The rise in metastasectomy across cancer types over the past decade

Although studies of metastasectomy have been limited primarily to institutional experiences, reports of favorable long-term outcomes have generated increasing interest. In the current study, the authors attempted to define the national practice patterns in metastasectomy for 4 common malignancies with varying responsiveness to systemic therapy.

The National (Nationwide) Inpatient Sample was used to estimate the national incidence of metastasectomy for colorectal cancer, lung cancer, breast cancer, and melanoma from 2000 through 2011. Incidence-adjusted rates were determined for liver, lung, brain, small bowel, and adrenal metastasectomies. The average annual percentage change (AAPC) in metastasectomy by cancer type was calculated using joinpoint regression.

Colorectal cancer was the most common indication for metastasectomy (87,407 cases; 95% confidence interval [95% CI], 86,307-88,507 cases) followed by lung cancer (58,245 cases; 95% CI, 57,453-59,036 cases), breast cancer (26,271 cases; 95% CI, 25,672-26,870 cases), and melanoma (20,298 cases; 95% CI, 19,897-20,699 cases). Metastasectomy increased significantly for all cancer types over the study period: colorectal cancer (AAPC, 6.83; 95% CI, 5.7-7.9), lung cancer (AAPC, 5.8; 95% CI, 5.1-6.4), breast cancer (AAPC, 5.5; 95% CI, 3.7-7.3), and melanoma (AAPC, 4.03; 95% CI, 2.1-6.0). Despite an increasing number of comorbidities in patients undergoing metastasectomy (P<.05 for each cancer type), inpatient mortality rates after metastasectomy fell for all cancer types, most significantly for colorectal (AAPC, -5.49; 95% CI, -8.2 to -2.7) and lung (AAPC, -6.2; 95% CI, -11.7 to -0.3) cancers. The increasing performance of metastasectomy was largely driven by high-volume institutions, in which patients had a lower mean number of comorbidities (P<.01 for all cancer types) and lower inpatient mortality (P<.01 for all cancers except melanoma).

From 2000 through 2011, the performance of metastasectomy increased substantially across common cancer types, notwithstanding various advances in systemic therapies. Metastasectomy was performed more safely, despite increasing patient comorbidity. High-volume institutions appeared to drive practice patterns.