title: Factors influencing surgical and adjuvant therapy in stage I breast cancer: a SEER 18 database analysis.
abstract: BACKGROUND
  Randomized trials have shown no survival difference for patients with stage I breast cancer treated with mastectomy versus breast-conserving surgery (BCS) with radiotherapy (RT). RT is recommended after BCS in order to decrease local recurrence and mortality. We sought to evaluate the treatment trends in patients with stage I breast cancer.
  
  
  METHODS
  We used the Surveillance, Epidemiology, and End Results (SEER) database to identify 194,860 women with stage I breast cancer diagnosed from 1988 to 2007. We evaluated factors that were associated surgical treatment and the utilization of RT after BCS.
  
  
  RESULTS
  There was a progressive decline in the proportion of patients with stage I breast cancer who were treated with mastectomy from 1998 to 2007. Significant predictors for being treated with mastectomy included single/divorced women (p = 0.007), white race (p < 0.001), estrogen receptor negativity (p < 0.001), earlier year of diagnosis (p < 0.001), smaller tumor size (p < 0.001), and region (p < 0.001). Twenty percent of the BCS cohort did not receive RT, and this proportion did not change over time. Significant predictors for not receiving RT included small tumor size (p < 0.001), African American race (p < 0.001), increasing age (p < 0.001), single/divorced women (p < 0.001), estrogen receptor negativity (p < 0.001), and region (p < 0.001). The survival for patients treated with BCS and RT was significantly higher than for those who did not receive RT (p < 0.001).
  
  
  CONCLUSIONS
  The use of BCS for the treatment of stage I breast cancer increased over time. A constant proportion of patients did not receive RT after BCS. Omission of RT in BCS is associated with an increase in mortality.
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Shayna L
authors.initials: SL
authors.lastname: Showalter
authors.forename: Surbhi
authors.initials: S
authors.lastname: Grover
authors.forename: Sonam
authors.initials: S
authors.lastname: Sharma
authors.forename: Lillie
authors.initials: L
authors.lastname: Lin
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Czerniecki
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental / Q000401:mortality*; D008875:Middle Aged; D009367:Neoplasm Staging; D011183:Postoperative Complications; D011379:Prognosis; D018714:Radiotherapy, Adjuvant / Q000401:mortality*; D012307:Risk Factors; D015996:Survival Rate; D044465:White People; D055815:Young Adult