RESUMO
BACKGROUND: Implementing mammogram screening means that clinicians are seeing many breast cancers that will never develop metastases. The purpose of this study was to identify subgroups of breast cancer patients who did not present events related to long-term breast cancer mortality, taking into account diagnosis at breast screening, absence of palpability and axillary involvement, and genomic analysis with PAM50. PATIENTS AND METHODS: To identify them, a retrospective observational study was carried out selecting patients without any palpable tumor and without axillary involvement, and a genomic analysis was performed with PAM50. RESULTS: The probability of distant metastasis-free interval (DMFI) of 337 patients was 0.92 (95% CI, 0.90-0.93) at 20 years and 0.96 (95% CI, 0.92-1.00) in 95 patients (28%) with available PAM50 tests. In 22 (23.15%) luminal A tumors and in 9 (9.47%) luminal B tumors smaller than 1 cm, and in HER2 and basal type tumors, there were no metastatic events (20-year DMFI of 1.00). CONCLUSION: Patients with nonpalpable breast cancer found at screening with negative nodes are at very low risk. It is possible to identify subgroups without metastatic events by determining the intrinsic subtype and tumor size less than 1 cm. Therefore, de-escalation of treatment should be considered.
RESUMO
BACKGROUND AND OBJECTIVE: To identify subgroups with good progress over an extended period, we used diagnostic screening, tumour palpability, tumour phenotype, and node involvement. PATIENTS AND METHODS: We identified patients with good progress by means of a descriptive, observational and retrospective study. RESULTS: Of 746 patients diagnosed with node-negative breast cancer between 2001 and 2015: 110 (14.75%) had non-palpable screening-diagnosed tumours; 88 (80%) were endocrine-sensitive, 10 (9.10%) were triple-negative and 11 (10%) were HER2. Only 3 patients developed metastases, and there were 4 deaths: 2 from breast cancer and 2 from other causes. The distant recurrence-free interval (DRFI) was 95.60%: 100% in 34 endocrine-sensitive histological grade 1 (equivalent to luminal A) tumours, and 94.40% (95% CI 86.76-102.04) in 54 grade 2-3 (luminal B) tumours. In triple-negative and HER2 cases, it was 100%. In tumours <1 cm it was 100%, and >1 cm it was 95.50% (95% CI 79.42-100.98). CONCLUSIONS: Patients with non-palpable tumours detected by mammogram screening have ultralow risk. The good progress in the luminal A, triple-negative, HER2, and less than 1 cm subgroups may explain the efficacy of the treatment but it also makes them candidates to de-escalation of their treatment.
