Statistical Analysis—Because of the rarity of DM and the subsequently limited sample size, summary and descriptive statistics were utilized to characterize the sample and identify patterns in the results. Continuous variables are presented with means and standard deviations, and proportions are presented with frequencies and percentages. All analyses were done using SAS Version 9.4 (SAS Institute Inc).
Results
Patient Demographics—Fifty-four patients were identified using StudyFinder, physician referral, and search of the electronic health record. Nine patients agreed to take part in the focus groups, and 27 offered email addresses to be contacted for the survey. Of those 27 patients, 16 (59.3%) fit our inclusion criteria and completed the survey. Patient demographics are detailed in Table 2. The mean age was 55 years, and most patients were White (88% [14/16]), female (81% [13/16]), and had at least a bachelor’s degree (69% [11/16]). Most patients (69% [11/16]) had an annual income of less than $50,000, and half (50% [8/16]) were employed. All patients had been diagnosed with DM in or after 2013. Two patients were diagnosed with basal cell carcinoma during or after cancer screening.
FIGURE 1. Patient preference regarding cancer screening in general following the diagnosis of dermatomyositis (“Would you rather have no cancer screenings at all to look for cancer?”)(N=16).
Patient Preference for Screening and WTP—A majority (81% [13/16]) of patients desired some form of screening for occult malignancy following the diagnosis of DM, even in the hypothetical situation in which screening did not provide survival benefit (Figure 1). Twenty-five percent (4/16) of patients expressed that a CSP was burdensome, and 12.5% of patients (2/16) missed a CSP appointment; all of these patients rescheduled or were planning to reschedule. Assuming that both screening methods had similar predictive value in detecting malignancy, all 16 patients felt annual whole-body PET/CT for a 3-year period would be less burdensome than a CSP, and most (73% [11/15]) felt that it would decrease the likelihood of missed appointments. Overall, 93% (13/14) of patients preferred whole-body PET/CT over a CSP when given the choice between the 2 options (Figure 2). This preference was consistent with the patients’ WTP for these tests; patients reliably reported that they would pay more for annual whole-body PET/CT than for a CSP (Figure 3). Specifically, 75% (12/16) and 38% (6/16) of patients were willing to spend $250 or more and $1000 or more for annual whole-body PET/CT, respectively, compared with 56% (9/16) and 19% (3/16), respectively, for an annual CSP. Many patients (38% [6/16]) reported that they would not be willing to pay any out-of-pocket cost for a CSP compared with 13% (2/16) for PET/CT.Indirect Costs of Screening for Patients—Indirect costs incurred by patients undergoing a CSP are summarized in Table 3. Specifically, a large percentage of employed patients missed work (63% [5/8]) or had family miss work (38% [3/8]), necessitating the use of vacation and/or sick days to attend CSP appointments. A subset (25% [2/8]) lost income (average, $1500), and 1 patient reported that a family member lost income due to attending a CSP appointment. Most (75% [12/16]) patients also incurred substantial transportation costs (average, $243), with 1 patient spending $1000. No patients incurred child or elder care costs. One patient paid a small sum for lodging/meals while traveling to attend a CSP appointment.
Comment
Patients with DM have an increased incidence of malignancy, thus cancer screening serves a crucial role in the detection of occult disease.13 Up to half of DM patients are MSA negative, and most cancers in these patients are found with blind screening. Whole-body PET/CT has emerged as an alternative to a CSP. Evidence suggests that it has similar efficacy in detecting malignancy and may be particularly useful for identifying malignancies not routinely screened for in a CSP. In a prospective study of patients diagnosed with DM and polymyositis (N=55), whole-body PET/CT had a positive predictive value of 85.7% and negative predictive value for detecting occult malignancy of 93.8% compared with 77.8% and 95.7%, respectively, for a CSP.17
FIGURE 2. Patient preference between annual whole-body positron emission tomography/computed tomography (PET/CT) and a conventional cancer screening panel (n=14).
The results of our study showed that cancer screening is important to patients diagnosed with DM and that most of these patients desire some form of cancer screening. This finding held true even when patients were presented with a hypothetical situation in which screening was proven to have no survival benefit. Based on focus group data, this desire was likely driven by the fear generated by not knowing whether cancer is present, as reported by the following DM patients:
“I mean [cancer screening] is peace of mind. It is ultimately worth it. You know, better than . . . not doing the screenings and finding 3 years down the road that you have, you know, a serious problem . . . you had the cancer, and you didn’t have the screenings.” (DM patient 1)
FIGURE 3. Patient willingness to pay out-of-pocket for whole-body positron emission tomography/computed tomography (PET/CT) vs a conventional cancer screening panel (CSP) in patients with dermatomyositis (DM)(N=16).
“I would rather know than not know, even if it is bad news, just tell me. The sooner the better, and give me the whole spiel . . . maybe all the screenings don’t need to be done, done so much, so often afterwards if the initial ones are ok, but I think too, for peace of mind, I would rather know it all up front.” (DM patient 2)
