with abnormally high baseline levels of LDL in their blood, making it likely that they carried genes which predisposed them to abnormal cholesterol metabolism.  Whether or not this factor played a role in the study’s findings is unclear.  In future studies, it would be advisable to study girls and young women who do not have abnormal cholesterol and LDL levels in their blood.

Retention of Surgical Foreign Bodies after Surgery

As a practicing surgeon who has performed thousands of operations, I am all too aware of the risk of leaving a surgical instrument or sponge within a patient’s body.  Despite the generally very high level of awareness about this danger among most surgeons, and despite proactive measures taken in every hospital in the United States to prevent such events, such unfortunate incidents still happen.  As with operations performed on the wrong site of the body, leaving a sponge or a surgical instrument within a patient is inevitably caused by human error, and by a breakdown in the safeguards instituted by virtually every hospital in this country.  In most elective surgical cases, an inventory of surgical instruments is conducted at the beginning of the procedure, and surgical sponges (the gauze pads used during surgery to dry the surgical incision) are carefully counted.  Sutures and suture needles, as well surgical clips and staples, are also tallied and recorded by the supervising nurse in the operating room.  At the end of the case, these items are all recounted to ensure that nothing was left behind in the patient.  The primary surgeon is then notified that “the count is correct.”  During my own career, I have never left anything inside a patient that did not belong there.  However, I have taken care of several patients who required another trip to the operating room to remove foreign objects left by other surgeons.  Needless to say, these patients are generally quite outraged and dumbfounded to learn that a foreign object was inappropriately left within their bodies.  In my own limited experience with such patients, I have found that the instrument and sponge counts were verified as being correct by the OR nurse in every case.  Thus, the operating surgeon had every reason to believe that all instruments and sponges had been accounted for (although, clearly, this turned out not to be the case). 

In contrast to electively scheduled surgeries, emergency cases, by their very nature, tend to be somewhat less rigorous in terms of the usual safeguards.  It is not always possible to perform a complete inventory of surgical instruments before such cases, although sponges, sutures, suture needles, clips and staples are always counted, even for emergency cases.  The potential for “losing” a surgical instrument is, therefore, considerably higher during emergency surgeries when compared to elective cases.

In the current issue of the New England Journal of Medicine, the incidence of retained surgical foreign bodies has been assessed by a new study, and the potential factors associated with such mishaps have been analyzed.  The study’s authors examined the medical records of patients who had filed claims between 1985 and 2001, after being diagnosed with a retained surgical foreign body in Massachusetts.  The claims were filed with a large malpractice insurance agency that represented one-third of all physicians in Massachusetts.  For each patient who filed a claim, four “control cases” were studied.  The “control patients” had each undergone, without incident, the same operation that each of the malpractice claimants had undergone. 

A total of 54 patients with retained surgical foreign bodies were identified by the study’s authors.  Among these 54 patients, 61 retained foreign bodies were involved (69% were retained sponges and 31% were retained surgical instruments).  An additional 235 “control patients” were studied as well.  Among the 54 patients with retained foreign bodies, 69 made another trip to the operating room to remove the foreign bodies, and one of these patients died from complications of reoperation.  When the authors analyzed factors associated with foreign body retention, they identified three significantly associated factors.  Patients with retained foreign bodies were much more likely to have undergone an emergency operation than the control patients who had the same procedure performed without complications (33% vs. 7%, respectively).  A second significant contributing factor was an unexpected change in the planned surgical procedure (which is more likely during an emergency operation).  Among the patients with retained foreign objects, 34% required a change in the operative plan while under anesthesia, as compared with only 7% of the matched “control patients.”  Finally, obese patients faced a significantly higher risk of having a sponge or surgical instrument left behind when compared with non-obese patients.  Among the patients with retained surgical objects, a higher body mass index was associated with a significantly increased risk of a retained foreign object.  (This is not a surprising finding, as it is manifestly easier to lose track of a sponge or small surgical instrument within the body of an obese patient, and within the abdominal cavity in particular.) 

Following statistical analysis of these findings, the risk of retention of a surgical foreign body during emergency surgery was noted to be nearly 9 times greater when compared to electively scheduled cases.  An unplanned change in surgical procedure was associated with more than 4 times the risk of retained foreign body when compared with procedures that were carried as per preoperative plans.   Finally, there was 1.1 times the risk of retained surgical foreign body associated with each one-unit increase in body mass index.  Interestingly, in about two-thirds of the cases studied, the final sponge and instrument count was verified as having been correct.

Surgery, like all human endeavors, is subject to human error.  Unlike many other professions, however, major errors or lapses in judgment on the part of surgeons can have catastrophic results for their patients.  This study provides important information for all surgeons, as it identifies circumstances where the risk of leaving a surgical foreign body within a patient may be particularly high.  While a “zero error rate” may be unobtainable within any human profession, studies such as this are instructive to the operating team, and should provoke serious vigilance at all times in the operating room, and particularly when especially high-risk situations arise.

Dietary Soy & Prostate Cancer Risks

Prostate specific antigen (PSA) levels in the blood are often elevated in premalignant and malignant conditions of the prostate gland.  PSA is secreted by the prostate gland, and the levels of this protein in the blood rise with prostate gland enlargement (benign prostatic hypertrophy, or BPH) as well as in men with prostate cancer.  Herbal remedies containing phytoestrogens, derived from soy protein, have been shown to reduce the blood levels of prostate specific antigen (PSA).  Whether or not this effect of phytoestrogens on PSA levels actually reduces the risk of prostate caner development (or progression) is currently the subject of much scientific debate and research. 

Another recent soy-related trend is the use of soy-derived products in the diet as a means of reducing blood cholesterol levels.  Since soy protein is rich in phytoestrogens, the impact of soy protein in the diet on blood PSA levels is a logical study to perform.  Just such a study has been published in the current issue of the Journal of Urology.  A total of 46 health middle-aged men participated in the study over a period of 3 months.  The men were divided into different groups that receive supplemental dietary soy protein at various levels, and a control group that received no supplemental soy protein in their diet.  Blood PSA levels were measured at the beginning and end of the study.  All of the men had a prior history of elevated cholesterol levels, and had originally participated in a larger study that looked at the effects of dietary soy protein on LDL and total cholesterol levels. 

In this study, supplemental soy protein in the diet significantly reduced LDL levels in the blood, but had no impact on PSA levels in the blood.  The authors, therefore, concluded that any potential prostate cancer prevention or treatment benefits that might be associated with dietary soy protein are not likely to be mediated via hormonal mechanisms.  More studies, with larger numbers of patients and greater durations of follow-up, will be necessary to identify any subtle prostate-protective effects that might potentially be associated with soy protein in the diet, and that might not have been apparent in this rather small study.

Dr. Robert A. Wascher