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.

[Perception of pT1a,b pN0 breast tumor prognosis by the French oncology community: Results of the EURISTIC national survey]

The prognosis of infracentimetric breast cancers (BC) is heterogeneous. The EURISTIC survey describes how French oncology specialists perceive the prognosis of pT1a,b pN0 BCs. A self-administered questionnaire has been sent to over 2000 French BC specialists. Six hundred and sixty-three physicians responded. Fifty-eight percent do not consider tumor size as a key prognostic criterion. They consider that the cutoff for poor prognosis is 22mm, 10mm and 7mm for hormone receptors (HRs)+, HER2+ and triple-negative (TN) tumors respectively. Eighty-three percent of respondents consider that a HR+ pT1a,b tumor has a good prognosis (21% and 8% for HER2+ and TN respectively). Factors perceived as most detrimental are: HER2 overexpression (29% of respondents); HR- (20%); high grade (20%); TN status (14%); high KI67 (5%); presence of lymphovascular invasion (3%); young age (2%) and high mitotic index (1%). For French specialists, immunohistochemical characteristics, in particular hormone and HER2 status, are strong prognostic factors in BCs below 1cm.

[Use of guidelines and heterogeneity of decision making for adjuvant chemotherapy in hormone-receptor positive, HER2-negative, early breast cancer: results of a French national survey]

Adjuvant chemotherapy for localised breast cancer aims at reducing the risk of relapse and at increasing overall survival. Decision criteria include tumour burden and biological profile. It appears currently difficult to evaluate the benefit/risk ratio in certain borderline cases, which are more and more frequent. We have evaluated through an anonymous web survey conducted as part of the 2013 Annual Saint-Paul-de-Vence breast conference, the chemotherapy decisions, use of guidelines and level of certainty with decisions in this type of situation through four clinical cases. The survey was proposed to 1,190 French physicians who are directly in charge of breast cancer care, whatever their specialty. Three hundred and fifty-three of them replied, of whom 67 % were oncologists and 15 % surgeons. A significantly heterogeneous decision was observed for two out of four cases, in which 52 and 69 % of the physicians opted for adjuvant chemotherapy, versus 48 and 21 % for abstention respectively. Eighty seven percent of responding physicians used guidelines to guide their decision. These guidelines were regional for 63 %, national for 36 %, local in 21 % and international in 16 % of the cases. The level of certainty varied with clinical cases but not with the physician's specialty, nor type of decision.

[Breast cancer classification is evolving]

Diagnostic strategy of breast cancer has changed enormously during the last thirty years. To classical obligatory morphological data on the macroscopical and microscopical levels are now added imunocytochemistry, which is capable of detecting therapeutic targets such hormonal receptors and HER2 (Human Epidermal growth factor Receptor2), and molecular biology, which yields the molecular profile of tumors and their multigenic properties. By leaning on up-to-date classifications (TNM system and UICC grades), the pathologist is able to evaluate not only diagnostic but also pronostic criteria, leading to personalized and predictive treatments.