Concepts and Controversies in Cancer Screening

Screening for cancer is a common and expected part of primary care medicine. However, the known effects of lead time, length, and selection bias confound our ability to objectively evaluate screening tests, and often result in an overestimation of the benefits of screening. Because of these biases, the randomized controlled trial remains the only reliable way to measure the true effects of a screening program. Significant controversy remains for many screening tests, because most common screening procedures have come into widespread use without the benefit of definitive trials. These concepts are illustrated by exploring current controversies in screening for cancer of the lung, colon, breast and prostate, which together account for more than 50% of US cancer deaths. In the face of ongoing controversy and uncertainty about the value of screening tests, physicians are advised to engage patients in a process of shared decision making and informed consent.     

Differential otomanometry

Management of otitis media, both acute and chronic, is one of the most common problems in clinical medicine. Among the many unresolved issues in otitis media research is accurate diagnosis which, in turn, depends heavily on valid otoscopic observation. Yet even today clinical otoscopy remains more of an art than a science. Because precise therapy is predicated on precise diagnosis, efforts to improve the validity and reliability of otoscopic techniques are warranted. Of great importance to the otoscopist is the visual estimate of tympanic membrane mobility secondary to hand-generated pneumatic pressure (pneumotoscopy). The degree of motion is usually graded in relative terms. In addition to pneumotoscopy, tympanometry is also used to assess the status of the middle ear. This is done indirectly through the plot of induced pressure versus acoustic immitance (tympanogram). Thus, both procedures depend on the differential application of induced pneumatic pressure on the tympanic membrane. If the middle ear is air-containing and the tympanic membrane is normal, even a slight pressure rise in the ear canal will displace the membrane. If the middle ear is fluid-filled, even large amounts of pressure produce no motion of the tympanic membrane. The pressure gradients, normal threshold, and optimal frequency of application for pneumotoscopy have not been studied previously in humans. Data are presented to compare the sensitivity, specificity, and predictive value of pneumotoscopy and tympanometry in the detection of effusion due to chronic secretory otitis media. In addition, preliminary data obtained by a new procedure, quantitative pneumotoscopy, are discussed.     

Outpatient and short-stay thyroid surgery

With the realization that simple thyroid procedures had a very low rate of complication and that patients often seemed well enough to go home from the recovery room, we began performing them in an ambulatory surgery setting. We review here 134 consecutive thyroid procedures performed at Columbia Presbyterian Medical Center between July 1987 and July 1989. Patients undergoing reoperation, neck dissection, sternal splits, or other concomitant procedures were excluded. There were 105 women and 29 men with an average age of 47 years. Fifty percent of the operations were performed for benign disease, although the most common diagnosis was papillary cancer (44%). Twenty-one operations (16%) were performed under local anesthesia. Most patients underwent surgery in our ambulatory surgery unit and 76 were discharged the day of surgery. Of these patients, 21 underwent total thyroidectomy, 13 subtotal thyroidectomy, and 42 simple thyroid lobectomy. Of the 58 patients who were admitted, 53 were discharged on the day following surgery. The average length of stay was 0.49 days. Extensive pre- and postoperative teaching was given regarding the signs and symptoms associated with the complications of thyroid surgery. All patients were felt to be reliable and capable of understanding the procedure and of complying with the postoperative plans. Postoperative complications included 8 patients (6%) with transient hypocalcemia and 1 patient (0.75%) with permanent unilateral recurrent laryngeal nerve paralysis. All complications occurred in patients who underwent total thyroidectomies. No patient had a postoperative complication requiring reoperation or readmission. We conclude that by using specific selection criteria, thyroid lobectomies and subtotal thyroidectomies can be performed safely in an ambulatory surgery setting without increase in morbidity or mortality.     

Air Transport of Patients with Unstable Aortic Aneurysms Directly into Operating Rooms

Objective. The purpose of this study was to describe an air transport service's protocol for direct transport of patients with abdominal aortic aneurysm leak (AAAL) into receiving hospital operating rooms (ORs). Methods. This retrospective consecutive-case analysis examined AAAL patients undergoing nurse-paramedic Boston MedFlight (BMF) transport during 1999–2004, who were taken directly into ORs at four academic centers. BMF uses a rotating roster system to assign receiving hospitals when referring physicians have no preidentified receiving facility, but this practice may prolong patient transport or be associated with less diagnostic certainty, andthus more delay, at receiving hospitals. Thus, the study compared “Roster” versus “Non-roster” patients' time andoutcome end points. Continuous nonparametric data (e.g., time intervals) were described with median andinterquartile range (IQR). Chi-square andKruskal-Wallis tests were used for univariate comparisons; regression analysis assessed dependent variables while adjusting for covariates (e.g., transport mileage). Results. There were 29 direct-to-OR transports, with median distance of 30 miles. All patients had AAAL diagnosis confirmed; 51.7% survived. System performance for end points was similar as assessed between Roster versus Non-roster patients. Conclusions. Interfacility direct-to-OR transport of AAAL patients is feasible. Use of a roster system allows for timely transport facilitation for patients needing specialized care; roster patients achieve similar end points as did patients who had already-identified receiving hospitals upon air medical transport request.     

Evaluating 90Y-glass microsphere treatment response of unresectable colorectal liver metastases by [18F]FDG PET: a comparison with CT or MRI

The purpose of this prospective study was to evaluate yttrium-90 glass microsphere treatment of unresectable liver metastases by fluorine-18 fluorodeoxyglucose positron emission tomography ([18F]FDG PET), and to compare the effectiveness of [18F]FDG PET for this purpose with that of computed tomography (CT) or magnetic resonance imaging (MRI) and determination of the serum carcinoembryonic antigen (CEA) level. Thirteen hepatic lobes from eight consecutive patients with colorectal cancer referred for 90Y-glass microsphere treatment of unresectable liver metastases who underwent both baseline (pretreatment) and 3-month posttreatment PET were studied. All patients also had correlative pre- and posttreatment CT or MRI for evaluation of the anatomic response and serum CEA determination for assessment of the total tumor load, as well as pretreatment hepatic intra-arterial technetium-99m macroaggregated albumin scan for lung shunting evaluation and hepatic arteriography for assessment of vascular anatomy and treatment. 90Y-glass microspheres were infused via an intra-arterial catheter under low pressure. Dedicated whole-body PET scans were analyzed visually and compared by lesion and by lobe with CT or MRI. A metabolic response after 90Y treatment to single or both hepatic lobes, assessed by PET, was present in a significantly higher proportion of the lobes than was an anatomic response, evaluated by CT or MRI (12 vs 2 lobes respectively, P<0.0002). Posttreatment PET showed no, stable, progressive, and new extrahepatic metastases in two, three, one, and two patients respectively. Following treatment, serum CEA decreased significantly, correlating with PET but not with CT or MRI. Thus, the study demonstrated a significant difference between the metabolic and the anatomic response after 90Y-glass microsphere treatment for unresectable liver metastases in colorectal cancer. PET appears to be an accurate indicator of treatment response.