{Reference Type}: Journal Article
{Title}: Comparative effectiveness of treatment approaches for early invasive breast cancer.
{Author}: Lu Y;Meadows RJ;Gehr AW;Narra K;Bullock J;Ghabach B;Ojha RP;
{Journal}: Ann Epidemiol
{Volume}: 96
{Issue}: 0
{Year}: 2024 Jun 22
{Factor}: 6.996
{DOI}: 10.1016/j.annepidem.2024.06.002
{Abstract}: <B>BACKGROUND: </B>Randomized controlled trials (RCTs) suggested breast conserving therapy (BCT) and mastectomy have similar survival for early-stage breast cancer, whereas observational studies reported survival advantage for BCT. We aimed to address biases in observational studies to compare the effect of BCT and mastectomy on survival.<BR><B>METHODS: </B>We emulated a target trial using institutional cancer registry. We included adult women diagnosed with early invasive first primary breast tumors ≤ 5 cm between July 2011 and December 2017. We used cloning, censoring, and weighting to estimate risk differences (RDs) and risk ratios (RRs) for all-cause mortality and recurrence or all-cause mortality between BCT and mastectomy (reference).<BR><B>RESULTS: </B>Our study population comprised 534 observations with breast cancer. Median age was 56 years and 65 % were racial/ethnic minorities. The 8-year RD was 1.5 % (95 % confidence limits [CL]: -7.0 %, 9.8 %) and RR was 1.1 (95 % CL: 0.57, 2.2) for all-cause mortality. Results for recurrence or mortality were similar.<BR><B>CONCLUSIONS: </B>Our results suggest that target trial emulation to mitigate selection and immortal-time biases in observational studies may generate estimates that are more compatible with RCTs when comparing the effects of BCT and mastectomy on survival. Studies with longer follow-up and more events are needed to confirm our findings.