Study: Surgeon attitude impacts rate of genetic testing after a breast cancer diagnosis

IN-DEPTH REVIEW OF RESEARCH
Study background:

Surgeons guide clinical management of their patients‘ treatment. Genetic testing can inform those decisions. Almost all patients see a surgeon after diagnosis, but only about one-third of eligible patients have genetic testing. Current National Comprehensive Cancer Network (NCCN) guidelines recommend genetic testing for women diagnosed with breast cancer who have risk of carrying a pathogenic mutation in a breast cancer gene based on family history and her own tumor characteristic.

Variability in surgeons’ attitudes about genetic testing are documented. The researchers for this study wanted to know how surgeons’ recommendations differed when faced with patients with similar clinical indications. If variability in genetic testing is due to surgeons rather than clinical findings, it suggests greater efforts be made to educate surgeons about genetic testing or to encourage patients to get a second opinion.

Researchers of this study wanted to know:

How surgeons impact genetic testing in women with breast cancer.

Populations looked at in this study:

Participants were 5,080 women from the iCanCare study ages 20 to 79. Each woman was diagnosed with either ductal carcinoma in situ (DCIS) or invasive cancer (stage 0 to II) between July 1, 2013 and August 31, 2015 that was reported to SEER registries in Georgia or Los Angeles County, California.

98% of patients identified their attending surgeon. Of these, 377 of 488 attending surgeons responded to a survey about their likelihood to order genetic testing or genetic counseling in different hypothetical clinical scenarios. These surgeons treated 3,910 patient-participants.

Study findings:  

Of 3,910 women with breast cancer in this study:

• 34% (1,350 of 3,910 women) had elevated risk of having a breast cancer gene mutation as determined by NCCN guidelines (i.e.,these women are candidates for genetic testing based on personal and family history).
• 27% (1,056 of 3,910 women) had genetic testing.

Researchers surveyed the attending surgeons to determine what factors impacted genetic testing rates in various hypothetical clinical scenarios. In these scenarios, elevated risk was based on NCCN testing guidelines:

• 20% of variation in genetic testing recommendations reflects variation in pretest genetic risk among the patients.
• About one-third of the variation in genetic testing recommendations is due to surgeon attitude and patient volume.
   
  • Surgeons’ attitudes most impacted genetic testing rates. Some surgeon's recommendations differ from national guidelines.
     
    • Surgeons who were most likely to recommend genetic testing (top 5%) recommended testing for 72% of patients with an elevated chance of carrying a mutation.
       
    • Surgeons who were least likely to recommend testing (bottom 5%) recommended testing for 26% of patients with an elevated chance of carrying a mutation.
       
  • Surgeons who see greater patient volumes (50 or more cases per year) were more likely to recommend genetic testing.
     
• Socioeconomic status and insurance coverage impacted genetic testing but did not track with surgeon's recommendation.
  • Patients with no insurance or public insurance were less likely to get genetic testing.
     
  • Genetic testing rates differed by ethnicity:
     
    • Black women were 51% less likely to have genetic testing than white women.
       
    • Latina women were 16% less likely to have genetic testing than white women.
       
    • Asian women were as likely to have genetic testing as white women.

Limitations:

Because participating women with breast cancer were identified from SEER registries, some information about their family history may not be available. Given the data available, it was not possible to directly determine whether attending surgeons recommended genetic testing for women who were later shown to have mutations and did not recommend genetic testing for women who were later shown to not have mutations. Some women and some surgeons did not participate in the surveys and that may have skewed the data. The study was based on participants in Georgia and California only; nationwide results may vary. 

Conclusions:

Recommendations for genetic testing after a breast cancer diagnosis can be strongly impacted by surgeon attitudes. The results of this study suggest that patients should be aware that some surgeons’ recommendations may differ from national guidelines and vary given similar situations. These results suggest greater efforts be made to educate surgeons about genetic testing and to encourage patients to get a second opinion. It also highlights the need for greater consensus among surgeons about genetic testing and genetic counseling needs.

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Posted 10/6/18