13P - A retrospective observational study on neoadjuvant chemotherapy in older adults based on the Joint Breast Cancer Registry Singapore

Background

According to the SEER cancer statistics from 2013 to 2017, 43.4% of all newly breast cancers are diagnosed in women aged 65 years and older. Despite a relatively high prevalence of older adults with newly diagnosed breast cancer, elderly patients are often under-represented in the pivotal neoadjuvant trials. Recommendations for treatment with neoadjuvant chemotherapy (NAC) are based on subgroup analyses and extrapolation of study results from younger patients.

Methods

This retrospective observational study collected data from the Joint Breast Cancer Registry (JBCR) on older adults aged ≥ 65 years treated with NAC for breast cancer at the National Cancer Centre Singapore from October 2014 to October 2019. Patients in the JBCR had detailed clinical and pathological information including hormone receptor (HR), HER2 status, type of NAC. Outcomes and adverse events were retrieved from electronic medical records. Pathological complete response(pCR) was defined by the absence of residual disease in the breast and lymph nodes following NAC.

Results

Of 353 patients who underwent NAC, 66(18%) patients were older adults aged ≥ 65 years. Patients characteristics are decribed in the table. The median age was 69 (65-83) years. 31(46%) patients had HER2+ disease. 13(19%) were triple negative breast cancer (TNBC). 18(27%) patients were unable to complete NAC, of which 10(15%) were due to side effects while 5 (7.5%) had progressive disease during treatment and the remainder 3(5%) refused the planned treatment. Half of the cohort with HER2+ disease had anthracycline/taxane based chemotherapy along with HER2 directed therapy of either trastuzumab or the combination trastuzumab and pertuzumab. 13 (19%) patients had pCR, 11 were HER2+ while 1 was HR+/HER 2- and the other was TNBC. Table: 13P

Patient characteristics

Conclusions

We report a cohort of older adults who had undergone NAC at our centre. Consistent with existing studies, 72 % of the patients completed NAC. In keeping with data on younger patients, older adults with HER2+ breast cancer had higher pCR. However, unlike younger women with TNBC, older adults in this study had lower rates of pCR which was also noted in a recent pooled analysis. This could reflect a heterogeneity of TNBC in older women which warrants further investigations in the future

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

CIRB Singhealth 2019/093/A.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.