Cancers du sein T1a,b N0 M0 (RPC 2013)

Local and Regional Breast Cancer Recurrences: Salvage Therapy Options in the New Era of Molecular Subtypes

Isolated local or regional recurrence of breast cancer (BC) leads to an increased risk of metastases and decreased survival. Ipsilateral breast recurrence can occur at the initial tumor bed or in another quadrant of the breast. Depending on tumor patterns and molecular subtypes, the risk and time to onset of metastatic recurrence differs. HER2-positive and triple-negative (TNG) BC have a risk of locoregional relapse between six and eight times than luminal A. Thus, the management of local and locoregional relapses must take into account the prognostic factors for metastatic disease development. It is important to personalize the overall management, including or not systemic treatment according to the metastatic risk. All isolated recurrence cases should be treated with curative intent. Complete surgical resection is recommended whenever possible. Patients who did not receive postoperative irradiation during their initial management should receive full-dose radiotherapy to the chest wall and to the regional lymph nodes if appropriate. Overall, total mastectomy is the “gold standard” among patients who were previously treated by conservative surgery followed by radiation therapy. In terms of systemic therapy, the benefits of additional treatments are not conclusively proven in cases of isolated recurrence. The beneficial role of chemotherapy has been reported in at least one randomized trial, while endocrine therapy and anti-HER2 are common practice. This review will discuss salvage treatment options of local and locoregional recurrences in the new era of BC molecular subtypes.

Adjuvant chemotherapy in pT1ab node-negative triple-negative breast carcinomas: Results of a national multi-institutional retrospective study

BACKGROUND

Triple-negative breast cancers (TNBCs) are considered as associated with poor outcome, but prognosis of subcentimetric, node-negative disease remains controversial and evidence that adjuvant chemotherapy (CT) is effective in these small tumours remains limited.

PATIENTS AND METHODS

Our objective was to investigate the impact of CT on survival in pT1abN0M0 TNBC. Patients were retrospectively identified from a cohort of 22,475 patients who underwent primary surgery in 15 French centres between 1987 and 2013. As rare pathological types may display very particular prognoses in these tumours, we retained only the invasive ductal carcinomas of no special type according to the last World Health Organisation (WHO) classification which is the most common TNBC histological type. End-points were disease-free survival (DFS) and metastasis-free survival (MFS). A propensity score for receiving CT was estimated using a logistic regression including age, tumour size, Scarff Bloom and Richardson (SBR) grade and lymphovascular invasion.

RESULTS

Of a total of 284 patients with pT1abN0M0 ductal TNBC, 144 (51%) received CT and 140 (49%) did not. Patients receiving CT had more adverse prognostic features, such as tumour size, high grade, young age, and lymphovascular invasion. CT was not associated with a significant benefit for DFS (Hazard ratio, HR = 0.77 [0.40-1.46]; p = 0.419, log-rank test) or MFS (HR = 1.00 [0.46-2.19]; p = 0.997), with 5-year DFS and MFS in the group with CT versus without of 90% [81-94%] versus 84% [74-90%], and 90% [81-95%] versus 90% [83%-95%], respectively. Results were consistent in all supportive analyses including multivariate Cox model and the use of the propensity score for adjustment and as a matching factor for case-control analyses.

CONCLUSIONS

This study did not identify a significant DFS or MFS advantage for CT in subcentimetric, node-negative ductal TNBC. Although current consensus guidelines recommend consideration of CT in all TNBC larger than 5 mm, clinicians should carefully discuss benefit/risk ratio with patients, given the unproven benefits.

Daily Practice Management of pT1a-b pN0 Breast Carcinoma: A Prospective French ODISSEE Cohort Study

BACKGROUND

Most breast cancer (BC) tumors ≤10 mm have an excellent prognosis. The subgroups with a higher risk for distant recurrence requiring adjuvant systemic therapy are not precisely defined in current international guidelines.

PATIENTS AND METHODS

The OBSERVATOIRE DES PETITS CANCERS DU SEIN HER2 +/- (ODISSEE) study was a prospective, multicenter, cohort study that aimed to describe the daily adjuvant management and outcome of 616 patients with unifocal, invasive pT1a-b pN0 nonmetastatic BC who underwent surgery.

RESULTS

At the time of diagnosis, the median age of patients was 61 years. Tumor was detected on imaging or during a screening program in 397 patients (64.6%). Most patients (96%) underwent conservative surgery with sentinel node biopsy (89%), completed with axillary lymph node dissection in 15%. At inclusion, 82% of tumors were pT1b, 73% were pN0 (i-), 53% were Scarff-Bloom-Richardson Grade I, 91% were estrogen receptor (ER)-positive, 5% overexpressed/amplified HER2, and 5% were triple negative (TNBC). Adjuvant treatments were radiotherapy (95%), hormone therapy (82%), chemotherapy (7%), and trastuzumab (3.5%). In patients with TNBC and HER2-positive BC, chemotherapy and trastuzumab (if needed) were administered in 45% and 68%, respectively. After 5 years of follow-up, 7 patients had contralateral BC, 7 had locoregional recurrence, and 1 had distant metastasis. At 5 years, overall survival, disease-free survival, and recurrence-free survival were: 98.4% (96.9%-99.1%), 94.7% (92.4%-96.3%), and 97.1% (95.2%-98.2%), respectively.

CONCLUSION

This prospective cohort study showed that in France, the routine practice in pT1a-b pN0 breast cancers follows international standard guidelines for practice including conservative surgery followed by radiotherapy and endocrine therapy for ER-positive patients. Adjuvant chemotherapy with or without trastuzumab was used but their benefit in breast cancer of ≤10 mm remains controversial.