Overdiagnosis and overtreatment of breast cancer: is overdiagnosis an issue for radiologists?

Overdiagnosis: epidemiologic concepts and estimation

Overdiagnosis of thyroid cancer was propounded regarding the rapidly increasing incidence in South Korea. Overdiagnosis is defined as 'the detection of cancers that would never have been found were it not for the screening test', and may be an extreme form of lead bias due to indolent cancers, as is inevitable when conducting a cancer screening programme. Because it is solely an epidemiological concept, it can be estimated indirectly by phenomena such as a lack of compensatory drop in post-screening periods, or discrepancies between incidence and mortality. The erstwhile trials for quantifying the overdiagnosis in screening mammography were reviewed in order to secure the data needed to establish its prevalence in South Korea.

[Overdiagnosis in cancer screening]

In screening programs, overdiagnosis is defined as the detection of a disease that would have gone undetected without screening when that disease would not have resulted in morbimortality and was treated unnecessarily. Overdiagnosis is a bias inherent in screening and an undesired effect of secondary prevention and improved sensitivity of diagnostic techniques. It is difficult to discriminate a priori between clinically relevant diagnoses and those in which treatment is unnecessary. To minimize the effects of overdiagnosis, screening should be done in patients at risk.

Malpractice claims in interventional radiology: frequency, characteristics and protective measures

PURPOSE

The use of interventional radiology procedures has considerably increased in recent years, as has the number of related medicolegal litigations. This study aimed to highlight the problems underlying malpractice claims in interventional radiology and to assess the importance of the informed consent process.

MATERIALS AND METHODS

The authors examined all insurance claims relating to presumed errors in interventional radiology filed by radiologists over a period of 14 years after isolating them from the insurance database of all radiologists registered with the Italian Society of Medical Radiology (SIRM) between 1 January1993 and 31 December 2006.

RESULTS

In the period considered, 98 malpractice claims were filed against radiologists who had performed interventional radiology procedures. In 21 cases (21.4%), the event had caused the patient's death. In >80% of cases, the event occurred in a public facility. The risk of a malpractice claim for a radiologist practising interventional procedures is 47 per 1,000, which corresponds to one malpractice claim for each 231 years of activity.

DISCUSSION

Interventional radiology, a discipline with a biological risk profile similar to that of surgery, exposes practitioners to a high risk of medicolegal litigation both because of problems intrinsic to the techniques used and because of the need to operate on severely ill patients with compromised clinical status.

CONCLUSIONS

Litigation prevention largely depends on both reducing the rate of medical error and providing the patient with correct and coherent information. Adopting good radiological practices, scrupulous review of procedures and efficiency of the instruments used and audit of organisational and management processes are all factors that can help reduce the likelihood of error. Improving communication techniques while safeguarding the patient's right to autonomy also implies adopting clear and rigorous processes for obtaining the patient's informed consent to the medical procedure.

Pulmonary embolism diagnosis and mortality with pulmonary CT angiography versus ventilation-perfusion scintigraphy: evidence of overdiagnosis with CT?

OBJECTIVE

The purposes of this study were to determine whether pulmonary emboli diagnosed with pulmonary CT angiography (CTA) represent a milder disease spectrum than those diagnosed with ventilation-perfusion (V/Q) scintigraphy, to determine the trends in incidence and mortality among patients with the diagnosis of pulmonary embolism from 2000 to 2007, and to correlate incidence and mortality trends with imaging modality trends.

MATERIALS AND METHODS

Diagnoses of pulmonary embolism from 2000 to 2007 at an urban academic medical center were retrospectively identified. Patient data were collected from the hospital database and the Social Security Death Index. Incident diagnoses, type of imaging used, and date of death were documented. Bivariate and multivariate analyses were used to explore the relations between imaging use and the incidence and mortality of pulmonary embolism. Logistic regression analysis was used to estimate the odds of death of pulmonary embolism diagnosed with pulmonary CTA versus V/Q scintigraphy.

RESULTS

The cases of 2087 patients (1361 women, 726 men; mean age, 61.8 years) with pulmonary embolism were identified. From 2000 to 2007 the incidence of pulmonary embolism increased from 0.69 to 0.91 per 100 admissions in strong correlation with increased use of pulmonary CTA. There was no change in mortality, but the case-fatality rate decreased from 5.7% to 3.3%. On average, pulmonary emboli diagnosed with pulmonary CTA were one half as lethal as those diagnosed with V/Q scintigraphy (odds ratio, 0.538; 95% CI, 0.314-0.921).

CONCLUSION

The results of this study are evidence that the shift in imaging from V/Q scintigraphy to pulmonary CTA resulted in increased diagnosis of a less fatal spectrum of pulmonary embolic disease, raising the possibility of overdiagnosis. Outcome-based clinical trials with long-term follow-up would be helpful to further guide management.

