Since the 12th International Breast Cancer Conference in St. Gallen in 2011, which first proposed “treatment strategies for subtypes of breast cancer”, the individualized treatment of breast cancer has been gaining more and more attention, and in 2015, the classification and management of breast cancer and individualized treatment remained a hot topic. In particular, three speakers gave excellent presentations on adjuvant chemotherapy for different subtypes of breast cancer, and the hot topics and controversies are summarized below for the readers. Adjuvant chemotherapy for Luminal-like breast cancer Adjuvant chemotherapy has improved the prognosis of patients with early-stage breast cancer, but with the better understanding of the biology of breast cancer and the increase of available chemotherapeutic agents, clinicians are often faced with two questions when making adjuvant treatment decisions for Luminal-like breast cancer: ① Who needs adjuvant chemotherapy? (2) How to choose the adjuvant chemotherapy regimen? In this session, Angelo Di Leo, an Italian scholar, focused on these two issues. While multigene tests such as Oncotype’s RS score can screen out high-risk patients who need chemotherapy, 24-30% of low-risk patients with low RS scores still develop recurrence or metastasis within 10 years. Therefore, in assessing the absolute benefit from adjuvant chemotherapy we should not only focus on the extent to which patients benefit from this treatment, but also consider the likelihood of residual postoperative micrometastases that affect the absolute risk of disease recurrence. The detection of micrometastases can be done by analyzing circulating tumor cells in blood, plasma microRNAs, and other techniques, but the speaker particularly emphasized the potential of a panel of tumor metabolite profiles to predict residual micrometastases, and a 2015 study published in Mol Oncol has again demonstrated the value of this test in predicting the risk of disease recurrence, which warrants further study. Regarding the choice of adjuvant chemotherapy regimens, HartC et al. compared the benefit of different chemotherapy regimens (CMF versus anthracycline chemotherapy and anthracycline chemotherapy versus anthracycline plus paclitaxel chemotherapy) in patients with different Luminal subtypes. The results suggest that patients with Luminal B subtype appear to benefit more from the stronger chemotherapy compared to patients with Luminal A subtype. Finally the speaker also pointed out that patient’s wishes are also an important factor to consider when choosing a chemotherapy regimen. Adjuvant chemotherapy for triple-negative breast cancer Triple-negative breast cancer accounts for approximately 10-15% of all breast cancers and may be higher in developing countries. Compared to other subtypes, triple negative breast cancer has a higher mortality rate. However, it should not be overlooked that triple-negative breast cancer is highly heterogeneous: on the one hand, some special types of breast cancer with better prognosis, such as medullary carcinoma and adenoid cystic carcinoma, also exhibit a triple-negative phenotype; on the other hand, existing studies suggest that triple-negative breast cancer can be further classified, and the sensitivity and prognosis of different subgroups of triple-negative breast cancer vary greatly in terms of chemotherapy, but the clinical significance of further classification still needs to be confirmed. In this session, De Eric Winer’s presentation provided insight into the issue of adjuvant chemotherapy for triple negative breast cancer. Overall, chemotherapy reduces the risk of recurrence in triple-negative breast cancer by 35% to 50%, so most stage I-III triple-negative breast cancers require adjuvant chemotherapy. However, the value of chemotherapy for specific types of patients with better prognosis and for patients with small tumors with T1a/bN0 triple-negative breast cancer is unclear. Therefore, the current clinical tendency is to consider no chemotherapy for special types of triple-negative breast cancer with better prognosis and no lymph node metastasis; to consider chemotherapy for such patients with lymph node metastasis; and to consider no chemotherapy for patients with T1a/bN0 triple-negative breast cancer. For other stage II-III triple-negative breast cancers, chemotherapy regimens containing anthracyclines and paclitaxel may be the more appropriate standard of care; short-course chemotherapy and or less toxic chemotherapy regimens (e.g., TC, CMF) may be used for stage I patients. Recent studies have shown that triple-negative breast cancer with a high proportion of tumor-infiltrating lymphocytes (TIL) has a better prognosis, which may be related to greater sensitivity to chemotherapy. In addition, a growing number of neoadjuvant (e.g., GeparSixto trial) and salvage therapy for advanced breast cancer (e.g., TNT trial) studies provide evidence for the use of platinum-based agents in BRCA-mutated triple-negative breast cancer with homologous recombination defects, so the value of platinum-based agents in the adjuvant chemotherapy of triple-negative breast cancer deserves further attention. Adjuvant chemotherapy for HER-2-positive breast cancer The recent emergence of two new drugs, T-DM1 and patuximab, has led to more treatment options for HER-2-positive breast cancer, but despite this, some HER-2-positive breast cancers still face the problems of recurrence and metastasis and treatment resistance. Due to the excellent efficacy of targeted therapy in the treatment of HER-2-positive breast cancer, the current research hotspots in HER-2-positive breast cancer focus on how to further improve the efficacy of targeted therapy and how to improve the targeting of anti-HER-2 therapy, and new biological markers such as very low tumor infiltrating lymphocytes (TIL), activation of STAT3 pathway, hormone receptor negativity and immune signaling pathway etc. may be of greater value in this regard. On the issue of adjuvant chemotherapy regimen selection for HER-2-positive breast cancer, Martine J from Belgium reported that a 2014 questionnaire for 465 oncologists in Europe showed that anthracycline-based chemotherapy followed by combination with trastuzumab and docetaxel was the most commonly used regimen. At the same time, studies have also shown that for some HER-2-positive patients, the choice of low-intensity chemotherapy or even no chemotherapy is an option to consider. For example, the Dana Farber phase II prospective study in lymph node-negative patients with HER-2-positive small tumors showed a 3-year disease-free survival rate of 98.7% with weekly paclitaxel in combination with trastuzumab alone; in addition, since hormone receptor-negative patients were treated in neoadjuvant studies such as the NeoSphere trial and the NeoAltto trial Even with dual-targeted therapy alone without chemotherapy, 29% of patients achieved complete pathological remission, and it is worth exploring the value of chemotherapy for such patients. The value of T-DM1 as a combination of chemotherapy and targeted therapy in the treatment of advanced breast cancer has been well recognized. It is noteworthy that some studies have recently started to use it in adjuvant therapy, such as the KAITLIN study that attempted to answer the question of whether T-DM1 can replace docetaxel in HER-2-positive adjuvant therapy, the final results of which are worth looking forward to. In conclusion, although chemotherapy can improve survival in early-stage breast cancer, the choice of adjuvant chemotherapy regimens for different subtypes and stages of breast cancer is quite thought-provoking today with increasing emphasis on individualization and refinement of treatment.