Patterns of diagnostic imaging and associated radiation exposure among long-term survivors of young adult cancer: a population-based cohort study

Clinical Impact of ASCO Choosing Wisely Guidelines on Staging Imaging for Early-Stage Breast Cancers: A Time Series Analysis Using SEER-Medicare Data

PURPOSE

American Society for Clinical Oncology released the Choosing Wisely list in 2012, highlighting low-value procedures that lack evidence, advising against the use of positron emission tomography, computerized tomography, and radionuclide bone scans for the staging of early-stage breast cancer at low risk for metastasis. The objective of the study was to assess the impact of the American Society of Clinical Oncology Choosing Wisely guidelines on inappropriate staging imaging among early-stage breast cancers.

METHODS

The Surveillance, Epidemiology, and End Results Program-Medicare data set was used to identify 50,004 women age 66 years and older with new incident diagnosis of early-stage breast cancer (stage 0 through stage 2a; T < 4, N = 0, and M = 0). The primary outcome was the incidence of patients with inappropriate imaging following an early-stage breast cancer diagnosis. The primary outcome was identified within 6 months of the first diagnosis. An interrupted time series analysis using negative binomial regression was performed for outpatient claims for these diagnostic studies versus the two interruptions of guidelines release and guidelines reinforcement. Mean images per patient, percent change for the study period, and rate of change per year were calculated.

RESULTS

Imaging rates fell by a modest 2.32% following guidelines release in April 2012 (point estimate = -2.32%; 95% CI, -6.34% to 1.88%). By contrast, imaging rates fell by a four-fold larger amount (point estimate = -9.36%; 95% CI, -13.20% to -5.35%) following guidelines published reminders in journals (or reinforcement) in October 2013. Mean imaging studies per patient (95% CI) declined from 1.80 (1.76 to 1.84) in January 2012 to 1.50 (1.48 to 1.53) by January 2015, representing a 16% decline in imaging overuse in 2015 compared with 3 years earlier. The rate of change (95% CI) in images per patient was initially small at -0.47% (-4.27% to 3.33%) per year between April 2012 and October 2013, but almost eight times faster at -3.70% (-5.81% to -1.60%) per year after October 2013.

CONCLUSION

This analysis demonstrates a substantial decrease in the prevalence of imaging overuse in early-stage breast cancers correlating with the 2013 reinforcement of American Society of Clinical Oncology's 2012 Choosing Wisely guidelines. The creation and dissemination of such resources serves as a powerful tool to improve clinical practice, cost-effectiveness, and patient safety from secondary malignancies, anxiety, and overdiagnosis.

Solid Organ Transplantation in Patients With Preexisting Malignancies in Remission: A Propensity Score Matched Cohort Study

BACKGROUND

Solid-organ transplant recipients with pretransplant malignancies (PTM) have worse overall survival (OS) compared to recipients without history of malignancy. However, it is unknown whether the increased risk of mortality is due to recurrent cancer-related deaths.

METHODS

All solid-organ transplant recipients in Ontario between 1991 and 2010 were identified and matched 1:2 to recipients without PTM using a propensity score. OS was compared using the Kaplan-Meier estimator and Cox proportional hazard models. For cancer-specific mortality and cancer recurrence, cause-specific hazard models were used and the cumulative incidence was plotted.

RESULTS

Recipients with PTM had a worse OS compared with recipients without PTM (median OS, 10.3 years vs 13.4 years). Recipients with PTM were not only at increased risk of cancer-specific mortality (cause-specific hazard ratio, 1.85; 95% confidence interval [CI], 1.20-2.86) but also at increased risk of noncancer death (cause-specific hazard ratio, 1.29; 95% CI, 1.08-1.54). Compared with recipients without PTM, recipients with high-risk PTM had higher all-cause mortality (hazard ratio, 1.81; 95% CI, 1.47-2.23). Recipients with low-risk PTM were not at increased risk (hazard ratio, 1.06; 95% CI, 0.86-1.31).

CONCLUSIONS

Recipients with PTM are at increased risk of all-cause mortality compared to recipients without PTM. This increased risk was noted for both cancer-specific and noncancer mortality. However, only those with high-risk PTM had worse outcomes.