The Effect of Budgetary Restrictions on Breast Cancer Diagnostic Decisions

We develop a finite-horizon discrete-time constrained Markov decision process (MDP) to model diagnostic decisions after mammography where we maximize the total expected quality-adjusted life years (QALYs) of a patient under resource constraints. We use clinical data to estimate the parameters of the MDP model and solve it as a mixed-integer program. By repeating optimization for a sequence of budget levels, we calculate incremental cost-effectiveness ratios attributable to consecutive levels of funding and compare actual clinical practice with optimal decisions. We prove that the optimal value function is concave in the allocated budget. Comparing to actual clinical practice, using optimal thresholds for decision making may result in approximately 22% cost savings without sacrificing QALYs. Our analysis indicates short-term follow-ups are the immediate target for elimination when budget becomes a concern. Policy change is more drastic in the older age group with the increasing budget, yet the gains in total expected QALYs related to larger budgets are predominantly seen in younger women along with modest gains for older women.

Lesion size is a major determinant of the mammographic features of ductal carcinoma in situ: findings from the Sloane project

AIM

To assess the radiological features of calcific ductal carcinoma in situ (DCIS) in a large, multicentre dataset according to grade and size, and to investigate the possibility that DCIS has different mammographic features when small.

MATERIALS AND METHODS

The dataset consisted of all Sloane Project DCIS cases where calcification was present mammographically and histological grade and size were available. The radiology data form classifies calcific DCIS as casting/linear, granular/irregular, or punctate. The pathology dataset includes cytonuclear grade and microscopic tumour size. Correlations were sought between the radiological findings and DCIS grade and size. The significance of differences was assessed using the chi-square test and chi-square test for trend.

RESULTS

One thousand, seven hundred and eighty-three cases were included in the study. Of these, 1128, 485, and 170 had high, intermediate, and low-grade DCIS, respectively. Casting calcification was more frequently seen the higher the grade of DCIS, occurring in 58% of high grade, 38% of intermediate grade, and 26% of low-grade cases, respectively (p<0.001). Casting calcification was also increasingly common with increasing lesion size, irrespective of the histological grade (p<0.001). Thus casting calcifications in small (<10mm) high-grade DCIS lesions were seen with a similar frequency (50%) to those in moderate-sized (21-30 mm) intermediate-grade lesions (48%), and to those in large (>30 mm) low-grade lesions (46%).

CONCLUSION

Lesion size has a strong influence on the radiological features of calcific DCIS; small, high-grade lesions often show no casting calcifications, whereas casting calcifications are seen in nearly half of large, low-grade lesions. As small clusters of punctate or granular calcifications may represent high-grade DCIS, an aggressive clinical approach to the diagnosis of such lesions is recommended as the adequate treatment of high-grade DCIS will prevent the occurrence of potentially life-threatening high-grade invasive disease.

Cancer screenings, diagnostic technology evolution, and cancer control

Screening should allow for the anticipation of cancer diagnosis at an earlier stage, when curative treatment is possible. Screening for cervical, large bowel, and breast cancer were shown to be effective in reducing mortality. The wide acceptance of the screening concept led to the wide diffusion also of screening of uncertain benefit against prostate cancer and skin melanoma. Diagnostic technologies are continuously evolving, and new tests are proposed to improve existing screenings or as screening tests for additional cancer sites (e.g., lung cancer). Cancer screening, however, is a complex and costly intervention that does not result only in benefits but also may cause harm. A major emerging problem of screening is overdiagnosis, or the detection of cases that would have not progressed to the symptomatic phase in the absence of screening. Thus, both experimental and observational evaluation studies are needed to reduce harm caused by screenings and to select effective interventions among many proposed innovations. Finally, the research of markers to assess the aggressive nature of screen-detected lesions is of great importance to improve screenings ' harm/benefit ratio.

The patient experience

The impact of improved treatments for the management of hormone-sensitive breast cancer extends beyond clinical responses. Thanks to appropriate literature and access to the internet, patient awareness of treatment options has grown and patients are now, in many cases, able to engage their oncologists in informed conversations regarding treatment and what to expect in terms of efficacy and safety. Indeed, patients realize that although there is no cure for metastatic disease, treatment can greatly reduce the risk of progression and in the adjuvant setting, where treatment is administered with a curative intent, current treatment options reduce the risk of relapse. The approval of letrozole throughout the breast cancer continuum has provided patients with many reassuring options. The improvement in outcome with letrozole is achieved without a detrimental effect on overall quality of life. Adverse events such as hot flushes, arthralgia, vaginal dryness, and potential osteoporosis are most significant from the patient's perspective, and it is important that caregivers pay attention to patients experiencing these events, as they can impact compliance unless effectively explained and managed. The major benefits of letrozole are to improve prospects for long-term survivorship in the adjuvant setting and to delay progression and the need for chemotherapy in the metastatic setting.