Adjuvant Chemotherapy and Trastuzumab Is Safe and Effective in Older Women With Small, Node-Negative, HER2-Positive Early-Stage Breast Cancer.
The benefit of adjuvant trastuzumab with chemotherapy is well established for women with higher risk human epidermal growth factor receptor 2-positive (HER2+) breast cancer. However, its role in older patients with smaller, node-negative tumors is less clear. We conducted a retrospective, sequential cohort study of this population to describe the impact of trastuzumab on breast cancer outcomes and cardiac safety.



Women ≥ 55 years with ≤ 2 cm, node-negative, HER2+breast cancer were identified and electronic medical records reviewed. A no-trastuzumab cohort of 116 women diagnosed between January 1, 1999 and May 14, 2004 and a trastuzumab cohort of 128 women diagnosed between May 16, 2006 and December 31, 2010 were identified. Overall survival and distant relapse-free survival were estimated by Kaplan-Meier methods.



The median ages of the trastuzumab and no-trastuzumab cohorts were 62 and 64 years, respectively. More patients in the trastuzumab cohort had grade III (P = .001), lymphovascular invasion (P = .001), or estrogen receptor-negative (P < .001) cancers. The majority of the trastuzumab cohort received chemotherapy versus one-half of the no-trastuzumab cohort (98% vs. 53%; P < .0001). The median follow-up was 4 versus 9 years in the trastuzumab versus no-trastuzumab cohorts; therefore, outcomes at 4 years are reported. Despite the higher-risk tumor features in the trastuzumab group, the 4-year overall survival was 99% in both cohorts; the distant relapse-free survival was 99% versus 97% in the trastuzumab versus no-trastuzumab cohorts. Four (3.1%; 95% confidence interval, 1.0%-7.8%) women in the trastuzumab cohort and 1 in the no-trastuzumab cohort developed symptomatic heart failure. There were no cardiac-related deaths in either arm.



Following adjuvant trastuzumab with chemotherapy, selected older women with small, node-negative, HER2+breast cancers have excellent disease control. The rate of cardiac events is low.
Breast Medicine Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY; Weill Cornell Medical College, New York, NY.
Karen A
KA
Cadoo
Breast Medicine Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY.
Patrick G
PG
Morris
Weill Cornell Medical College, New York, NY.
Elizabeth P
EP
Cowell
Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
Sujata
S
Patil
Breast Medicine Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY; Weill Cornell Medical College, New York, NY.
Clifford A
CA
Hudis
Breast Medicine Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY; Weill Cornell Medical College, New York, NY. Electronic address: mcarthuh@mskcc.org.
Heather L
HL
McArthur
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000401:mortality* / Q000473:pathology; D066126:Cardiotoxicity / Q000453:epidemiology*; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D018572:Disease-Free Survival; D005260:Female; D006333:Heart Failure / Q000139:chemically induced / Q000453:epidemiology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012189:Retrospective Studies; D000068878:Trastuzumab / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use
D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human
Breast cancer; Cardiac outcomes; Chemotherapy; HER2 positive; Trastuzumab