Impact of Surveillance Imaging Modality on Survival After Recurrence in Patients With Favorable-Histology Wilms Tumor: A Report From the Children's Oncology Group

PURPOSE

The use of computed tomography (CT) for routine surveillance to detect recurrence in patients with Wilms tumor (WT) has increased in recent years. The utility of CT, despite increased risk and cost, to improve outcome for these patients is unknown. We conducted a retrospective analysis with patients enrolled in the fifth National Wilms Tumor Study (NWTS-5) to determine if surveillance with CT correlates with improved overall survival (OS) after recurrence compared with chest x-ray (CXR) and abdominal ultrasound (US).

PATIENTS AND METHODS

Overall, 281 patients with recurrent unilateral favorable-histology WT were reviewed to assess how WT recurrence was detected: sign/symptoms (SS), surveillance imaging (SI) with CT scan, or SI with CXR/US.

RESULTS

The estimated 5-year OS rate after relapse was 67% (95% CI, 61% to 72%). Twenty-five percent of recurrences were detected with SS; 48.5%, with CXR/US; and 26.5%, with CT. Patients with SS had a 5-year OS rate of 59% (95% CI, 46% to 72%) compared with 70% (95% CI, 63% to 77%; P = .23) for those detected by SI. Recurrences detected by CT had a shorter median time from diagnosis to recurrence (0.60 years) compared with SS (0.91 years) or CXR/US (0.86 years; P = .003). For recurrences detected by SI, more tumor foci at relapse ( P < .001) and size of the largest focus greater than 2 cm ( P = .02) were associated with inferior OS. However, there was no difference in OS after relapse when recurrence was detected by CT versus CXR/US (5-year OS rate, 65% v 73%; P = .20).

CONCLUSION

In patients with favorable-histology WT, elimination of CT scans from surveillance programs is unlikely to compromise survival but would result in substantial reduction in radiation exposure and health care costs.

Prevalence and Correlates of Worry About Medical Imaging Radiation Among United States Cancer Survivors

PURPOSE

Cancer survivors undergo lifelong surveillance regimens that involve repeated diagnostic medical imaging. As many of these diagnostic tests use ionizing radiation, which may modestly increase cancer risks, they may present a source of worry for survivors. The aims of this paper are to describe cancer survivors' level of worry about medical imaging radiation (MIR) and to identify patterns of MIR worry across subgroups defined by cancer type, other medical and demographic factors, and physician trust.

METHOD

This cross-sectional study used the 2012-2013 Health Information National Trends Survey of US adults conducted by the National Cancer Institute. The analysis focused on the 452 respondents identifying as cancer survivors. Weighted logistic regression analysis was used to evaluate factors associated with higher MIR worry (reporting "some" or "a lot" of MIR worry).

RESULTS

Nearly half (42%) of the sample reported higher worry about MIR. Unadjusted and adjusted logistic regressions indicated higher rates of MIR worry among those with lower incomes, those who self-reported poorer health, and those who completed cancer treatment within the past 10 years. Receipt of radiation treatment was associated with higher MIR worry in unadjusted analysis.

CONCLUSION

Worries about MIR are relatively common among cancer survivors. An accurate assessment of the rates and patterns of worry could aid efforts to improve these individuals' survivorship care and education.

Factors associated with imaging in patients with early breast cancer after initial treatment

Background

Overuse of surveillance imaging in patients after curative treatment for early breast cancer (ebc) was recently identified as one of the Choosing Wisely Canada initiatives to improve the quality of cancer care. We undertook a population-level examination of imaging practices in Ontario as they existed before the launch of that initiative.

Methods

Patients diagnosed with ebc between 2006 and 2010 in Ontario were identified from the Ontario Cancer Registry. Records were linked deterministically to provincial health care databases to obtain comprehensive follow-up. We identified all advanced imaging exams [aies: computed tomography (ct), bone scan, positron-emission tomography] and basic imaging exams (bies: ultrasonography, chest radiography) occurring within the first 2 years after curative treatment. Poisson regression was used to assess associations between patient or provider characteristics and the rate of aies.

Results

Of 30,006 women with ebc, 58.6% received at least 1 bie, and 30.6% received at least 1 aie in year 1 after treatment. In year 2, 52.7% received at least 1 bie, and 25.7% received at least 1 aie. The most common aies were chest cts and bone scans. The rate of aies increased with older age, higher disease stage, comorbidity, chemotherapy exposure, and prior staging investigations (p < 0.001). Imaging was ordered mainly by medical oncologists (38%), followed by primary care physicians (23%), surgeons (13%), and emergency room physicians (7%).

Conclusions

Despite recommendations against its use, imaging is common in ebc survivors. Understanding the factors associated with aie use helps to identify areas for further research and is required to lower imaging rates and to improve survivorship care.