Factors associated with guideline-concordant use of radiotherapy after mastectomy in the national comprehensive cancer network.
OBJECTIVE
We examined the rates and determinants of appropriate and inappropriate use of postmastectomy radiotherapy (PMRT), as defined by the National Comprehensive Cancer Network (NCCN) practice guidelines, among women with Stage I-II breast cancer (American Joint Committee on Cancer, 5th edition).


METHODS
Using clinical characteristics, 1,620 consecutive patients at eight NCCN institutions who had undergone mastectomy between July 1997 and June 2002 were classified into three cohorts according to whether the guidelines (1) recommended PMRT, (2) recommended against PMRT, or (3) made no definitive PMRT recommendation. We defined the absence of PMRT in the first cohort as underuse and receipt of PMRT in the second cohort as overuse. Multivariate logistic regression analysis was applied to investigate the association of clinical and sociodemographic factors with PMRT.


RESULTS
Overall, 23.8% of patients received PMRT. This included 199 (83.6%) of 238 in the "recommend PMRT" cohort, 58 (5.6%) of 1,029 in the "recommend against PMRT" cohort, and 127 (38.6%) of 329 in the "consider PMRT" cohort. The only factor associated with underuse in the "recommend PMRT" cohort was nonreceipt of chemotherapy (odds ratio [OR], 0.08; p <0.0001). In addition to tumor characteristics, the factors associated with overuse in the "recommend against PMRT" cohort included age <50 years (OR, 2.28; p = 0.048), NCCN institution (OR, 1.04-8.29; p = 0.026), higher education (OR, 3.49; p = 0.001), and no reconstructive surgery (OR, 2.44; p = 0.019). The factors associated with PMRT in the "consider PMRT" cohort included NCCN institution (OR, 1.1-9.01; p <0.0001), age <50 years (OR, 2.26; p = 0.041), and tumor characteristics.


CONCLUSIONS
The results of our study have shown that concordance with definitive treatment guidelines was high. However, when current evidence does not support a definitive recommendation for PMRT, treatment decisions appear to be influenced, not only by patient age and clinical characteristics, but also by institution-specific patterns of care.
Punglia
Rinaa S
RS
Dana-Farber Cancer Institute, Boston, MA, USA.
Hughes
Melissa E
ME
Edge
Stephen B
SB
Theriault
Richard L
RL
Bookman
Michael A
MA
Wilson
John L
JL
Ottesen
Rebecca A
RA
Niland
Joyce C
JC
Weeks
Jane C
JC
D000328:Adult; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008408:Mastectomy; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D011960:Receptors, Estrogen / Q000032:analysis; D019651:Plastic Surgery Procedures / Q000706:statistics & numerical data; D012189:Retrospective Studies; D017741:Survivors
D011960:Receptors, Estrogen