322P - Incidence patterns for locally advanced operable breast cancer by receptor status: SEER 2010-2021

Background

Prospective trials testing predictive capacity of genomic assays in hormone receptor (HR)+ breast cancer (bc) have largely excluded patients with high anatomic stage tumors. Questions remain about chemotherapy benefit for those with large HR+ tumors or ≥4 involved nodes. Concurrently, data supporting omission of axillary lymph node dissection has increased. As such, we evaluated contemporary epidemiological patterns for these locally advanced, operable tumors. Given that invasive lobular carcinoma (ILC) may be overrepresented in this population and associated with reduced chemotherapy sensitivity, we also assessed the proportion of ILC diagnoses.

Methods

Stage I-III bc diagnoses during 2010-2021 were identified from the Surveillance, Epidemiology and End Results (SEER 17) database, representing 26.5% of the US population. Diagnoses were categorized in this analytical sample by tumor anatomic stage and receptor status. Average annual percentage changes (AAPC) in incidence over the study period were estimated using weighted least squares.

Results

A total of 660,451 diagnoses were identified with 486,031 (73.6%) being HR+/HER2- bc [Table]. Of these, 28,585 (5.9%) were N2+M0 bc, 23,495 (4.8%) were T3-4N0-1 bc and 9,124 (1.9%) were in the overlapping T3+N2+ group. ILC represented 19.4% and 27.2% of N2+M0 and T3+N0-1M0 HR+/HER2- diagnoses respectively. Over the study period, incidence decreased for HR+/HER2- N2+M0 bc and increased for T3+N0-1M0 bc. For all other disease subtypes, N2+M0 disease saw greater decreases in incidence. Table: 322P

Diagnoses of stage I-III breast cancer 2010-2021

Conclusions

Patients presenting with T3+ or N2+ HR+/HER2- operable bc continue to represent a sizeable portion of new diagnoses. We observed an overrepresentation of ILC in this group. Stage migration downward over the last decade has largely been in subtypes other than HR+/HER2-. Further delineating chemotherapy benefit for the HR+ population, particularly in the era of adjuvant CDK inhibition, remains an important clinical opportunity.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

