Prevalence of Distant Metastases in High-Risk Operable Breast Cancer (HROBC) pT1-2 N2a or Higher at Diagnosis

TL;DR

This study finds that about 8% of high-risk early breast cancer patients have undetected distant metastases, suggesting routine staging could improve treatment planning.

Contribution

The study identifies a higher-than-expected prevalence of de novo distant metastases in high-risk operable breast cancer patients with heavy nodal disease.

Findings

Distant disease was detected in 8.24% of high-risk early breast cancer patients.

Oligometastatic disease was found in 5.15% of patients, and polymetastatic in 3.09%.

Abstract

Current standard guidelines do not recommend a routine staging workup in early operable breast cancer (OBC) as the incidence of de novo metastasis is only 1–2%. Some of these patients are at high risk for relapse based on the higher axillary nodal burden. This prospective study evaluated the presence of de novo asymptomatic distant metastases in HROBC with pT1/2 N2a/N3 on upfront surgery. A single-centre study was carried out in upfront operated OBC patients with four or more axillary nodes positive after definitive surgery. Comprehensive metastatic workup was carried out, including an ultrasound abdomen, bone scan, and CT scan (thorax-abdomen-pelvis) or PET scan before initiating adjuvant treatment. If a distant disease was detected, the adjuvant treatment intent was tailored accordingly. The study accrued a prospective consecutive cohort of 97 women with pT1-2 N2a-3 during 2015–2018 operated upfront for OBC with cT1-2 N0-1. Forty percent of women were premenopausal, 54 (55.6%) had pN2a, and 43 (44.3%) had pN3 disease. Distant disease was seen in 8 of 97 women (8.24%) of these high-risk early cancers, 5 had oligometastatic denovo disease (5.15%), and 3 had polymetastatic (3.09%). Between the 2 groups, the pickup rate of distant disease was higher in pN3 (11.4%) as against pN2a (5.6%), p = NS. Only 3.09% of patients with extensive metastases were treated with palliative intent. The study shows potential to optimize the management of HROBC with heavy nodal disease identified post-primary surgery by selective staging investigations, adequate resource stratification, and thereby improved management, including modifying treatment plans early.