On-Site Nurse-Led Cancer Genetics Program Increases Cancer Genetic Testing Completion in Black Veterans

Abstract

Purpose: Telegenetics services can expand access to guideline-recommended cancer genetic testing. However, access is often not distributed equitably to all races and ethnicities. We evaluated the impact of an on-site nurse-led cancer genetics service in a diverse Veterans Affairs Medical Center (VAMC) oncology clinic on likelihood of germline testing (GT) completion.

Methods: We conducted an observational retrospective cohort study of patients who were referred for cancer genetics services at the Philadelphia VAMC between October 1, 2020, and February 28, 2022. We evaluated the association between genetics service (on-site v telegenetics) and likelihood of GT completion in a subcohort of new consults, excluding patients with prior consults and those referred for known history of germline mutations.

Results: A total of 238 Veterans, including 108 (45%) seen on site, were identified for cancer genetics services during the study period, with the majority referred for a personal (65%) or family (26%) history of cancer. In the subcohort of new consults, 121 Veterans (54% self-identified race/ethnicity [SIRE]-Black), including 60 (50%) seen on site, were included in the analysis of germline genetic testing completion. In a univariate analysis, patients who were seen by the on-site genetics service had 3.2-fold higher likelihood of completing GT (relative risk, 3.22; 95% CI, 1.89 to 5.48) compared with the telegenetics service. In multivariable regression analysis, the on-site genetics service was associated with higher likelihood of GT completion, but this association was only statistically significant in SIRE-Black compared with SIRE-White Veterans (adjusted RR, 4.78; 95% CI, 1.53 to 14.96; P < .001; P-interaction of race × genetics service = .016).

Conclusion: An on-site nurse-led cancer genetics service embedded in a VAMC Oncology practice was associated with higher likelihood of germline genetic testing completion than a telegenetics service among self-identified Black Veterans.

FIG 1.

(A) Outcomes of genetics services consults among all patients with an active consult during the study period. (B) Outcomes of genetics services consults among all patients with cancer. Outcomes of all genetics services consults among all (C) SIRE-Black and (D) SIRE-White patients. (E) Flowchart depicting the analysis of predictors of germline testing completion. GT, germline testing; Pref, preferred; PV, pathogenic variant; Rec, recommended; SIRE, self-identified race/ethnicity; VUS, variant of uncertain significance.

FIG A1.

Flowchart illustrating the workflow of an on-site, nurse-led genetics service. MD, medical doctor; NCCN, National Cancer Care Network.

FIG A2.

On-site, nurse-led genetics service process. Graph of the E-value sensitivity analysis, which illustrates how an unmeasured confounder would have to be strongly associated with the exposure (type of genetics service) and outcome (germline testing completion) among Black Veterans, given the observed adjusted RR to explain away the observed association (RR 4.78). The upper right portion of the graph represents all combinations of exposure-confounder relationships and confounder-outcome relationships that would be necessary for an unmeasured confounder to move the point estimate of the RR (4.78) or the lower 95% CI (1.53) to 1.0. The inflection points represent the points at which the unmeasured confounder is equally associated with both the exposure and outcome. RR, relative risk.