A. Thomas: Financial Interests, Personal, Advisory Board, One time Ad Board received <$1000: AstraZeneca; Financial Interests, Personal, Stocks/Shares: Pfizer, BristolMyersSquibb, Gilead Sciences, Johnson and Johnson, Doximity; Financial Interests, Personal, Royalties, Husband: UpToDate; Financial Interests, Institutional, Local PI: Sanofi, Merck; Non-Financial Interests, Leadership Role, Working Group Chair: Breast International Group - NCTN; Non-Financial Interests, Leadership Role, Protocol Operations Management Committee - Vice Chair: NRG; Non-Financial Interests, Sponsor/Funding, Donated approximately $300: ASCO Political Action Committee. S. O'Reilly: Financial Interests, Personal, Other, data monitoring committee membership: AstraZeneca; Financial Interests, Personal, Other, travel expenses: roche; Financial Interests, Personal, Other, travel: Novartis, nordic pharma; Financial Interests, Personal, Advisory Board, ad board: merck; Financial Interests, Personal and Institutional, Other, funding for educational meetings: roche; Non-Financial Interests, Member of Board of Directors, member executive board: breast international group; Non-Financial Interests, Advisory Role, advisory board member: irish cancer society; Non-Financial Interests, Leadership Role, clinical lead: cancer trials ireland; Non-Financial Interests, Other, advisory board member: national cancer registry. E. Mayer: Financial Interests, Personal, Advisory Role: Novartis, AstraZeneca, Eli Lilly. N. Harbeck: Financial Interests, Personal, Invited Speaker: AstraZeneca, Daiichi Sankyo, Lilly, MSD, Novartis, Pierre Fabre, Roche, Seagen, Art Tempi, Onkowissen, Medscape, Gilead, Sanofi, Zuelligpharma, Viatris; Financial Interests, Personal, Other, IDMC: Roche; Financial Interests, Personal, Advisory Board: Sandoz-Hexal, Seagen, Aptitude Health, Pfizer, Gilead, Sanofi; Financial Interests, Personal, Other, Husband: WSG (Husband); Financial Interests, Personal, Ownership Interest: West German Study Group; Financial Interests, Institutional, Coordinating PI: AstraZeneca; Financial Interests, Institutional, Funding: BMS, Daiichi Sankyo, MSD, Roche, Seagen, TRIO, WSG, Gilead; Financial Interests, Institutional, Steering Committee Member: Lilly, Pierre Fabre; Non-Financial Interests, Member, Member German AGO Breast Guideline Committee: AGO Breast Committee; Non-Financial Interests, Member, Breast Cancer Educational Programs: ESO/ESCO; Other, Founding Editor: BreastCare Journal. G. Curigliano: Financial Interests, Personal, Invited Speaker: Roche, AstraZeneca, Daiichi Sankyo, Novartis, Pfizer; Financial Interests, Personal, Advisory Board: Roche, AstraZeneca, Daiichi Sankyo, Lilly, Pfizer, Veracyte, BMS, Merck, Exact Sciences, Celcuity; Financial Interests, Personal, Writing Engagement: Pfizer; Financial Interests, Personal, Advisory Board, Advisory Board: Menarini, Gilead; Financial Interests, Personal, Other, Advisory Board: Ellipsis; Financial Interests, Institutional, Research Grant, Investigator Initiated Trial: Merck; Financial Interests, Institutional, Funding, Phase I studies: BMS, Novartis, AstraZeneca, Daiichi Sankyo, Roche, Blueprint Medicine, Kymab, Astellas, Sanofi, Philogen; Financial Interests, Institutional, Coordinating PI, Phase I clinical basket trial: Relay Therapeutics; Non-Financial Interests, Officer, Italian National Health Council as Advisor for Ministry of Health: Consiglio Superiore di Sanità; Non-Financial Interests, Advisory Role, Member of the Scientific Council. Patient advocacy association: Europa Donna; Non-Financial Interests, Advisory Role, Cancer Research Foundation: Fondazione Beretta; Non-Financial Interests, Officer, Editor of Chief of ESMO Open: ESMO; Non-Financial Interests, Leadership Role, Until the end of 2024: EUSOMA. V.S. Adam: Financial Interests, Personal, Full or part-time Employment, I am an employee of the Breast International Group (BIG).: Breast International Group (BIG); Financial Interests, Institutional, Funding, My institution receives funding from AstraZeneca for OlympiA.: AstraZeneca; Financial Interests, Institutional, Funding, My institution receives funding from GSK for BRAVO.: GSK; Financial Interests, Institutional, Funding, My institution receives funding from Novartis for Alphabet, Altto, And Dianer.: Novartis; Financial Interests, Institutional, Funding, My institution receives funding from Pfizer for Pallas and Pythia.: Pfizer; Financial Interests, Institutional, Funding, My institution receives funding from Roche for Decrescendo, ALEXANDRA/IMpassion030, and APHINITY.: Roche; Financial Interests, Institutional, Funding, My institution received funding from Novartis for AMEERA-6.: Sanofi; Financial Interests, Institutional, Funding, My institution receives funding from Genentech for LORELEI.: Genentech; Non-Financial Interests, Member, I am a member of the American Society for Clinical Oncology (ASCO).: American Society for Clinical Oncology (ASCO). N. Chan: Non-Financial Interests, Principal Investigator, Study chair of investigator initiated trial Study of Pembrolizumab Plus Fulvestrant in Hormone Receptor Positive, HER-2 Negative Advanced/Metastatic Breast Cancer Patients NCT03393845: Merck. A. DeMichele: Financial Interests, Personal, Invited Speaker, Speaker/Moderator 2020 meetingBest of SABCS 2020 meeting: San Antonio Breast Cancer Symposium; Financial Interests, Personal, Invited Speaker, CME activity: Fox Chase Cancer Center, Johns Hopkins University, Indiana University; Financial Interests, Personal, Invited Speaker, Annual Meeting speaker 2020: American Society of Clinical Oncology; Financial Interests, Personal, Invited Speaker, Invited Speaker for several educational and scientific sessions in 2022 meeting: San Antonio Breast Cancer Symposium; Financial Interests, Personal, Invited Speaker, CME Activity: Medscape; Financial Interests, Institutional, Local PI, Clinical trial agreement: Genentech, Neogenomics; Financial Interests, Institutional, Local PI, clinical trial agreement: Novartis, Pfizer; Non-Financial Interests, Advisory Role, Attended Ad Hoc Scientific Advisory Board Meeting at San Antonio Breast Cancer Symposium 2023. Did not accept any compensation.: Novartis; Non-Financial Interests, Member, Participated in 2020 Advocacy activities - Washington DC: American Society of Clinical Oncology. M. Ignatiadis: Financial Interests, Personal, Invited Speaker: Novartis, Daichi, Menarini Group; Financial Interests, Personal, Other, Independent monitoring committee: Seattle Genetics; Financial Interests, Personal, Other, Grants review: Gilead Sciences; Financial Interests, Personal, Other, consultant: Rejuveron Senescence Therapeutics; Financial Interests, Institutional, Other, travel grants: AstraZeneca; Financial Interests, Institutional, Coordinating PI: Pfizer, Roche, Natera, Inivata Inc; Non-Financial Interests, Officer: EORTC. K. Kalinsky: Financial Interests, Personal, Advisory Board: Daiichi Sankyo, Eli-Lilly, Pfizer, Novartis, Eisai, AstraZeneca, Immunomedics, Merck, Seattle Genetics, Cyclacel, Oncosec, 4D Pharma, Puma; Financial Interests, Personal, Stocks/Shares, Employment + Stock = spouse: Grail; Financial Interests, Personal and Institutional, Local PI, Consultant: Novartis, Eli-Lilly, AstraZeneca, daicchi sankyo; Financial Interests, Personal and Institutional, Local PI, consultant: Genentech; Financial Interests, Institutional, Local PI, consultant: Pfizer; Financial Interests, Institutional, Local PI: Seattle Genetics, Ascentantage; Financial Interests, Personal, Other, Consultant: Myovant, Takeda, Menarini, Prelude; Financial Interests, Personal, Other, consultant: RayzeBio; Other, Support for attending meetings and/or travel: Eli-Lilly, AstraZeneca, Pfizer; Other, Steering Committee: Immunomedics, AstraZeneca, Ambryx, Genentech. All other authors have declared no conflicts of interest.